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Revision of the extant Polypteridae (Actinopterygii: Cladistia)

Authors:
  • Senckenberg Natural History Collections Dresden

Abstract and Figures

The species-level taxonomy of all extant members of the family Polypteridae is revised. Two genera are recognised: Polypterus and the monotypic Erpetoichthys. Thirteen species of Polypterus are regarded as valid: P. bichir (type species), P. ansorgii, P. congicus, P. delhezi, P. endlicherii, P. mokelembembe, P. ornatipinnis, P. palmas, P. polli, P. retropinnis, P. senegalus, P. teugelsi and P. weeksii. Polypterus lapradei and P. bichir katangae are considered junior synonyms of P. bichir. Polypterus senegalus meridionalis is synonymized with P. senegalus, and P. buettikoferi and P. retropinnis lowei are regarded as junior synonyms of P. palmas. Lectotypes of P. ansorgii, P. congicus and P. delhezi are designated. Distribution maps for each species are compiled and a key for all species of Polypteridae is provided.
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Ichthyological Exploration of Freshwaters/IEF-1094/pp. 1-96 Published 23 July 2019
LSID: http://zoobank.org/urn:lsid:zoobank.org:pub:9FEAF636-6AA5-49B0-BEA4-2CCD75EBE13E
DOI: http://doi.org/10.23788/IEF-1094
Ichthyol. Explor. Freshwaters – ISSN 0936-9902 (print)
© 2019 by Verlag Dr. Friedrich Pfeil, München, Germany www.pfeil-verlag.de
Revision of the extant Polypteridae
(Actinopterygii: Cladistia)
Timo Moritz* and Ralf Britz**
The species-level taxonomy of all extant members of the family Polypteridae is revised. Two genera are recog-
nised: Polypterus and the monotypic Erpetoichthys. Thirteen species of Polypterus are regarded as valid: P. bichir
(type species), P. ansorgii, P. congicus, P. delhezi, P. endlicherii, P. mokelembembe, P. ornatipinnis, P. palmas, P. polli,
P. retropinnis, P. senegalus, P. teugelsi and P. weeksii. Polypterus lapradei and P. bichir katangae are considered junior
synonyms of P. bichir. Polypterus senegalus meridionalis is synonymized with P. senegalus, and P. buettikoferi and P. re-
tropinnis lowei are regarded as junior synonyms of P. palmas. Lectotypes of P. ansorgii, P. congicus and P. delhezi are
designated. Distribution maps for each species are compiled and a key for all species of Polypteridae is provided.
* Deutsches Meeresmuseum, Katharinenberg 14-20, 18439 Stralsund, Germany; and Institute of Systematic
Zoology and Evolutionary Biology, Friedrich-Schiller-University Jena, Erbertstr. 1, 07743 Jena, Germany.
E-mail: timo.moritz@outlook.com (corresponding author)
** Department of Life Sciences, The Natural History Museum, Cromwell Road, London, SW7 5BD, United
Kingdom. E-mail: r.britz@nhm.ac.uk
Introduction
Since their discovery, polypterids continue to puz-
zle scientists. Due to their phylogenetic position as
the most basal extant actinopterygians (Patterson,
1982; Min & Schultze, 2001), polypterids have at-
tracted a lot of scientific attention (see Gosse, 1984
for literature until 1983). Polypterids show several
character states that are considered primitive for
actinopterygians or even bony fishes, e. g. a pair
of true lungs, a body armour of thick ganoid
scales (Sire, 1995), a holoblastic egg development,
(Kerr, 1907; Bartsch et al., 1997) and functional
spiracles (Magid, 1966). They also show many
autapomorphies most of them not known from
any other fish group, fossil or extant, like separate
dorsal finlets, cartilaginously preformed epicen-
tral intermusculars that articulate with the ganoid
scales distally (Britz & Bartsch, 2003), a highly-
specialized anatomy of the pectoral fin (Jessen,
1973), a reduced number of gill arches (Britz &
Johnson, 2003), convergent in some anguilliforms
(Nelson, 1966), and a unique sexually dimorphic
anal fin associated with a unique mating behavior
(Holden, 1971; Britz & Bartsch, 1998).
Despite the numerous papers that have fo-
cussed on bichirs in the past, the species-level
taxonomy of polypterids is still poorly studied.
The number of nominal valid species of poly-
pterids is inconsistently cited as 9 species and 5
sub-species (= 14 taxonomic units in Poll, 1941a),
9 species and 6 sub-species (= 15 taxonomic units
in Gosse, 1984), 18 species of which 5 supposedly
represent undescribed species (Schäfer, 2004), or
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Moritz & Britz: Revision of Polypterus
10-15 species (Britz, 2004). The major reason for
the inconsistency in species numbers is the un-
resolved nomenclatural status of several species-
group names. The goal of the present study is a
species-level revision of the extant Polypteridae
in order to provide a comprehensive taxonomic
framework for future studies on extant members
of this family.
Material and methods
Studied specimens are listed under each species.
The material is divided into two categories: Mate-
rial examined contains all specimens for which
meristic information and/or measurements were
incorporated into the study. Additional mate-
rial contains lots, which have been verified for
their species identity and of which their locality
information has been used for the compilation of
distribution maps.
Measurements used are listed below and
illustrated in Figure 1. All measurements were
taken point to point with digital callipers (CD-
20DCX Absolute Digimatic, Mitutoyo) to the
nearest 0.1 mm for all distances up to 160 mm.
Any measurements above this value were taken
with rulers to the nearest mm. In the case of dis-
torted specimens we used a non-elastic cord to
record the distance between landmarks and then
measured this distance on a ruler.
The following abbreviations have been used
for morphometric and meristic data: AFB, length
of anal-fin base; AFL, length of longest ray in
anal fin; AR, number of anal-fin rays; BD, body
depth at tip of pectoral fin; BW, body width at
tip of pectoral fin; CPL, caudal-peduncle length:
distance between end of anal fin and ventral
origin of caudal fin; D1L, length of first dorsal-
fin spine; D1W, width of first dorsal-fin spine
at its base; D2L, length of second dorsal-fin
spine; DCR, number of soft rays in confluent
dorsal and caudal fin; DFL, length of spinous
part of dorsal fin: distance between base of first
dorsal-fin spine and base of first dorsal-fin soft
ray; DisPD, distance from distal tip of adducted
pectoral fin to first finlet (if first finlet is positioned
in front of tip of pectoral fin, measurement will
have negative value); DS, number of dorsal-fin
spines, including separate finlets and posterior-
most spine connected to soft-rayed portion of
dorsal fin; EyD, eye diameter; GuL, gular length:
distance between tip of lower jaw along mid-
ventral line and caudal most extension of both
gularia; HL, head length: distance between tip
of snout and posterior border of opercle (not in-
EyD
prePL
NOD
preVL
preAL
AFL
GuL
SnL PoL
HL
SnPL
preDL
SL
DFL
TL
DistPD
AFB
BD CPL
IOW HW D1W IPW
PBW
D1L
D2L
AFB
BD CPL
IOW HW D1W IPW
PBW
D1L
D2L
EyD
prePL
NOD
preVL
preAL
AFL
GuL
SnL PoL
HL
SnPL
preDL
SL
DFL
TL
DistPD
AFB
BD CPL
IOW HW D1W IPW
PBW
D1L
D2L
AFB
BD CPL
IOW HW D1W IPW
PBW
D1L
D2L
Fig. 1. Representation of measurements used in this study. For abbreviations see text. Based on the figure of
Polypterus senegalus from Boulenger (1907).
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Ichthyol. Explor. Freshwaters, IEF-1094
cluding fleshy opercular membrane); HW, head
width at anterior border of opercle; IoW, inter-
orbital width: distance between upper margins
of orbitae; IPW, inter-pectoral width: distance
between ventral bases of left and right pectoral
fins measured in ventral view; NoD, nostril
distance at base of nasal tentacle; PBW, width of
pectoral-fin base directly at insertion; PoL, post-
orbital length: distance from posterior border of
orbit to posterior border of opercle; PR, number
of pectoral-fin rays; preAL, pre-anal length:
distance between tip of snout and origin of anal
fin; preDL, pre-dorsal length: distance between
tip of snout and first dorsal-fin spine; prePL,
pre-pectoral length: distance between tip of snout
and base of pectoral fin at insertion; preVL, pre-
pelvic length: distance between tip of snout and
base of pelvic fin at insertion; PvR, number of
pelvic-fin rays; ScB, scales around body at tip of
pectoral fin; ScpD, pre-dorsal scales; ScL, scales
in longitudinal series; ScpP, pre-pelvic scales
(including interpelvic scale); SL, standard length:
distance between tip of snout and posterior most
body scale; SnL, snout length: distance between
tip of snout and anterior margin of orbit; SnPL,
extension of pectoral fin: distance between tip of
snout and posterior end of adducted pectoral fin
placed flat on the body; TL, total length: from tip
of snout to tip of caudal fin; TVer, total number of
vertebrae, only vertebrae with an ossified centrum
are counted here, so that the actual first vertebra
which has no centrum (Britz & Johnson, 2010) is
not counted.
In addition to meristic and morphometric dif-
ferences species of the Polypteridae can also be
distinguished by their color pattern. The recurring
elements of the color pattern are (Fig. 2): pectoral-
fin base blotch: a well-defined dark brown to
black blotch laterally in the distal portion of the
pectoral-fin base; dorsal blotches: a series of black
markings, several scale rows in width, usually
reaching across dorsum to other side forming
saddle-like blotches; lateral blotches: a series
of midlateral dark markings extending several
scale rows in width; dorsolateral bars: formed
by confluence of dorsal and lateral blotches, ei-
ther directed obliquely anteriorly (when dorsal
blotch is confluent with preceding lateral blotch),
or directed obliquely posteriorly (when dorsal
blotch is confluent with succeeding lateral blotch);
sometimes expressed as x/y-shaped bars (when
dorsal blotches confluent with both preceding
and succeeding lateral blotches); ventrolateral
markings: dark brown to black markings along
the ventrolateral sides of the body, often expressed
as series of dark spots, one scale wide and form-
ing irregular interrupted lines (as in some color
morphs of P. bichir or in P. ansorgii) or irregular
speckling of ventrolateral body; sometimes also
forming larger blotches that may be confluent
with lateral blotches (as in P. endlicherii); subor-
bital stripe: an oblique dark brown to black stripe
below the eye extending from the posterior base
of the nasal tentacle to the margin of the jaw ar-
ticulation or sometimes expressed only in part of
this distance (as in the postorbital area in P. polli)
and/or expressed as a line of separate spots rather
than as a continuous stripe (as in P. retropinnis);
lip markings: brown to black markings of varying
shape and size, can be expressed as vermicula-
tions on both lips, as peppering with tiny spots,
as a series of bar-like markings or a combination
of all; dorsal and lateral head markings: brown
to black or light beige markings of varying shape
and size, can be expressed as vermiculations, spots
or blotches.
Distribution data of all checked museum
specimens were critically evaluated and, when
found to be lacking precision, were given ap-
proximated GPS coordinates. Locality information
that was considered too general, such as River
Nile, Senegal or Congo was not included.
dorsal head markings
lip markings
suborbital stripe
pectoral-fin base blotch lateral blotches ventrolateral markings
dorsal blotches
dorsolateral bars
lateral head markings
Fig. 2. Overview of principal color patterns in Polypterus.
4
The distribution data were complemented by
information obtained by TM during several field
trips. In addition, museum and internet databases,
i. e. Fishbase (Froese & Pauly, 2016) and fishnet2
(www.fishnet2.net), were checked for distribution
data, but this information was critically evaluated
and questionable records were not included. Last-
ly, numerous published sources of distributional
information were evaluated, [e. g. Pellegrin (1900),
Blanc & Daget (1957), Paugy & Bénech (1989), Ro-
man (1966), Moritz (2010), Neumann et al. (2016)].
Locality records are grouped into four categories
(1) type locality, (2) verified records, i. e. the spe-
cies identity of the respective specimens has been
checked and confirmed in this study, (3) other
records, i. e. records from literature and database,
for which specimens could not be checked, but
for which locality records are plausible, and (4)
questionable records; i. e. records that could not
be verified but that seem to be based on correct
identifications, but are considered questionable in
the context of the other records. Doubtful records,
i. e. records that are almost certainly based on
misidentifications have been excluded from the
maps, but discussed for each respective species, to
produce the most comprehensive, up to date dis-
tributional information for the different species.
Data were collected in tables from which maps
were created with the freeware QGIS 2.12.3 (www.
qgis.org) using freely available shape files from
FAO, as e. g. Rivers of Africa and Inland Water
Bodies of Africa (www.fao.org/geonetwork).
Simple diagrams and box-plots were created
directly in table calculation software EXCEL
(Microsoft Corp.) or CALC (OpenOffice 4.1.1,
www.openoffic.org); statistical calculations such
as Principal Components Analyses (PCAs) were
conducted in PAST 3.11 (Hammer et al., 2001).
Graphics including figures were either created
or at least finalized with the software GIMP 2.8
(www.gimp.org). For Polypterus palmas several
characters were analyzed and displayed accord-
ing to the river system where the specimens were
collected, following a North to South sequence of
the respective deltas of the basins.
The following institutional abbreviations have
been used: BMNH, The Natural History Muse-
um, London; DMM, Deutsches Meeresmuseum,
Stralsund; IRSNB, Institut Royal des Sciences Na-
turelles de Belgique; MNHN, Muséum national
dHistoire naturelle, Paris; MRAC, Musée Royal
de lAfrique Centrale, Tervuren; NMSZ, National
Museums Scotland, Edinburgh; NMW, Naturhis-
torisches Museum, Vienna; RMNH, Naturalis
Biodiversity Centre, Leiden; USNM, National
Museum of Natural History, Washington, D.C.;
ZSM, Bavarian State Collection of Zoology, Mu-
nich.
Family Polypteridae Bonaparte, 1835
Polypterini Bonaparte, 1835: 8.
Type genus. Polypterus Lacépède, 1803 (see re-
marks under Polypterus below).
Diagnosis. Polypterids are distinguished from
all other living actinopterygians by the presence
of complete ganoid scales covering the entire
body, a unique skeletal anatomy of the pectoral
fin, first part of dorsal fin separated into finlets,
i. e. sharp spines with secondary supporting rays
and attached membrane, as well as paired lungs
with ventral connection to oesophagus, a modi-
fied anal fin in males, adhesive eggs and larval
stages with external opercular gills.
Descriptive synopsis. Two types of body shapes
among polypterids: elongated, cylindrical in
Polypterus (body depth 7.0-16.5 % SL) and an-
guilliform in Erpetoichthys (body depth 2.9-5.2 %
SL); body in both types round in cross section at
anterior third and laterally flattened at posterior
third. Head in cross-section round or moder-
ately to strongly dorso-ventrally flattened. Body
completely covered with fully developed ganoid
scales consisting of three layers: bone, dentin and
ganoin (Goodrich, 1907; Sire, 1995). Anterior part
of dorsal fin separated into 5-18 finlets, i. e. single
spines with sharp bilaterally paired distal tips
with posterior fin membrane supported by soft
rays originating from posterior margin of spine
perpendicular to spine body. Posterior part of
dorsal fin confluent with caudal fin. Pectoral-fin
skeleton with unique pro-, meso- and meta-
pterygium between pectoral girdle and pectoral
radials. Sexually dimorphic anal fin: fin of males
greatly enlarged mainly as result of anteropos-
terior widening of anal-fin rays; number of
anal-fin rays on average only slightly higher in
males of Polypterus, but clearly higher in males
of Erpetoichthys.
Mouth large, with posterior angle situated
behind vertical through posterior margin of orbit;
lips thick, supported by labial cartilage. Anterior
Moritz & Britz: Revision of Polypterus
5
nostril extended as tube well beyond tip of snout.
Paired gular plates present. Interopercle absent.
Series of spiracular plates between lateral margin
of skull roof and opercular series, with some of
them covering the functional spiraculum (Bartsch,
1997; Claeson et al., 2007). Dermohyal present.
Maxilla immovably attached to skull (akinetic
upper jaw). Fifth gill arch absent and lower phar-
yngeal tooth plates associated with fourth cerato-
branchial (Britz & Johnson, 2003); pseudobranch
absent. Juveniles with well-developed external
opercular gills. Mesocoracoid absent; clavicles
well developed. Unique epicentral intermuscular
bones with cartilaginous tip articulating with
lateral line scales (Britz & Bartsch, 2003). Intestine
with spiral valve. Caudal fin rounded or pointed
(especially in juveniles) confluent with posterior
dorsal fin; posterior most vertebrae smaller than
preceding ones.
Biology. For most species information on ecology
and life history is scarce. From the available and
published information it seems that species are
quite similar to each other in various aspects. All
are predominantly nocturnal and strictly fresh-
water species. They are predators, apparently
mostly guided by their sense of smell (Pfeiffer,
1968, 1969), feeding on aquatic and terrestrial
invertebrates and fish, sometimes amphibians,
with prey size mainly depending on the size of
the mouth cleft of the respective specimen. Some
plant material has occasionally been reported
from stomach contents (e. g. Daget, 1948), but was
likely ingested accidentally. Polypterus species
are able to prey on fishes of more than half their
size (pers. obs. TM). Prey can be sucked in with
force and speed by enlarging the mouth cavity
and projecting the cartilage-supported labial folds
to form a funnel (Bartsch, 1997). All polypterids
show sexual dimorphism in their anal fin, which
is important for courtship: during spawning, the
male forms a cup with its anal fin into which
the female releases her eggs. Eggs are then ferti-
lized in this cup before being scattered by rapid
lateral movements of the caudal and anal fins of
the male (Bartsch & Britz, 1996; Britz & Bartsch,
1998). The anal fin of males does not function
as a copulatory organ as initially hypothesized
by Harrington (1899). In nature, spawning takes
place in (densely) vegetated areas, usually flood
plains (Budgett, 1900; Daget, 1948). The eggs are
relatively large and adhesive (Arnoult, 1961, 1964;
Bartsch & Britz, 1996) with a single micropyle
(Britz & Bartsch, 1998). The larval development
was described in detail for P. senegalus (Kerr, 1907;
Bartsch et al., 1997; Schugardt & Kirschbaum,
2006), and for P. ornatipinnis and E. calabaricus
(Britz & Bartsch, 1998). When larvae start to
feed in captivity, they wait for prey rather than
actively search for it (Bartsch, 1997). Juveniles
have external gills (Boulenger, 1902b), which may
persist for a long time up to even larger sizes in
some species (e. g. large external gills were still
present in a 335 mm SL specimen of P. weeksii
[MRAC A7-033-P-0028], a 334 mm SL specimen
of P. bichir [BMNH 1900.6.28.9], a 315 mm SL
specimen of P. congicus [IRSNB 9960], and in
a 279 mm SL specimen of P. endlicherii [NMW
63218]). In captivity larvae and juveniles initially
show fast growth up to a certain, species-specific,
size but subsequently growth rates slow down
(Daget et al., 1965). At least in some species sexual
maturity may be reached in one year (Svensson,
1933). The lungs of bichirs are paired and well
developed and vascularized and atmospheric air
is regularly taken in for respiration. Air uptake
may be realized in two different ways: inhaling
air via the mouth, or via the spiracles (Budgett,
1900; Bartsch, 1997).
Remarks. The oldest available family group name
for polypterids dates back to Bonaparte (1835: 8)
who listed Subfamilia 36. Polypterini in his
Prodromus Systematis Ichthyologiae.
Genus Erpetoichthys Smith, 1865
Erpetoichthys Smith, 1865a: 2.
Calamichthys Smith, 1866a: 113.
Calamoichthys Smith, 1866a: 112.
Type species. Erpetoichthys calabaricus Smith, 1865.
Diagnosis. Erpetoichthys is distinguished from
all other members of the family by absence
of pelvic fin and subopercle (vs. presence in
Polypterus), body depth 2.9-5.2 % SL (vs. 7.0-16.5
in Polypterus), 109-115 vertebrae (vs. fewer than
67 in Polypterus), short head (7.2-10.5 % SL vs.
14.4-26.8 in Polypterus), and 16-21 pectoral fin-
rays (vs. 24-48 in Polypterus).
Descriptive synopsis. Body greatly elongated,
anguilliform with 109-115 vertebrae and 102-115
scales in lateral series. Sexual dimorphism in anal
Ichthyol. Explor. Freshwaters, IEF-1094
6
fin much pronounced: males with 11-14 (mean
13) and female with 8-13 (mean 10) anal-fin rays;
each ray in mature males widened along its an-
teroposterior axis. For meristic and morphometric
data refer to Tables 1-2.
Etymology. Erpetoichthys is derived from the
Greek ρπετ)+, reptile or snake; and θς, fish.
Remarks. Confusion about the valid name of
the genus arose from multiple descriptions by
Smith (1865a-b; 1866a-c) and from a subsequent
change of the generic name by Smith one year later
(1866a, c), because he erroneously considered the
original name Erpetoichthys to be preoccupied. De-
tails on this nomenclatural issue were discussed
by Swinney & Heppell (1982) and Rizzato &
Bockmann (2017) with contradicting results. We
follow Swinney & Heppells (1982) view and
consider the name Erpetoichthys calabaricus to be
available from Smith (1865a). This is in contrast
to the recent conclusion by Rizzato & Bockmann
(2017) which rests solely on their interpretation of
Art. 8.1.1 of the Internacional Code of Zoological
Nomenclature (ICZN, 1999; hereafter treated as
the Code). Rizzato & Bockmann (2017) argued
that publication of Smiths (1865a) name in the
newspaper Daily Review was not issued for
the purpose of providing a public and permanent
scientific record as the Art. 8.1.1. requires for a
name to be available. The authors argue in detail,
that First, and most importantly, the report was
clearly intended solely to publicize a scientific
breakthrough for the general public of Edinburgh,
not to name the fish according to formal scientific
standards. While Rizzatto & Bockmann (2017)
present this argument as a fact, we consider this
to be speculation, as the intention of the author
is unknowable. Rizzatto & Bockmanns (2017)
main conclusion that Smiths (1865a) name is not
available centers very much around the intention
of a given author and they mention intention,
intend, intentionally, unintentionally 21 times
in their lengthy paper. However, according to
the Code it is not the intention that is decisive.
While it cannot be objectively decided whether
Smiths (1865a) first publication of the name was
issued for the purpose of providing a public
and permanent scientific record, we argue that
publication of the name Erpetoichthys calabaricus in
the Daily Review in 1865, which is still available
today, in conjunction with a diagnosis, makes
this name available, as concluded previously by
Swinney & Heppell (1982). We therefore reject
Rizzatto & Bockmanns (2017) conclusion and
retain Erpetoichthys calabaricus as the valid name
for the rope eel. Furthermore, following Rizzatto
& Bockmanns (2017) rationale would also greatly
destabilize nomenclature generally, as numerous
nomenclatural acts in the 1800s and early 1900s
were published in minutes and proceedings of
scientific sessions before the more comprehensive,
actual paper was published. Fricke et al. (2018)
also decided not follow the conclusions of Rizzato
& Bockmann (2018).
Erpetoichthys calabaricus Smith, 1865
(Figs. 3-5; Tables 1-2)
Erpetoichthys calabaricus Smith, 1865a: 2.
Erpetoichthys robbianus Smith, 1865b: 2.
Polypterus erpetoideus Smith, 1865a: 2.
Material examined. 32 specimens. Ouém é Basi n:
RMNH 24896, 1, 187 mm SL; Benin: Cotonou, L. B.
Holthuis & H. Hoestland, 1963. niger Delta: RMNH
10327, 1, 313 mm SL; Nigeria: Warri, Diergaarde Rot-
terdam, 20 Nov 1918. – RMNH 8858, 2, 293-318 mm
SL; Nigeria: Warri, J. Büttikofer, Oct 1912. – BMNH
1977.11.8.1-4, 4, 262-300 mm SL; Nigeria: Lagos: En-
ergo project site near Lagos, D. Thomas. – MNHN
2008-2103, 9, 252-307 mm SL; Nigeria: Port Harcourt
[market]; T. Roberts, 5 Nov 1987. CrOss river Basin:
MNHN 0000-4599, 2, 223-301 mm SL; Nigeria: Old
Calabar, J. A. Smith, before 1867. – NMW 22831, 1,
147 mm SL; Nigeria: Old Calabar, 1874. – NMW 22832,
1, 162 mm SL; Nigeria: Old Calabar, 1874. – NMW 50282,
1, 343 mm SL; Nigeria: Old Calabar. – NMW 63194, 1,
205 mm SL; Nigeria: Old Calabar, 1874. – NMW 63195,
2, 247-320 mm SL; Nigeria: Old Calabar, 1877. limBe
river Basin: MNHN 1900-0218, 1, 180 mm SL; Cam-
eroon: Victoria, Lennier. sanaga river Basin: MNHN
1978-0732, 1, 313 mm SL; Cameroon: Sanaga River at
Mouanko, Depierre, 1978. – MRAC 73-002-P-0001-0003,
3, 271-286 mm SL; Cameroon: Sanaga River at Edea
[below waterfalls], D. F. E. Thys van den Audenaerde,
15-16 Oct 1964. – MRAC 75-005-P-4758, 1, 305 mm SL;
Cameroon: km 5 on the road Douala to Edea, D. F. E.
Thys van den Audenaerde, 21 Oct 1966. WOuri river
Basin: MNHN 1928-0080, 1, 321 mm SL; Cameroun:
Vouri [= Wouri] River at Nono, Monod.
Additional material. Ouémé Basin: DMM IE/10401, 5,
Benin: Zou: Lokoli swamp forest, 7°03'40" N 2°15'32" E;
T. Moritz, 16 Jan 2005. iguiDi river Basin: DMM
IE/14378, 2, Benin: Iguidi River at Igolo, 6°39'18" N
2°42'43" E; T. Moritz & V. von Vietinghoff, 11 May 2005.
– DMM IE/14388, 1, Benin: Iguidi River at Tchakou,
Moritz & Britz: Revision of Polypterus
7
Fig. 3. Erpetoichthys calabaricus, NMW 63195:1, 320 mm SL, male, non-type, Nigeria: Old Calabar [type locality];
1877.
a
b
cc
Fig. 4. Erpetoichthys calabaricus, a-b, ~280 mm SL; Nigeria: aquarium import; c-d, ~180 mm SL; Benin: Ouémé
Basin: Lokoli swamp forest.
6°28'27" N 2°42'48" E; T. Moritz, 22 Mar 2007. CrOss
river Basin: MNHN 1988-0253, 1, Nigeria, Cross River
at Uyo, King, 1987.
Diagnosis. Same as presented for the genus.
Descriptive synopsis. Meristic and morpho-
metric data in Tables 1-2. Body anguilliform
(body depth 18-34 times in SL); body circular
in cross section along most of body; but later-
ally compressed in posterior most part towards
Ichthyol. Explor. Freshwaters, IEF-1094
8
caudal peduncle. Mouth subterminal with upper
jaw strongly projecting beyond lower jaw; head
only slightly depressed. Maximum observed size
343 mm SL (355 mm TL). Occasionally reported
maximum sizes of up to 900 mm (e. g. Terofal,
1970; Gosse, 1984) are erroneous.
Coloration. In life: dorsal half of body brown-
yellowish with borders of vertical scale rows
darker; no additional markings (Fig. 4). Ventral
half of body yellowish-orange. No clear border
between upper and lower half of flank colora-
tion. Head coloration same as that on body, but
nasal tentacles lighter; suborbital stripe absent.
Table 2. Meristic characters of Erpetoichthys calabaricus. Numbers in brackets indicate number of specimens with
the respective value.
all material
Dorsal-fin spines 9 (8), 10 (11), 11 (9)
Dorsal- and caudal-fin rays 10 (1), 12 (2), 13 (7), 14 (10), 15 (6), 16 (1)
Pectoral-fin rays 16 (3), 17 (3), 18 (6), 19 (10), 20 (4), 21 (1)
Anal-fin rays 8 (3), 9 (4), 10 (3), 11 (6), 12 (4), 13 (4), 14 (3)
Scales in longitudinal series 102 (1), 104 (1), 105 (1), 106 (3), 107 (5), 108 (1), 109 (8), 110 (4), 111 (1), 112 (1), 113 (1),
114 (1)
Scales around body 27 (3), 28 (3), 29 (5), 30 (10), 31 (5), 32 (1), 33 (1)
Pre-dorsal scales 44 (1), 48 (1), 49 (5), 50 (2), 51 (5), 52 (2), 53 (4), 54 (2), 55 (2), 56 (1), 57 (1), 58 (1), 59 (1)
Total number of vertebrae 109 (1), 110 (1), 112 (2), 113 (1), 115 (1)
Table 1. Morphometric characters of Erpetoichthys calabaricus. SD: standard deviation
range mean SD n
Standard length [mm] 147-343 266.5 51.2 28
Total length [mm] 171-355 281.2 47.5 27
In percent of standard length
Body depth 2.9-5.2 4.2 0.7 28
Body width 3.5-5.5 4.6 0.5 28
Head length 7.2-10.5 8.1 0.7 28
Pre-dorsal length 41.0-54.2 47.5 3.1 28
Dorsal-fin length 34.9-53.9 47.8 4.0 28
Pectoral to dorsal fin 28.6-40.7 34.6 2.8 26
Pre-pectoral length 7.8-10.7 8.8 0.7 28
Pectoral-fin extension 10.6-19.3 12.8 1.6 26
Inter-pectoral width 2.8-4.1 3.6 0.3 28
Pectoral-fin base width 0.8-1.5 1.2 0.2 28
Pre-anal length 93.0-95.1 94.1 0.5 28
Anal-fin ray length 3.6-5.5 4.6 0.5 27
Anal-fin base length 1.2-3.6 2.8 0.5 27
Caudal-peduncle length 0.8-1.6 1.1 0.2 27
In percent of head length
Head width 49.1-68.0 58.5 5.7 28
Interorbital width 21.6-28.5 25.4 1.8 28
Nostril distance 11.2-19.6 15.3 2.2 28
Snout length 21.9-26.9 24.8 1.3 28
Eye diameter 8.8-16.3 12.0 1.6 28
Postorbital length 60.4-65.2 63.3 1.2 28
Gular length 54.5-63.3 59.0 2.1 28
Length of first spine 8.8-22.5 17.0 2.9 28
Length of second spine 6.7-25.9 17.6 3.9 28
Width : length of first spine 24.3-51.2 35.2 7.1 28
Length of second : first spine 70.2-143.2 103.9 19.0 28
Moritz & Britz: Revision of Polypterus
9
Iris orange, brownish or grey; lips of upper and
lower jaw yellowish-orange without any mark-
ings. Pectoral fin yellowish-orange, at its proximal
part with black blotch extending onto distalmost
part of pectoral-fin base, leaving most of pectoral-
fin base without markings. Soft part of dorsal fin
and caudal fin brown, grey or olive with yellow-
orange fin membranes. Dorsal-fin spines brown,
grey or olive, their distal part orange; membrane
of finlets transparent or slightly yellowish with
only very few small dark spots.
In preservative: dorsal half of body and head
brown or brownish-grey (Fig. 3); ventral half of
body and head including lips and nasal tenta-
cles pale beige or brownish, sometimes slightly
orange-brown.
Distribution. From the Ouémé Basin in Benin,
across the Niger Delta in Nigeria to the Sanaga
River in Cameroon along West Africas coastal
basins (Fig. 4). A single record from the Chiloango
River (= Rio Hi) in the Cabinda region of Angola
mentioned in Boulenger (1909: 18) seems ques-
tionable; the species has not been reported since
from that area (Boulenger, 1912; Pellegrin, 1928;
Daget & Stauch, 1968).
Biology. Prefers small streams and swamps
(Smith, 1866a). Feeds on terrestrial insects, e. g.
termites (Smith, 1866c), insect larvae and aquatic
invertebrates. Reproduction in captivity and
early development were described by Britz &
Bartsch (1998).
Etymology. Smith (1865a) used calabaricus to refer
to . . . the locality [Old Calabar, Nigeria] where
it was discovered.
Remarks. Originally two syntypes were present,
but both were lost (see Swinney & Heppell, 1982).
The original description was based on two poorly
preserved specimens from Old Calabar, Calabar
River and adjacent water bodies, Nigeria, col-
lected by A. Robb on an unspecified date. There
are two specimens in the Paris Museum, MNHN
0000-4599, which are labelled as TYPES, and
listed as paratypes in the museums on-line
collection database (https://science.mnhn.fr/
30°N
20°N
10°N
10°S
30°N
20°N
10°N
10°S
10°W 10°E 20°E 30°E
10°W 10°E 20°E 30°E
Fig. 5. Records of Erpetoichthys calabaricus. , type locality; , verified records; , other records; , question-
able records.
Ichthyol. Explor. Freshwaters, IEF-1094
10
19
17
15
13
11
9
7
5
69
64
59
54
49
55
50
45
40
35
30
ı ı ı ı ı ı ı ı ı ı ı ı ı ı
P.ans P.bic P.con P.end P.del P.mok P.orn P.pal P.pol P.ret P.sen P.teu P.wek
P.ans P.bic P.con P.end P.del P.mok P.orn P.pal P.pol P.ret P.sen P.teu P.wek
ı ı ı ı ı ı ı ı ı ı ı ı ı ı
ı ı ı ı ı ı ı ı ı ı ı ı ı ı
ı ı ı ı ı ı ı ı ı ı ı ı ı ı
DSScLScB
Fig. 6. Box-and-whisker plots of selected meristic data of Polypterus species. DS, number of dorsal spines;
ScL, number of scales in lateral series; ScB, number of scales around body; ScpD, number of pre-dorsal scales;
ScpP, number of pre-pelvic scales; P.ans, P. ansorgii (n = 7); P.bic, P. bichir (n = 139); P.con, P. congicus (n = 66);
P.end, P. endlicherii (n = 64); P.del, P. delhezi (n = 44); P.mok, P. mokelembembe (n = 26); P.orn, P. ornatipinnis (n = 63);
P.pal, P. palmas (n = 122); P.pol, P. polli (n = 85); P.ret, P. retropinnis (n = 46); P.sen, P. senegalus (n = 226);
P.teu, P. teugelsi (n = 4); P.wek, P. weeksii (n = 45).
institution/mnhn/collection/ic/item/search/
form). Smith sent these specimens to the MNHN
and Duméril (1870) used them for his account of
the species in his Histoire naturelle des poissons.
Bertin (1940) finally listed the MNHN specimens
as paratypes referring to the redescription of
Duméril (1870). Although the specimens were sent
by Smith and come from the type locality they are
not part of the original type series. Smith (1865a)
had only two males, for his species description,
while the two specimens in the MNHN are male
and female; furthermore, the MNHN collection
database provides 1867 as the collection date for
these specimens, thus two years after the descrip-
tion of the species.
Polypterus erpetoideus was proposed as another
name for the species by Smith and reported in the
same newspaper article which served as original
description. This name was not used subsequently
and Swinney & Heppell (1982), as first revisers,
Moritz & Britz: Revision of Polypterus
11
Ichthyol. Explor. Freshwaters, IEF-1094
40
35
30
25
20
15
10
55
50
45
40
35
30
ı ı ı ı ı ı ı ı ı ı ı ı ı ı
P.ans P.bic P.con P.end P.del P.mok P.orn P.pal P.pol P.ret P.sen P.teu P.wek
P.ans P.bic P.con P.end P.del P.mok P.orn P.pal P.pol P.ret P.sen P.teu P.wek
ı ı ı ı ı ı ı ı ı ı ı ı ı ı
ı ı ı ı ı ı ı ı ı ı ı ı ı ı
ScpDScpP
Fig. 6. (continued).
selected Erpetoichthys calabaricus as the valid name
for the taxon.
Smiths (1865b) description of Erpetoichthys
robbianus was based on specimens with a small,
narrower anal fin, which is the condition in fe-
males of the sexually dimorphic anal fin (Traquair,
1866a-b; Smith, 1866a-c) in polypterids. Follow-
ing Swinney & Heppell (1982) NMSZ 1867.18.1;
NMSZ 1979.006.002 and BMNH 1908.1.27.2 pre-
sumably are part of the type series of E robbianus.
Herman et al. (1990) additionally listed NMSZ
1885.052 as part of this type series.
Genus Polypterus Lacèpede, 1803
Polyptere Geoffroy [Saint Hilaire], 1802a: 12, Plate
V.
Polypterus Lacépède, 1803: 340.
Type species. Polypterus bichir (Geoffroy, 1802)
by monotypy.
Diagnosis. Distinguished from Erpetoichthys by
presence of pelvic fin, presence of subopercle,
more pectoral-fin rays (24-48 vs. 16-21) and
comparatively shorter body (body depth 6-12
times in SL vs. 18-29 times) with fewer vertebrae
(67 or fewer vs. 109-115).
Descriptive synopsis. Body elongated to highly
elongated and eel-like, circular in cross section,
but laterally compressed in the postabdominal
part of the body. Polypterus is characterized by
50-70 scales in the lateral series, 10-38 pre-dorsal
scales, 31-54 scales around the body, 34-53 pre-
pelvic scales, 5-18 dorsal-fin spines, 13-24 soft
rays in confluent soft dorsal plus caudal fin, 24-
48 pectoral-fin rays; and pelvic fin present, with
7-17 rays. Figures 6 and 7 summarize selected
meristic and morphometric characters for the
genus. Sexual dimorphism in number of anal-fin
rays less pronounced than in Erpetoichthys: males
on average with one additional ray compared
to females; equally conspicuous enlargement of
anal fin in mature males through antero-posterior
widening of individual anal-fin rays.
Biology. See remarks for Polypteridae.
12
70
60
50
40
30
20
10
40
30
20
10
0
10
ı ı ı ı ı ı ı ı ı ı ı ı ı ı
P.ans P.bic P.con P.end P.del P.mok P.orn P.pal P.pol P.ret P.sen P.teu P.wek
P.ans P.bic P.con P.end P.del P.mok P.orn P.pal P.pol P.ret P.sen P.teu P.wek
ı ı ı ı ı ı ı ı ı ı ı ı ı ı
ı ı ı ı ı ı ı ı ı ı ı ı ı ı
ı ı ı ı ı ı ı ı ı ı ı ı ı ı
preDLdistPD
65
60
55
50
45
40
35
30
25
DFL
Fig. 7. Box-and-whisker plots for selected morphometric characters of Polypterus species. preDL, pre-dorsal
length; DFL, dorsal-fin length; distPD, distance between end of pectoral fin and origin of dorsal fin; HL, head
length; IOW, inter-orbital width; SnL, snout length; for other abbreviations and number of specimens see Figure 6.
Etymology. Polypterus is derived from the Greek
πλς – many and πτερ)+ – wing, apparently re-
ferring to the anterior part of the dorsal fin which
comprises multiple separate finlets.
Remarks. The genus name was originally spelled
Polyptère by Geoffroy (1802a). Lacépède (1803)
used this original name but also provided a
Latinized version. Only a few years later also
Geoffroy (1809) used both names, the original
French spelling and the Latinised version in his
Histoire naturelle des Poissons du Nil.
Eschmeyer (1998) originally listed the type
species as Polypterus bichir Geoffroy St. Hilaire
but changed it in the on-line edition of the Catalog
of Fishes (Fricke et al., 2018) to Polypterus bichir
Lacépède, 1803, arguing that the generic name
was not Latinised in Geoffroys (1802a) descrip-
tion. Holly (1933) had come to this conclusion and
Schäfer (2004) shared this same view. Likewise,
Shaw (1804) regarded Geoffroys (1802a) name
as not valid, and even introduced a new species-
name, i. e. P. niloticus, but using at the same time
the Latinised genus of the name given by Geof-
Moritz & Britz: Revision of Polypterus
13
Ichthyol. Explor. Freshwaters, IEF-1094
Fig. 7. (continued).
26
24
22
20
18
16
14
28
26
24
22
20
18
16
14
ı ı ı ı ı ı ı ı ı ı ı ı ı ı
P.ans P.bic P.con P.end P.del P.mok P.orn P.pal P.pol P.ret P.sen P.teu P.wek
P.ans P.bic P.con P.end P.del P.mok P.orn P.pal P.pol P.ret P.sen P.teu P.wek
ı ı ı ı ı ı ı ı ı ı ı ı ı ı
ı ı ı ı ı ı ı ı ı ı ı ı ı ı
ı ı ı ı ı ı ı ı ı ı ı ı ı ı
HLSnL
35
30
25
20
15
IOW
froy. The argumentation of the above mentioned
authors, however, is not in congruence with Art.
11.3 of the Code, which clearly states that a name
may be a word in or derived from any language.
Thus Polyptere (without apostrophe following
Arts. 27 and 32.5.2 of the Code) Geoffroy is an
available name and a senior synonym of Polypterus
Lacépède. However, because Polyptere has not
been used as a valid genus name since 1899 (Art.
23.9.1.1 of the Code) we declare Polyptere Geof-
froy, 1802 a nomen oblitum under Art. 23.9.2 of the
Code and the name Polypterus Lacépède a nomen
protectum because the latter has been used in at
least 25 works in the last 50 years by at least 10 dif-
ferent authors (Art. 23.9.1.2 of the Code) (Banister
& Bailey, 1979; Daget & Desoutter, 1983; Gosse,
1984, 1988, 1990, 2003; Bailey, 1994; Hanssens
et al., 1995; Bartsch & Britz, 1996; Seegers, 1996;
Bartsch, 1997; Britz & Bartsch, 1998, 2003; Britz
& Johnson, 2003; Britz, 2004; Lalèyè et al., 2004;
Schäfer, 2004; Poplin & Dutheil, 2005; Schliewen
& Schäfer, 2006; Schugardt & Kirschbaum, 2006;
Claeson et al., 2007; Claeson & Hagadorn, 2008;
Suzuki et al., 2010; Cuervo et al., 2012; Trape, 2013;
Near et al., 2014; Neumann et al., 2016; Grandstaff
et al., 2017; Moritz, 2017).
Thirteen valid species of Polypterus are herein
recognised. Morphologically two groups can be
14
a
b
c
a
b
c
Fig. 9. Changes in head shape during growth in Poly-
pterus endlicherii. a, DMM IE/10399, 102 mm SL; Benin:
Pendjari National Park; b, DMM IE/10393, 150 mm SL;
Benin: Pendjari National Park; c, BMNH 1949.10.20.1,
272 mm SL; Ghana: Volta Basin.
Moritz & Britz: Revision of Polypterus
121 2
3
ab
Fig. 8. Anteriormost scale row running continuously from dorsal to ventral mid-line is a, third row in Polypterus
ansorgii, and b, second row in P. senegalus.
distinguished: the large species group (P. ansor-
gii, P. bichir, P. congicus and P. endlicherii), and the
small species group, including all the remaining
members of the genus. Available molecular data
(Suzuki et al., 2010; Near et al., 2014) support the
monophyly of the large species, a taxon we call
herein the Polypterus bichir group. The small
species apparently do not form a monophyletic
group. The typical character states of the P. bichir
group seem to be rather derived conditions, e. g.
high number of dorsal-fin spines, low number
or pre-dorsal scales (Fig. 6), the third scale row
being the first to continue from dorsal to ventral
midline (vs. second scale row being the first to
continue all the way to the ventral midline; Fig. 8).
Our taxonomic study offers no obvious character
evidence that would support additional clades
among the small polypterid species group sup-
ported by molecular data.
Accurate identification of polypterids is often
complicated due to the similarity in their general
appearance, but also because of changes in body
shape during growth. One example is the project-
ing lower jaw of specimens of Polypterus bichir,
P. congicus and P. endlicherii. This character is often
used in identification keys (e. g. Boulenger, 1898;
Pellegrin, 1923a; Holly, 1933; Poll, 1941a; Gosse,
1990, 2003). In juveniles of these species, however,
jaws are still equal and the mouth is in a terminal
position. This has occasionally resulted in the er-
roneous identifications of juvenile P. endlicherii or
P. bichir as P. ansorgii in collections (e. g. AMNH
215310, USNM 339728) or in publications (e. g., La-
lèyè et al., 2004). Polypterus ansorgii is the smallest
species of the P. bichir group with jaws remaining
almost equal in size throughout life. In general
the head shape of members of the P. bichir group
changes during growth becoming flatter and thus
wider in appearance; this is most pronounced
in P. endlicherii (Fig. 9). A similar flattening of
the head can be seen to a smaller extent in large
specimens of P. weeksii.
Furthermore, the finlet membranes attached
to each dorsal-fin spine are supported by second
order dorsal-fin rays (Fig. 10a), the number of
which is only of limited, if any, diagnostic value
because during growth finlets acquire more of
these secondary rays (Fig. 10b; Sewertzoff, 1924).
As a result, adults of large species of the P. bichir
group seem to have more of these second order
15
a b
Fig. 10. Dorsal-fin spines and secondary rays in live Polypterus delhezi, lateral view. a, juvenile of 72 mm SL; b,
adult 240 mm SL.
dorsal-finlet rays than their juveniles or than
adults of other species.
The position of the first dorsal-fin spine in
relation to the posterior margin of the pectoral fin
is often used (e. g. Gosse, 1990, 2003) to distinguish
between the large and small species, i. e. the
P. bichir group and the remaining Polypterus spe-
cies. Although helpful to identify certain species,
this character does not allow a clear distinction be-
tween the two groups: occasionally in specimens
of P. senegalus the first dorsal-fin spine is situated
directly above the posterior tip of the pectoral fin
and some P. bichir specimens show a clear gap
between the vertical through the posterior margin
of the adducted pectoral fin and that of the base
of the first dorsal-fin spine (Fig. 8). Unusual in
this regard is P. delhezi which usually has its first
dorsal-fin spine anterior to the posterior margin of
the pectoral fin, a condition typical of the P. bichir
group, although other characters are consistent
with its inclusion among the small Polypterus
species. The commonly used number of dorsal-fin
spines and number of scales to characterize species
are often overlapping between species, but there
are still a number of useful meristic and morpho-
metric characters to distinguish poly pterid species
(Fig. 6-7). In general, certain polypterid species
have a somewhat similar morphology and are
best distinguished by differences in coloration.
Polypterus ansorgii Boulenger, 1910
(Figs. 11-13, Tables 3-4)
Polypterus ansorgii Boulenger, 1910: 424.
Material examined. 7 specimens. type speCimens:
BMNH 1910.9.13.4, lectotype (Fig. 11; present designa-
tion), 169 mm SL; likely juvenile female, Guinea-Bissau:
Corobal River at Tchitoli, W. J. Ansorge, Jun 1909. –
NMW 63252: 1-2, 2, paralectotypes, 147-160 mm SL;
collected with the lectotype. géBa river Basin: MRAC
73-005-P-0031, 1, 180 mm SL; Senegal: Geba River Basin:
Kanyanga River at Kounkane, 12°55' N 14°06' W; D. F.
E. Thys van den Audenaerde, 6 Apr 1966. – MRAC
73-005-P-0032-0033, 2, 179-210 mm SL; Senegal: Geba
River Basin: Kanyanga River at Kounkane, 12°55' N
14°06' W; D. F. E. Thys van den Audenaerde, 8 Apr
1966. CasamanCe river Basin: MRAC 73-005-P-0030, 1,
210 mm SL; Senegal: Casamance River at Kolda, 12°53' N
14°57' W; D. F. E. Thys van den Audenaerde, 8 Apr 1966.
Diagnosis. Distinguished from all Polypterus spe-
cies, except P. bichir, P. congicus and P. endlicherii
by 13-15 dorsal finlets (vs. 5-12) and the second
dorsal scale row not reaching ventral midline
(vs. reaching ventral midline). Distinguished
from P. congicus and P. endlicherii by smaller
interorbital width (15.7-18.5 % HL vs. 17.9-
27.4 %) and by coloration consisting of more or
less regular, rectangular lateral blotches usually
not confluent with dorsal saddle blotches (vs.
no separate regular rectangular lateral blotches,
but series of bars formed by confluence of dorsal
blotches with lateral blotches in P. congicus and
with lateral blotches and ventrolateral markings
in P. endlicherii). Polypterus ansorgii differs from
P. bichir by fewer scales in lateral series (54-56
vs. 55-70), fewer scales around body (43-45 vs.
43-54) and smaller adult size (maximum recorded
size 313 mm SL vs. 750); in specimens between
150 and 200 mm SL, external gills usually com-
pletely reduced in P. ansorgii (vs. present in most
specimens of P. bichir). Specimens smaller than
147 mm SL of P. ansorgii have not been available
for this study and it remains unclear, whether
it would be possible to distinguish them from
equally small specimens of P. bichir based on
external characters.
Ichthyol. Explor. Freshwaters, IEF-1094
16
Descriptive synopsis. Meristic and morphomet-
ric data in Tables 3-4. Body moderately elongated.
Jaws terminal, in larger specimens (> 200 mm
SL) lower jaw slightly projecting beyond upper
jaw. Head flattened. Likely the smallest species
among the Polypterus bichir group with the largest
specimens in collections measuring 210 mm SL
(246 mm TL), and unpreserved aquarium speci-
men reaching 313 mm SL (371 mm TL).
Table 3. Morphometric characters of Polypterus ansorgii. Range, mean and standard deviation (SD) include values
of lectotype. Negative values under Pectoral to dorsal fin refer to dorsal-fin origin in front of pectoral-fin end.
lectotype range mean SD n
Standard length [mm] 169.0 147-210 178.0 22.1 7
Total length [mm] 205.0 178-246 211.3 21.3 7
In percent of standard length
Body depth 11.6 10.8-12.3 11.6 0.5 7
Body width 12.9 11.2-12.9 12.4 0.6 7
Head length 23.3 22.6-24.9 23.5 0.8 7
Pre-dorsal length 30.1 30.1-33.5 31.9 1.2 7
Dorsal-fin length 59.9 52.0-59.9 56.1 2.6 7
Pectoral to dorsal fin -6.0 -6.3--3.1 -4.5 1.2 7
Pre-pectoral length 22.9 22.9-25.0 23.8 0.7 7
Pectoral-fin extension 35.7 35.4-38.2 37.0 1.1 7
Inter-pectoral width 8.6 7.7-9.6 8.9 0.6 7
Pectoral-fin base width 3.3 3.3-3.6 3.5 0.1 7
Pre-pelvic length 70.2 69.8-72.1 71.1 0.9 7
Pre-anal length 85.9 84.1-86.0 85.3 0.8 7
Anal-fin ray length 14.2 12.3-14.6 13.5 0.8 7
Anal-fin base length 5.0 4.5-5.6 5.2 0.4 7
Caudal-peduncle length 3.6 2.8-3.7 3.3 0.3 7
In percent of head length
Head width 56.0 49.8-62.3 55.2 4.9 7
Interorbital width 17.3 15.7-18.5 17.4 0.9 7
Nostril distance 12.2 10.6-12.2 11.7 0.6 7
Snout length 19.5 17.2-21.2 19.5 1.6 7
Eye diameter 12.6 11.1-13.5 12.3 0.9 7
Postorbital length 67.5 65.1-68.5 66.4 1.2 7
Gular length 70.3 53.9-70.3 59.5 5.2 7
Length of first spine 19.7 19.4-22.5 21.0 1.1 7
Length of second spine 23.8 23.1-25.5 23.9 0.8 7
Width : length of first spine 23.1 16.7-23.1 19.7 2.2 7
Length of second : first spine 120.7 103.3-122.8 114.3 7.2 7
Table 4. Meristic characters of Polypterus ansorgii. Numbers in brackets indicate number of specimens with the
respective value. All material includes values of lectotype.
lectotype all material
Dorsal-fin spines 15 13 (5), 14 (1), 15 (1)
Dorsal- and caudal-fin rays 17 17 (2), 19 (5)
Pectoral-fin rays 39 35 (1), 37 (1), 39 (2), 40 (1), 42 (2)
Pelvic-fin rays 10 10 (2), 11 (3), 12 (2)
Anal-fin rays 11 11 (2), 12 (2), 13 (2), 14 (1)
Scales in longitudinal series 56 54 (1), 55 (4), 56 (2)
Scales around body 44 43 (1), 44 (4), 45 (2)
Pre-dorsal scales 11 11 (1), 12 (2), 13 (4)
Pre-pelvic scales 40 40 (1), 41 (5), 42 (1)
Total number of vertebrae 57 57 (1)
Moritz & Britz: Revision of Polypterus
17
Coloration. In life (based on photographs of two
imported specimens of ca. 300 mm SL): dorsal
half of body grey or brown with dark grey to dark
brown dorsal saddle blotches; along flanks dark,
more or less regular, rectangular lateral blotches in
longitudinal series; separated from dorsal bars by
narrow light stripe (Fig. 12). Ventral half of body
whitish to cream with ventrolateral markings
expressed as interrupted dark line below lateral
blotches. Head dark grey dorsally, becoming
lighter laterally and whitish ventrally; irregular
dark spots all over head. Iris light grey with dark
grey irregular pattern. Coloration of upper lips
not differing from dorsal head coloration; lower
lips light beige with large dark spots. Pectoral,
pelvic and confluent dorsal-caudal fin yellowish;
small number of dark spots in pelvic and anal
fins, spots more numerous in soft part of dorsal
fin and in caudal fin; spots arranged in regular
rows on pectoral fin. Dorsal-fin spines dark grey
on anterior face, more yellowish on lateral and
posterior faces; finlet membrane transparent to
slightly greyish.
In preservative: all studied preserved speci-
mens considerably depigmented: no blotches or
spots on lower jaw, head or lower half of flanks.
Dorsal saddle blotches and rectangular blotches
along flank, however, appearing more prominent
than in life.
Distribution. Known only from three river ba-
sins in Guinea-Bissau and the Senegal: Corobal
River, Géba River and Casamance River (Fig. 13).
Records from eastern Niger basin (MRAC 92-014-
P-0001-0002) are based on confusion with P. bichir
(see below). Dagets (1954: 57) record of P. ansorgii
from the Upper Niger basin was subsequently
regarded by Daget & Iltis (1965) as based on an
atypical P. bichir lapradii.
Biology. At least in captivity not different in
behaviour from other species of P. bichir-complex:
voracious predator, predominantly active during
night.
Etymology. Named after Dr. W. J. Ansorge who
collected type specimens.
Remarks. Three specimens were mentioned in
the original description. They are syntypes and are
currently housed in the collections of BMNH and
NMW. We hereby designate BMNH 1910.9.13.4
(Fig. 11) as the lectotype of P. ansorgii.
Fig. 11. Polypterus ansorgii, BMNH 1910.9.13.4, 169 mm SL, juvenile or female, lectotype (present designation);
Guinea Bissau: Corobal River at Tchitoli; W. J. Ansorge; Jun 1909.
Ichthyol. Explor. Freshwaters, IEF-1094
18
Previous confusion of P. ansorgii with other
Polypterus species was probably caused by the sig-
nificant variation in coloration in P. bichir across
its range, and by changes in head shape during
growth in large Polypterus species. The jaws are
of equal length in juveniles in those species that
have a projecting lower jaw in adults, a condition,
which may have led to confusion with P. ansorgii.
Several keys list the equal length of the jaws as
a distinguishing character of P. ansorgii from the
other large species (e. g. Daget & Iltis, 1965). Ad-
ditional records of P. ansorgii from Lake Kainji,
Ogun River (AMNH 215310, USNM 339728)
and Ouémé River (Lalèyè et al., 2004) represent
misidentifications.
a
b
c
a
b
c
Fig. 12. Polypterus ansorgii, aquarium import from Guinea Bissau. a, 313 mm SL, male with light coloration; b, same
specimen with darker coloration; c, detail of head.
Moritz & Britz: Revision of Polypterus
19
Polypterus bichir (Geoffroy, 1802)
(Figs. 14-20, Tables 5-6)
Polyptere bichir Geoffroy [Saint-Hilaire], 1802a: 98.
Polypterus bichir katangae Poll, 1941a: 145.
Polypterus bichir lapradei Steindachner, 1869: 103.
Polypterus niloticus Shaw, 1804: 122.
Material examined. 148 specimens. MNHN 0000-5761,
lectotype (Fig. 14), 585 mm SL; Egypt: Nile River, E.
Geoffroy Saint-Hilaire, 1799. – MNHN 0000-5806, 1,
paralectotype, 549 mm SL; dry mounted specimen,
Egypt: Nile River, E. Geoffroy Saint-Hilaire, 1799. sen-
egal: NMW 63244, 1, 464 mm SL; syntype of P. lapradei,
Senegal: Taoué close to Richar-Toll [= Touey-Marigot],
16°31' N 15°41' W; F. Steindachner, Nov 1868 [but jar
labelled with March 1869, likely referring to date of
registration] (Fig. 15). – NMW 63242, 1, 182 mm SL;
syntype of P. lapradei, Senegal: Podor, ca. 16°39' N
14°57' W; F. Steindachner, Nov 1868 [but jar labelled
with March 1869, likely referring to date of registration].
– NMW 63243:1-2, 2, 166-190 mm SL; syntypes of
P. lapradei, Senegal: Dagana, ca. 16°31' N 14°57' W; F.
Steindachner, Nov 1868 [but jar labelled with March
1869, likely referring to date of registration]. – BMNH
1900.6.28.1, 1, 536 mm SL; Senegal: St. Louis, M. Delhez.
– BMNH 1900.6.28.2-3, 2, 625-675 mm SL; Senegal:
Kaedi, M. Delhez. – BMNH 1900.6.28.4-7, 4, 284-364 mm
SL; Senegal: Kaedi, M. Delhez. – BMNH 1900.6.28.9, 1,
334 mm SL; Senegal: Kaedi, M. Delhez. – MRAC 140104,
1, 308 mm SL; Senegal: Kaedi, M. Delhez, around 1900.
– MRAC 73-005-P-0024, 1, 226 mm SL; Senegal: Djeuss
[St. Louis] River at Bouben, D. F. E. Thys van den
Audenaerde, 8 Mar 1966. – MRAC 73-005-P-0027-0028,
2, 377-399 mm SL; Senegal: Lampsar River [in Senegal
River Delta] at Ross Bethio, D. F. E. Thys van den
Audenaerde, 10 Mar 1966. – MRAC 73-005-P-0029, 1,
494 mm SL; Senegal: Casamance River at Kolda, D. F.
E. Thys van den Audenaerde, 3 Apr 1966. – NMW 63053,
1, 750 mm SL; Senegal, Steindachner. – MNHN 1907-
0250, 1, 338 mm SL; Senegal, Gruvel. gamBia river
Basin: BMNH 1901.7.17.1, 1, 387 mm SL; Gambia, J. S.
Budgett. – BMNH 1905.11.13.10, 1, 326 mm SL; Gambia,
Capt. Vipan. – MNHN 1980-1603, 1, 293 mm SL; Sen-
egal: Gambia River at Wassadou, D. Paugy. geBa
river: BMNH 1912.4.1.2-3, 2, 525-630 mm SL; Guinea-
Bissau: Geba River at Bafata, W. Ansorge. vOlta river
Basin: MRAC 140927-140929, 2, 198-213 mm SL; Bur-
kina Faso: Kou River [tributary of Mouhoun], 4 Jun
1964, B. Roman. – MRAC 143517-143518, 2, 194-220 mm
SL; Burkina Faso: north of Bobo-Dioulasso, B. Roman.
niger river anD triButaries: BMNH 1884.6.9.9-10, 2,
510-517 mm SL; Nigeria: Niger River, Esq. W. Forbes.
– BMNH 1884.6.9.14-18, 5, 257-330 mm SL; Nigeria:
Niger River, Esq. W. Forbes. – BMNH 1907.5.3.1, 259 mm
SL; Nigeria: Benue River north of Ibi, Capt. Vipan. –
BMNH 1928.7.3.1, 1, 255 mm SL; Nigeria: Kiyawa
30°N
20°N
10°N
10°S
30°N
20°N
10°N
10°S
10°W 10°E 20°E 30°E
10°W 10°E 20°E 30°E
Fig. 13. Records of Polypterus ansorgii. , type locality; , verified records.
Ichthyol. Explor. Freshwaters, IEF-1094
20
River at Katagum, Esp. L. Lloyd. – BMNH 1953.4.28.126,
1, 503 mm SL; Nigeria: Hadeija-River, E. Trewavas. –
BMNH 1969.3.25.10, 1, 315 mm SL; Nigeria: Sokoto
River, M. H. Holden, Jun 1957. – BMNH 1902.11.10.28-
30, 2, 80-87 mm SL; Nigeria: Assay, W. Ansorge. –
BMNH 1902.11.10.27, 1, 161 mm SL; Nigeria: Abo, W.
Ansorge. – BMNH 1913.12.5.1, 1, 89 mm SL; Nigeria:
Anambra River, W. Crocombe. – MNHN 1925-0172, 1,
242 mm SL; Guinea: Kouroussa, Thomas. – MNHN
1961-0012, 4, 205-295 mm SL; Mali: Diafarabé, J. Daget,
22 May 1951. – MNHN 1961-0013, 2, 160-175 mm SL;
Mali: Diafarabé, J. Daget, 8 Apr 1950. – MNHN 1961-
0014, 1, 116.6 mm SL; Mali: Diafarabé, J. Daget, 27 Oct
1949. – MNHN 1961-1130, 1, 224 mm SL; Guinea: Niger
River at Faranah, Raimbault, 28 Aug 1958. – MNHN
1992-0769, 4, 210-233 mm SL; Guinea: Banie [= Niger]
River at Sanassiya, D. Paugy and R. Bigorne, 2 Mar
1989. – MRAC 72790-72793, 4, 179-253 mm SL; Mali:
Diafarabé, J. Daget, Nov 1946. – MRAC 73-012-P-0007-
0008, 2, 344-448 mm SL; Mali, Niger River at Mopti, H.
Matthes, 17 Sep 1969. – MRAC 92-014-P-0001, 1, 253 mm
SL; Nigeria: Orashi River at Odieke, C. B. Powell, 15
Nov 1991. – MRAC 92-014-P-0002, 1, 264 mm SL; Nige-
ria: Isemu Lake, C. B. Powell, 1-9 Nov 1991. lake ChaD
anD triButaries: BMNH 1928.7.4.1, 1, 361 mm SL; Chad:
Chari River below junction of Lodgone River, C.
Markham. – BMNH 1930.8.7.1-2, 2, 517-554 mm SL;
Chad: Chari River at Logone, J. Glover. – MNHN 1904-
0066, 1, 470 mm SL; Chad: Chari River, Chevalier and
Decorse. – MNHN 1928-0069, 1, 351 mm SL; Cameroon:
El Beid River at Afade, J. Monod. – MNHN 1959-0390,
1, 187 mm SL; Cameroon: El Beid; J. Blache and A.
Stauch, 5 Oct 1954. – MRAC 66466, 1, 405 mm SL;
Cameroon: Benoue River at Lere, J. Monod. – MRAC
153839-153840, 2, 416-486 mm SL; Chad: Mandoul
River at Bahr-Sara, A. Sutter, Mar 1965. – MRAC 73-
015-P-0034, 1, 336 mm SL; Cameroon: Logone River at
Guémé; W. Verheyen et al., 26 Nov 1970. – MRAC 73-
015-P-0035, 1, 608 mm SL; Cameroon: Logone River at
Guémé; W. Verheyen et al., 26 Nov 1970. – MRAC 73-
015-P-0036-0038, 2, 448-503 mm SL; Cameroon: Logone
River at Guémé, W. Verheyen et al., 26 Nov 1970. –
MRAC 73-015-P-0044-0046, 3, 211-377 mm SL; Came-
roon: Benoué River at Garoua, W. Verheyen et al., 7 Dec
1970. – MRAC 73-015-P-0047, 1, 269 mm SL; Cameroon:
Benoué River at Garoua, W. Verheyen et al., 8 Dec 1970.
nile Basin: BMNH 1850.7.29.1, 1, 517 mm SL; Egypt:
Nile, E. Rüppell. – BMNH 1899.4.28.1, 1, 550 mm SL;
Egypt: lower Nile River, Harrington and Harrington.
– BMNH 1899.4.28.2, 1, 466 mm SL; Egypt: lower Nile
River, Harrington and Harrington. – BMNH 1900.9.22.37,
1, 512 mm SL; Sudan: Bahr-el-Jebel, Capt. S. Fowler. –
BMNH 1906.3.3.1-3, 2, 261-299 mm SL; Egypt: west
Damietta, J. Mitchell. – BMNH 1907.12.2.117, 1, 261 mm
SL; Egypt: Nile River near Cairo; W. L. S. Loat, 15 Mar
1899. – BMNH 1907.12.2.118, 1, 667 mm SL; Sudan:
White Nile at Kawa, W. L. S. Loat. – BMNH 1907.12.2.119-
121, 3, 255-273 mm SL; Sudan: White Nile at Goz Abou
Gumah, W. L. S. Loat, 1 May 1901. – BMNH 1907.12.2.123-
124, 2, 203-214 mm SL; Sudan: White Nile at Ghab-el-
Aish, W. L. S. Loat. – BMNH 1907.12.2.125-134, 11,
252-554 mm SL; Sudan: White Nile at Fashoda, W. L.
S. Loat. – BMNH 1907.12.2.135, 1, 655 mm SL; Sudan:
White Nile near Kerro; W. L. S. Loat. – BMNH
1907.12.2.136, 1, 615 mm SL; Sudan: Lako No; W. L. S.
Loat. – MNHN 0000-2609, 2, 482-520 mm SL; Nile; Hit-
torf and Ehrenberg; 1844. – MNHN 0000-5762, 1, 583 mm
SL; Egypte: Nile; Clotbey; 1856. – MNHN 0000-5763, 1,
451 mm SL; Nile; Lenormand. – MRAC 140103, 1,
244 mm SL; Sudan: White Nile at Goz Abou Gumah,
W. L. S. Loat; 1907. – NMW 30297, 2, 426-429 mm SL;
Sudan: Bahr-el-Gazal; Marno, 1882. – NMW 30299, 1,
386 mm SL; Nile, Steindachner. – NMW 3302, 1, 443 mm
SL; Nile, Kotschy, 1842. – NMW 63209, 3, 245-267 mm
SL; Sudan: Khartoum, Drasche, 1876. – NMW 63210, 1,
465 mm SL; Nile, Steindachner, Nov 1910. – NMW 63211,
2, 321-357 mm SL; Nile; Steindachner, Oct 1910. – NMW
63212, 1, 364 mm SL; Sudan: Bahr-el-Seraf, Marno, 1881.
– NMW 63213, 1, 518 mm SL; Sudan: Bahr-el-Ghazal,
Steindachner, 1882. – NMW 63214, 1, 495 mm SL; Sudan:
Zuflüsse des oberen Nil [affluents of the Upper Nile],
Marno, 1881. – NMW 63215, 1, 497 mm SL; Sudan: White
Nile at Khor Attac, Werner, 1907. – NMW 63216, 1,
457 mm SL; Nile, Steindachner, Oct 1910. – NMW 63217,
1, 212 mm SL; Nile, Steindachner, 2 Nov 1910. – NMW
63219, 1, 434 mm SL; Sudan, Steindachner, Aug 1910.
– NMW 77728, 1, 528 mm SL; Sudan: Melut, 10°27' N
32°13' E; W. Sixl, 1981. – NMW 79061, 2, 485-572 mm
SL; Sudan: Melut, 10°27' N 32°13' E; W. Sixl, 1983. – NMW
9584, 1, 340 mm SL; side branch of Nile, Steindachner
and Marno, 1981. – ZSM 34546, 1, 330 mm SL; Sudan:
Omdourman [fishmarket], N. Pöllath, 14 Feb 2006.
katanga regiOn: MRAC 20671, 1, 389 mm SL; holotype
of P. bichir katangae, Democratic Republic of Congo:
Nyonga: Lake Upemba, G.-F. de Witte, 8-12 May 1925.
– MRAC 49319, 1, 109.5 mm SL; paratype of P. bichir
katangae, Democratic Republic of Congo: Lualaba Rivert
at Bukuma, P. Brien, Jun 1937. – MRAC 66561, 1,
134.5 mm SL; paratype of P. bichir katangae, Demo-
cratic Republic of Congo: Lualaba Rivert at Bukuma, P.
Brien, 23-26 Jun 1937. – MRAC 66562, 1, 149.2 mm SL;
paratype of P. bichir katangae, Democratic Republic of
Congo: Lualaba Rivert at Bukuma, P. Brien, 23-26 Jun
1937. – MRAC 66563, 1, 123.6 mm SL; paratype of
P. bichir katangae, Democratic Republic of Congo: Lu-
alaba Rivert at Bukuma, P. Brien, 23-26 Jun 1937
(Fig. 16). – IRSNB 68, 1, 415 mm SL; paratype of P. bichir
katangae, Democratic Republic of Congo: Lualaba River
at Maka, H. J. Bredo, 1 Feb 1939. – MRAC 178671, 1,
52.7 mm HL [only head preserved], paratype of P. bichir
katangae, Democratic Republic of Congo: Lake Kazi-
baziba, W. de Smet, 17 Nov 1956. – MRAC 178672, 1,
45.6 mm HL [only head preserved], paratype of P. bichir
katangae, Democratic Republic of Congo: Make, 50 km
from Bukuma, W. de Smet, 27 Dec 1955. – MRAC 178673,
1, 51.4 mm HL [only head preserved], paratype of
P. bichir katangae, Democratic Republic of Congo: Make,
50 km from Bukuma, W. de Smet, 27 Dec 1955. – MRAC
Moritz & Britz: Revision of Polypterus
21
69702, 1, 445 mm SL; Democratic Republic of Congo:
Lualaba River at Maka, M. Poll, 25 Jun 1947. – MRAC
79-01-P-0003, 1, 396 mm SL; Democratic Republic of
Congo: Lake Upemba: Mabwe, F. de Witte, 7-9 Sep
1947. WithOut lOCality Data: NMW 50276, 1, 585 mm
SL.
Additional material. nile Basin: DMM IE/10412, 2,
Sudan: Khartoum [central fish market]; T. Moritz et
al., Apr 2008.
Diagnosis. Polypterus bichir is distinguished from
all other members of the genus except P. ansorgii,
P. endlicherii and P. congicus, by 13 or more dorsal-
fin spines (vs. 12 or fewer) and the third dorsal
scale row being the first to reach ventral midline
(vs. second dorsal scale row reaching ventral
midline). Polypterus bichir is distinguished from
P. endlicherii and P. congicus by dorsal saddle-like
blotches, when present not confluent with, but
separate from lateral blotches (vs. dorsal and
lateral blotches confluent and always present).
When present, dorsal saddle blotches are more
numerous in P. bichir, with 9 or more such blotches
(vs. 6-8 in P. congicus and 4-6 in P. endlicherii), and
wide, i. e. at least 3 scale rows wide in P. bichir
(vs. less than 3 scale rows wide in P. congicus).
Polypterus bichir is distinguished from P. ansorgii
by more scales around the body (43-54 vs. 43-45)
and a larger maximum adult size (750 mm SL vs.
313). Most specimens can be distinguished from
P. ansorgii, P. congicus and P. endlicherii by 61 or
more scales in lateral series (55-70 [lower quartile
61] vs. 54-60 [upper quartile 60]).
Descriptive synopsis. Meristic and morphomet-
ric data in Tables 5-6. Body elongated with 55-70
scales and 57-67 vertebrae. Jaws terminal only in
juveniles; in large specimens lower jaw project-
ing beyond upper jaw. In large specimens head
and anterior body region often slightly dorso-
ventrally flattened (but never to the degree as in
large P. endlicherii and P. congicus). Size up to at
least 750 mm SL (820 mm TL).
Coloration. In life: coloration highly variable
(Fig. 17). Dorsal half of body brownish, light
brown, light grey or yellowish with dark brown
or grey markings varying from very faint to
conspicuous and pronounced: dorsal and lateral
blotches expressed only from about midlength,
more anteriorly replaced by two dark brown
longitudinal bands separated by lighter narrow
longitudinal stripe. Ventral half of body uniform
beige with no dark ventrolateral markings or with
few to many markings formed by aggregated dark
scales in anterior two-thirds of flanks, forming
irregular to regular lines; on posterior part of
ventrolateral body sometimes with several ventro-
lateral blotches in confluence with lateral blotches
forming irregular network of blotch lines. Dorsal
half of head light brown, grey or yellowish with
dark marbling of varying density. Ventral half of
head and cheek lighter with numerous dark spots
of variable sizes; often spotting extending down
onto gular plates. Lip markings formed by small
blotches. Iris yellow or orange with irregular dark
spots. Nasal tentacles showing same uniform or
marbled coloration as dorsal half of head. Also
markings on head very variable ranging from
virtually absent to much pronounced.
Pectoral fin yellow with dark brown elongate
spot-like markings arranged in several transversal
more or less regular bands; pectoral-fin base with
numerous large dark spots arranged to form a
blotch varying in expression from almost absent to
pronounced. Pelvic fin yellowish transparent with
or without dark spots arranged in more or less
regular bands. Soft part of dorsal fin and conflu-
ent caudal fin brown, yellowish or grey with dark
markings frequently expressed as densely set dark
spots loosely arranged in stripes. Dorsal-fin spines
grey, dark grey or brown with light or yellowish
spots arranged at approximately the same level as
in succeeding spines; similar pattern continuing
onto first and second order secondary fin rays
originating from spines; finlet-membrane grey-
transparent, usually without pattern, sometimes
with some dark marbling.
Different intensity of coloration not restricted
to any geographic areas, except the intensely
colored specimens from Koliba River. Plain
colored and more intensely pigmented specimens
present in same river basins at same time.
In preservative: all areas which are light
in life become pale in preservative; dark color
markings less pronounced; fine marbling on head
sometimes absent; dark spots on lower half of
head and body less intense. Dry paralectotype
(MNHN 0000-5806) without any color pattern;
ethanol preserved lectotype (MNHN 0000-5761)
only with faint color markings.
Distribution. Widely distributed in the major
river basins of the Nilo-Sahelo-Sudan region: Nile,
Chad, Niger, Volta and Senegal (Fig. 18). Addi-
tionally in few West African coastal basins: Gam-
Ichthyol. Explor. Freshwaters, IEF-1094
22
Fig. 14. Polypterus bichir, MNHN 0000-5761, 585 mm SL, male, lectotype; Egypt: Nile; E. Geoffroy Saint-Hilaire;
1799.
Fig. 15. Polypterus bichir, NMW 63244, 464 mm SL, male, syntype of P. lapradei; Taoué close to Richar-Toll [= Touey-
Marigot]; F. Steindachner; Nov 1868.
Moritz & Britz: Revision of Polypterus
23
bia, Casamanche and Geba River. Also distributed
in the Katanga area of the Congo basin, mainly
the Lualaba River. Occurrences of P. bichir in Lake
Turkana (e. g. Pellegrin, 1914; Holly, 1933; Poll,
1941a; Reitzer et al., 1972; Gosse, 1990; Seegers et
al., 2003) and Ouémé River basin (Gosse, 1990) are
questionable, as they are not supported either by
museum specimens or photographs.
Biology. Apparently most active at night, active
swimmer and not essentially a bottom-liver or a
mudfish (Harrington, 1899), living on muddy
substrates (Chad: Pellegrin, 1914). Polypterus bichir
prefers deeper depressions of muddy river beds
(Nile: Harrington, 1899) and feeds on small fish
of all types and on crustaceans (Chad: Pellegrin,
1914). Reproduction takes place during flood
season (Senegal: Reitzer et al., 1972) and mature
fishes enter flood plains for spawning (Gambia:
Budgett, 1900; Niger: Daget, 1954).
Etymology. The name refers to the local Egyptian
name, bichir, for the species (Geoffroy, 1802a-b).
Remarks. Some confusion has arisen about
which of three publications represents the origi-
nal description of this species (Geoffroy 1802a-b;
Lacépède, 1803). Geoffroys publication in the
Bulletin des Sciences (1802a) was published
between 21st of March and 20th of April in 1802.
This predates his publication in the Annales du
Muséum dHistoire naturelle (Geoffroy, 1802b),
which was not published before 22nd of September
of the same year. Thus Geoffroy (1802a) made the
species name available, with the original spelling
as Polyptère bichir (which needs to be amended
to Polyptere bichir in accordance with Art. 33.3 of
the Code). One year later, Lacépède (1803: 340)
used the Latinised version, Polypterus bichir, in his
publication and this work that has been cited by
some authors, though incorrectly, as the descrip-
tion of the species (e. g. Holly, 1933; Schäfer, 2004;
Claeson & Hagadorn, 2008; Grandstaff et al., 2012;
Fricke et al., 2018). See also above under remarks
for the genus Polypterus.
Geoffroy Saint-Hilaire (1802a) did not specify
any type material and did not mention on how
Fig. 16. Polypterus bichir, MRAC 66563, 124 mm SL, juvenile, paratype of P. bichir katangae; Democratic Republic
of Congo: Lualaba Rivert at Bukuma; P. Brien; 23-26 Jun 1937.
Ichthyol. Explor. Freshwaters, IEF-1094
24
Table 5. Morphometric characters of Polypterus bichir. Range, mean and standard deviation (SD) include values
of lectotype. Negative values under Pectoral to dorsal fin refer to dorsal-fin origin in front of pectoral-fin end.
lectotype range mean SD n
Standard length [mm] 585.0 109.5-750 364.0 140.9 139
Total length [mm] 660.0 131.9-820 407.7 155.5 131
In percent of standard length
Body depth 10.1 7.1-14.5 11.0 1.3 137
Body width 11.6 8.2-14.1 11.9 1.0 137
Head length 19.2 17.8-26.9 21.4 1.9 139
Pre-dorsal length 28.0 25.3-37.7 30.2 2.0 138
Dorsal-fin length 59.8 46.8-62.5 56.5 3.0 138
Pectoral to dorsal fin 4.0 -8.4-4.00 -3.6 1.7 135
Pre-pectoral length 19.6 16.7-26.6 21.6 1.8 137
Pectoral-fin extension 31.6 27.5-41.6 34.0 2.7 135
Inter-pectoral width 7.0 5.9-10.4 7.7 0.9 136
Pectoral-fin base width 3.1 1.8-3.9 2.9 0.4 137
Pre-pelvic length 70.3 64.8-73.6 70.0 1.5 138
Pre-anal length 85.1 80.6-88.3 85.0 1.4 138
Anal-fin ray length 11.4 7.3-16.3 12.3 1.6 136
Anal-fin base length 6.3 3.2-7.6 5.3 0.7 136
Caudal-peduncle length 4.1 2.2-4.8 3.4 0.5 136
In percent of head length
Head width 51.6 38.9-63.6 50.9 3.8 142
Interorbital width 17.8 15.6-24.8 19.0 1.7 141
Nostril distance 12.2 8.0-15.4 12.2 1.2 141
Snout length 19.0 14.6-22.3 19.5 1.4 141
Eye diameter 8.7 7.4-15.2 10.1 1.6 142
Postorbital length 72.5 62.3-74.2 69.6 2.1 142
Gular length 50.4 48.6-75.0 61.4 6.5 142
Length of first spine 22.7 11.0-28.5 22.4 3.0 133
Length of second spine 18.3 13.4-30.4 24.3 2.6 134
Width : length of first spine 15.2 12.7-36.7 17.8 3.8 133
Length of second : first spine 80.6 63.8-215.5 110.5 17.5 132
Table 6. Meristic characters of Polypterus bichir. Numbers in brackets indicate number of specimens with the
respective value. All material includes values of lectotype.
lectotype all material
Dorsal-fin spines 16 13 (17), 14 (36), 15 (30), 16 (37), 17 (16), 18 (2)
Dorsal- and caudal-fin rays 19 18 (1), 19 (9), 20 (39), 21 (65), 22 (22), 23 (2), 24 (1)
Pectoral-fin rays 41 34 (1), 35 (4), 36 (1), 37 (13), 38 (15), 39 (21), 40 (25), 41 (25), 42 (18), 43 (8),
44 (3), 45 (1), 46 (1), 48 (1)
Pelvic-fin rays 13 10 (8), 11 (23), 12 (42), 13 (45), 14 (18), 15 (3)
Anal-fin rays 16 9 (1), 10 (3), 11 (11), 12 (28), 13 (44), 14 (33), 15 (16), 16 (1)
Scales in longitudinal series 67 55 (1), 56 (1), 58 (3), 59 (11), 60 (11), 61 (11), 62 (17), 63 (14), 64 (16), 65 (21),
66 (23), 67 (6), 68 (2), 70 (1)
Scales around body 44 43 (6), 44 (7), 45 (15), 46 (22), 47 (26), 48 (18), 49 (11), 50 (16), 51 (8), 52 (5),
53 (2), 54 (2)
Pre-dorsal scales 13 10 (2), 11 (6), 12 (23), 13 (39), 14 (35), 15 (25), 16 (3), 17 (4)
Pre-pelvic scales 48 38 (1), 39 (1), 40 (5), 41 (2), 42 (5), 43 (10), 44 (15), 45 (20), 46 (23), 47 (19),
48 (16), 49 (15), 50 (5), 51 (1)
Total number of vertebrae 57 (4), 58 (2), 59 (1), 61 (3), 62 (3), 63 (3), 64 (4), 65 (2), 66 (6), 67 (2)
Moritz & Britz: Revision of Polypterus
25
a
b
c
d
Fig. 17. Polypterus bichir. a-b, 351 mm SL, aquarium import, Koliba-coloration, Guinea; c, Senegal: Nikologo-
Koba National Park (photo by M. Reichard); d, 340 mm SL; Sudan: Khartoum [central fish market] (photo by N.
Pöllath).
many specimens he based his description. His
remark that P. bichir has 16, 17 or 18 finlets indi-
cates that he had at least three specimens. In the
MNHN there are only two specimens preserved
from Geoffroys collection dated to 1799: MNHN
0000-5761 (Fig. 14) and MNHN 0000-5806. Both
were originally stored in ethanol, but the latter
specimen was made into a dry specimen in 1810,
according to Bertin (1940) who listed these two
specimens as holotype and paratype, respectively.
This view was followed by Gosse (1984). Subse-
quently, Eschmeyer (1998) designated MNHN
Ichthyol. Explor. Freshwaters, IEF-1094
26
0000-5761 as lectotype thus rendering MNHN
0000-5806 a paralectotype.
In 1869, Steindachner published the descrip-
tion of a new bichir from the Senegal, Polypterus
lapradei. He noted that the essential difference
between P. lapradei and P. bichir is the shape of
the head, whereas counts of dorsal-fin spines
and scales show an overlapping gradient: 14-15
vs. 15-17 dorsal-fin spines, 60-62 vs. 64 scales
in lateral row, 13-14 vs. 12-13 pre-dorsal scales
(values given in Steindachner, 1869).
Steindachner (1870) mentioned four speci-
mens, which he used for his description. All
four specimens are deposited at the Naturhis-
torisches Museum in Vienna and catalogued as
three objects with numbers NMW 63242, NMW
3243 (2 specimens) and NMW 63244 (Fig. 15).
Regarding P. lapradei, Eschmeyer (1998: 870) noted
Syntypes: (3) NMW 63053 (1)., thus indicating
the presence of four syntypes, although he only
provided the catalog number for one of them.
This specimen, NMW 63053, however, was not
mentioned in the original description, as it ex-
ceeds the maximal length given by Steindachner
(1870) and therefore cannot be regarded as part
of the type series. One syntype (NMW 63244) was
photographed by F. Schäfer (2004) and referred to
as holotype with the catalogue number NMW
32244 in the text, a lapsus for NMW 63244, as
evidenced by the photographed label.
Polypterus lapradei had been regarded as a
valid species until Poll (1941a-b, 1942) referred to
it as a subspecies of P. bichir. Since the beginning
of the 1970s this view has become widely ac-
cepted (Gosse, 1984). In his keys for West African
polypterid species, Gosse (1990, 2003) employed
the following criteria to distinguish both subspe-
cies: number of scales in a longitudinal series and
number of dorsal-fin spines, but noted that both
meristic characters show overlap. He also stated
and illustrated disjunct distribution areas for the
two subspecies: the Benoué River and river basins
west of it for P. bichir lapradei, and the Chad basin
and river basins east of it for P. bichir bichir (Gosse,
1990, 2003). Schäfer (2004) in his popular book on
bichirs treated P. lapradei again as a valid species,
and distinguished it from P. bichir by details of
the color pattern: P. lapradei was considered to
possess usually clearly marked longitudinal
stripes in the anterior region of body (vs. absence
30°N
20°N
10°N
10°S
30°N
20°N
10°N
10°S
10°W 10°E 20°E 30°E
10°W 10°E 20°E 30°E
Fig. 18. Records of Polypterus bichir. , type locality; , verified records; , other records; , questionable
records.
Moritz & Britz: Revision of Polypterus
27
-3.0 -2.5 -2.0 -1.5 -1.0 -0.5 0.5 1.0 1.5
PC1
PC2
-2.4
-1.6
-0.8
0.8
1.6
2.4
3.2
4.0
-3.0 -2.5 -2.0 -1.5 -1.0 -0.5 0.5 1.0 1.5
-2.4
-1.6
-0.8
0.8
1.6
2.4
3.2
4.0
PC1
PC2
a
b
Fig. 19. Scatterplots of first and second components (PC 1 and PC 2) of Polypterus bichir specimens throughout its
distributional range. a, meristic characters: scales in longitudinal series, pre-dorsal scales, pre-pelvic scales,
dorsal-fin spines, pectoral-fin rays, pelvic-fin rays, anal-fin rays, soft rays in confluent dorsal and caudal fin;
b, meristic characters as in Figure 19a, plus morphometric characters: body depth, body width, head length, head
width, pre-dorsal length, length of spinous part of dorsal fin, distance from distal tip of adducted pectoral fin to
first finlet, pre-pectoral length, extension of pectoral fin, inter-pectoral width, width of pectoral-fin base, pre-
pelvic length, pre-anal length, length of longest ray in anal fin, length of anal-fin base, caudal-peduncle length,
inter-orbital width, nostril distance, eye diameter, post-orbital length. All data are normalized. , , West Africa
[, Western coastal basins; , Senegal basin; , Volta basin; , Niger basin, without Benoue]; , , Chad and Benoué
[, Benoué basin; , Chad basin]; , , Nile basin; , , Katanga region.
of such stripes) and a uniformly plain colored
area above the anal fin (vs. a pattern consisting
of light blotches on a darker background). In our
view the color pattern of P. bichir is more variable
throughout the distribution area (see above).
Furthermore, the aquarium-specimens regarded
by Schäfer (2004) as P. lapradei originated from
Nigeria, and the one regarded as P. bichir came
Ichthyol. Explor. Freshwaters, IEF-1094
28
from the upper Niger in Guinea. These putative
origins of his P. bichir and P. lapradei individuals
do not fit the distribution patterns published by
Gosse (1990, 2003).
A second subspecies, Polypterus bichir katangae
(Fig. 16), was described by Poll (1941a) from the
Katanga region in the Congo basin based on a
holotype and five paratypes. He distinguished
this sub-species from P. bichir bichir by fewer
dorsal-fin spines (12-14 vs. 14-18), fewer scales in
a lateral series (58-60 vs. 63-70) and fewer scales
around the body (44-46 vs. 46-54; values given
by Poll, 1941a). For his comparison Poll (1941a)
used only the values provided by Boulenger (1907)
for P. bichir and studied just a single additional
non-Katanga specimen of P. bichir, an individual
from Cameroon.
Our analysis of the meristic and morphometric
data collected for this study revealed no clear
distinction between the supposed subspecies of
P. bichir (Fig. 19) and show great overlap between
the West African specimens and those with a Nile,
Chad or Katanga origin. Exclusion of all West
African specimens from the analysis results in a
distinction between Nile plus Chad specimens
on the one hand and the Katanga specimens on
the other hand (Fig. 19a). The PCA analysis dem-
onstrates that distant populations within a large
distribution area can become distinguishable from
each other. But, if sampling covers the whole area
the values merge and form a continuous range.
Plotting several meristic data grouped according
to their geographical origin on box-and-whisker-
plots (Fig. 20) shows some trends for P. bichir: the
Katanga
W.Africa
Chad
Nile
12 13 14 15 16 17 18 19
Katanga
W.Africa
Chad
Nile
54 56 58 60 62 6 4 66 68 70 72
ScL
DS
Katanga
W.Africa
Chad
Nile
9 10 11 12 13 14 15 16 17 18
ScpD
Katanga
W.Africa
Chad
Nile
36 38 40 42 44 46 48 50 52
ScpP
Fig. 20. Box-and-whisker plots of selected meristic data of P. bichir from throughout its distributional range,
grouped into geographical regions. Nile (n = 54); Lake Chad, including Chari and Benoué (n = 17); West Africa,
from Niger on to the West (n = 58); Katanga region (n = 8). DS, dorsal-fin spines; ScL, scales in longitudinal series;
ScpD, pre-dorsal scales; ScpP, pre-pelvic scales.
Moritz & Britz: Revision of Polypterus
29
more west they occur individuals from the Nile
across the Chad basin to West Africa tend to have
fewer scales in the lateral line, fewer dorsal-fin
spines and fewer pre-pelvic scales; specimens
from the Katanga region also show low values
in these parameters similar to the West African
individuals (Fig. 20). Despite the geographical
trend in the number of dorsal-fin spines there is
no such trend in the number of pre-dorsal scales
(Fig. 20).
At first glance the color pattern appears to fol-
low a similar geographical trend: specimens are
more pigmented and contrasted the more west
they were collected. This trend is culminating in
the coloration of the population from the Corubal
River [= Koliba River] along the border of Guinea-
Bissau and Guinea from which conspicuously pig-
mented specimens (Fig. 17 a,b) enter the aquarium
trade under the trade name P. lapradei Koliba
or P. sp. Koliba. Specimens from Katanga also
show a more pronounced, contrasted coloration
(Fig. 16). Specimens collected in the Lower Niger,
Chad area and Nile basin (Fig. 17d) on the other
hand are often much more faintly pigmented, and
faint specimens are also common in rivers of West
Africa. Yet, conspicuously colored specimens
are not just restricted to the Corubal River and
Katanga region, but have also been collected in
the Niger River close to its delta (e. g. MRAC 92-
014-P-0001, MRAC 92-014-P-0002) and from the
Nile north of Cairo (e. g. BMNH 1907.12.2.117).
Based on analysis of our data we synonymise
P. lapradei and P. bichir katangae with P. bichir and
only recognize a single species, however, with
geographical variation in meristic counts. The
cause of the sometimes striking differences in
coloration remains unclear.
Recently, Otero et al. (2006) described a well-
preserved almost complete fossil of Polypterus as a
new species, P. faraou. Meristic and morphometric
characters of the fossil P. faraou (values taken
from Otero et al., 2006), however, fall completely
within the ranges we report here for P. bichir.
Thus, there is little reason to consider the fossil
P. faraou distinct from P. bichir. Polypterus faraou
may potentially be conspecific with P. bichir, a
conclusion that needs to be further tested.
Polypterus congicus Boulenger, 1898
(Figs. 21-23, Tables 7-8)
Polypterus congicus Boulenger, 1898: 418.
Material examined. 66 specimens. type speCimens:
BMNH 1897.9.30.28, lectotype (Fig. 21, present des-
ignation), male, 656 mm SL; Democratic Republic of
Congo: Stainley Falls. – BMNH 1899.2.20.33, 1, para-
lectotype, 167 mm SL; juvenile; Democratic Republic
of Congo: New Antwerp [Makanza]. – MRAC 79, 1,
paralectotype, male, 580 mm SL; Democratic Republic
of Congo: Mayanga, Wilventh, 1896. – MRAC 119, 1,
paralectotype, 205 mm SL; juvenile, Democratic Re-
public of Congo: Leopoldville [= Kinshasa], Wilventh,
1896. COngO river: BMNH 1899.6.27.1, 1, 579 mm SL;
Democratic Republic of Congo: Upper Congo. – BMNH
1899.6.28.1, 1, 202 mm SL; Democratic Republic of
Congo: Brazaville, M. Meuse. – BMNH 1900.6.23.14,
192 mm SL; Democratic Republic of Congo: Bolobo, G.
Grenfell. – BMNH 1919.9.10.1, 1, 270 mm SL; Democratic
Republic of Congo: Stanley Falls. – BMNH 1919.9.10.1,
1, 265 mm SL; Democratic Republic of Congo: Luvua
River at Ankoro, K. Banister, 1974/1975. – IRSNB 9960,
1, 315 mm SL; Democratic Republic of Congo: Congo
River at Yangambi, A. Hulot, Dec 1949. – IRSNB 100015,
1, 471 mm SL; Democratic Republic of Congo: Congo
River at Yangambi, A. Hulot, 1948. – MNHN 1886-0292,
1, 485 mm SL; Democratic Republic of Congo: Congo
River at Nangtchou; S. de Brazza. – MRAC 2243, 1,
271 mm SL; Democratic Republic of Congo: Stanleyville,
C. Christy, before 1913. – MRAC 19804, 1, 145.9 mm SL;
Democratic Republic of Congo: Stanleyville, Richard,
1929. – MRAC 43966, 1, 225 mm SL; Democratic Republic
of Congo: Kinshasa, A. Tinant, 1933. – MRAC 103366,
1, 260 mm SL; Democratic Republic of Congo: Stanley
Pool, A. Werner, Jun 1955. – MRAC 103993-103996, 4,
239-274 mm SL; Democratic Republic of Congo: Stanley
Pool, A. Werner, Jun 1955. – MRAC 115689, 1, 205 mm
SL; Democratic Republic of Congo: Stanley Pool, Brien
and Poll, 6 Apr 1956. – MRAC 115692, 1, 724 mm SL;
Democratic Republic of Congo: Stanley Pool, Brien and
Poll, Sep 1957. – MRAC 73-022-P-0012, 1, 237 mm SL;
Democratic Republic of Congo: Stanley Pool: marai
Limgundu, J. Mandeville, 9 Apr 1958. – MRAC 73-022-
P-0013-0015, 3, 194-245 mm SL; Democratic Republic of
Congo: Stanley Pool, J. Mandeville, 9 Apr 1958. – MRAC
A7-033-P-0029, 1, 361 mm SL; Democratic Republic
of Congo: Malebo Pool: Mipongo island, 4°16'19" S
15°30'41" E; Hanssens et al., 11 Sep 2007. – MRAC
A7-033-P-0030, 1, 257 mm SL; Democratic Republic
of Congo: Malebo Pool: Mipongo island, 4°16'19" S
15°30'41" E; Hanssens et al., 11 Sep 2007. – RMNH 20873,
1, 207 mm SL; Democratic Republic of Congo: Stanley
Pool, A. Werner, Jul 1955. – ZSM 38691, 1, 505 mm SL:
Democratic Republic of Congo: Malbeo Pool: Kenkole
[fishmarket], U. Schliewen et al., 29 Jul 2008. kasai
river anD triButaries: MRAC 66950, 1, 374 mm SL;
Democratic Republic of Congo: Kasai River: region de
Ichthyol. Explor. Freshwaters, IEF-1094
30
Mushie, Vleeschouwers, Oct 1945. – MRAC 67073, 2,
453-503 mm SL; Democratic Republic of Congo: Kasai
River: region de Mushie, Vleeschouwers, Oct 1945. Ou-
Bangui river: MRAC 58071, 1, 216 mm SL; Democratic
Republic of Congo: Oubangui River at Yakoma, Rosy,
1938. – MRAC P-182255, 1, 354 mm SL; Democratic
Republic of Congo: Dungu River at Gangala na Bodio,
C. dElzius, 1954/1955. – MRAC P-179888-179889,
2, 386-412 mm SL; Democratic Republic of Congo:
Dungu River at Gangala na Bodio, M. Poll, Nov 1956.
Table 8. Meristic characters of Polypterus congicus. Numbers in brackets indicate number of specimens with the
respective value. All material includes values of lectotype.
lectotype all material
Dorsal-fin spines 14 11 (1), 12 (2), 13 (13), 14 (39), 15 (11), 16 (1)
Dorsal- and caudal-fin rays 19 17 (1), 18 (4), 19 (37), 20 (21), 21 (3)
Pectoral-fin rays 43 37 (2), 38 (2), 39 (6), 40 (6), 41 (10), 42 (12), 43 (14), 44 (8), 45 (7), 46 (1)
Pelvic-fin rays 13 10 (1), 11 (3), 12 (15), 13 (23), 14 (21), 15 (3), 16 (1)
Anal-fin rays 16 10 (2), 11 (2), 12 (13), 13 (17), 14 (16), 15 (12), 16 (5)
Scales in longitudinal series 56 54 (2), 55 (10), 56 (24), 57 (17), 58 (9), 59 (4), 60 (1)
Scales around body 49 41 (1), 42 (1), 44 (4), 45 (3), 46 (14), 47 (14), 48 (11), 49 (8), 50 (10), 51 (1)
Pre-dorsal scales 14 11 (5), 12 (22), 13 (28), 14 (10), 15 (2)
Pre-pelvic scales 42 39 (1), 40 (3), 41 (15), 42 (18), 43 (18), 44 (8), 45 (4)
Total number of vertebrae 55 52 (1), 53 (1), 55 (3), 57 (1)
Table 7. Morphometric characters of Polypterus congicus. Range, mean and standard deviation (SD) include values
of lectotype. Negative values under Pectoral to dorsal fin refer to dorsal-fin origin in front of pectoral-fin end.
lectotype range mean SD n
Standard length [mm] 656.0 145.9-788 405.5 168.6 66
Total length [mm] 740.0 174.8-876 478.0 189.6 58
In percent of standard length
Body depth 12.3 9.2-16.6 11.8 1.6 66
Body width 14.9 10.8-17.1 14.1 1.3 66
Head length 20.9 20.0-26.1 22.6 1.5 66
Pre-dorsal length 32.3 27.2-36.3 31.5 1.8 66
Dorsal-fin length 56.9 49.3-64.7 55.9 3.0 66
Pectoral to dorsal fin -3.2 -8.4--1.0 -4.6 1.7 66
Pre-pectoral length 20.6 19.5-26.8 23.2 1.6 66
Pectoral-fin extension 34.8 31.6-43.2 36.6 2.8 66
Inter-pectoral width 9.0 6.8-12.1 9.5 0.9 65
Pectoral-fin base width 3.7 2.8-4.3 3.5 0.3 66
Pre-pelvic length 70.7 64.5-73.1 70.2 1.4 66
Pre-anal length 85.8 82.6-90.6 85.4 1.2 66
Anal-fin ray length 11.3 10.3-17.4 13.4 1.5 66
Anal-fin base length 6.1 3.1-7.4 5.7 0.8 66
Caudal-peduncle length 3.7 2.3-4.9 3.5 0.5 66
In percent of head length
Head width 62.4 50.5-67.2 57.7 3.3 67
Interorbital width 24.9 18.3-27.4 21.5 1.7 67
Nostril distance 15.9 10.0-16.6 13.8 1.4 67
Snout length 22.0 19.4-24.5 21.9 1.0 67
Eye diameter 7.9 6.7-13.1 9.3 1.3 67
Postorbital length 70.5 63.3-72.0 68.6 1.9 67
Gular length 72.7 52.3-72.3 61.6 6.0 67
Length of first spine 17.5 17.1-27.2 22.0 2.3 65
Length of second spine 18.6 19.7-29.1 23.6 2.2 65
Width : length of first spine 26.0 13.1-27.3 18.2 3.4 65
Length of second : first spine 106.7 91.5-128.5 108.0 7.6 65
Moritz & Britz: Revision of Polypterus
31
lake tanganyika anD triButaries: BMNH 1906.9.6.1-
4, 4, 465-577 mm SL; Democratic Republic of Congo:
Lake Tanganyika at Kalambo, J. E. S. Moore. – BMNH
1906.9.8.1, 1, 540 mm SL; Zambia: Lake Tanganyika
at Kituta, W. Cunnington. – BMNH 1936.6.15.18, 1,
601 mm SL; Lake Tanganyika, C. Christy. – BMNH
1936.6.15.19-21, 3, 381-603 mm SL; Lake Tanganyika,
C. Christy. – BMNH 1936.6.15.23-26, 6, 579-693 mm SL;
Lake Tanganyika, C. Christy. – BMNH 2005.4.22.1-2,
2, 576 mm SL [of one specimen only head preserved],
Zambia: Lake Tanganyika: mouth of Lufubu River,
8°33'40" S 30°43'24" E; H. Buescher, 10 Nov 2004. – IRSNB
9443, 1, 600 mm SL; Tanzania: delta of Malagarasi River,
20 May 1947. – MRAC 88875, 1, 788 mm SL; Democratic
Republic of Congo: Albertville [= Kalemie] [fishmarket],
M. Poll, 1 Feb 1944. – MRAC 190227, 1, 375 mm SL;
Zambia: Lake Tanganyika: Chinyika bay: Kasaba, H.
Matthes, 20-23 Apr 1967. – MRAC 93-152-P-0323, 1,
251 mm SL; Tanzania: delta of Malagarasi River, L.
de Vos, 21 Aug 1993. katanga: BMNH 1975.6.20.1,
1, 265 mm SL; Democratic Republic of Congo: Luvua
River at Akoro, K. Banister, 1974/1975. – MRAC 3205,
1, 523 mm SL; Democratic Republic of Congo: Sankuru
River at Kondue, Luja, before 1913. – MRAC 3206, 1,
470 mm SL; Democratic Republic of Congo: Sankuru
River at Kondue, Luja, before 1913. – MRAC 3207, 1,
329 mm SL; Democratic Republic of Congo: Sankuru
River at Kondue, Luja, before 1913. – MRAC 3210, 1,
584 mm SL; Democratic Republic of Congo: Sankuru
River at Kondue, Luja, before 1913. – MRAC 34775,
1, 360 mm SL; Democratic Republic of Congo: Luvua
River at Kiambi, G. F. de Witte, 18 Apr-3 May 1931.
– MRAC 35030, 1, 351 mm SL; Democratic Republic of
Congo: Luvua River at Kiambi, G. F. de Witte, 4-20
May 1931. – MRAC 49320, 1, 625 mm SL; Democratic
Republic of Congo: Lualaba River at Maka, P. Brien, Jul
1937. – MRAC 66560, 1, Democratic Republic of Congo:
Lualaba River at Maka, P. Brien, Jul 1934. – MRAC
69701, 1, 688 mm SL; Democratic Republic of Congo:
Lualaba River at Maka, M. Toll, 9 Apr 1958. – MRAC
90-047-P-0088, 1, 274 mm SL; Democratic Republic of
Congo: Lualaba River at km 47 on road Kisangani-Wanie
Rukula, L. de Vos, 28 May 1990.
Fig. 21. Polypterus congicus, BMNH 1897.9.30.28, 656 mm SL, male, lectotype (present designation); Democratic
Republic of Congo: Stainley Falls.
Ichthyol. Explor. Freshwaters, IEF-1094
32
Additional material. COngO river: MRAC 72-022-P-
0010, 1, Democratic Republic of Congo: Stanley Pool, J.
Mandeville, 10 Jan 1955. OuBangui river: MRAC 1306,
1, juvenile, Democratic Republic of Congo: Oubangui
River at Banzyville [= Mobayi-Mbongo], Royanne, 1901.
– MRAC 58057-58070, 14, Democratic Republic of Con-
go: Oubangui River at Yakoma, Rosy, 1939. katanga:
IRSNB 4870, 1, Democratic Republic of Congo: Lualaba
River at Maka, J. H. Bredo, 1 Feb 1939. – MRAC 30547,
[only remnants], Democratic Republic of Congo: Luvua
River at Kiambi, 1930. – MRAC 178712, 1, Democratic
Republic of Congo: Kikondja, W. de Smet, 14 Apr 1956.
Diagnosis. Polypterus congicus is distinguished
from all other members of the genus except P. an-
sorgii, P. bichir and P. endlicherii, by third dorsal
scale row being the first to reach ventral midline
(vs. second). Polypterus congicus is distinguished
from P. ansorgii, and P. bichir by 6-8 (rarely 9)
dorsolateral bars formed by the confluence of
dorsal and lateral blotches (vs. dorsal and lateral
blotches separated, not forming continuous bars)
and from P. endlicherii by more numerous (6-8,
rarely 9 vs. 4-6) and narrower bars (less than 3
scale rows wide vs. wider than 3 scale rows).
Descriptive synopsis. Meristic and morpho-
metric data in Tables 7-8. A large species of
the P. bichir-group reaching at least 788 mm SL
(876 mm TL). Body moderately elongated. Jaws
terminal in juveniles only; in large specimens
lower jaw projecting beyond upper jaw. Anterior
body region and head becoming dorso-ventrally
flattened with increasing size.
Coloration. In life: dorsal half of body grey to
brown with slender dark grey to black dorsolateral
bars; on anterior body bars directed obliquely
posteriorly, on posterior body obliquely anteriorly
(Fig. 22). Ventral half of body light, white or yel-
lowish, sometimes with few irregular dark grey
spots arranged approximately in a horizontal line
as ventrolateral markings (much less conspicuous
than in P. endlicherii). Dorsal half of head including
upper jaw brown or yellowish-brown with dense
irregular dark brown to black spots and marbling;
cheeks lighter. Ventral half of head with fewer but
larger dark spots; lower jaw light with dark spots
usually forming several vertical lines. Iris yellow
to orange with dense brown marbling. Pectoral,
a
b
a
b
Fig 22. Polypterus congicus. a-b, aquarium import (photos: Schuzo Nakano/Aqualog).
Moritz & Britz: Revision of Polypterus
33
pelvic and anal fins yellowish with fine, densely
set, dark brown spots and marbling (usually not
expressed as lines as in P. endlicherii). Base of pec-
toral fin with dark spots and blotches concentrated
in distal part. Soft dorsal fin and confluent caudal
fin hyaline to grey with light yellowish spots, rays
darker. Dorsal-fin spines grey or brownish with
dark brown irregular pattern; finlet membrane
translucent with color pattern similar to that of
soft dorsal fin.
A conspicuously colored specimen from Lake
Tanganyika was depicted by Schäfer (2004: 61-63).
The specimen had strongly contrasted color mark-
ings on body and regularly, radially arranged
dark markings on roof of head and opercular
region. Schäfer (2004) suggested that this might
represent a new species, by labelling it Polypterus
sp. aff. congicus. We see, however, no reason to
regard it as anything other than a strongly and
particularly colored P. congicus.
In preservative: color pattern similar to life
coloration, but yellow and yellowish markings in
life now white, and black markings in life dark
grey (Fig. 21).
Distribution. Polypterus congicus is widely dis-
tributed in the Congo River basin, and tributaries
and southern part of Lake Tanganyika (Fig. 23).
Biology. Within the Congo basin the species
seems to be restricted to the main river and
neighbouring water bodies and it has been re-
ported to enter the flooded forest during high
water levels (Gosse, 1965). In the southern part
of Lake Tanganyika the species inhabits areas
with clear water and sandy substrate with large
boulders (Büscher, 2004). Interestingly, so far only
large specimens have been recorded from Lake
Tanganyika; it remains unclear in which areas
breeding and juvenile growth take place (Büscher,
2004). Polypterus congicus feeds on bottom dwell-
ing organisms (Gosse, 1965).
Etymology. Not explicitly stated, but apparently
an allusion to the type locality (Congo).
Remarks. Boulengers (1898) original description
was based on four syntypes. One specimen which
can be clearly assigned to the original type series
(based on collection date, collection place, number
30°N
20°N
10°N
10°S
30°N
20°N
10°N
10°S
10°W 10°E 20°E 30°E
10°W 10°E 20°E 30°E
Fig. 23. Records of Polypterus congicus. , type locality; , verified records.
Ichthyol. Explor. Freshwaters, IEF-1094
34
of dorsal-fin spines and number of lateral line
scales) is: BMNH 1897.9.30.28 (Fig. 21). Fricke et
al. (2018) incorrectly listed this specimen as holo-
type. We designate herein BMNH 1897.9.30.28
as lectotype of P. congicus. Three additional
specimens from New Antwerp, Leopoldville and
Manayanga were mentioned by Boulenger (1898)
and these paralectotypes are most likely: BMNH
1899.2.20.33, MRAC 79 and MRAC 119.
Polypterus delhezi Boulenger, 1899
(Figs. 24-26, Tables 9-10)
Polypterus delhezi Boulenger, 1899: 61, Pl. XXX,
Fig. 2.
Material examined. 44 specimens. type speCimens:
MRAC 422, lectotype (Fig. 24, present designation),
male, 314 mm SL; Democratic Republic of Congo: Lake
Leopold at Kutu, P. Delhez. – BMNH 1899.2.20.17, 1,
paralectotype, female, 270 mm SL; Democratic Republic
of Congo: New Antwerp [= Makanza], Wilvert and Wa-
genaar. COngO river: BMNH 1975.8.15.67, 1, 241 mm SL;
Democratic Republic of Congo: Congo River, A. Fraser-
Brunner. – MNHN 1886-0294, 1, 311 mm SL; Democratic
Republic of Congo: Nangtchou, S. de Brazza. – MRAC
103987, 1, 260 mm SL; Democratic Republic of Congo:
Stanley Pool, A. Werner, Jun 1955. – MRAC 154587, 1,
165.4 mm SL; Democratic Republic of Congo: Stanley
Pool, P. Brichard, 1966. – MRAC 177711, 1, 277 mm
SL; Democratic Republic of Congo: Stanley Pool, J. van
Orshoven, 5 May 1964. – MRAC 177717, 1, 251 mm SL;
Democratic Republic of Congo: Bolobo; NKele, 1958.
– MRAC 73-022-P-0008-0009, 2, 250-285 mm SL; Demo-
cratic Republic of Congo: Stanley Pool, J. Mandeville,
5 Sep 1958. – MRAC 88-025-P-0642, 1, 135.0 mm SL;
Democratic Republic of Congo: Congo River at Bumba,
L. de Vos, 30 Jan 1988. – MRAC 91-013-P-0640-0642, 3,
214-295 mm SL; Democratic Republic of Congo: N' Sele
River [affluent of Congo River] close to Kinshasa, 4°08' S
16°40' E; M. Tshibwabwa Sinaseli, 1985/1987. – MRAC
A7-0033-P-0031-0033, 3, 226-234 mm SL; Democratic
Republic of Congo: Canal Kisanga at Inga, 5°27'55" S
13°34'58" E; Hanssens et al., 29 Aug 2007. – RMNH 20874,
1, 190 mm SL; Democratic Republic of Congo: Stanley
Pool, A. Werner, Jul 1955. kasai river: MRAC 67060,
1, 280 mm SL; Democratic Republic of Congo: Fimi
River at Bungi, Vleeschouwers, 22 Oct 1945. – MRAC
68750-68754, 4, 173-250 mm SL; Democratic Republic
of Congo: Fimi River at Mushie, Vleeschouwers, 21 Sep
1946. – MRAC 138889, 1, 278 mm; Democratic Republic
of Congo: Mushie, M. Creeter, 1957. – MRAC 66832, 1,
258 mm SL; Democratic Republic of Congo: Kasai River
at Fimi, Vleeschouwers, Sep 1941. – MRAC 66852, 1,
260 mm SL; Democratic Republic of Congo: Kasai River
at Fimi, Vleeschouwers, Sep 1941. lake tumBa: IRSNB
4871, 1, 350 mm SL; Democratic Republic of Congo: Lake
Tumba at NKosso Norma, G. de Loneux, 31 Dez 1938.
– MRAC 14688, 1, 102.4 mm SL; Democratic Republic
of Congo: Lake Tumba at Bikoro, D. Schouteden, 1921.
– MRAC 14689, 1, 99.5 mm SL; Democratic Republic
of Congo: Lake Tumba at Bikoro, D. Schouteden, 1921.
– MRAC 57751-57752, 2, 340-348 mm SL; Democratic
Republic of Congo: Lake Tumba, G. de Loneux, 1928.
– MRAC 14690; Democratic Republic of Congo: Lake
Tumba, G. de Loneux, 1928. likOuala river: MNHN
1962-0349, 9, 60.8-111.6 mm SL; Democratic Republic
Fig. 24. Polypterus delhezi, MRAC 422, 314 mm SL, male, lectotype (present designation); Democratic Republic of
Congo: Lake Leopold at Kutu; P. Delhez.
Moritz & Britz: Revision of Polypterus
35
of Congo: Likouala River at Mossaka, Stauch, 24 Feb
1961. OuBangui river: MRAC 179773, 1, 247 mm SL;
Democratic Republic of Congo: Ngiri River [affluent
of Oubangui River], P. van Leynseele, 1970. ruki river
anD triButaries: MRAC 80642, 1, 329 mm SL; Demo-
cratic Republic of Congo: Tshuapa River at Bokuma, P.
Lootens, 20 Sep 1952. – MRAC 73-022-P-003, 1, 158.4 mm
SL; Democratic Republic of Congo: Tshuapa River at
Boende, R. Philippe, Jun 1956. aquarium speCimen:
NMW 90940, 1, 217 mm SL; Tiergarten Schönbrunn.
Additional material. COngO river: MRAC 39459-
39461, 3, Democratic Republic of Congo: Leopoldville
[= Kinshasa], A. Tinant, 1933. – MRAC 43978, 1, Demo-
cratic Republic of Congo: Leopoldville [= Kinshasa], A.
Tinant, 1935. – MRAC 47995, 1, Democratic Republic
of Congo: Leopoldville [= Kinshasa], A. Tinant, 1937.
– MRAC 67462, 1, Democratic Republic of Congo:
Leopoldville [= Kinshasa], Bureau. – MRAC 68034, 1,
Democratic Republic of Congo: Leopoldville [= Kin-
shasa], De Vier, Aug 1945. – MRAC 102572-102576,
5, Democratic Republic of Congo: Kingabwa, J. Man-
deville, Aug-Sep 1955. – MRAC 115693, 1, Democratic
Republic of Congo: Stanley Pool, Brien and Poll, 4 May
1956. – MRAC 115694, 1, Democratic Republic of Congo:
Stanley Pool, Brien and Poll, 23 Jul 1956. – MRAC 115695,
1, Democratic Republic of Congo: Stanley Pool, Brien
and Poll, 26 Sep 1957. – MRAC 115696, 1, Democratic
Republic of Congo: Stanley Pool, Brien and Poll, 4 Oct
1957. – MRAC 115697-115701, 5, Democratic Republic of
Congo: Stanley Pool, Brien and Poll, Sep 1957. – MRAC
118720, 1, Democratic Republic of Congo: Stanley Pool,
P. Brichard, 1956. – MRAC 140106-140108, 3, Democratic
Republic of Congo: environs of Leopoldville [= Kinsha-
sa], van de Weyer, 1960. – MRAC 177721, 1, Democratic
Republic of Congo: Bolobo, NKele, 1956. – MRAC 73-
a
b
c
a
b
c
Fig. 25. Polypterus delhezi, aquarium specimens. a, 240 mm SL, adult; b, 72 mm SL, juvenile; c, early juvenile
(photo c: Schuzo Nakano/Aqualog).
Ichthyol. Explor. Freshwaters, IEF-1094
36
33-P-1, 1, Democratic Republic of Congo: environs of
Leopoldville [= Kinshasa], R. Henrion, 1971. – MRAC
73-022-P-0001-0002, 2, Democratic Republic of Congo:
Stanley Pool: Mikunga passage, J. Mandeville, 29 Oct
1957. – MRAC 73-022-P-0003, 1, Democratic Republic of
Congo: Stanley Pool: Nsele River, J. Mandeville, 29 Oct
1957. – MRAC 73-022-P-0004, 1, Democratic Republic of
Congo: Stanley Pool: Ndjiili River, J. Mandeville, 30 Oct
1957. – MRAC 73-022-P-0006, 1, Democratic Republic
of Congo: Stanley Pool, J. Mandeville, 8 Nov 1957.
Table 10. Meristic characters of Polypterus delhezi. Numbers in brackets indicate number of specimens with the
respective value. All material includes values of lectotype.
lectotype all material
Dorsal-fin spines 10 10 (3), 11 (33), 12 (8)
Dorsal- and caudal-fin rays 16 15 (7), 16 (34), 17 (3)
Pectoral-fin rays 39 31 (1), 32 (1), 33 (3), 34 (11), 35 (9), 36 (3), 37 (6), 38 (7), 39 (3)
Pelvic-fin rays 10 9 (9), 10 (24), 11 (10), 12 (1)
Anal-fin rays 12 9 (4), 10 (8), 11 (9), 12 (11), 13 (9), 14 (2), 15 (1)
Scales in longitudinal series 55 54 (4), 55 (19), 56 (17), 57 (4)
Scales around body 37 35 (1), 36 (6), 37 (9), 38 (9), 39 (11), 40 (6), 41 (2)
Pre-dorsal scales 17 13 (7), 14 (24), 15 (8), 16 (3), 17 (2)
Pre-pelvic scales 37 35 (1), 36 (8), 37 (16), 38 (15), 39 (3)
Total number of vertebrae 54 (1), 55 (2)
Table 9. Morphometric characters of Polypterus delhezi. Range, mean and standard deviation (SD) include values
of lectotype. Negative values under Pectoral to dorsal fin refer to dorsal-fin origin in front of pectoral-fin end.
lectotype range mean SD n
Standard length [mm] 314.0 60.8-350 212.9 87.2 44
Total length [mm] 339.0 77.9-382 235.6 89.8 40
In percent of standard length
Body depth 10.4 8.5-14.2 11.6 1.1 44
Body width 10.8 9.9-13.2 11.7 0.8 44
Head length 17.0 16.2-23.4 19.0 2.0 44
Pre-dorsal length 34.0 28.0-38.2 32.5 2.1 44
Dorsal-fin length 56.0 47.1-61.7 56.0 3.1 44
Pectoral to dorsal fin 2.4 -3.8-3.3 -0.3 1.5 44
Pre-pectoral length 17.2 15.4-23.2 19.4 1.8 44
Pectoral-fin extension 30.3 28.4-38.0 32.9 2.7 44
Inter-pectoral width 5.8 5.8-9.7 7.6 0.9 44
Pectoral-fin base width 2.9 2.6-3.7 3.1 0.3 44
Pre-pelvic length 65.6 62.5-67.6 65.0 1.1 44
Pre-anal length 84.7 81.8-87.8 84.4 1.2 44
Anal-fin ray length 9.0 7.9-15.2 11.9 1.8 44
Anal-fin base length 6.2 3.9-7.0 5.2 0.7 44
Caudal-peduncle length 3.6 2.2-5.0 3.5 0.6 44
In percent of head length
Head width 53.2 45.3-63.7 56.7 3.6 44
Interorbital width 21.8 18.1-24.5 21.5 1.3 44
Nostril distance 13.5 9.6-17.1 13.2 1.5 44
Snout length 19.2 18.0-24.3 21.4 1.4 44
Eye diameter 12.3 10.8-18.0 13.3 1.8 44
Postorbital length 66.9 57.5-68.9 64.8 2.6 44
Gular length 58.0 56.0-69.5 60.1 2.7 44
Length of first spine 34.2 17.9-35.9 26.0 3.8 44
Length of second spine 35.2 21.0-40.4 29.0 3.4 43
Width : length of first spine 16.8 15.4-35.1 22.4 3.9 43
Length of second : first spine 103.0 89.2-142.1 112.8 11.8 42
Moritz & Britz: Revision of Polypterus
37
kasai river: MRAC 2804, 1, Democratic Republic of
Congo: Bokala, D. J. Maes. – MRAC 2805, 1, Democratic
Republic of Congo: Bokala, D. J. Maes. lake tumBa:
MRAC 14686, 1, Democratic Republic of Congo: Lake
Tumba at Tondu, D. Schouteden, 1921. – MRAC 14687,
1, Democratic Republic of Congo: Lake Tumba at Tondu,
D. Schouteden, 1921. – MRAC 14690, 1, Democratic Re-
public of Congo: Lake Tumba at Bikoro, D. Schouteden,
1921. – MRAC 14691, 1, Democratic Republic of Congo:
Lake Tumba at Bikoro, D. Schouteden, 1921. ruki river
anD triButaries: IRSNB 21048, 1, Democratic Republic
of Congo: Ruki River, Kiss, Feb 1980. – MRAC 74871,
1, Democratic Republic of Congo: Bokungu, L. Dupuis,
1950. – MRAC 177776, 1, Democratic Republic of Congo:
Boende, P. Brichard, 1969.
Diagnosis. Polypterus delhezi is distinguished
from species of the P. bichir group by its second
dorsal scale row reaching ventral midline (vs.
third scale row) and lateral line scales with cen-
tral pores and entire posterior margin (vs. with
incision at posterior margin). Polypterus delhezi
is distinguished from all remaining Polypterus
species except P. senegalus by low number of pre-
dorsal scales (13-17 vs. 20-37). It is distinguished
from P. senegalus by the presence of a series of
vertical dark brown to black dorsolateral bars
(vs. absence) and by more dorsally located eyes
(lower margin of orbit visible in dorsal view vs.
not visible). Furthermore, Polypterus delhezi differs
from P. senegalus in usually having more dorsal-
fin spines (10-12, median 11 vs. 8-11, median 9)
and smaller interorbital width (18.1-24.5 % HL
vs. 22.4-30.7).
Descriptive synopsis. Meristic and morpho-
metric data in Tables 9-10. Body moderately
elongated. Mouth terminal, upper jaw usually not
projecting beyond lower jaw; in rare cases upper
jaw very slightly projecting. Eyes in dorso-lateral
position. First dorsal-fin spine at about vertical
through posterior margin of pectoral fin. Size up
to at least 350 mm SL (382 mm TL).
Coloration. In life: dorsal half of body light
grey with 5-9 black, vertical or oblique dorsolat-
eral bars of approximately two scale rows width
formed by the confluence of dorsal with preceding
(rarely succeeding) lateral blotches; bars some-
times with light or yellowish margin; confluence
frequently incomplete resulting in separate dorsal
and lateral blotches (Fig. 25). Ventral half of body
30°N
20°N
10°N
10°S
30°N
20°N
10°N
10°S
10°W 10°E 20°E 30°E
10°W 10°E 20°E 30°E
Fig. 26. Records of Polypterus delhezi. , type locality; , verified records.
Ichthyol. Explor. Freshwaters, IEF-1094
38
whitish or cream, sometimes with ventrolateral
markings expressed as longitudinal stripe and/or
blotches surrounding lighter yellowish blotches,
especially in juveniles (Fig. 25c). Dorsal half of
head, iris and upper lip grey with irregular dark
grey to black marbling; ventral half of head and
cheeks white, with suborbital stripe expressed as
line of dark spots and extending posteriorly to
dark spots and blotches on lower half of opercular
region. Frequently with dark line formed by series
of spots ventral and parallel to suborbital stripe;
lower lip and jaw whitish with distinct black spots.
Pectoral fin with dark spots arranged in two or
three narrow rows; distal part of pectoral-fin base
with dark markings, not forming a distinct blotch.
Pelvic fin with dark spots sometimes arranged
in thin rows. Otherwise pectoral and pelvic fins
whitish, yellowish or translucent. Dorsal, caudal
and anal fins dark grey with light, yellowish,
irregular pattern; distal parts of fins sometimes
darker. Dorsal-fin spines grey with dark grey to
black markings at mid-level and in distal parts;
finlet-membrane transparent with dark markings,
often a dark irregular area at mid-level.
In preservative: dorsal half of body light
brown to beige; bars conspicuous, black or dark
brown; color pattern on head, including subor-
bital stripe less distinct than in life; ventrolateral
markings less distinct (Fig. 24).
Distribution. Restricted to the major rivers in the
central and lower Congo basin (Fig. 26).
Biology. Life history largely unknown.
Etymology. Named after Paul Delhez who col-
lected the lectotype.
Remarks. Boulenger (1899) mentioned two speci-
mens in the original description of Polypterus
delhezi, without designating a holotype. Fricke et
al. (2018) stated that Boulenger (1909) provided a
lectotype designation in his catalogue of African
fishes. There, however, Boulenger (1909: 14) only
mentioned one type deposited in MRAC and
another type being part of the BMNH collection,
clearly regarding both specimens as syntypes.
We designate herein MRAC 422, the specimen
illustrated by Boulenger (1899, pl. XXX, fig. 2;
1909, fig. 9), as the lectotype of P. delhezi (Fig. 24).
Polypterus endlicherii Heckel, 1848
(Figs. 27-31, Tables 11-12)
Polypterus endlicherii Heckel, 1848: 310, Pl. 22,
fig. 1.
Material examined. 64 specimens. type spe Cimen :
NMW 91244, holotype (Fig. 27), 684 mm SL; dry speci-
men; Sudan: Nile River at Khartoum, [likely] Kotschy.
COastal river Basins Of Côte DivOire anD ghana:
BMNH 1923.3.2.2-3, 2, 136-211 mm SL; Côte dIvoire:
Bandama River, W. Lowe. – BMNH 1934.8.31.1, 1,
167 mm SL; Ghana: Ashanti Forest: Ejura, W. Lowe.
– BMNH 1969.4.28.10, 1, 296 mm SL; Ghana: Afram
River at Aframoso, W. R. Smith, 5 Sep 1952. – MNHN
1894-0392, 1, 206 mm SL; Côte dIvoire: Bandama
River at Tiassale, Pobeuin. – MNHN 1894-0393, 1,
192 mm SL; Côte dIvoire: Bandama River at Tiassale,
Pobeuin. – MNHN 1960-0177, 193 mm SL; Burkina
Faso: Yanon River [tributary of Comoé], Arnoult and
dAubenton. – MNHN 1991-0439, 1, 344 mm SL; Côte
dIvoire: Bandama River at Lamto, Lamotte, Jul 1970.
– MRAC 74-014-P-0003, 1, 449 mm SL; Côte dIvoire:
Lake Kossou, S. Kyeli, 17 Dec 1973. – MRAC 79-036-
P-0001, 1, 261 mm SL; Côte dIvoire: Lagune Ebrié at
Layo, D. F. E. Thys van den Audenaerde, 20 Oct 1979.
– MRAC 80-019-P-0001, 1, 388 mm SL; Côte dIvoire:
Sassandra River at Soubré, G. Teugels and L Risch,
24-25 Apr 1980. – MRAC 85-029-P-0001, 1, 281 mm
SL; Côte dIvoire: Boubo River at Babokon, G. Teugels,
8-9 May 1985. – MRAC 85-029-P-0002, 1, 285 mm SL;
Côte dIvoire: Boubo River at Babokon, G. Teugels,
9-10 May 1985. – MRAC 85-055-P-001, 1, 188 mm SL;
Burkina Faso/Côte dIvoire [border]: Léreba River at
Léreba, G. Teugels, 24 Nov 1985. – MRAC 86 013-P-0001,
201 mm SL; Côte dIvoire: Bandama River at Tiassale,
G. Teugels, 3-4 Apr 1986. – MRAC 87-018-P-0001,
1, 188 mm SL; Burkina Faso/Côte dIvoire [border]:
Léreba River at Léreba, G. Teugels, 29 Jan 1987. lake
ChaD anD triButaries: MNHN 1919-0074, 1, 175 mm
SL; Central African Republic: Gribingui River, Baudon.
– MNHN 1928-0071, 1, 234 mm SL; Chad: Mayo Kebbi:
Lere, Monod. – MNHN 1938-0032, 1, 213 mm SL; Chad:
Logone River at Lai, Thomas. – MRAC 73-026-P-0006, 1,
209 mm SL; Chad: south of Hollom: Tofoul, 11°10'20" N
15°03'10" E; M. Y. Brandily, 24 Aug 1969. Ouémé river
Basin: MRAC 73-001-P-0006, 1, 262 mm SL; Benin:
Porto Novo, P. de Kimpe, 15 Nov 1963. vOlta river
Basin: BMNH 1949.10.20.1, 1, 272 mm SL; Ghana: Volo,
Buxton. – MNHN 2007-0246, 1, 344 mm SL; Togo: Oti
River at Mango, C. Lévêque, 3 Nov 1982. – MRAC
140923-140924, 2, 183.1-206 mm SL; Burkina Faso: Kou
River [tributary of Mouhoun], B. Roman, 4 Jun 1964.
niger river anD triButaries: BMNH 1902.11.10.31, 1,
139.2 mm SL; Nigeria: Abo, S. W. J. Ansorge, 20 Oct 1901.
– BMNH 1913.12.5.2-3, 2, 96.4-129.7 mm SL; Nigeria
Anambra River, W. Crocombe. – BMNH 1936.11.24.1,
1, 241 mm SL; Nigeria: Kaduna River, J. Welman. –
Moritz & Britz: Revision of Polypterus
39
BMNH 1959.8.18.79, 1, 153.1 mm SL; Nigeria: Lokoja,
Maclaren, 1 Nov 1948. – MNHN 1961-0015, 1, 276 mm
SL; Mali: Niager River at Diafarabe, J. Daget, 8 Apr 1950.
– MNHN 1961-0016, 1, 205 mm SL; Mali: Niager River at
Diafarabe, J. Daget, 8 Apr 1950. – MNHN 1962-0444, 1,
197 mm SL; Cameroon: Benoue River at Mayo-Rey, A.
Stauch, May 1960. – MNHN 1986-0051, 3, 226-294 mm
SL; Guinea: Milo River at Boussoule, C. Lévêque, Feb
2006. – MRAC 140111, 1, 219 mm SL; Cameroon: Benoue
River, A. Stauch. nile river Basin: BMNH 1865.11.15.4,
Table 12. Meristic characters of Polypterus endlicherii. Numbers in brackets indicate number of specimens with
the respective value. All material includes values of holotype.
holotype all material
Dorsal-fin spines 12 11 (5), 12 (34), 13 (22), 14 (3)
Dorsal- and caudal-fin rays (damaged) 18 (12), 19 (33), 20 (15), 21 (1), 22 (1)
Pectoral-fin rays 40 35 (1), 38 (4), 39 (9), 40 (7), 41 (7), 42 (16), 43 (5), 44 (8), 45 (5), 46 (2)
Pelvic-fin rays 14 11 (3), 12 (13), 13 (17), 14 (17), 15 (8), 16 (3), 17 (3)
Anal-fin rays 13 9 (1), 10 (1), 11 (2), 12 (16), 13 (24), 14 (16), 15 (3)
Scales in longitudinal series 55 53 (3), 54 (9), 55 (18), 56 (24), 57 (6), 58 (1), 59 (1), 60 (1)
Scales around body 43 39 (4), 40 (2), 41 (8), 42 (13), 43 (11), 44 (12), 45 (9), 46 (3), 47 (1), 48 (1)
Pre-dorsal scales 13 12 (18), 13 (28), 14 (10), 15 (7), 16 (1)
Pre-pelvic scales 40 39 (1), 40 (11), 41 (16), 42 (13), 43 (14), 44 (6), 45 (3)
Total number of vertebrae 53 (1), 54 (4), 55 (1), 56 (2)
Table 11. Morphometric characters of Polypterus endlicherii. Range, mean and standard deviation (SD) include values
of holotype. Negative values under Pectoral to dorsal fin refer to dorsal-fin origin in front of pectoral-fin end.
holotype range mean SD n
Standard length [mm] 684.0 96.4-780 324.5 169.4 64
Total length [mm] (damaged) 115.9-764 356.1 170.6 59
In percent of standard length
Body depth 10.6 8.6-16.0 11.2 1.6 64
Body width 15.1 11.9-16.2 14.1 1.1 64
Head length 20.8 18.4-26.4 22.4 1.8 64
Pre-dorsal length 30.0 27.4-47.5 32.1 3.0 64
Dorsal-fin length 59.8 49.5-62.8 56.2 3.4 64
Pectoral to dorsal fin -2.0 -7.7-0.0 -3.9 1.8 63
Pre-pectoral length 20.1 19.4-27.4 22.8 1.9 64
Pectoral-fin extension 32.2 31.4-43.2 36.3 2.8 64
Inter-pectoral width 9.1 8.0-12.2 9.6 0.9 64
Pectoral-fin base width 3.6 3.0-4.5 3.8 0.3 64
Pre-pelvic length 67.3 66-73 70.1 1.6 64
Pre-anal length 88.2 82.6-89.9 85.6 1.5 64
Anal-fin ray length 12.0 9.9-14.9 12.4 1.3 63
Anal-fin base length 6.4 3.2-7.3 5.3 0.7 64
Caudal-peduncle length 2.8 1.5-5.4 3.7 0.7 64
In percent of head length
Head width 57.9 51.1-71.7 59.5 4.1 64
Interorbital width 21.7 17.9-26.7 21.8 2.1 64
Nostril distance 11.4 10.9-16.8 13.4 1.2 64
Snout length 15.9 14.9-22.9 19.8 1.6 64
Eye diameter 7.6 7.0-13.2 9.7 1.5 64
Postorbital length 68.7 64.1-74.4 69.1 2.2 64
Gular length 53.0 50.9-73.8 60.3 5.4 64
Length of first spine 22.2 11.0-28.6 22.0 3.5 63
Length of second spine 22.6 18.5-29.7 25.0 2.4 62
Width : length of first spine 21.5 12.8-44.8 21.5 5.6 63
Length of second : first spine 101.6 85.7-269.8 117.0 25.6 61
Ichthyol. Explor. Freshwaters, IEF-1094
40
1, 335 mm SL; Egypt: Nile River below cataracts, Peth-
erick. – BMNH 1907.12.2.137, 1, 230 mm SL; Sudan:
near Goz Shebesha, W. L. S. Loat, 3 Jan 1901. – BMNH
1907.12.2.138, 1, 611 mm SL; Sudan: White Nile near
Kawa, W. L. S. Loat, 5 Jan 1901. – BMNH 1907.12.2.139,
1, 565 mm SL; Sudan: White Nile at Goz Abu Gumah,
W. L. S. Loat. – BMNH 1907.12.2.140, 1, 574 mm SL;
Sudan: White Nile at Fashoda, W. L. S. Loat, 28 Mar
1901. – BMNH 1907.12.2.141, 1, 525 mm SL; Sudan: Lake
No, W. L. S. Loat, 15 Feb 1901. – BMNH 1907.12.2.142, 1,
444 mm SL; Sudan: White Nile at Gondokoro, W. L. S.
Loat, 11 Mar 1902. – BMNH 1907.12.2.143-144, 2, 248-
652 mm SL; Sudan: Omdurman: Sheduah, W. L. S. Loat,
31 Dec 1900. – MNHN 2001-2180, 1, 224 mm SL; Sudan:
aab
Fig. 27. Polypterus endlicherii, NMW 91244, 684 mm SL, female, holotype; Sudan: Nile River at Khartoum; [likely]
Kotschy.
Fig. 28. Polypterus endlicherii, view of predorsal region. a, NMW 91244, holotype; b, illustration of holotype
(Fenzl et al., 1849); arrow points to scale anomaly.
Moritz & Britz: Revision of Polypterus
41
White Nile: Jebel Aulia reservoire at Kowa, T. Roberts.
– NMW 10954, 1, 304 mm SL; Nil, Steindachner, Nov
1910 (Fig. 29). – NMW 50278, 1, 340 mm SL; Sudan: Bahr
el Seraf, Steindachner, 1881. – NMW 63023, 1, 704 mm
SL; Sudan: Bahr el Arab, Marno, 1881. – NMW 63024, 1,
705 mm SL; Sudan: White Nile, Kotschy, 1852. – NMW
63054, 1, 698 mm SL; Sudan: Bahr el Ghazal, [likely]
Marno, 1881. – NMW 63218, 1, 279 mm SL; Sudan:
Khartoum, Drasche and Steindachner [?], 1876. – NMW
63237, 2, 270-343 mm SL; Sudan, Steindachner, 1910. –
NMW 63239, 1, 367 mm SL; Sudan, Steindachner, 1910.
– NMW 63240, 2, 381-388 mm SL; Sudan, Steindachner,
Aug 1910. – NMW 63241, 1, 550 mm SL; Sudan: White
Nile at Ed Dueim, Werner, 1907. – NMW 91233, 1,
780 mm SL; [likely] Sudan: Khartoum, [likely] Reitz,
[likely] 1851. – ZSM 35162, 1, 254 mm SL; Sudan: White
Nile at Kosti, 13°10'17" N 32°40'07" E; D. Neumann, 13
Jan 2007. – ZSM 39631, 1, 558 mm SL; Sudan: Omdour-
man [fishmarket], T. Moritz et al., Apr 2008. aquarium
traDe: ZSM 34041, 1, 216 mm SL; Guinea: [likely] Niger
River at Faranah and Kobikoro, F. Schäfer, 2004.
Additional material. COastal river Basins Of Côte
DivOire anD ghana: MRAC 140109, 1, Côte dIvoire:
Bandama River, Lowe. niger river Basin: MRAC 91-100-
P-0004, 1, Nigeria: Nun River at Kaiama, 5°08' N 6°18' E;
C. B. Powell, 12-13 Sep 1991. vOlta river Basin: DMM
IE/10393, 1, Benin: Pendjari National Park: Pendjari
River at Pont Arly, 11°28'05" N 1°34'01" E; T. Moritz,
25 Nov 2002. – DMM IE/10399, 1, Benin: Pendjari Na-
tional Park: Mare Hippotrague, 11°23'14" N 1°22'15" E;
T. Moritz, 14 Apr 2007. – DMM IE/10400, 3, Benin:
Pendjari National Park: Pendjari River at Hotel Pendjari,
11°24'33" N 1°35'22" E; T. Moritz, Apr 2007 . – MRAC
93-127-P-0001, 1, Ghana: Daka River [tributary of Lake
Volta] at Dindu, 8°10' N 0°20' W; P. C. Goudswaard, 16
Apr 1993. – MRAC 93-127-P-0002, 1, Ghana: White Volta
at Kope, 8°45' N 1°28' W; P. C. Goudswaard, 24 Sep 1992.
Diagnosis. Polypterus endlicherii is distinguished
from all other members of the genus except P. an-
sorgii, P. bichir and P. congicus, by third dorsal
scale row being the first to reach ventral midline
(vs. second). Furthermore, Polypterus endlicherii
is distinguished from all Polypterus species ex-
cept P. bichir and P. congicus by short pre-dorsal
length of only 21.7-27.4 % SL (vs. 27.4-47.5).
Polypterus endlicherii is distinguished from P. an-
sorgii, P. bichir and P. congicus by its unique color
pattern: few (4-5, rarely 6), broad (more than 3
scale rows wide), dark transverse bars extending
from dorsum to middle of flank by confluence of
dorsal and lateral blotches sometimes including
ventrolateral markings (vs. dorsal and lateral
blotches distinct, not confluent and forming bars
in P. bichir and P. ansorgii, or 6-8 narrow bars in
P. congicus).
Descriptive synopsis. Meristic and morphomet-
ric data in Tables 11-12. Large species, up to at
least 780 mm SL. Body moderately elongated.
Jaws terminal in juveniles but in larger specimens
lower jaw projecting beyond upper jaw. Anterior
Fig. 29. Polypterus endlicherii, NMW 10954, 304 mm SL, female; Nile River.
Ichthyol. Explor. Freshwaters, IEF-1094
42
body region and head becoming more dorso-
ventrally flattened with increasing size (Fig. 9).
Coloration. In life: dorsal half of body grey to
brownish-grey with broad dark-grey saddle-
like dorsolateral bars; bars more than three scale
rows wide, frequently also confluent with ven-
trolateral markings; bars less regular in caudal
area (Fig. 30). Ventral half of body light, whitish,
with ventrolateral markings usually expressed as
irregular dark-grey to black blotches sometimes
confluent with wide bars; occasionally with an
additional longitudinal line further ventrally.
Dorsal half of head including upper jaw dark
grey with dark brown to black spots. Lower half
of head including lower jaw light, whitish, with
dark spots on lateral side of head and lower jaw,
but not on gular plate; spots sometimes arranged
in more or less regular lines. Iris and skin around
eye with same coloration as head. Pectoral and
a
b
c
Fig. 30. Polypterus endlicherii. a, large specimen ~400 mm SL; Côte dIvoire: Comoé National Park: Comoé River;
b-c, ~100 mm SL, juvenile; Benin: Pendjari National Park: Pendjari River.
Moritz & Britz: Revision of Polypterus
43
pelvic fins light, whitish, with dark spots and
small blotches; pelvic fin usually with no or faint
darker markings; pattern on pectoral fin arranged
in 3-5 more or less regular lines. Base of pectoral
fin with irregular spots and small blotches, more
concentrated in distal portion; pectoral-fin base
blotch also present; well developed blotch also on
medial side of pectoral fin base. Dorsal, caudal
and anal fins grey with dark irregular mark-
ings. Dorsal-fin spines lighter than dorsal part
of body, with few dark spots; finlet membranes
translucent with irregular grey color markings,
more pronounced in distal part; coloration and
markings of finlet membranes similar to those of
soft dorsal fin, caudal fin and anal fin.
In preservative: color pattern similar to that
in live specimens, but generally less contrasted
(Fig. 29).
Two specimens from the Niger River at Diafa-
rabé, Mali, (MNHN 1961-0015, MNHN 1961-0016)
with unusual color pattern resembling that of
P. congicus, however, consisting of narrow rather
than broad bars and with ventrolateral markings
expressed as irregular blotches on ventral half of
flanks.
Distribution. Widely distributed in Nile, Chad
and Niger basins; and in coastal rivers of Côte
dIvoire, i. e. Sassandra River, Boubo River, Ban-
dama River, Ebrié Lagoon and Comoé River, and
Volta Basin; a single record from coastal lagoon
of Ouémé River (Fig. 31).
Etymology. Named after Stephan Ladislaus
Endlicher (1804-1849), an Austrian botanist and
colleague of Heckel.
Remarks. The exact date of the original descrip-
tion of P. endlicherii remains somehow obscure,
as the publication of Heckel is labelled as 1846-
1849. Kottelat (2013: 492) convincingly argued
that the most likely actual year of publication
of this article is 1848, which we follow here. The
corresponding figure for the original description
was not published in Heckel (1848), but in Fenzl
et al. (1849: plate 22).
There is some confusion about the holotype
of P. endlicherii. Heckel (1848) did not refer to any
collection number, but the description clearly
refers to a single specimen. About 50 years later,
Steindachner, then curator at the Vienna museum,
30°N
20°N
10°N
10°S
30°N
20°N
10°N
10°S
10°W 10°E 20°E 30°E
10°W 10°E 20°E 30°E
Fig. 31. Records of Polypterus endlicherii. , type locality; , verified records; , other records.
Ichthyol. Explor. Freshwaters, IEF-1094
44
added Polypterus endlicheri Heck. Typ. to the la-
bel of NMW 63024, a spirit specimen of about the
same size of that in the original description. This
specimen was subsequently referred to by several
authors (Eschmeyer, 1998; Schäfer, 2004; Fricke
et al., 2018) as the holotype. In the original de-
scription, however, Heckel (1848) provided some
additional comments on the holotype, stating
among other things that it is a dry specimen with
12 dorsal-fin spines. Both these features clearly
exclude NMW 63024 from being the holotype.
There are two dry specimens of P. endlicherii in the
Vienna collection, NMW 91233 and NMW 92144,
both with 12 dorsal-fin spines. Only NMW 92144
(Fig. 27), however, has the matching size and its
color pattern corresponds quite well to that of the
drawing accompanying the original description.
In addition, the shape of the spiracular bones
on the skull roof of NMW 92144 matches that of
the same bones in the drawing of the holotype
(Fig. 28), with the exception of the second bone on
the right side, which is divided in three parts in
NMW 92144, but illustrated as a single bone. The
number and arrangement of the small spiracular
bones and the color pattern are quite variable in
the species and thus provide a useful source to
identify the holotype. Finally, a scale anomaly in
the 10th and 11th pre-dorsal scale row of NMW
92144 matches a similar anomaly in the draw-
ing of the holotype: the third scale of the tenth
row on the left side and the second scale of the
eleventh row seem to be fused (Fig. 28b; Fenzl et
al., 1849). This, in our opinon, demonstrates that
NMW 91244 is the holotype of P. endlicherii. It is
the specimen collected by Kotschy in Sudan, likely
in Khartoum, and sold to the NMW as Polypterus
bichir in 1840 (acquisition book 1840.XI.17). The
second dry specimen of P. endlicherii in Vienna,
NMW 91233, is very likely a specimen collected
on 30 Nov 1851 in Khartoum by C. Reitz (Reitz,
1852) and has no type status.
Polypterus mokelembembe
Schliewen & Schäfer, 2006
(Figs. 32-34, Tables 13-14)
Polypterus mokelembembe Schliewen & Schäfer,
2006: 24, fig. 1a.
Material examined. 32 specimens. type speCimens:
MRAC 87921, holotype (Fig. 32), female, 166 mm
SL; Democratic Republic of Congo: Maringa River
at Wamba, 0°11' N 22°28' E; H. Bertels, 8 Nov 1952. –
Fig. 32. Polypterus mokelembembe, MRAC 87921, 166 mm SL, female, holotype; Democratic Republic of Congo:
Maringa River; H. Bertels; 8 Nov 1952.
Moritz & Britz: Revision of Polypterus
45
MRAC 101372, 1, paratype, female, 221 mm SL; Demo-
cratic Republic of Congo: Bokuma, Hulstaert, 28 Aug
1955. – MRAC 79224-79225, 2, paratypes, 71-78 mm
SL; Democratic Republic of Congo: Bokuma, Lootens,
1-15 Jul 1952. – MRAC 72434-72435, 2, paratypes, 81-
172 mm SL; Democratic Republic of Congo: surround-
ing of Leopoldville. – BMNH 1907.12.3.4, 1, paratype
of P. mokelembembe and paralectotype of P. retropinnis,
male, 192 mm SL; Democratic Republic of Congo: Alima
River at Diele, S. de Brazza. – MNHN 1886-0297, 1, male,
paratype of P. mokelembembe and paralectotype of P. re-
tropinnis, 207 mm SL; Democratic Republic of Congo:
Alima River at Leketi, S. de Brazza. lefini river: MRAC
A4-046-P-0716, 1, 207.1 mm SL; Democratic Republic of
Congo: Itsotso River 5 km upstream of confluence with
Lefini River. – MRAC unreg., 1, 179 mm SL; Democratic
Republic of Congo: Lefini River, 17 Sep 2007. – MRAC
unreg., 6, 175.4-195 mm SL; Democratic Republic of
Congo: Lefini River, 8 Sep 2007. – MRAC unreg., 1,
218 mm SL; Democratic Republic of Congo: Lefini River,
15 Sep 2007. – MRAC unreg., 9, 127.3-244 mm SL; Demo-
cratic Republic of Congo: small tributary of Lefini River,
2 Sep 2008. – MRAC unreg., 1, 181 mm SL; Democratic
Republic of Congo: Lefini River, 17 Sep 2007. – MRAC
unreg., 1, 214 mm SL; Democratic Republic of Congo:
Lefini River, 19 Sep 2007. – MRAC unreg., 1, 261 mm
SL; Democratic Republic of Congo: Lefini River, 30 Apr
2007. aquarium traDe: ZSM 33571, 3, 194-232 mm SL;
Democratic Republic of Congo: exported via Kinshasa.
a
b
c
c
Fig. 33. Polypterus mokelembembe, aquarium import from Congo. a, 232 mm SL, female; b, head of specimen in a;
c, 149 mm SL, male.
Ichthyol. Explor. Freshwaters, IEF-1094
46
Table 14. Meristic characters of Polypterus mokelembembe. Numbers in brackets indicate number of specimens
with the respective value. All material includes values of holotype.
holotype all material
Dorsal-fin spines 76 (7), 7 (17), 8 (3)
Dorsal- and caudal-fin rays 15 13 (1), 15 (16), 16 (10)
Pectoral-fin rays 27 24 (1), 25 (3), 26 (3), 27 (8), 28 (6), 29 (2), 30 (4)
Pelvic-fin rays 98 (3), 9 (14), 10 (9), 11 (1)
Anal-fin rays 9 (4), 10 (11), 11 (2), 12 (5), 13 (4)
Scales in longitudinal series 58 57 (2), 58 (8), 59 (12), 60 (4), 61 (1)
Scales around body 36 31 (1), 32 (4), 33 (3), 34 (5), 35 (9), 36 (5)
Pre-dorsal scales 33 30 (2), 31 (2), 33 (5), 34 (2), 35 (10), 36 (2), 37 (4)
Pre-pelvic scales 43 43 (1), 44 (3), 45 (4), 46 (11), 47 (6), 48 (2)
Total number of vertebrae 58 (2), 59 (3), 60 (1), 61 (1)
Table 13. Morphometric characters of Polypterus mokelembembe. Range, mean and standard deviation (SD) include
values of holotype.
holotype range mean SD n
Standard length [mm] 166.1 125.5-261 194.5 30.2 27
Total length [mm] 142.7-280 214.0 31.8 26
In percent of standard length
Body depth 10.0 9.5-12.8 11.2 0.9 27
Body width 9.9-12.4 11.0 0.6 26
Head length 16.9 14.8-16.9 15.8 0.6 27
Pre-dorsal length 59.2 52.8-66.3 59.8 3.2 27
Dorsal-fin length 32.5 26.8-40.0 32.3 3.2 27
Pectoral to dorsal fin 29.7 23.3-38.4 31.2 3.4 27
Pre-pectoral length 16.0 15.5-17.6 16.6 0.5 27
Pectoral-fin extension 26.8-30.6 28.5 1.0 26
Inter-pectoral width 6.1-8.0 7.0 0.5 26
Pectoral-fin base width 2.7-3.4 3.1 0.2 26
Pre-pelvic length 70.3 70.3-76.2 74.0 1.5 27
Pre-anal length 87.7 84-89 86.2 1.2 27
Anal-fin ray length 8.8-12.7 10.9 1.2 26
Anal-fin base length 4.2-7.5 6.0 0.9 26
Caudal-peduncle length 2.2-3.8 2.8 0.4 26
In percent of head length
Head width 65.2 56.6-71.2 62.4 3.3 27
Interorbital width 40.9 23.3-30.8 27.8 1.9 27
Nostril distance 20.1 11.1-16.2 13.7 1.5 27
Snout length 40.9 20.7-25.8 23.9 1.1 27
Eye diameter 25.6 12.6-16.3 14.3 0.9 27
Postorbital length 61.4-69.5 63.5 1.7 26
Gular length 53.5-65.9 58.0 2.9 26
Length of first spine 19.8-32.5 26.6 3.0 26
Length of second spine 25.9-34.5 30.8 2.6 26
Width : length of first spine 23.6-37.4 23.6 3.9 26
Length of second : first spine 98.4-133.7 133.7 9.2 26
Diagnosis. Polypterus mokelembembe is distin-
guished from all other species of Polypterus except
P. palmas, P. retropinnis and P. teugelsi by the
number of pre-dorsal scales (30-37 vs. 11-29); it
is distinguished from P. teugelsi and from all other
congeners except P. palmas, P. retropinnis, P. sene-
galus and P. weeksii by the number of pectoral-fin
rays (24-30 vs. 31-48). Polypterus mokelembembe is
Moritz & Britz: Revision of Polypterus
47
distinguished from P. teugelsi by fewer scales in
lateral series (57-61 vs. 64-65) and fewer pectoral-
fin rays (24-30 vs. 40-43). Polypterus mokelembembe
is distinguished from P. palmas and P. retropinnis
by a distinct continuous dark suborbital stripe
strongly contrasted against a plain background
(vs. suborbital stripe absent or hardly distinguish-
able from background coloration in P. palmas; and
a series of small spots rather than a continuous
suborbital stripe in P. retropinnis), dorsal half of
head with uniform grey or with slightly marbled
coloration (vs. dorsal half of head with dark grey
or brown marbling); margins of opercular and
spiracular bones clearly marked in dark grey or
almost black (vs. respective margins hardly or
not at all contrasted by coloration), and iris pure
orange without any dark speckles or stripes (vs.
grey with dark grey radial pattern in P. retropin-
nis, and white to yellow with numerous dark
spots in P. palmas, respectively). Furthermore,
P. mokelembembe differs from P. palmas in having
more pre-dorsal scales (30-37, median 35 vs.
21-31, median 26, respectively), fewer pectoral-
fin rays (24-30, median 27 vs. 30-38, median 35,
respectively) a distinct dark blotch on distal part
of pectoral-fin base (vs. absence of such blotch).
Polypterus mokelembembe differs from P. retropin-
nis by the number of pectoral-fin rays (24-30,
median 27 vs. 28-36, median 32, respectively),
color pattern of iris (uniform vs. with radial pat-
tern, respectively) and first dorsal-fin spine width
(7.2-9.8 % HL vs. 4.6-7.5, respectively).
Descriptive synopsis. Meristic and morpho-
metric data in Tables 13-14. A small species,
maximum size 261 mm SL (280 mm TL). Body
moderately elongated with dorsal fin positioned
further posteriorly. Upper jaw slightly projecting
beyond lower jaw.
Coloration. In life: dorsal half of body light grey
to brown with 5-7 large dark brown irregular
dorsolateral saddle-like bars, sometimes conflu-
ent with blotch-like ventrolateral markings and
then extending onto upper part of ventral half of
flank. Ventral half of body light: white or yellow-
ish (Fig. 33). Border between coloration of upper
and lower half of flank not conspicuous. Dorsal
half of head uniform grey or with slight dark
grey marbling on light grey background; margins
of opercular and spiracular bones marked as
prominent black lines; lower half of cheek white;
30°N
20°N
10°N
10°S
30°N
20°N
10°N
10°S
10°W 10°E 20°E 30°E
10°W 10°E 20°E 30°E
Fig. 34. Records of Polypterus mokelembembe. , type locality;