Schistura kampucheensis, a new species of loach from Cambodia (Teleostei: Nemacheilidae)

Abstract

Schistura kampucheensis, new species, is described from several localities in Cambodia. It is distinguished from all other species of Schistura by a combination of the following characters: 6-11 more or less regular, continuous black bars on body, reaching ventrally usually to level of pectoral fins; no black midlateral stripe; 8 1 /2 branched dorsal-fin rays; 8 + 8 branched caudal-fin rays; 7 pelvic-fin rays; anus situated 1.7-2.5 eye diameters before anal-fin origin; males without suborbital flap; axillary pelvic lobe present. Schistura kampucheensis had earlier been mis-identified as S. pellegrini.

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Verlag Dr. Friedrich Pfeil
ISSN 0936-9902
Ichthyological Exploration
of Freshwaters
Volume 26
Number 4
An international journal for field-orientated ichthyology

Ichthyological Exploration of Freshwaters
An international journal for field-orientated ichthyology
Volume 26 • Number 4 • March 2016
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353
Ichthyol. Explor. Freshwaters, Vol. 26, No. 4, pp. 353-362, 5 figs., 1 tab., March 2016
© 2016 by Verlag Dr. Friedrich Pfeil, München, Germany – ISSN 0936-9902
Schistura kampucheensis,
a new species of loach from Cambodia
(Teleostei: Nemacheilidae)
Jörg Bohlen*, Miloslav Petrtýl**, Petra Chaloupková** and Chhouk Borin***
Schistura kampucheensis, new species, is described from several localities in Cambodia. It is distinguished from all
other species of Schistura by a combination of the following characters: 6-11 more or less regular, continuous
black bars on body, reaching ventrally usually to level of pectoral fins; no black midlateral stripe; 8
1
/
2 branched
dorsal-fin rays; 8 + 8 branched caudal-fin rays; 7 pelvic-fin rays; anus situated 1.7-2.5 eye diameters before anal-fin
origin; males without suborbital flap; axillary pelvic lobe present. Schistura kampucheensis had earlier been mis-
identified as S. pellegrini.
* Institute of Animal Physiology and Genetics, Academy of Sciences of the Czech Republic, Rumburská 89,
277 21 Libechov, Czech Republic. E-mail: bohlen@iapg.cas.cz (corresponding author).
** Czech University of Life Sciences, Kamýcká 129, 165 21 Prague 6, Czech Republic.
*** Royal University of Agriculture, Chamkar Daung, 12401 Phnom Penh, Cambodia.
Introduction
The loach genus Schistura includes more than
190 valid species (Kottelat, 2012) distributed
throughout South and Southeast Asia and new
species are still regularly discovered (e. g. Bohlen
& Šlechtová, 2011, 2013a-b, 2014; Bohlen et al.,
2014; Chen & Neely, 2012; Freyhof & Serov, 2001;
Lalramliana, 2012; Lokeshwor et al., 2012; Lokesh-
wor & Vishwanath, 2012; Kottelat & Leisher, 2012;
Suvarnaraksha, 2012; Zheng et al., 2012). The
taxonomic understanding of the genus is far from
being complete, and misidentifications occur.
One example is the most widespread species of
Schistura in Cambodia. Kottelat (1985) listed this
species under the name Nemacheilus sp. B from
the Srepok River in northeastern Cambodia and
the province Battambang in western Cambodia.
Kottelat (1990) gave a detailed description of the
species and assigned it to S. pellegrini, a species
that was formerly known only from its type local-
ity in Central Vietnam. Kottelat (1990) stated that
this identification was tentative since he could
not examine the types of S. pellegrini. The species
appeared under the name S. pellegrini again in
Rainboth (1996), who gave as distribution area
‘the Tonle San and several tributaries’.
Freyhof & Serov (2001) studied the types of
S. pellegrini as well as of S. spiloptera and found
S. pellegrini to be a junior synonym of S. spiloptera.
In their survey of mountain streams of Central
Viet nam, Freyhof & Serov (2001) found S. spilo-
ptera to be endemic to a small coastal area around
the Hai Van pass in Central Vietnam. They pro-
vided a detailed description of S. spiloptera, based
on type specimens of S. pellegrini and S. spiloptera

354
Bohlen et al.: Schistura kampucheensis
as well as freshly collected material. According
to their description, S. spiloptera differs from the
Cambodian material described by Kottelat (1990)
by having 9 + 8 (vs. 8 + 8) branched caudal-fin
rays, 8 (vs. 7) pelvic-fin rays, a plain (vs. spotted
or vermiculated) top of head and 56-100 (vs. 32-
70) pores in lateral line. These differences suggest
that the Cambodian species is not conspecific with
S. spiloptera. Since no other name is available for
it, we describe it here as S. kampucheensis, new
species.
Material and methods
The specimens were either fixed in 10 % forma-
line and later transferred into 70 % ethanol for
storage or fixed and stored in 96 % ethanol. All
measurements and counts follow Kottelat (1990).
Measurements were made point-to-point with
dial callipers to the nearest 0.1 mm. Collection
abbreviations: CMK, Collection of Maurice Kot-
telat, Delémont; IAPG, Institute of Animal Physi-
ology and Genetics, Libechov; NMP, National
Museum Prague, Prague; ZFMK, Zoologisches
Forschungs museum Alexander König, Bonn;
ZRC, Lee Kong Chian Natural History Museum,
National University of Singapore, Singapore.
Schistura kampucheensis, new species
(Figs. 1-2)
Holotype. ZRC 54439, 43.9 mm SL; Cambo-
dia: Kampot province: stream Ta Da Ou Bey
(Tek Chhou drainage); 10°41.173' N 104°06.948' E;
J. Bohlen, M. Petrtýl et al., 16 March 2013.
Paratypes. ZRC 54440, 28, 17.6-45.7 mm SL; CMK
24724, 10, 22.5-45.9 mm SL; ZFMK 56833-56838,
6, 18.7-41.6 mm SL; NMP P6V 142854-142858,
5, 18.6-43.4 mm SL; IAPG A8339-8341, 3, 25.5-
41.6 mm SL; same data as holotype.
Additional material (non-types). ZRC 54441, 9, 20.0-
36.3 mm SL; CMK 24725, 4, 22.7-27.8 mm SL; IAPG
A8067-8070, 4, 19.2-21.6 mm SL; Cambodia: Kampot
province: stream Anlong Kmeng Leng (Mekong drain-
age); 11°08.597' N 104°08.113' E; J. Bohlen, M. Petrtýl et
al., 10 March 2013. – ZRC 54442, 3, 32.1-37.5 mm SL;
IAPG A8108, 1, 19.8 mm SL; Cambodia: Kaoh Kong
province: stream Thmor Rung (Srae Ambel drainage);
11°11.405' N 103°56.049' E; J. Bohlen, M. Petrtýl et al., 11
March 2013. – ZRC 54443, 3, 31.2-34.3 mm SL; Cambo-
dia: Kaoh Kong province: stream Stung Chral (Srae
Ambel drainage); 11°11.102' N 104°01.857' E; J. Bohlen,
M. Petrtýl et al., 10 March 2013. – CMK 23887, 2, 37.2-
55.9 mm SL: Cambodia: Ratanakiri: tributary of Tonle
San in Virachey National Park (Mekong drainage);
14°14'44" N 107°20'59" E; 3 March 2008. – IAPG A7620-
7630, 11, 16.5-39.9 mm SL; IAPG A7963-7969, 7, 21.6-
31.5 mm SL; Kampot province: stream Ou Bey (Tek
Chhou drainage); 10°41.033' N 104°07.260' E; J. Bohlen,
M. Petrtýl et al., 8 March 2013. – CMK 5878, 5, 20.9-
42.4 mm SL: Cambodia: Ratanakiri: Bounlon (= Krong
Ban Lung), tributary of Tonle Srepok? (Mekong drain-
age); F. d’Aubenton, 25 February 1964.
Diagnosis. Schistura kampucheensis is distin-
guished from all other species of Schistura by
the combination of the following characters: 8
1
/
2
branched dorsal-fin rays; 8 + 8 branched caudal-fin
rays; 7 pectoral-fin rays, position of anus 1.7-2.5
eye diameter before anal-fin origin, no sexual
dimorphism, 6–11 regular black bars, usually not
interrupted, no black midlateral stripe, anterior
nostril not reaching margin of eye and axillary
pelvic lobe present.
Fig. 1. Schistura kampucheensis, ZRC 54440, paratype, 37.3 mm SL; Cambodia: Kampot province: stream Ta Da Ou
Bey; shortly after capture.

Ichthyol. Explor. Freshwaters, Vol. 26, No. 4
355
Description. See Figures 1-2 for general ap-
pearance and Table 1 for morphometric data of
holotype and 31 paratypes. A relatively small
nemacheilid loach with elongated body (body
depth 6.2-7.5 times in SL). Body slightly com-
pressed, caudal peduncle compressed. Maximum
body depth at dorsal-fin origin, dorsal outline be-
tween nape and dorsal-fin origin nearly straight.
Head slightly depressed. Snout round or slightly
pointed in lateral view. Depth of caudal peduncle
0.9-1.3 times in its length. Axillary pelvic lobe
present and free. A small adipose crest on dorsal
midline of caudal peduncle and on ventral midline
along posterior half of caudal peduncle. Largest
known size 55.9 mm SL.
Dorsal fin with 4 simple and 8
1
/
2 branched
rays. Distal margin of dorsal fin straight or slightly
convex. Anal fin with 3 simple and 5 1
/
2 branched
rays, not reaching caudal-fin base. Caudal fin
with 8 + 8 branched rays, emarginate, lobes round.
Pelvic fin with 7 rays; origin before or on verti-
cal through dorsal-fin origin; reaching distinctly
Fig. 2. Schistura kampucheensis; Cambodia. a-f, Kampot province: stream Ta Da Ou Bey (a-b, ZRC 54439, holotype,
43.9 mm SL; c-e, ZRC 54440, paratypes [c, 36.2 mm SL; d, 33.5 mm SL; e, 21.4 mm SL]; f, CMK 24724, paratype,
30.2 mm SL); g, ZRC 54442, 37.5 mm SL; Kaoh Kong province: stream Thmor Rung; h, ZRC 54441, 36.3 mm;
Kampot province: stream Anlong Kmeng Leng.
a
b
cd
ef
gh

356
beyond half of distance to anal-fin origin and
beyond anus, which is situated slightly posterior
from mid-distance between pelvic-fin base and
anal-fin origin. Pectoral fin with 10 rays, exceed-
ing half of distance between bases of pectoral and
pelvic fins.
Posterior half of body from dorsal-fin origin
covered by small scales except belly; anterior half
of body naked. Length of lateral line variable,
ranging from ending below dorsal fin to nearly
complete. Cephalic lateral line system with 6
supraorbital, 4 + 9 infraorbital, 9 pre-operculo-
mandibular and 3 supratemporal pores. Lips and
barbels covered with unculi.
Anterior nostril pierced in front side of a flap-
like tube, not reaching margin of eye, with a low
anterior rim. Eye moderately large (4.2-6.4 times
in lateral head length), eye diameter 1.1-1.8 times
in interorbital width. Mouth gape about two times
wider than long (Fig. 3). Processus dentiformis
wide, very low, broadly rounded. Slight notch
in lower jaw. Lips thick; upper lip usually with
small median incision and furrows, but median
incision absent in about one third of specimens.
Lower lip with a broad median interruption, no
furrows. Inner rostral barbel reaching corner of
mouth, outer one just reaching vertical through
posterior rim of eye, maxillary barbel reaching
behind vertical through posterior rim of eye.
Sexual dimorphism. None observed. Many spe-
cies of Nemacheilidae are sexually dimorphic
with adult males having a suborbital flap, a sub-
orbital groove, tubercles on the cheeks or fins or
specific genital papillae. None of the investigated
specimens of S. kampucheensis shows any of such
indicators of sexual dimorphism.
Colouration. Ground colour of body and head in
preserved specimens light beige, slightly darker
dorsally. Body with 6-11, usually 8 or 9, light
brown to olive bars, usually continuous across
dorsum, rarely bars barely visible on dark back-
ground. Bars nearly always (> 90 % of specimens)
continuous on sides. Bars on body reaching
ventrally below midlateral line, usually reaching
level of base of pectoral fin; on caudal peduncle
bars reaching further ventrally, sometimes fusing
ventrally with counterpart of other side. Bars usu-
ally regular, only in very few cases irregular, split,
narrowing towards ventral part or incomplete;
broader in anterior half of body than in posterior
half. In two specimens (Fig. 2c,g) whole dorsal
half of body darker and bars faint or reduced to
blotches along lateral line. No dark midlateral
stripe visible as in some other species of Schistura.
Top of head brown, darker than ground colour
of body but lighter than bars on body. A dark
grey blotch between eyes, two triangular dark
grey blotches stretching from posterior margin
of eyes to neck; in a deeper layer than the other
pigmentation elements, therefore often not vis-
ible without strong light and a dissecting scope.
A dark grey stripe in front of each nostril, stretch-
ing anteriorly to half distance between nostril and
base of inner rostral barbel; a second dark grey
stripe in front of eye, stretching anteriorly to half
distance between outer rostral barbel and eye.
Ventral side of head with scattered melanophores,
upper lip, innermost part of lower lip and outer
side of second rostral barbel densely covered
with melanophores, inner rostral and maxillary
barbels without pigments or pigments restricted
to base of barbel.
A dark grey bar on base of caudal fin, always
much thinner than last body bar, usually broadest
at mid-height and narrowing dorsally and ven-
trally, not reaching dorsal and ventral midline;
in most specimens, a little narrowing at base of
uppermost branched ray or adjacent unbranched
ray, and in about one third of specimens bar in-
terrupted at various places along base of upper
caudal-fin lobe.
Base of dorsal fin with a dark brown stripe, in-
terrupted around base of first or second branched
ray, height decreasing posteriorly. On first view,
all fins with a weak dark band at about half height
of fin; at closer inspection, bands not continuous
Fig. 3. Schistura kampucheensis; ZRC 54439, holotype,
43.9 mm SL; mouth. Scale bar 1 mm.
Bohlen et al.: Schistura kampucheensis

Ichthyol. Explor. Freshwaters, Vol. 26, No. 4
357
but each fin ray with a brown dot. Bands on
half height of fins faint in pelvic and anal fins,
conspicuous in dorsal, caudal and pectoral fins.
Caudal fin sometimes with an additional, very
faint ‘band’ in distal half of fin.
In life, ground colour slightly darker beige
than in preserved specimens and bars on body
dark grey instead of brown. A red dot on base of
dorsal fin at base of first or second branched ray
(in gap of above mentioned dark brown stripe).
In about half of specimens red colour present on
proximal half of caudal fin, intensity variable
from a faint hue to intensely colour, no direct
correlation between intensity of red fin colour
and body size, stage of maturity and sex visible.
Specimens from stream Anlong Kmeng Leng
(Mekong drainage) (Fig. 2h) differ from remain-
ing samples in having 6-7 body bars (vs. 7-11),
narrower than interspaces (vs. wider), dark grey
bar on caudal-fin base always interrupted and
black pigment of fin rays nearly invisible in most
specimens, giving impression of non-pigmented
fins.
Genetic data. The sequence of the complete mi-
tochondrial cytochrome b gene of paratype IAPG
A8339 has been deposited on Genebank under
accession number KU187892.
Habitat. The largest stream in which the species
was collected measured about 20 m in width, but
the species was most abundant in small streams
up to 6 m wide with moderate flow and many
stones (Fig. 4). Fishes were hiding between the
stones.
Distribution. The investigated material origi-
nated from tributaries of the rivers Mekong, Tek
Chhou and Srae Ambel in the provinces Kam-
pot, Ratanakiri and Kaoh Kong in northern and
Table 1. Morphometric data of holotype and 31 specimens of Schistura kampucheensis. Range, mean and SD
include holotype. Specimens from all known localities included in measurements.
holotype range mean SD
Standard length (mm) 43.9 24.2-55.9
In percentage of standard length
Total length 122.6 120.4-128.2 123.6 1.7
Dorsal head length 18.5 17.7-23.1 19.9 1.2
Lateral head length 22.3 21.0-26.6 22.9 1.5
Predorsal length 53.1 50.8-58.6 53.9 1.7
Pre-pelvic length 51.0 49.1-56.4 52.5 1.4
Pre-anus length 67.4 65.7-71.7 68.2 1.6
Preanal length 77.7 74.3-80.1 77.2 1.3
Anus-anal distance 10.7 7.3-11.6 9.3 1.0
Head depth at eye 10.7 8.7-12.3 9.9 0.7
Head depth at nape 12.3 11.5-13.4 12.4 0.5
Body depth 15.5 13.3-17.7 14.7 0.9
Depth of caudal peduncle 12.3 10.5-12.8 11.6 0.6
Length of caudal peduncle 12.8 10.4-14.2 12.5 1.0
Snout length 9.8 6.9-10.2 8.8 0.7
Head width at nares 10.9 7.3-11.1 9.1 0.9
Maximum head width 16.6 12.2-16.6 14.8 0.9
Body width at dorsal origin 13.2 10.5-13.7 12.2 0.9
Body width at anal origin 8.4 4.8-8.9 7.3 1.0
Eye diameter 4.6 3.6-5.8 4.7 0.6
Interorbital width 7.1 5.2-8.0 6.9 0.6
Height of dorsal fin 15.5 12.7-20.8 15.7 1.6
Length of upper caudal lobe 21.9 20.3-25.0 22.5 1.3
Length of median caudal ray 19.4 13.4-21.9 18.8 2.0
Length of lower caudal lobe 23.0 20.0-25.2 22.9 1.5
Depth of anal fin 17.5 15.7-19.8 17.4 1.1
Length of pelvic fin 16.9 15.4-19.8 17.4 1.1
Length of pectoral fin 18.2 16.5-21.9 19.2 1.3

358
southern Cambodia (Fig. 5). Rainboth (1996) listed
the species from the Tonle San and tributaries. It
seems that S. kampucheensis is distributed over a
large part of Cambodia, but has up to now not
been reported from any other country.
Etymology. From Kampuchea, the Khmer name
for Cambodia. The name refers to the fact that
the species is widespread in Cambodia, but up
to now is not known from outside the country.
An adjective.
Remarks
The genus Schistura is presently defined by the
combination of the following characters: a mod-
erately arched mouth, lower lip with a median
interruption, but not forming two lateral trian-
gular pads, colour pattern usually with more or
less regular bars and a black bar at base of caudal
fin, dorsal fin with one or two black marks along
its base, no acuminate scales on caudal peduncle
and caudal fin usually emarginated (Kottelat,
1990). The new species matches this definition
of Schistura and also bears the most common
pigmentation pattern of this genus, which consists
of dark bars on the body, a dark grey or black
bar on the base of the caudal fin and a dark grey
or black dot on the base of the dorsal fin. It is
also identical with S. pellegrini in Kottelat (1990)
and some of the material used by Kottelat (1990)
has also been used in this study. As mentioned
above, S. pellegrini has been demonstrated to be
conspecific with S. spiloptera, a species restricted to
a small area in Central Vietnam (Freyhof & Serov,
2001). The descriptions in Freyhof & Serov (2001)
as well as our comparison of S. kampucheensis
with S. spiloptera confirm that S. kampucheensis
differs from S. spiloptera by having 8 + 8 (vs. 9 + 8)
branched caudal-fin rays, 7 (vs. 8) pelvic-fin rays,
a spotted or vermiculated (vs. plain) top of head
Fig. 4. Stream Ta Da Ou Bey in Kampot province, Cambodia. Type locality of Schistura kampucheensis. View up-
stream and to northwest.
Bohlen et al.: Schistura kampucheensis

Ichthyol. Explor. Freshwaters, Vol. 26, No. 4
359
and a shorter lateral line (32-70 vs. 56-100 pores),
and therefore represents a different species.
The most remarkable character of S. kampu-
cheensis within the genus Schistura is a low number
(7, usually 8 in Schistura) of rays in the pelvic
and the rare count of 8 + 8 (usually 9 + 8 or 8 + 7)
branched rays in the caudal fin. A combination
of these two characters is found only in five other
species of Schistura namely S. balteata from western
Thailand and Myanmar, S. bairdi from southern
Laos, S. daubentoni from northeast Cambodia,
S. fusinotata from southern Laos and S. namboensis
from southern Vietnam. It occurs as part of the
intraspecific variability in some specimens of
S. malaisei from northern Myanmar and S. robertsi
from southern Thailand. Schistura kampucheensis
differs from S. balteata by having 6-11 regular
body bars usually continuous across dorsum (vs.
2-3 thin bars below dorsal fin and 3-5 pairs of
round spots in front of dorsal fin), 8 1
/
2 branched
dorsal-fin rays (vs. 7
1
/
2) and presence of a black
bar at caudal-fin base (vs. missing). Schistura
kampucheensis differs from S. daubentoni by reach-
ing a larger size (55.9 mm SL vs. 29.0 mm SL), by
having usually seven or more bars on body (vs. 6)
and the tip of the anterior nostril not reaching the
eye (vs. reaching) and from S. malaisei by having
the anus 1.7-2.5 eye diameters in front of anal-
fin origin (vs. about 0.8 eye diameter). Schistura
kampucheensis is distinguished from S. bairdi by
having the lateral line reaching vertical through
anal-fin origin (vs. dorsal-fin origin), the nostril
flap not reaching (vs. reaching) anterior margin
of eye and an axillary lobe well-developed (vs.
rudimentary). Schistura kampucheensis differs from
S. fusinotata by having 6-11 (vs. 11-16) bars and
Kaoh Kong
Phnom Penh
Tonle Sap
Thailand Laos
Cambodia
Vietnam
Kampot
Banlung
Virachay Park
Battambang
Kampot
Ratanakiri
*
S
r
a
e
A
m
b
e
l
M
e
k
o
n
g
T
o
n
l
e
K
o
n
g
T
o
n
l
e
S
a
n
T
o
n
l
e
S
r
e
p
o
k
A
n
l
o
n
g
K
m
e
n
g
L
e
n
g
Tek Chhou
Fig. 5. Known populations of Schistura kampucheensis in Cambodia (
!
). *, Type locality.

360
not having (vs. having) a broad dark midlateral
stripe. Schistura kampucheensis can be separated
from S. robertsi by lateral line reaching vertical
through anal-fin origin (vs. pelvic-fin origin),
presence (vs. absence) of axillary pelvic lobe and
absence (vs. presence) of black marks on lower
lip. Freyhof & Serov (2001) described S. namboensis
from the upper Srepok basin (Mekong drainage)
and neighbouring coastal rivers of Vietnam and
hypothesised that the material identified by Kot-
telat (1990) as S. pellegrini from northeast Cambo-
dia (including specimens from the lower Srepok)
might be S. namboensis. Our direct comparison
of the Cambodian populations with paratypes
and other material of S. namboensis revealed that
S. kampucheensis differs from S. namboensis by
having continuous bars in more than 90 % of
specimens (vs. separated into dorsal saddles and
lateral bars in all analysed paratypes and 13 out of
16 analysed specimens from Azun River), by bars
nearly reaching ventrally to level of pelvic- and
anal-fin bases in more than 90 % of specimens
(vs. ending shortly below midlateral line in more
than 80 % of specimens) and by not having (vs.
usually having) a dark grey midlateral stripe.
Additionally, the dorsal outline between nape
and dorsal-fin origin is always nearly straight in
S. kampucheensis (vs. convex in most specimens of
S. namboensis). From the material that was identi-
fied as S. pellegrini by Kottelat (1990), CMK 23887
contains two specimens that match the characters
of S. kampucheensis and therefore are identified as
S. kampucheensis; the specimens in CMK 5878 are
discoloured and therefore important characters
that separate S. kampucheensis from S. namboensis
could not be checked.
Other species of Schistura with 8 + 8 branched
caudal-fin rays are S. albirostris from southern
China, S. kohchangensis from southeastern Thai-
land, S. leukensis, S. punctifasciata and S. suber
from central Laos, S. maejotigrina and S. pridii
from northern Thailand and S. obliquofascia from
northern India, but these species differ from
S. kampucheensis by having 5, 6 or 8 (vs. 7) pelvic-
fin rays. Moreover, S. kampucheensis differs from
S. leukensis by having 6-11 (vs. 10-13) bars, from
S. punctifasciata by lateral line reaching vertical
through anal-fin origin (vs. pelvic-fin origin) and
absence of black dots on body (vs. black dots su-
perimposed on bars), and from S. suber by having
8 1
/
2 (vs. 7 1
/
2) branched rays in dorsal fin, an incom-
plete (vs. complete) lateral line, and nostril tube
not reaching (vs. reaching) anterior margin of eye.
Schistura kampucheensis co-occurs with S. koh-
changensis in the Tek Chhou basin in southern
Cambodia. Both species have 8 + 8 branched
caudal-fin rays, but S. kampucheensis differs from
S. kohchangensis by having 7 rays in the pelvic fin
(vs. 8), absence of suborbital flap in males (vs.
present), first rostral barbel not reaching base of
maxillary barbel (vs. reaching beyond base) and
the anus 1.7-2.5 eye diameters in front of anal-fin
origin (vs. about 1 eye diameter).
Rainboth (1996) listed seven species of Schist-
ura as occurring or potentially occurring in Cam-
bodia: S. daubentoni, S. kengtungensis, S. kohchan-
gensis, S. laterimaculata, S. magnifluvis, S. nicholsi
and S. pellegrini. Additionally, Ou et al. (2011)
described S. diminuta from the Tonle Kong. The
differences between S. kampucheensis (= S. pelle-
grini in Rainboth 1996) and S. daubentoni and
S. kohchangensis are discussed above. Schistura
kampucheensis differs from S. kengtungensis by
having the origin of the dorsal fin in front of
pelvic-fin origin (vs. above), an incomplete (vs.
complete) lateral line, 7 (vs. 8) pelvic-fin rays
and 8 + 8 (vs. 9 + 8) branched caudal-fin rays. It
differs from S. laterimaculata by having continu-
ous bars on body (vs. blotches along midlateral
line), 7 (vs. 8) pelvic-fin rays and 8 + 8 (vs. 9 + 8)
branched caudal-fin rays and from S. magnifluvis
and S. nicholsi by having the origin of the dorsal
fin in front of pelvic-fin origin (vs. above), an in-
complete (vs. complete) lateral line and 8 + 8 (vs.
9 + 8) branched caudal-fin rays. Schistura kampu-
cheensis differs from S. diminuta by the presence
of an axillary pelvic lobe (vs. absence), depth of
caudal peduncle 10.5-12.8 % SL (vs. 8.2-8.9 % SL)
and 8 + 8 (vs. 7 + 7) branched caudal-fin rays.
The basins of Xekong and Srepok in Laos,
Vietnam and Cambodia are rich in fish species
and house at least 15 species of Schistura, namely
S. bairdi, S. bolavenensis, S. clatrata, S. daubentoni,
S. diminuta, S. fusinotata, S. imitator, S. kampuche-
ensis, S. khamtanhi, S. kongphengi, S. namboensis,
S. nicholsi, S. nomi, S. rikiki and S. tizardi (Freyhof &
Serov, 2001, Kottelat, 2001, Rainboth, 1996, Ou et
al., 2011). All of these except the above discussed
S. daubentoni, S. fusinotata and S. namboensis dif-
fer from S. kampucheensis by having 8 (vs. 7) rays
in pelvic-fin rays and 9 + 8 (vs. 8 + 8) branched
caudal-fin rays.
Within and across the known localities, S. kam-
pucheensis shows a remarkably variability in sev-
eral characters. Specimens from stream Anlong
Kmeng Leng (Mekong drainage) differ from the
Bohlen et al.: Schistura kampucheensis

Ichthyol. Explor. Freshwaters, Vol. 26, No. 4
361
remaining samples in having 6-7 body bars (vs.
7-11) and a few details of pigmentation pattern.
In 26 out of 27 analysed specimens from the type
locality in the Tek Chhou basin the lateral line
ends above or behind the anal-fin base, some-
times nearly reaches the caudal-fin base, while
in specimens from the Mekong populations the
lateral line ends before or above the anal-fin base
and in all six analysed specimens from the Srae
Ambel basin it ends before the dorsal-fin origin.
A small to medium sized incision of the upper
lip is present in 70 % of the specimens from the
Tek Chhou and in 84 % of the specimens from
the Srae Ambel, but only 42 % of the specimens
from the Mekong populations have a small inci-
sion and medium size incisions do not occur
here. However, all of these characters also show
a remarkable variability within populations, and
therefore the differences between populations
can be assigned to founder effect, local selection
or genetic drift. Since all populations together
share an invariable synapomorphic combination
of characters (see diagnosis), we consider them
all to be conspecific.
Comparative material. Schistura balteata: IAPG A4413-
4416, 1, 27.2-58.9 mm SL; Thailand: Kanchanaburi: Huay
Ulang.
S. daubentoni: CMK 5877, 3 paratypes, 19.1-28.0 mm
SL; Cambodia: Kratie: stream flowing to Mekong.
S. fusinotata: CMK 21456, 2, 22.0-30.2 mm SL; Laos:
Attapeu: Xe Kong. – IAPG A5065, 1, 34.2 mm SL; Laos:
Xekong: Xe Kong. – IAPG A4817, 1, 28.1 mm SL; Laos:
Xekong: Xe Kong.
S. kengtungensis: IAPG A9445–9448, 4, 32.1-44.9 mm
SL;Thailand: Petchabun: Mun.
S. kohchangensis: IAPG A7619, A 7671, 2, 35.8-
40.6 mm SL; Cambodia: Kampot: Ou Bey. – IAPG A
910-919, 10, 29.5-33.7 mm SL; Thailand: Chanthaburi:
Sai Khao.
S. laterimaculata: IAPG A6848-6853, 6, 26.6-43.8 mm;
Thailand: Petchabun: Mun.
S. leukensis: CMK 24420, 13, 26.7-59.1 mm SL; Laos:
Saysomboune: Nam Mang.
S. namboensis: ZFMK 24095-24104, 10 paratypes,
45.8-54.8 mm SL; Vietnam: Dac Lac: small stream at Ea
Nuol. – IAPG 3386-3391, 6, 24.6-36.0 mm SL; Vietnam:
Gia Lei: Azun. – IAPG 3266-3279, 14, 20.5-35.5; Vietnam:
Gia Lei: Azun.
S. nicholsi: IAPG A9456-9464, 9, 41.6-63.3 mm SL;
Thailand: Phetchabun: Mun. – IAPG 7362-7366, 5, 33.2-
48.9 mm SL; Thailand: Chiang Mai: Mae Nam Fang. –
CMK 24709, 3, 39.7-51.1 mm SL: Laos: Bolikhamsai:
Nam Ngiep.
S. pridii: IAPG A2393, 1, 26.8 mm SL; Thailand:
Chiang Mai: Huay Mae Tae. – IAPG A928-929, 2, 27.2-
29.1 mm SL; Thailand: Chiang Mai: Doi Chiang Dao.
S. punctifasciata: IAPG A1270-1274, 5, 12.8-28 mm
SL; Laos: Khammouan: Xe Bangfai.
S. robertsi: IAPG A7452-7454, 3, 31.4-35.5 mm;
Thailand: Phang Nga: unnamed forest stream. – IAPG
A7040-7048, 9, 12.6-30.2 mm SL; Thailand: Kapong:
Takua Pa. – IAPG A6990-6995, 6, 32.8-39.8 mm SL;
Thailand: Nakhon Sri Thammarat: Khao Mhen.
S. suber: CMK 22484, 2, 32.0-37.6 mm SL; Laos:
Vientianne: Mam Ngone. – CMK 22643, 3, 28.1-46.9 mm
SL; Laos: Xiangkhouang: Nam Ngum. – CMK 22434, 1,
37.8 mm SL; Laos: Vientiane: Nam Ngum.
S. spiloptera: IAPG A3401-3417, 17, 23.7-44.4 mm;
Vietnam: Thua Thien-Hue: unnamed mountain stream.
Data for other species from Chen & Neely (2012),
Kottelat (1990), Lokeshwor et al. (2012), Suvarnaraksha
(2012) and Ou et al. (2011).
Acknowledgements
We wish to thank Soth Vithun and Hok Samphea for
their help with the field work. The study was sup-
ported by project No. 09/2014/06 of Czech Development
Agency, grant 206/08/0637 of the Czech Science Foun-
dation and by the IRP IAPG No. RVO 67985904.
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Received 29 December 2014
Revised 30 November 2015
Accepted 28 January 2016
Bohlen et al.: Schistura kampucheensis

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Conway, Kevin W. and Daemin Kim: Redescription of the Texas Shiner Notropis amabilis
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Ichthyological Exploration of Freshwaters
An international journal for field-orientated ichthyology
Volume 26 • Number 4 • March 2016
Cover photograph
Notropis megalops (photograph by Kevin W. Conway)
Kevin W. Conway and Daemin Kim
(this volume pp. 305-340)