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Accepted by A. Gill: 5 Nov. 2012; published: 11 Dec. 2012
ZOOTAXA
ISSN 1175-5326 (print edition)
ISSN 1175-5334 (online edition)
Copyright © 2012 · Magnolia Press
Zootaxa 3579: 1–36 (2012)
www.mapress.com/zootaxa/Article
1
urn:lsid:zoobank.org:pub:7CC3476C-AC83-4401-8236-53F59CB88C8F
Revision of Hastatobythites and Saccogaster (Teleostei, Bythitidae) with three new
species and a new genus
JØRGEN G. NIELSEN1, WERNER SCHWARZHANS2 & DANIEL M. COHEN3
1Natural History Museum of Denmark, University of Copenhagen, Universitetsparken 15, DK-2100 Copenhagen Ø, Denmark. Email:
jgnielsen@snm.ku.dk
2Ahrensburger Weg 103 D, 22359 Hamburg, Germany. Email: wwschwarz@aol.com
3100 Thorndale Dr., San Rafael, CA 94903, USA.
Abstract
Material of three similar and probably related genera of the viviparous ophidiiform family, Bythitidae, has been studied.
The monotypic Hastatobythites is only known from the original two specimens; re-examination of the paratype and infor-
mation of the holotype clearly demonstrates the validity of the genus. The revision of Saccogaster (Cohen & Nielsen
1972) was based on 15 specimens. Since then 29 additional specimens have been collected representing 11 species, three
of which are here described: S. brayae, horrida and nikoliviae. Three of the 11 Saccogaster species, S. melanomycter, S.
normae and S. rhamphidognatha, differ so much from the remaining eight that a new genus, Parasaccogaster, is de-
scribed. The main diagnostic characters used for the three genera are: A pair of spines on frontal plate behind eyes, spines
on snout, length of gill filaments on anterior arch, number and length of developed gill rakers, size of gill opening, thick-
ness of skin, head pores, otolith morphology, color marks on head, neuromasts on head and head morphometrics, fin ray
counts.
Key words: Bythitidae, notes on Hastatobythites, revision of Saccogaster with three new species, Parasaccogaster n. gen.
Introduction
Fishes of the family Bythitidae are widely distributed in all oceans. They are generally near-bottom fishes,
occurring benthopelagically in the deeper parts of the oceans and often hidden on the continental rise and in reef or
rocky bottom habitats. The secretive mode of life of many of the species of the subfamily Bythitinae results in
relatively few catches. Investigations during the last decade as well as ongoing research indicate that bythitins may
not really be as rare as long perceived.
A group of genera mostly adapted to rocky bottom environments on the deep shelf and continental rise from
about 200 to 800 m comprises the genera Bellottia Giglioli, 1883, Cataetyx Günther, 1887, Hastatobythites
Machida, 1997, Saccogaster Alcock, 1889, Tuamotuichthys Møller, Schwarzhans and Nielsen, 2004a and
Timorichthys Nielsen and Schwarzhans, 2011. The knowledge of this group is rapidly increasing with more bottom
trawls performed on the deep shelf and the continental rises as evidenced by recent publications of Machida (1997),
Møller et al. (2004b), Nielsen et al. (2006, 2009, 2011) and with the three species and one genus described in the
following.
The monotypic Hastatobythites Machida, 1997 from the Arafura Sea and Saccogaster Alcock, 1889 with eight
species represent viviparous species occurring benthically with one species on shallow coral reefs and the
remainder in deeper water to 834 m. Nielsen et al. (1999) classified all nine species as “rare” indicating that none
of them was known from more than ten specimens. Recent discoveries have increased the number of Saccogaster
tuberculata specimens to 18 and the remaining species are known from 1–6 specimens.
Since the revision of Saccogaster by Cohen and Nielsen (1972), which was based on 15 specimens, 29
additional Saccogaster specimens have been caught representing three new species, which are described in this
NIELSEN ET AL.
2 · Zootaxa 3579 © 2012 Magnolia Press
paper. Three of the 11 species are so different from the other eight Saccogaster species that we consider them
representing a separate genus – Parasaccogaster n.gen.
Nielsen et al. (1999: 105) noted that Hastatobythites is “apparently closely related to if not identical to
Saccogaster”. Based on re-examination of the paratype and information on the holotype we found additional
characters that demonstrate the validity of the genus Hastatobythites.
Mature species of the two genera reach from 36 to 160 mm in SL. The distribution of most species is very
restricted, with the exception of S. tuberculata known from Madagascar in the Western Indian Ocean to Hawaii in
the Central Pacific.
Material and methods
A total of 46 specimens of the genera Saccogaster, Hastatobythites and Parasaccogaster n.gen. are studied for this
review. Institutional abbreviations follow Fricke and Eschmeyer (2011). The distribution maps were created using
Microsoft Encarta 2001 digital world atlas.
Morphometric characters are given as percentage of standard length (SL) and head length (HL). In the
descriptions holotype values are given first followed by paratype values in parentheses. Size of eye is measured as
horizontal diameter of orbit. Number of rays in dorsal, caudal and anal fins and of vertebrae were made from
radiographs. Abbreviations used for counts are: D/V = anterior dorsal fin ray above vertebra number; D/A =
anterior anal fin ray below dorsal fin ray number; V/A = anterior anal fin ray below vertebra number.
Otoliths were removed through the gill cavity by making a small incision in the otic capsule above the gills on the
right side. Otolith measurements include length, height and thickness of the otolith and length of the colliculum, a
structure filling the sulcus on the inner face (for otolith terminology see Schwarzhans et al. 2005, fig. 3). Measuring of
the colliculum was selected over measuring the sulcus, the usual measurement in otoliths, because in the otoliths of
many bythitins the colliculum has a sharper outline than the sulcus, resulting in more repeatable values.
Head drawings and pore counts follow the standards established for the description of Dinematichthyini in
Møller et al. (2004b) and Schwarzhans et al. (2005). The present three genera, however, exhibit a wealth of
characters in head morphology that warrants more detailed descriptions. The heads show a variety of spines both
extruding and sub-dermal (hidden) only visible on radiographs or by lifting of skin. The most prominent is a set of
paired spines inserted on the anterior rim of the frontal plate above and behind the eyes in Saccogaster and
Parasaccogaster n.gen. In Hastatobythites and Parasaccogaster rhamphidognatha only a single median spine is
present and in Parasaccogaster melanomycter a broad fused ridge. All three genera have a median, mostly hidden
sub-dermal spine on the ethmoid in front of the eyes (except Parasaccogaster normae and Saccogaster parva),
which is cartilaginous and thus difficult to see on x-rays in S. horrida n.sp. and S. nikoliviae n.sp.. The species of
the three genera Hastatobythites, Parasaccogaster n.gen. and Saccogaster are the only bythitids with spines on the
frontal or the ethmoid. Most species of Parasaccogaster n.gen. and Saccogaster have furthermore developed a
broad, blunt, sub-dermal spine above each eye. Saccogaster horrida n.sp. has a bony ridge above each eye.
Hastatobythites and Saccogaster horrida have developed bony ridges on the dorsum (3 and 1 respectively). Several
species show coarsely textured surfaces of the frontal plate behind the frontal spines. Certain species have a thin,
translucent skin over the head, and some of those show sub-dermal neuromasts. The neuromasts are diamond-
shaped, made of somewhat thickened tissue and are usually lighter in colour than the surrounding tissue. The
pattern resembles that of head pores of other ophidiiforms, for instance in Dinematichthyini, and is stable in
distribution and extend and of diagnostic value. Other specific features of Saccogaster specimens refer to
pigmentation on the head, thickness of skin and reduction of the gill opening dorsally.
Key to Hastatobythites, Saccogaster and Parasaccogaster n. gen.
1 Gill opening ends at or below level of dorsal margin of pectoral peduncle; pectoral peduncle attached to body; skin thick; eye
sunk in, subdermal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Parasaccogaster n. gen.(p.26)
- Gill opening ends above level of dorsal margin of pectoral peduncle; pectoral peduncle free of body; skin thin (except in S.
tuberculata); eye not subdermal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2
Zootaxa 3579 © 2012 Magnolia Press · 3
REVISION OF HASTATOBYTHITES & SACCOGASTER
2 Narrow head (5.6–6.0 % SL) and body (3.5–3.9 % SL); one anteriorly directed median spine above eyes; three bony ridges on
frontal plate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Hastatobythites (p.3)
- Broad head (10.5–15.0 % SL) and body (4.2–9.5 % SL); pair of spines above and behind eyes (absent in S. parva); no or single
bony ridge on frontal plate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Saccogaster (p. 5)
Hastatobythites Machida, 1997
Hastatobythites Machida 1997: 385, type species by original designation Hastatobythites arafurensis Machida, 1997.
Hastatobythites: Nielsen et al. 1999: 105.
Diagnosis. A monotypic genus of the subfamily Bythitinae (Cohen & Nielsen 1978: 42) with the following
characters: two spines placed in midline of head, one anteriorly directed on frontal above eye and another upward
directed, weak and thin on ethmoid, three bony ridges on dorsum behind frontal spine; maximum width of head
5.6–6.0% SL and of body 3.5–3.9 % SL. Also the following combination of characters is diagnostic: Elongate body
with joined vertical fins; head naked and anterior part of body with scattered scales in midline and posterior half of
body almost fully scaled; skin thin, translucent; eye diameter less than snout-length; opercular spine covered by
skin; posterior part of maxilla greatly expanded vertically; dentigerous bones with granular teeth; palatines with
2–3 tooth rows; pectoral peduncle slightly longer than broad, not adnate; gill opening extending well above
opercular spine; anterior gill arch with three long rakers; precaudal vertebrae 15 and total vertebrae 57–58; fin rays
in dorsal 99–100, caudal 12, anal 64–65 and pectoral 16–17; otolith length to height = 2.5, sulcus undivided, placed
in central part of inner face, otolith length to sulcus length = 2.7.
Similarity. Hastatobythites is most similar to Saccogaster in having more or less prolonged pectoral radials,
naked head, teeth on palatines and thin skin. Hastatobythites differs from Saccogaster by having one median spine
on frontal plate (vs. a pair or none), very narrow head (5.6–6.0 % SL vs. 10.5–15.0 % SL) and body (3.5–3.9 % SL
vs. 4.2–9.5 % SL) and three median bony ridges behind frontal spine (absent or one in Saccogaster).
Hastatobythites differs from Parasaccogaster n. gen. in the very narrow head, three median bony ridges behind
frontal spine, prolonged free pectoral radials (vs. adnate) and the thin, tight head skin (vs. thick and loose).
TABLE 1. Meristic characters of Hastatobythites, Parasaccogaster n.gen. and Saccogaster
Species Precaudal vertebrae Total vertebrae
12
13
14
15
16
17
18
19
20
21
45
46
47
48
49
50
51
52
53
54
55
56
57
58
H. arafurensis + + +
P. melanomycter + +
P. normae + + + + +
P. rhamphidognatha + +
S. brayi + +
S. hawaii + +
S. horrida + +
S. maculata + +
S. nikoliviae + + + +
S. parva + +
S. staigeri + + + + +
S. tuberculata + + + + + +
NIELSEN ET AL.
4 · Zootaxa 3579 © 2012 Magnolia Press
TABLE 2. Meristic characters of Hastatobythites, Parasaccogaster n. gen. and Saccogaster.
Hastatobythites arafurensis Machida, 1997
Figs. 1, 2, 25, Tables 1–3
Hastatobythites arafurensis Machida 1997: 386, figs. 1–2 (type locality: Arafura Sea, 9°18’S, 133° 25’E).
Material examined (1 specimen and photo and radiograph of holotype NTM S. 12904-011):
Paratype: NTM S.12904-018, female, 57 mm SL, NNE of Money Shoal, Arafura Sea. 9°18’S, 133°25’E, otter
trawl, 146 m, 7 Nov. 1990.
Remarks on material: Two specimens known from the same locality. A specimen (AMS I.29749-002) caught
off New South Wales was originally identified as H. arafurensis and cited by Nielsen et al. (1999: 105). It is now
correctly referred to Saccogaster tuberculata (Chan, 1966).
FIGURE 1. Hastatobythites arafurensis: A—Paratype, NTM S.12904-018, SL 57 mm (photo M. Krag). B-Paratype, dorsal
view of head (photo N. Ioannou). C—Embryo from paratype, 4.5 mm (photo M. Krag).
Species Pectoral Dorsal Anal
12
13
14
15
16
17
18
19
20
21
22
23
74–75
76–77
78–79
80–81
82–83
84–85
86–87
88–89
90–91
92–93
94–95
96–97
98–99
100
36–37
38–39
40–41
42–43
44–45
46–47
48–49
50–51
52–53
54–55
56–57
58–59
60–61
62–63
64–65
H. arafurensis + + + + +
P. melanomycter + + +
P. normae + + + + + + + +
P. rhamphidognatha + + +
S. brayi + + +
S. hawaii + + +
S. horrida + + +
S. maculata + + + + + + +
S. nikoliviae + + + + + + + +
S. parva + + +
S. staigeri + + + + + + +
S. tuberculata + + + + + + + + + + + + + +
Zootaxa 3579 © 2012 Magnolia Press · 5
REVISION OF HASTATOBYTHITES & SACCOGASTER
Diagnosis. See diagnosis for Hastatobythites
Description. The major meristic and morphometric characters are shown in Table 3. Head and body elongate
and strongly compressed with tapering caudal part and blunt snout. Posterior part of body fully scaled, anterior part
with a few scales in midline and head naked. No visible lateral line. Dorsal fin origin above proximal part of
pectoral fin and anal fin origin well behind midpoint of fish. Pectoral fin ending less than halfway to anus with
peduncle a little longer than broad. Anterior gill arch (Fig. 2 D) with 4–5 knobs on upper branch, a developed raker
in angle and lower branch with two developed rakers with a knob between followed by 11 knobs; all rakers and
knobs with small, densely placed spines. Long rakers about twice the length of gill filaments. Two small
pseudobranchial filaments. Head pores on paratype difficult to observe.
TABLE 3. Meristic and morphometric characters of Hastatobythites arafurensis.
*Data from Machida (1997) and radiographs
HT NTM 12904-011* PT NTM
12904-018
Standard length 52 57
Meristic characters
Dorsal fin rays 100 99
Caudal fin rays 12 12
Anal fin rays 64 65
Pectoral fin rays 16 17
Pseudobranch. fil. 2 2
Precaudal vertebrae 15 15
Total vertebrae 57 58
Long rakers on
anterior gill arch 33
Ant. dorsal ray above vertebra no. 6 6
Ant. anal ray below dorsal fin ray no. 38 39
Ant. anal ray below vertebra no. 26 26
Morphometric characters in % SL
Head length 25.0 23.0
Head width 6.0 5.6
Depth origin anal fin 14.5 13.0
Body width 3.9 3.5
Upper jaw 14.0 13.5
Posterior maxil. height 6.0 5.6
Diameter of orbit 2.5 2.5
Interorbital width 2.5 1.9
Postorbital length - 18.0
Preanal length 61 57
Predorsal length 31.5 29.5
Base of pelvic fin to anal fin origin 39.0 40.5
Pectoral fin length 16.0 16.0
Pelvic length 1.3 1.4
NIELSEN ET AL.
6 · Zootaxa 3579 © 2012 Magnolia Press
Axial skeleton (based on radiographs): Number of precaudal vertebrae 15. Anterior neural spine one fifth the
length of second spine. Neural spines 4–5 to 6–7 gradually decreasing in length. Pointed tips on neural spines 1–2
to 4–5, blunt tips on spines 6 to 9–11 and remaining vertebrae with neural and haemal spines pointed. Vertebrae
3–4 to 6 with depressed tips and vertebrae 3–7 with enlarged basal parts. Parapophyses developed on vertebrae
6–15. Pleural and epipleural ribs show up so poorly on radiographs that counts are questionable.
Dentition (based on paratype): Vomer and palatines with granular dentition in irregular rows and no fangs.
Dentaries with 15–20 fangs in inner row and many small, pointed teeth in irregular outer rows. Premaxillaries with
many small, pointed teeth in irregular rows and a few fangs near symphysis.
Head morphology (Fig. 2 A–C): Head profile with minor concavity above eyes. Two spines in midline of head;
a larger, free, forward-directed frontal spine placed above eyes and a smaller, ethmoidal spine partly covered by
skin in front of eyes. Three median bony ridges on dorsum behind frontal spine (length 6.5 % SL). Anterior nostril
placed close to upper lip and larger posterior nostril placed close to eye. Head pores: 1 supraorbital pore at tip of
snout, 2 anterior infraorbital pores below and in front of eye, 1 anterior mandibular pore at tip of jaw. Head skin
thin, tight. No neuromasts visible. No head pigmentation visible. Upper jaw ends well behind eye with posterior
margin vertically expanded. Opercular spine flat but pointed not reaching hind margin of opercle. No spine at lower
angle of preoperculum.
Otolith (Fig. 2 E–F): Otolith elongate, thin; otolith length to height = 2.5, otolith height to thickness = 2.1.
Dorsal and ventral rims regularly and shallow curved, dorsal rim with slight predorsal lobe. Anterior and posterior
tips regularly rounded resulting in an oval appearance of the otolith. Inner face flat with centrally positioned,
undivided small, oval, shallow sulcus; otolith length to colliculum length = 2.7. Outer face flat.
Coloration. Paratype uniformly lightbrown, dorsal part of head darker and eyes bluish with light lens.
FIGURE 2. Hastatobythites arafurensis, paratype: A-Lateral view of head. B-Dorsal view of head. C-Lateral radiograph of
head. D-Anterior right gill arch. E-Median view of right sagitta. F-Dorsal view of right otolith.
Zootaxa 3579 © 2012 Magnolia Press · 7
REVISION OF HASTATOBYTHITES & SACCOGASTER
Biology and distribution (Fig. 25). A viviparous species occurring on the lower continental shelf. Holotype a
male with simple intromittant organ. Paratype a female with 4 embryos (4–5 mm long) with red-brown eyes, up to
20 scattered, red-brown spots on body and a short, brown stripe above abdomen (Fig. 1 C). Known from two
specimens caught in the same trawl haul in the Arafura Sea from a depth of 146 m.
Saccogaster Alcock, 1889
Saccogaster Alcock 1889: 389, type species by monotypy Saccogaster maculata Alcock, 1889.
Barbuliceps Chan 1966: 4, type species by original designation Barbuliceps tubercularis (lapsus pro tuberculatus) Chan, 1966.
Saccogaster: Cohen & Nielsen 1972; Nielsen et al. 1999: 109.
Diagnosis. A genus of the subfamily Bythitinae (Cohen & Nielsen 1972) characterized by the following
combination of characters: A pair of bony spines free or sub-dermal on frontal plate above and behind eyes and one
median spine on ethmoid (except none in S. parva); elongate body with joined vertical fins; anal fin origin behind
midpoint of fish; pectoral fins with elongated radials, not adnate; skin thin, translucent (except thick in adult S.
tuberculata); scales absent on head and reduced or absent on body; opercular spine present, free in some species,
covered by skin in others; maxilla vertically expanded posteriorly; palatine teeth present; gill opening extending
well above dorsal margin of pectoral peduncle; developed gill rakers on anterior arch 3–6; pseudobranchial
filaments 2; fin rays in dorsal 80–93, anal 51–64 and pectoral fin 14–22; precaudal vertebrae 12–21, total vertebrae
51–58; males with stalked intromittent organ.
Similarity. The most similar genus is Hastatobythites (see p. 3).
Species. The genus Saccogaster contains eight species known from 41 specimens of which three seem to be
lost and two are only accessible at ZSI, Kolkata. Four are known from one specimen only, three species from 3–6
specimens and one species from 18 specimens.
Key to the species of Saccogaster
1 Scales present on body . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
- Scales absent from body . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6
2 Opercular spine free, with 3 prongs; pectoral fin rays 22; dorsal fin rays 92 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .hawaii
- Opercular spine free or hidden, with single prong; pectoral fin rays 16–19; dorsal fin rays 80–88. . . . . . . . . . . . . . . . . . . . . . .3
3 Gill filaments on anterior arch short (1/3–1/5 times length of developed rakers) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
- Gill filaments on anterior arch about equal to or longer than developed gill rakers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5
4 Scales present on predorsal; 12–13 precaudal vertebrae; no brown stripe on head; numerous neuromasts. . . . . .nikoliviae n.sp.
- Scales absent on predorsal; 21 precaudal vertebrae; broken brown stripe on sides of head; no neuromasts . . . . . . . brayae n.sp.
5 Gill filaments on anterior arch distinctly longer than developed gill rakers; opercular spine free; palatines with several tooth rows;
dorsal fin rays 83–85; posterior infraorbital pores 2, posterior supraorbital pore 1, posterior mandibular pore 1 . . . . . . . maculata
- Gill filaments on anterior arch 0.5–1 times length of developed gill rakers; opercular spine hidden; palatines with a single tooth
row; dorsal fin rays 86–88; no posterior infraorbital pores, no posterior supraorbital pore, no posterior mandibular pore. . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .staigeri
6 Developed gill rakers on anterior arch 5–6; pectoral fin rays 14; numerous neuromasts. . . . . . . . . . . . . . . . . . . . . . . . . . .parva
- Developed gill rakers on anterior arch 3; pectoral fin rays 19–22; 0–3 neuromasts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7
7 Skin thin; opercular spine free; spines on frontal plate visible, bony ridges above eyes; distance from base of pelvic fins to ori-
gin of anal fin 46.0% SL; vomer and premaxillaries with fangs; no posterior mandibular pore . . . . . . . . . . . . . . . . . . . .horrida
- Skin thick; opercular spine hidden; spines on frontal plate sub-dermal, no bony ridge above eyes; distance from base of pelvic
fins to origin of anal fin 32.0–39.0 % SL; no fangs, dentition granular; large posterior mandibular pore. . . . . . . . . tuberculata
Saccogaster brayae n. sp.
Figs. 3, 4, 25, Table 1, 2, 4
Material examined (1 specimen, 36 mm, SL). Holotype: NMV A 29655-002, male, 36 mm SL, off northwestern
Australia, Barrow L1 transect, 21°00’49’’S, 114°39’09’’E to 21°00’47’’S, 114°38’54’’E, R/V Southern Surveyor,
Sherman sledge, 250–258 m, 10 June 2007.
NIELSEN ET AL.
8 · Zootaxa 3579 © 2012 Magnolia Press
FIGURE 3. Saccogaster brayae, holotype, NMV A 29655-002, SL 36 mm (photo M. Krag).
Diagnosis. Saccogaster brayae differs from all other Saccogaster species in having a broken brown stripe
between eye and hind margin of opercle (except for S. hawaii), precaudal vertebrae 21 and total vertebrae 53,
and becoming ripe at a very small SL (36 mm). Also the following combination of characters is diagnostic: A
pair of free spines on frontal above and behind eyes, a large median sub-dermal ethmoidal spine in front of
eyes with forward pointed tip; antero-ventrally directed spine at lower angle of preopercle; thin transparent
skin; scales present on sides of body; three long gill rakers on anterior arch 4–5 times the length of gill
filaments; palatines with 1–2 rows of teeth; pectoral peduncle longer than high; fin rays in dorsal 85, anal 52
and pectoral 18; otolith length to height = 1.9, otolith length to colliculum length = 3.1, sulcus without anterior
projection.
Similarity. Saccogaster brayae seems most similar to S. hawaii by the brown stripe behind eye, the forward
pointed tip of the ethmoidal spine and the scaled body. They differ by S. brayae having opercular spine ending in
one prong (vs. three prongs), by long rakers on anterior arch 4–5 times length of filaments (vs. long rakers and
filaments almost equal in length), precaudal vertebrae 21 (vs. 18), pectoral fin rays 18 (vs. 22) and dorsal fin rays
85 (vs. 92).
Description. The principal meristic and morphometric characters are shown in Table 4. Head and body
elongate and compressed with tapering caudal part and blunt snout. Most scales rubbed off but scale-pockets and a
few remaining scales (0.8 mm long) indicate squamation on sides of body. Lateral line not visible. Dorsal fin origin
above proximal part of pectoral fin and anal fin origin well behind midpoint of fish. Pectoral fin ending less than
halfway to anus with peduncle a little longer than broad and free of body. Anterior gill arch with three spiny knobs
on upper branch, a developed raker in angle and lower branch with two developed rakers with a knob in between
followed by eight knobs. Developed rakers 4–5 times length of gill filaments (Fig. 4 D). Two small
pseudobranchial filaments. The well developed testes and intromittent organ (Fig. 4 G) show that the specimen is a
ripe male.
Axial skeleton (from radiographs): Number of precaudal vertebrae 21. Anterior neural spine very short. Neural
spines 2–4 long, depressed and with pointed tips. Neural spines 5–20 short and with large basal parts, length of
spines increasing posteriorad. Parapophyses developed on vertebrae 6–20. Pleural ribs distinct at vertebrae 1–8, but
pleural ribs on remaining precaudal vertebrae and presence of epipleural ribs are questionable.
Dentition: Palatines with about 25 pointed teeth in 1–2 rows; larger teeth in inner row. Vomer boomerang-
shaped with about 25 pointed teeth in 2–3 irregular rows; six longer teeth in inner row. Premaxillaries with granular
teeth except for five fangs at symphysis. Dentaries with 3–4 irregular tooth rows, outer rows with granular teeth
and inner row with fangs.
Head morphology (Fig. 4 A–C): Head profile concave above eyes. Head with pair of free spines as an
integrated part of a transverse rim on frontal above and slightly behind eyes and a large, median sub-dermal
ethmoidal spine in front of eyes with forward pointed tip. Anterior nostril placed close to upper lip and small
posterior nostril placed close to eye. Head pores: 1 supraorbital pore at tip of snout, 2 anterior infraorbital pores
below and in front of eye, 1 anterior mandibular pore at tip of jaw. Head skin thin, tight. No neuromasts visible.
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Head with dusky background pigmentation, broken brown stripe between eye and hind margin of opercle and
broken brown pigmentation patches below and behind eye. Upper jaw ends well behind eye with posterior margin
vertically expanded. Opercular spine pointed, just reaching hind margin of operculum. Antero-ventrally directed
spine at lower angle of preoperculum.
Otolith (Fig. 4 E–F): Otolith oval, moderately thick; otolith length to height = 1.9, otolith height to thickness =
1.9. Dorsal and ventral rims gently curved, dorsal rim broadly undulating. Anterior and posterior tips regularly
rounded resulting in a regular oval appearance of the otolith. Inner face flat with centrally positioned, undivided,
small, oval, shallow sulcus without anterior projection. Otolith length to colliculum length = 3.1. Outer face
convex.
Coloration: After five years of preservation body uniformly brownish with faint dark pigmentation dorsally.
Head with dusky, dense pigmentation and a dark brown stripe from eye to hind margin of opercle. Larger, dark
pigment spots on frontal plate seen through skin on dorsum. Eyes blue with yellow lens.
Biology and distribution (Fig. 25). A viviparous species occurring on the upper continental slope. Known
from a 36 mm male with well developed testes and intromittent organ, caught off northwestern Australia organ
(Fig. 4G), caught at a depth of 250–258 m.
Etymology. Named after Dianne Bray, MNV, for her support with material for this revision.
FIGURE 4. Saccogaster brayae, holotype: A—Lateral view of head. B—Lateral radiograph of head. C—Dorsal view of head.
D— Anterior right gill arch. E—Median view of right otolith. F—Dorsal view of right otolith. G—Intromittent organ.
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TABLE 4. Meristic and morphometric characters of Saccogaster brayi, S. hawaii and S. horrida.
Saccogaster hawaii Cohen & Nielsen, 1972
Figs. 5, 6, 25, Tables 1, 2, 4
Saccogaster hawaii Cohen & Nielsen 1972: 455, figs. 1, 3 (type locality: off Maui, Hawaian Islands); Nielsen et al. 1999: 109.
Material examined (1 specimen, 69 mm SL). Holotype: USNM 207355, female, 69 mm SL, off Maui, Hawaii,
21°00’N, 156°47’W, R/V Townsend Cromwell, st. 40–62, bottom trawl, bottom temp. 15.9°C, 234 m, 19 Nov.
1968.
Diagnosis. Saccogaster hawaii differs from all other Saccogaster species by the opercular spine ending in
three prongs. Also the following combination of characters is diagnostic: A pair of sub-dermal spines on frontal
behind and above eyes, median sub-dermal ethmoidal spine in front of eyes with forward pointed tip; three
developed rakers on anterior gill arch hardly longer than the knobs, extremely small filaments on anterior gill arch;
S. brayi HT NMV
29655-002 S. hawaii HT USNM
207355 S. horrida HT NMV
29718-019
Standard length 36 69 59
Meristic characters
Dorsal fin rays 80/85 92 84
Caudal fin rays 11 11
Anal fin rays 52 55 57
Pectoral fin rays 18 22 21
Pseudobranch. fil. 2 2
Precaudal vertebrae 21 18 14
Total vertebrae 53 54 56
Long rakers on
anterior gill arch 33 3
Ant. dorsal ray above vertebra no. 7 7 8
Ant. anal ray below dorsal fin ray
no. 35 28 29
Ant. anal ray below vertebra no. 24 25 23
Morphometric characters in % SL
Head length 28.5 26.0 27.0
Depth origin anal fin 10.0 12.0 12.5
Body width 7.8 9.1 9.8
Upper jaw 15.0 14.0 12.5
Posterior maxil. height 5.6 5.1 4.7
Diameter of orbit 2.2 2.2 3.4
Interorbital width 2.7 2.8 2.7
Postorbital length 19.0 19.0
Preanal length 61 62 61
Predorsal length 31.5 31.5 33.0
Base of pelvic fin to anal fin origin 38.0 46.0
Pectoral fin length 15.5 13.5 16.0
Pelvic length 10.0 12.5 16.5
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scales absent on predorsal and present on median part of body; thin, transparent skin; palatines with single row of
teeth; elongate pectoral peduncle longer than high; precaudal vertebrae 18 and total vertebrae 54; fin rays in dorsal
92, anal 55 and pectoral 22.
Similarity. Saccogaster hawaii seems most similar to S. brayae (see comparison above).
Description. The principal meristic and morphometric characters are shown in Table 4. Head and body
elongate and compressed with tapering caudal part and blunt snout. Scales absent from predorsal part and from
band along bases of dorsal and anal fins. Anteriormost scales widely scattered, those more posteriorly positioned
closely spaced and on rear of body regularly imbricate. Lateral line indistinct. Dorsal fin origin above distal part of
pectoral peduncle, anal fin origin well behind midpoint of fish and pelvic fins inserted below hind margin of
opercle, ending below middle of pectoral fin. Anterior gill arch (Fig. 6D) with three barely developed rakers
scarcely longer than the three spiny knobs on upper branch and the knobs on lower branch. Very short gill filaments
on anterior arch. No pseudobranchial filaments observed. No intromittent organ developed so it is probably an
immature female. A pair of elongate gonads visible through transparent skin.
Axial skeleton (from radiographs): Number of precaudal vertebrae 18. Anterior neural spine very short. Neural
spines 2–4 long, depressed and with pointed tips. Neural spines 5–18 with short, blunt spines. Parapophyses
developed on vertebrae 7–18. Pleural ribs distinct on vertebrae 3–6.
FIGURE 5. Saccogaster hawaii, holotype, USNM 207355, SL 69 mm (from Cohen & Nielsen 1972).
FIGURE 6. Saccogaster hawaii, holotype: A—Lateral view of head. B—Lateral radiograph of head (photo S. Raredon).
C—Dorsal view of head. D—Anterior right gill arch.
Dentition: Palatines with 10–15 sharp, pointed teeth in a single row. Vomer with 6 teeth similar to the longer
premaxillary teeth plus a scattering of smaller teeth. Premaxillaries with band of small, granular teeth and near
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symphysis as series of 8 elongate, needlelike teeth in a widely spaced row. Dentaries with an irregular row of about
15 longer, pointed teeth and an outer narrow band of shorter teeth.
Otolith: Not extracted from unique holotype.
Head morphology (Fig. 6A–C): A pair of forward directed sub-dermal frontal spines behind and above eyes, a
large, median, sub-dermal ethmoidal spine in front of eyes with forward pointed tip and a blunt sub-dermal spine
above each eye. Five faint neuromasts below eye curving upwards and two on snout inward of posterior nostril.
Upper jaw ends well posterior to eye with posterior margin vertically expanded and not sheathed dorsally. Opercle
with a flattened, antler-like, 3–pronged spine (Fig. 6A).
Coloration: Body pale with fine, brown pigmentation along the bases of dorsal and anal fins. Similar
pigmentation on head, particularly on snout and between eyes, and an intense dark band from behind eye becoming
more diffuse posteriorad.
Biology and distribution (Fig. 25). Saccogaster hawaii is only known from the holotype caught at the upper
continental shelf at a depth of 234 m off Maui, Hawaiian Islands.
Saccogaster horrida n. sp.
Figs. 7, 8, 25, Tables 1, 2, 4
Hastatobythites arafurensis (non Machida): Hoese & Gates 2006: 573.
Material examined (1 specimen, 59 mm SL). Holotype: NMV A 29718-019, female, 59 mm SL, off northwestern
Australia, Leveque L27 transect, 14°51’12’’S,121°25’53’’E to 14°50’43’’S, 121°27’01’’E, R/V Southern Surveyor,
beam trawl, 403–396 m, 2 July 2007.
Diagnosis. Saccogaster horrida differs from all other Saccogaster species by the following combination of
characters: Distinct pair of free spines on frontal plate above and behind eyes, bony ridge above eye and
cartilaginous ethmoidal spine in front of eyes; no scales, thin, transparent skin, no neuromasts; long gill rakers on
anterior arch 2–3 times length of gill filaments; palatines with 2–3 tooth rows; pectoral peduncle twice as long as
high; precaudal vertebrae 14 and total vertebrae 56; fin rays in dorsal 84, anal 57 and pectoral 21; otolith length to
height = 1.75, otolith length to colliculum length = 2.1, sulcus with long pointed anterior projection.
Similarity. Saccogaster horrida seems most close to S. tuberculata, both lacking scales on the body. They
differ from each other by S. horrida having a distinct frontal plate with a pair of well-developed spines (vs. no
distinct plate and small sub-dermal spines), bony ridge above eye (vs. no bony ridge), vomer and premaxillaries
with fangs (vs. no fangs), distance from base of pelvic fins to origin of anal fin 46% SL (vs. 32–39 % SL) and ratio
otolith length to height = 1.75 (vs. 2.1–2.2).
Description. The principal meristic and morphometric characters shown in Table 4. Head and body elongate
and compressed with tapering caudal part and blunt snout. Scales absent. Lateral line not visible. Dorsal fin origin
above middle pectoral fin and anal fin origin well behind midpoint of fish. Pectoral fin ending more than halfway
to anus and with prolonged peduncle. Anterior gill arch (Fig. 8D) with six spiny knobs on upper branch, a
developed raker in angle and lower branch with two developed rakers with a knob in between followed by 11
knobs. Developed rakers on anterior arch 2–3 times length of gill filaments. Pseudobranchial filaments not found.
Ovaries well developed.
FIGURE 7. Saccogaster horrida, holotype, NMV A 29718-019, SL 59 mm, (photo M. Krag).
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Axial skeleton (from radiographs): Number of precaudal vertebrae 14. Anterior neural spine one third length of
second spine. Neural spines 2–4 long and depressed with pointed tips. Neural spines 5–14 shorter, with large basal
parts and with pointed tips except for blunt in spines 6–9. Parapophyses developed on vertebrae 7–14. Pleural ribs
on vertebrae 3–6 and epipleural ribs not seen.
Dentition: Palatines with 2–3 irregular rows of small, pointed teeth. Vomer boomerang-shaped and with 2–3
irregular tooth rows; inner row with ten large, pointed teeth and outer rows with small, pointed teeth.
Premaxillaries with 3–5 irregular rows of granular teeth except for 2–3 fangs at symphysis. Dentaries with 3–4
irregular rows of small, pointed teeth except for larger teeth in inner row.
Head morphology (Fig. 8A–C): Head profile concave above eyes. Head with pair of free spines on frontal
plate above and behind eyes, bony ridge above eye, frontal plate with rough-textured surface below skin, median,
sub-dermal cartilaginous ethmoidal spine in front of eyes and median bony ridge (3 mm long) on dorsum behind
frontal plate. Anterior nostril placed close to upper lip and small posterior nostril placed close to eye. Head pores: 1
supraorbital pore at tip of snout, 1 anterior infraorbital pore below and in front of eye, 1 anterior mandibular pore at
tip of jaw. Head skin thin, tight. No neuromasts visible. Head with pigmentation patches around mouth and above
eyes and opercular spine. Upper jaw ends well behind eye with posterior margin vertically expanded. Opercular
spine pointed, almost reaching hind margin of operculum. No spine at lower angle of preoperculum.
FIGURE 8. Saccogaster horrida, holotype: A—Lateral view of head. B—Lateral radiograph of head. C—Dorsal view of head.
D—Anterior right gill arch. E—Median view of right otolith. F—Dorsal view of right otolith.
Otolith (Fig. 8E–F): Otolith oval, moderately thick; otolith length to height = 1.75, otolith height to thickness =
1.9. Dorsal and ventral rims gently and regularly curved, smooth. Anterior and posterior tips regularly rounded
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resulting in a symmetrical outline of the otolith. Inner face slightly convex with centrally positioned, undivided
oval, shallow sulcus with long and pointed anterior projection; otolith length to colliculum length = 2.1. Outer face
convex.
Coloration: After five years of preservation body uniformly brownish. Head with scattered, small, black
pigment mainly dorsally and on jaws. Frontal plate with a few larger, black pigment spots. Eyes blue with whitish
lens.Biology and distribution (Fig. 25). A viviparous species caught on the upper continental slope at a depth of
396–403 m off northwestern Australia. Known from a female with ovaries containing many eggs but no embryos.
Etymology. The name “horrida” (meaning horrifying) refers to the spines and bony ridges above the eyes.
Saccogaster maculata Alcock, 1889
Figs. 9, 10, 25, Table 1, 2, 5
Saccogaster maculatus Alcock 1889: 389 (type locality: Bay of Bengal).
Saccogaster maculata: Alcock 1891: 226, fig.; Wood-Mason & Alcock 1891: 30, pl. 7, fig. 3.; Alcock & McArdle 1900: pl. 29,
figs. 2 and 2a (intromittent organ); Cohen & Nielsen 1972: 448, fig. 2; Cohen 1987: 1; Nielsen et al. 1999: 109.
Saccogaster maculatus: Menon & Yazdani 1968: 150 (types in ZSI).
Diplacanthopoma (Saccogaster) maculatum: Alcock 1899: 102.
Material examined (5 specimens and radiograph of syntype (ZSI 11673), 75–87 mm SL). ZSI 13527, female, 81
mm SL and ZSI 13528, female, 75 mm SL, Bay of Bengal, R/V Investigator, bottom trawl, 265–458 m. ZSI 13045,
male, 77 mm SL, Bay of Bengal, R/V Investigator, bottom trawl, 439 m. IOM no cat. no., male, 87 mm SL, Bay of
Bengal, 16°56’08’’N, 83°13’04’’E, R/V Vityaz, cr. 33, st. 4929, bottom trawl, 600 m, 1 Jan. 1961. IOM, no cat. no.,
72 mm SL, Gulf of Aden, 10°32’12’’N, 49°22’12’’E, R/V Dmitry Stefanov, cr. 5, st. 98, bottom trawl, 450–445 m,
6 Dec. 1989.
Remarks on material: It was not possible to borrow any of the five specimens from ZSI for this revision and the
IOM specimens seem lost so information about S. maculata is based on Cohen & Nielsen (1972: 448–451).
Consequently, our information on ethmoid and frontal spines is not based on direct observation, but from available
radiographs.
FIGURE 9. Saccogaster maculata, IOM, SL 87 mm (from Cohen & Nielsen 1972).
Diagnosis. Saccogaster maculata differs from all other Saccogaster species by the following combination of
characters: Distinct pair of (probably) free spines on frontal plate above and behind eyes, strong ethmoidal spine in
front of eyes; scales present on sides of body but not on predorsal; some specimens with ventral arm of opercle
terminating in a short spine; opercular spine free and with one prong; presence of 2 posterior infraorbital pores, 1
supraorbital pore at upper angle of gill opening and 1 posterior mandibular behind maxillary; anterior gill arch with
three long rakers about half length of longest filaments; elongate pectoral peduncle; palatines with several tooth
rows; precaudal vertebrae 12–13 and total vertebrae 53– 55; fin rays in dorsal 83–85, anal 53–56 and pectoral
17–18.
Similarity. Saccogaster maculata is most similar to S. staigeri as both are scaled, have gill filaments 1–2 times
length of developed rakers and fangs on dentigerous bones. They differ by S. maculata having palatines with
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REVISION OF HASTATOBYTHITES & SACCOGASTER
several tooth rows (vs. single tooth row) and opercular spine free (vs. hidden). Also S. maculata has posterior
infraorbital, supraorbital and posterior mandibular pores, which are all missing in S. staigeri.
Description (from Cohen & Nielsen 1972: 449) The principal meristic and morphometric characters are
shown in Table 5. Head and body elongate and compressed with tapering tail and blunt snout. Skin thin and
transparent. Scales absent on predorsal and in a band along bases of dorsal and anal fins except posteriorly, where
entire body is scaled. Anteriorly scales widely scattered, posteriorly scales imbricate. The scale pattern in Alcock
and McArdle (1900, pl. 29, fig. 2) is inaccurate. Lateral line (Fig. 9) in two non-overlapping sections; anterior,
dorsal part with about 12 small papillae extending from upper angle of opercle to about anus; posterior, median part
with 8–10 small papillae ending somewhat anterior to base of caudal fin. Dorsal fin origin above pectoral peduncle
and anal fin origin well behind midpoint of fish. Pectoral fin extending to more than half the distance from upper
angle of peduncle to anal fin; peduncle longer than broad and free of body. Snout depressed and rounded. Small,
darkly pigmented papillae and dermal fringes sparsely distributed on snout and a few on posterior part of head.
Posterior tip of opercle ends in blunt spine. In some specimens ventral arm of opercle ends in a short spine. Upper
jaw ends well behind eyes with posterior part vertically expanded. Anterior gill arch (Fig. 10B) with 3–4 spiny
knobs on upper branch, one developed raker in angle and lower branch with two developed rakers with a knob in
between followed by 12 spiny knobs. Gill filaments 2–3 times length of developed rakers. Two pseudobranchial
filaments. Intromittent organ a thick, fleshy, posteriorly-directed stalk with two prominent lobes on tip from which
a penis protrudes. Paired testes of “Vityaz” specimen not notably enlarged; a histological section shows
spermatozoa arranged in spermatophores.
FIGURE 10. Saccogaster maculata, IOM, SL 87 mm: A—Lateral radiograph of head. B—Anterior right gill arch (from Cohen
& Nielsen 1972).
Axial skeleton (from radiographs): Number of precaudal vertebrae 13. Anterior neural spine considerably
shorter than second spine. Neural spines on precaudal vertebrae 2–5 with pointed tips and decreasing in length,
spines 6–9 with blunt tips and remaining neural and haemal spines with pointed tips. Parapophyses on vertebrae
7–13. Ribs difficult to observe.
Dentition: Palatines with sharp, pointed teeth in a narrow band several teeth wide. Vomer boomerang-shaped
with sharp, pointed teeth. Premaxillaries with band of granular teeth, but near symphysis an inner row of 7–9
elongate, needlelike teeth. Dentaries with a band of granular teeth and an inner row of about 15 pointed teeth.
Head pores (from Cohen & Nielsen 1972: 449): 1 supraorbital pore at tip of snout and 1 at upper angle of gill
opening, 3 anterior infraorbital pores below and in front of eye and 2 posterior infraorbital pores below and behind
eyes, 2–3 anterior mandibular pore at tip of jaw, 1 posterior mandibular pore behind posterior end of maxillary.
Head morphology from radiograph (Fig. 10A): Pair of forward directed strong spines, probably visible, on
frontal above and behind eyes, strong upward directed median ethmoidal spine in front of eyes and blunt sub-
dermal spine above eyes. The surface of the frontal plate behind the frontal spines appears to be roughly textured.
Otolith: No data available.
Coloration: Except for dusky pigmentation on snout preserved specimens are without color patterns.
Biology and distribution (Fig. 25). A viviparous species caught in bottom fishing gear on the upper
continental slope at depths between 265 and 600 m. Six specimens were caught in the Gulf of Bengal and one in
the Gulf of Aden.
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TABLE 5. Meristic and morphometric characters of Saccogaster maculata, S. nikoliviae and S. parva.
*Dorsal fin, anal fin and vertebral counts from only two specimens
Saccogaster nikoliviae n. sp.
Figs.11, 12, 25, Tables 1, 2, 5
Material examined (3 specimens, 50–69 mm SL). Holotype: NMV A 29674-010, female, 69 mm SL, off
northwestern Australia, Imperieuse L23 transect, 17°31’44’’S, 118°50’37’’E to 17°32’30’’S, 118°50’31’’E, R/V
Southern Surveyor, beam trawl, 407–403 m, 15 June 2007. Paratypes: CSIRO H 6602-01, female, 57 mm SL (same
data as for holotype). NMV A 29670-021, male, 50 mm SL, off northwestern Australia, Hedland L22 transect,
18°34’12’’S, 117°27’52’’E to 18°34’04’’S, 117°28’38’’E, R/V Southern Surveyor, beam trawl, 405–401 m, 14
June 2007.
S. maculata
4 specimens* S. nikoliviae
3 specimens S. parva
HT
ZMH 25268
HT 2 PT
Standard length 75–87 69 50–57 58
Meristic characters
Dorsal fin rays 83–85 80 82–84 91
Caudal fin rays no data 10 10 12
Anal fin rays 53–56 51 48–52 64
Pectoral fin rays 17(17.3)18 17 17–18 14
Pseudobranch. fil. 2 2 2
Precaudal vertebrae 12–13 13 12 16
Total vertebrae 53–55 53 52–53 54
Long rakers on
anterior gill arch 333 5–6
Ant. dorsal ray above vertebra no. 6–7 7 6–7 8
Ant. anal ray below dorsal fin ray no. 32–33 34 33–39 30
Ant. anal ray below vertebra no. 21 23 23–24 23
Morphometric characters in % SL
Head length 29.0(30.3)33.0 26.5 27.0–28.5 25.5
Head width 14.0 11.0–13.0 13.0
Depth origin anal fin 13.5 13.5 11.0 13.5
Body width 5.2 4.0–4.2 6.4
Upper jaw 13.5(14.2)14.5 15.0 15.0 12.5
Posterior maxil. height 4.8–5.9 5.4 5.1–5.4 4.6
Diameter of orbit 2.4(2.9)–3.1 2.4 2.4 3.6
Interorbital width 3.9(4.4)–4.8 2.9 2.5–2.6 6.2
Postorbital length 19.0 19.5–21.0 18.5
Preanal length 59(60.9)64 61 57–60 58
Predorsal length 30.5(33.1)36.0 32.5 31.0–32.5 35.0
Base of pelvic fin to anal fin origin 40.5 37.5–41.0 43.5
Pectoral fin length 12.0(12.8)14.0 15.0 16.0–19.0 17.0
Pelvic length 9.2(10.6)12.0 14.5 14.0–15.0 9.8
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Diagnosis. Saccogaster nikoliviae differs from all other Saccogaster species by presence of predorsal scales
and by the following combination of characters: A more or less distinct pair of frontal spines above and behind
eyes and a median, sub-dermal, cartilaginous, ethmoidal spine in front of eyes; numerous neuromasts below
translucent head-skin arranged in four distinct clusters; scales on body; three long gill rakers on anterior arch 3–5
times length of filaments; pectoral peduncle prolonged; palatines with 2–3 tooth rows; an antero-ventrally directed
spine on lower angle of preoperculum; precaudal vertebrae 12–13 and total vertebrae 52–53; fin rays in pectoral
17–18, dorsal 80–84 and anal 48–52; otolith length to height = 1.9, otolith length to colliculum length = 2.8–3.1.
Similarity. Saccogaster nikoliviae and S. parva are the only species with numerous developed neuromasts on
the head. They differ in number of developed gill rakers (3 vs. 6 in S. parva), presence of scales vs. none in S.
parva, and a pair of spines behind eyes vs. none in S. parva.
FIGURE 11. Saccogaster nikoliviae, holotype, NMV A 29674-010, SL 69 mm (photo N. Ioannou).
Description. The principal meristic and morphometric characters are shown in Table 5. The description is
based on the holotype; differences from the two paratypes are mentioned in brackets. Body moderately compressed
and elongate with tapering caudal part and blunt snout. Body covered with thin, overlapping scales on sides and on
predorsal; length of scale from above pectoral fin 0.8 mm. No scales on head and abdomen. Lateral line indistinct
(observed close to dorsal margin of body ending above tip of pectorals). Dorsal fin origin above proximal part of
pectoral fin and anal fin origin well behind midpoint of fish. Pectoral fins ending half way to anus with peduncle
not attached to body. Pelvic fins ending below anterior part of pectoral fins. Anterior gill arch (Fig. 12F) with three
(4) knobs on upper branch, a long raker in angle and lower branch with two long rakers with a knob in between
followed by seven (10) knobs; all knobs and long rakers with small densely placed spines. Long rakers on anterior
gill arch 3 (5) times length of filaments. Ca. 35 very small gill filaments. Two thin pseudobranchial filaments.
Axial skeleton (from radiographs): Number of precaudal vertebrae 12–13. Anterior neural spine one fourth the
length of second spine. Neural spines 4 to 8–9 gradually decreasing in length. Pointed tips on vertebrae 2 to 4–5,
blunt tips on vertebrae 6 to 10–11 and the remaining vertebrae with neural and haemal spines pointed. Vertebrae
3–7 with depressed tips and vertebrae 3 to 7–8 with enlarged basal parts. Parapophyses developed on vertebrae
7–13, pleural ribs on vertebrae 3 to 7–8 and epipleural ribs on vertebrae 3–10.
Dentition: Vomer boomerang-shaped with 5–10 fangs in inner row and 20–25 small, close-set teeth in 2–3
outer rows. Palatines with about 10 fangs in inner row and many small teeth in 1–2 outer rows. Dentaries with
10–20 fangs in inner row and many, small teeth in 2–3 outer rows. Premaxillaries with 2–3 long fangs near
symphysis and with granular teeth in several, irregular rows further back.
Head morphology (Fig. 12A–D): Head profile concave above eyes. Head with pair of small free, closely set
spines on frontal above and behind eyes, sub-dermal surface of frontal plate very uneven, a median, subdermal,
cartilaginous, ethmoidal spine in front of eyes and a blunt sub-dermal spine above eyes. Anterior nostril with a low
rim placed close to upper lip; posterior nostril a mere hole placed close to eye. Head pores: 1 supraorbital pore at
tip of snout, 2 anterior infraorbital pores below and in front of eye, 1 anterior mandibular pore at tip of jaw. Head
skin thin, tight. Total of 17–18 diamond-shaped, light-colored neuromasts visible below transparent skin arranged
in four cluster: 5–6 infraorbital along upper lip and curving around eye, 2 pairs between eyes, 6 supraorbital along
line above opercle and behind eyes, 4 mandibular along jaw. Upper jaw ends well behind eye; posterior end of
maxilla vertically expanded. Opercular spine pointed but flat, free, not reaching hind margin of opercle. Small,
subdermal anterior-ventrally pointed spine at lower angle of preoperculum.
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Otolith (Fig. 12E, G–H): Otolith oval, moderately thick; otolith length to height = 1.9, otolith height to
thickness = 2.2. Dorsal and ventral rims gently and regularly curved, smooth. Anterior and posterior tips regularly
rounded resulting in a symmetrical outline of the otolith. Inner face slightly convex with centrally positioned,
undivided oval, shallow sulcus without anterior projection; otolith length to colliculum length = 2.8–3.1. Outer face
convex.
Coloration: Head and body light brown. Head with dusky background coloration. Eyes black with lighter lens.
Biology and distribution (Fig. 25). A viviparous species occurring on the upper continental slope. The holotype
and a 57 mm SL paratype are females with extended ovaries and eggs up to 0.5 mm in diameter; no embryos were
observed. The 50 mm SL paratype is a male with ripe testes and well developed intromittent organ. Known from three
specimens caught off northwestern Australia in bottom fishing gear at depths between 401 and 407 m.
Etymology. The new species is named after two of the senior author’s grandchildren: Nikolaj and Olivia.
FIGURE 12. Saccogaster nikoliviae, holotype: A—Lateral view of head. B—Lateral radiograph of head. C—Dorsal view of
head. D—Ventral view of head. E—Median view of otolith. F—Anterior right gill arch. G—Dorsal view of right otolith.
H—Median view of right otolith (paratype, NMV A 29670-021).
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Saccogaster parva Cohen & Nielsen, 1972
Figs 13, 14, 26, Table 1, 2, 5
Saccogaster parva Cohen & Nielsen 1972: 459, fig. 5 (type locality: off southern Brazil).
Saccogaster parva: Nielsen et al. 1999: 110.
Material examined (1 specimen, 58 mm SL). Holotype: ZMH 25268, female, 58 mm SL, off southern Brazil,
24°21’S, 43°54’W, R/V Walther Herwig, st. 90/68, bottom trawl, 500 m, 2 Mar. 1968.
Diagnosis. Saccogaster parva differs from all other Saccogaster species in having 5–6 developed rakers on
anterior gill arch and no spines on frontal plate and ethmoid. Also the following combination of characters is
diagnostic: Skin thin and transparent; numerous neuromasts below translucent head skin arranged in five distinct
clusters; scales absent; three developed rakers on anterior gill arch 3–4 times length of gill filaments; palatines with
one row of teeth; antero-ventrally directed spine on lower angle of preoperculum; prolonged pectoral peduncle;
precaudal vertebrae 16 and total vertebrae 54; fin rays in dorsal 91, anal 64 and pectoral 14.
FIGURE 13. Saccogaster parva, holotype, ZMH 25268, SL 58 mm, (from Cohen & Nielsen 1972).
FIGURE 14. Saccogaster parva, holotype: A—Lateral view of head. B—Lateral radiograph of head (photo R. Thiel).
C—Dorsal view of head. D—Ventral view of head. E—Anterior right gill arch.
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20 · Zootaxa 3579 © 2012 Magnolia Press
Similarity. Saccogaster parva and S. nikoliviae are the only species with numerous, developed neuromasts on
the head, but they differ in other characters such as number of developed gill rakers 6 vs. 3 in S. nikoliviae, absence
of scales vs. present in S. nikoliviae and no spines behind eyes or on ethmoid vs. present in S. nikoliviae.
Description. The principal meristic and morphometric characters are shown in Table 5. Body compressed and
relatively short. Scales absent. Lateral line continuous, originating above preopercle descending gradually to
midline over anus and ending close to basis of caudal fin; ca. 20 lateral line papillae. Dorsal fin origin above
proximal part of pectoral fin and anal fin origin well behind midpoint of fish. Pectoral fins end halfway to anus.
Pectoral peduncle prolonged. Head compressed with blunt snout. Opercular spine flat, preopercular spine hidden.
Posteror, vertically expanded part of maxillary strongly sheathed dorsally. Anterior gill arch (Fig. 14E) with two
knobs on upper branch, a developed raker in angle, and lower branch with 5–6 developed rakers followed by 6–8
knobs. Pseudobranchial filaments 2. Ovaries with developing eggs.
Axial skeleton (from radiographs): Number of precaudal vertebrae 16. Anterior neural spine 1/3 length of
second spine. Neural spines 2–5 decreasing in length and with pointed tips. Neural spines 6–10 with blunt tips and
all remaining neural and haemal spines with pointed tips. Parapophyses developed on vertebrae 7–16. Pleural ribs
on vertebrae 2–11 and epipleural ribs seen on vertebrae 3–6.
Dentition: Vomer boomerang-shaped with about six fangs and a scattering of smaller teeth. Palatines with one
row of fang-like teeth. Dentaries with an irregular row of about 15 fangs and an outer narrow band of shorter teeth.
Premaxillaries with a narrow band of small, granular teeth and five needle-like teeth at the symphysis
Head morphology (Fig. 14A–D): Head profile straight above eyes. Head without spines on frontal plate and on
ethmoid, but blunt, sub-dermal spine above eyes. Fig. 14B shows a conspicuous thickening of the frontal at the
location where spines would be expected, indicating that larger specimens might in fact have small frontal spines.
Also a broad hump is indicated on the snout at the position where a (cartilaginous) spine might be expected.
Anterior nostril placed close to upper lip; posterior nostril moderately large with anterior flap, placed close to eye.
Head pores: 2 supraorbital pores near tip of snout, 1 anterior infraorbital pore below and in front of eye, 1 anterior
mandibular pore at tip of jaw. Head skin thin, tight. Total of 17–18 diamond-shaped, light-colored neuromasts
visible below transparent skin arranged in five clusters: 4 infraorbital along upper lip and curving around eye, 2
pairs between eyes, one of them slightly in front of eyes, 6 supraorbital along line above opercle and behind eyes,
2–3 mandibular along jaw, 3 on the lower preopercle. Head with dusky background pigmentation chiefly around
neuromasts. Upper jaw ends well behind eye; posterior end of maxilla vertically expanded. Opercular spine pointed
but flat, subdermal, not reaching hind margin of opercle. Small, subdermal anterior-ventrally pointed spine at lower
angle of preoperculum.
Otolith: Dissolved.
Coloration: Violet when caught.
Biology and distribution (Fig. 26). Caught on the bottom on the upper continental slope at a depth of 500 m.
Known only from the holotype off southern Brazil.
Saccogaster staigeri Cohen & Nielsen, 1972
Figs. 15, 16, 26, Table 1, 2, 6
Saccogaster staigeri Cohen & Nielsen 1972: 2, fig. 1 (type locality: east coast of Florida).
Saccogaster staigeri: Cohen 1987: 2; Nielsen et al. 1999: 109.
? Saccogaster staigeri: Séret & Andreatta 1992: 92 (off Brazil).
Material examined (5 specimens, 49–93 mm SL)*. Holotype: USNM 207357, male, 93 mm SL, east coast of
Florida, 27°11’N, 79°49’W, R/V Gerda, st. 657, 10’ otter trawl, 201–216 m, 16 July 1965. Paratype: USNM
164144, female, 61 mm SL, off Tortugas, Gulf of Mexico, 24°20’ N, 82°55’W, R/V Oregon, st. 1005, 40’ shrimp
trawl, 347 m, bottom temp. 10.0°C, 13 Apr. 1954. Non-types: USNM 158640, female, 72 mm SL, off Dry
Tortugas, Florida, 24°20’N, 83°20’W, R/V Oregon, st. 1005, 347 m, 13 Apr. 1954. TCWC 6146.1, female, 65 mm
SL, northwestern Gulf of Mexico, 27°44.9’N, 95°20.1’W, R/V Alaminos, st. 68A13–19, 2 m dredge, 338–384 m,
19 Nov.1968. TCWC 7027.20, male, 49 mm SL, northern Gulf of Mexico, 28°28’47’’N, 86°2’32’’W, R/V Gyre, st.
E1, 9 m otter trawl, 351–357 m, 14 May 1985.
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REVISION OF HASTATOBYTHITES & SACCOGASTER
* The following specimen of S. staigeri was reported upon by Séret and Andreatta (1992) but it has not been
available to us for checking the identification. It is tentatively referred to S. staigeri: USU 01501, 80 mm SL, off
Rio de Janeiro, 23°41.64’S, 42°06.53’W, R/V Marion Dufresne, st. 63 CB 104, Blake trawl, 430–450 m, 1 June,
1987.
FIGURE 15. Saccogaster staigeri, holotype, USNM 207357, SL 93 mm, (photo Sandra Raredon).
FIGURE 16. Saccogaster staigeri: A—Lateral view of head (paratype, USNM 164144). B—Lateral radiograph of head
(holotype, 207357, photo S. Raredon). C—Dorsal view of head (paratype, 164144). D—Anterior right gill arch (holotype, from
Cohen & Nielsen 1972). E—Median view of right otolith (USNM 158620). F—Dorsal view of right otolith (USNM 158640).
Diagnosis. Saccogaster staigeri differs from all other Saccogaster species by the following combination of
characters: Frontal plate with a pair of small, hidden, sub-dermal spines above and behind eyes and a small,
median, sub-dermal, ethmoidal spine in front of eyes; opercular spine hidden by skin, preopercular spine absent;
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22 · Zootaxa 3579 © 2012 Magnolia Press
pectoral peduncle prolonged; three developed rakers on anterior gill arch 1.5–2 times length of gill filaments;
palatines with one tooth row and fang-like teeth on all dentigerous bones; precaudal vertebrae 13–14 and total
vertebrae 53–54; fin rays dorsal 86–88, in anal 53–57 and pectoral 18–19; otolith length to height = 2.1, otolith
length to colliculum length = 2.8.
Similarity. Saccogaster staigeri is most similar to S. maculata as both are scaled, have gill filaments 1.5–2
times length of developed rakers and fangs on dentigerous bones. They differ by S. staigeri having palatines with a
single tooth row (vs. several tooth rows) and opercular spine and pair of spines on frontals hidden (vs. free). Also S.
staigeri has no posterior infraorbital, supraorbital and posterior mandibular pores, which all are present in S.
maculata.
Description. The principal meristic and morphometric characters are shown in Table 6. Body moderately
compressed and elongate with tapering caudal part and blunt snout. Scales on body concentrated around midline,
hardly overlapping; no scales on head and abdomen. Lower part of lateral line in holotype with about 20 papillae.
Dorsal fin origin above proximal part of pectorals and anal fin origin well behind midpoint of fish. Pectoral fin
ending almost halfway to anus with prolonged peduncle not attached to body. Pelvic fins ending below anterior part
of pectoral fins. Anterior gill arch (Fig. 16D) with four flat, spiny knobs on upper branch, a developed raker in the
angle and lower branch with two longer rakes with a knob in between followed by 11 low knobs. Developed rakers
on anterior arch 1.5–2 times length of filaments. Two pseudobranchial filaments. Holotype with 9 mm long penis
and rear part of body cavity with swollen testes. Eggs are visible through the body wall of paratype.
Axial skeleton (from radiographs): Number of precaudal vertebrae 13–14. Anterior neural spine very short.
Neural spines 2–4 long and with pointed tips and neural spines 5–12 distinctly shorter, with blunt tips and enlarged
basis. All remaining neural and haemal spines with pointed tips. Parapophyses developed on vertebrae 7 to 13–14.
Pleural ribs on vertebrae 3–4 to 9. Epipleural ribs on vertebrae 3–9.
Dentition: Vomer boomerang-shaped with 7–8 fangs in 1–2 rows. Palatines with 10–12 fangs in a single row.
Dentaries with 15–20 fangs in one row. Premaxillaries with granular teeth in many rows and 2–3 fangs near
symphysis.
Head morphology (Fig. 16A–C): Head profile straight above eyes. Head with pair of tiny sub-dermal spines on
frontal plate above and behind eyes, distinct on radiographs, small, median, sub-dermal, ethomoidal spine in front
of eyes and blunt sub-dermal spine above eyes. Frontal plate behind frontal spines with coarsely textured sub-
dermal surface. Anterior nostril placed close to upper lip; posterior nostril a mere hole placed close to eye. Head
pores: 1 supraorbital pore at tip of snout, 2 anterior infraorbital pores below and in front of eye, 1 anterior
mandibular pore at tip of jaw. Head skin thin, loose. No neuromasts visible. No head pigmentation visible. Upper
jaw ends well behind eye; posterior end of maxilla vertically expanded. Opercular spine pointed, subdermal, not
reaching hind margin of opercle. No spine at lower angle of preoperculum.
Otolith (Fig. 16E–F): Otolith elongate, moderately thick; otolith length to height = 2.1, otolith height to
thickness = 2.3. Dorsal and ventral rims regularly curved, smooth. Anterior and posterior tips pointed resulting in a
symmetrical outline of the otolith. Inner face slightly convex with centrally positioned, undivided, oval, shallow
sulcus without anterior projection; otolith length to colliculum length = 2.8. Outer face convex.
Coloration: After about 50 years of preservation the specimens are uniformly brownish except for the darkblue eyes.
Biology and distribution (Fig. 25). Caught in bottom fishing gear at the upper continental slope at a depth of
201–450 m. The holotype is from off the east coast of Florida and the paratype and three more specimens from the
Gulf of Mexico. According to Séret and Andreatta (1992) a fifth specimen was trawled off Rio de Janeiro, which is
here recorded as tentatively assigned.
Saccogaster tuberculata (Chan, 1966)
Figs. 17, 18, 25, Table 1, 2, 6
Barbuliceps tuberculatus Chan 1966: 4, figs. 1–2 (type locality: South China Sea).
Saccogaster tuberculata: Cohen 1987: 3; Nielsen et al. 1999: 110.
Material examined (18 specimens, 84–160 mm SL). Holotype: BMNH 1965.11.6.1, male, 106 mm SL, South China
Sea, 6°01’48’’N, 109°57’24’’E, R/V Cape St. Mary, cr. 7/64, st. 32, Agassiz trawl, 823–834 m, 5 Nov. 1964. Non-
types: USNM 207354, 2 females (1 cleared and stained) and ZMUC P77550, female, 95 mm SL, off Hawaiian
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REVISION OF HASTATOBYTHITES & SACCOGASTER
Islands, 21°06’N, 156°13’W, R/V Townsend Cromwell, 52–88, shrimp trawl, 585–640 m, 3 Mar. 1971. BSKU 29526,
female, 138 mm SL, Kyusu-Palau ridge, 28°04’N, 134°41’E, R/V Shinkai-Maru, No. 53, beam trawl, 523 m, 18 Dec.
1979. AMS I.22814-029, female, 160 mm SL, off Northwest Australia, 18°29’S, 116°36’E, R/V Soela, st. SO 2/82/
26,27, Engel trawl, 696–704 m, 6 Apr. 1982. AMS I.26002-005, female, 84 mm SL, off New South Wales, 33°34’S,
152°2’E, R/V Kapala, st. K 86-01-06, bottom trawl, 658 m, 11 Feb. 1986. IOM 00498, male, 94 mm SL, Mozambique
Channel, 12°28’30’’S, 48°09’54’’E to 12°26’S, 48°08 E, R/V Vityaz, cr. 17, st. 2601, bottom trawl, 700–710 m, 12
Nov. 1988. AMS I.29749-002, female, 90 mm SL, off New South Wales, 32°40’S, 152°51’E to 32°38’S, 152°54’E,
R/V Kapala, K 89-17-02, bottom trawl, 814–850 m, 15 Aug. 1989. MNHN 2002-3143, female, 119 mm SL,
Chesterfield Islands, 19.7°S, 158.83°E, Musorstom 5, st. cc384, bottom trawl, 756–772 m, 21 Oct. 1986. MNHN
2000-0677, female, 147 mm SL, Vanua Balavu, Fiji Islands, 17.33°S, 178.7°W, R/V Buge, cr. 40, st. cp 1431, bottom
trawl, 495–500 m, 2 Mar. 1999. MNHN 2006-0588, female, 100 mm SL, Solomon Islands, 8.38°S, 159.47°E, Camp.
Salomon 2, st. cp2194, bottom trawl, 440–521 m, 24 Oct. 2004. MNHN 2006-0702, male, 112 mm SL, Solomon
Islands, 7.62°S, 157.75°E, Camp. Solomon 2, cr. cp2214, 550–682 m, 26 Oct. 2004. MNHN 2006-0090, male, 113
mm SL, Solomon Islands, 7.71° S, 156.47°E, Camp. Salomon 2, st. cp2246, bottom trawl, 664–682 m, 1 Nov. 2004.
MNHN 2006-0464, male, 84 mm SL, Solomon Islands,7.7°S, 156.43°E, Camp. Salomon 2, st. cp2247, bottom trawl,
686–690 m, 1 Nov. 2004. MNHN 2006-0061, 2 females, 91–98 mm SL, Solomon Islands, 7.9°S, 156.95°E, Camp.
Salomon 2, st. cp2267, bottom trawl, 590–600 m, 4 Nov. 2004. IOM (no cat. no.), 137 mm SL, off Vietnam, R/V
Odissey tr. 52; no further data available.
FIGURE 17. Saccogaster tuberculata, holotype, BMNH 1965.11.6.1, SL 106 mm, (photo M. Krag).
Diagnosis. Saccogaster tuberculata differs from the other Saccogaster species by the following combination
of characters: No body scales; a pair of small, sub-dermal spines on frontal plate just behind eyes, median sub-
dermal ethmoidal spine in front of eyes; skin rather thick; large posterior mandibular pore behind end of maxilla;
cartilaginous ethmoidal spine on snout; opercular spine hidden, no preopercular spine; three developed rakers on
anterior gill arch almost equal in length to developed rakers; pectoral peduncle prolonged; no fangs on dentigerous
bones, palatines with 3 to several tooth rows; precaudal vertebrae 14–15 and total vertebrae 55–58; fin rays in
dorsal 82–93, anal 54–60 and pectoral 19–22; otolith length to height 2–2.1, otolith length to colliculum length
variable, 2.5–3.3.
Similarity. Saccogaster tuberculata seems most close to S. horrida, both having developed gill rakers on
anterior arch equal to or longer than long filaments, three developed gill rakers and no scales. They differ from
each other by S. tuberculata having an indistinct frontal plate and small subdermal spines (vs. a distinct frontal
plate with a pair of well developed, visible spines), no transverse, bony ridge on frontal plate (vs. bony ridge
present), presence of a posterior mandibular pore (vs. absent), dentigerous bones without fangs (vs. vomer and
premaxillaries with fangs), distance from base of pelvic fins to origin of anal fin 32.0–39.0 % SL (vs. 46.0 % SL)
and ratio otolith length to height 2.1–2.2 (vs. 1.75).
Description. The principal meristic and morphometric characters are shown in Table 6. Body compressed and
elongate with tapering caudal part and blunt snout. Scales absent. Skin relatively thick, loose and semitransparent.
Lateral line indistinct, originating above gill opening, descends gradually above anus and continues in midline
becoming obscure posteriorly. In some specimens the 25–30 lateral line papillae are black clearly showing the
course of the line. Dorsal fin origin above vertebrae 6–8 and anal fin origin below vertebrae 21–23. Pectoral fin
reaching more than halfway to anus. Anterior gill arch (Fig. 18F) with 3–4 spiny knobs on upper branch, a
developed raker in angle and lower branch with two developed rakers with a knob between followed by 7–11
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knobs. Number of knobs varies between 14 and 19. Two pseudobranchial filaments. Intromittent organ of holotype
on a thick, fleshy, posteriorly directed stalk with the vent immediately anterior to its base; distal rim of stalk
swollen and divided into two lobes, with a small penis in the middle; sections of the testes show spermatozoans
arranged in spermatophores. In USNM 207354 (SL 130 mm) ovaries contain several hundred dark-eyed, uniformly
brownish embryos with yolk sacs.
TABLE 6. Meristic and morphometric characters of Saccogaster staigeri and S. tuberculata.
S. staigeri S. tuberculata
HT PT + 3 spms HT 17 non-types
Standard length 93 49–65 106 84–160
Meristic characters
Dorsal fin rays 87 86(87.2)88 85 82(87.7)93
Caudal fin rays 12 12 12 11(11.9)12
Anal fin rays 54 53(54.2)57 59 54(57.6)60
Pectoral fin rays 18 18(18.4)19 22 19(19.8)21
Pseudobranch. fil. 2 2 2
Precaudal vertebrae 14 13(13.8)14 14 14(14.5)15
Total vertebrae 51 53(53.2)54 56 55(56.5)58
Long rakers on
anterior gill arch 333 3
Ant. dorsal ray above
vertebra no. 7 6(7.0)8 7 6(7.2)8
Ant. anal ray below dorsal
fin ray no. 32(34.3)35 31 28(32.6)36
Ant. anal ray below vertebra
no. 23 23(23.6)24 21 21(21.8)23
Morphometric characters in
% SL
Head length 27.0 26.0(27.0)28.0 27.0 24.0(26.3)30.5
Head width 11.6(13.5)15.0 14.5 10.5(12.7)15.0
Depth origin anal fin 16.0 10.0(10.8)11.5 13.5 12.0(14.0)17.0
Body width 4.5(5.0)5.8 10.5 6.2(7.6)9.5
Upper jaw 13.6 13.5(14.1)14.5 14.0 12.0(13.4)14.5
Posterior maxil. height 4.8 4.3(4.5)4.6 4.5 3.8(4.3)4.9
Diameter of orbit 2.1 2.5 1.8 1.9(2.5)3.1
Interorbital width 5.4 2.8(3.1)3.8 5.2 3.4(4.6)5.6
Postorbital length 18.0(19.4)20.5 19.0 16.5(18.1)20.5
Preanal length 60 60(61.6)61 54 49.5(54.3)58
Predorsal length 31.0 29.5(30.7)32.0 31.0 28.5(30.6)33.0
Base of pelvic fin to anal fin
origin 39.5(40.5)41.5 34.0 32.0(35.7)39.0
Pectoral fin length 14.5 10.0(12.8)15.5 11.0(15.1)18.5
Pelvic length 12.5 10.0(12.0)13.0 13.5 9.2(12.8)14.5
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REVISION OF HASTATOBYTHITES & SACCOGASTER
FIGURE 18. Saccogaster tuberculata: A—Lateral view of head (USNM 207354). B—Lateral radiograph of head (ZMUC
P77550). C—Dorsal view of head (USNM 207354). D—Ventral view of head (USNM 207354). E—Lateral view of head
(AMS I.26002-005). F-Anterior right gill arch (USNM 207354, from Cohen & Nielsen 1972). G—Median view of right otolith
(ZMUC P77550). H—Dorsal view of right otolith (ZMUC P77550). I—Median view of right otolith (MNHN 2000-0667).
J—Median view of right otolith (IOM 00498).
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Axial skeleton (based on radiographs): Number of precaudal vertebrae 14–15. Anterior neural spine one fourth
length of second spine. Neural spines 2 to 4–5 long and compressed and with pointed tips, spines 6–11 with blunt
tips and vertebrae 4–8 with enlarged basal part. Parapophyses on vertebrae 7 to 14–15, pleural ribs on vertebrae
2–10 and epipleural ribs on vertebrae 4–10. Pleural and epipleural ribs often indistinct.
Dentition: Fangs absent. Dentition granular. Palatines with 3 to several, irregular tooth rows. Vomer
boomerang-shaped and with 3–4 tooth rows. Premaxillaries and dentaries with several, irregular tooth rows.
Number of tooth rows seems to increase with standard length.
Head morphology (Fig. 18A–E): Head profile straight above eyes. Head with pair of small, sub-dermal spines
on frontal plate above and behind eyes, small, median, sub-dermal, ethmoidal spine in front of eyes and blunt sub-
dermal spine above eyes. Sub-dermal surface of frontal plate behind frontal spines slightly textured. Anterior
nostril placed close to upper lip; posterior nostril a mere hole placed close to eye. Head pores: 1 supraorbital pore at
tip of snout, 2 anterior infraorbital pores below and in front of eye, 1 anterior mandibular pore at tip of jaw. Head
skin thin, loose, tighter in small specimens and then translucent and sometimes with faint indications of 1–3
subdermal neuromasts below and behind eyes. No head pigmentation visible. Upper jaw ends well behind eye;
posterior end of maxilla vertically expanded. Opercular spine pointed, subdermal, not reaching hind margin of
opercle. No spine at lower angle of preoperculum.
Otolith (Fig. 18G–J): Otolith elongate, moderately thick; otolith length to height = 2.0–2.2, otolith height to
thickness = 1.9–2.2. Ventral rim regularly curved, smooth; dorsal rim regularly curved or broadly undulating.
Anterior tip moderately pointed; posterior tip slightly pointed or rounded. Inner face flat with centrally positioned,
undivided oval, shallow sulcus with distinct anterior projection and somewhat elevated colliculum; otolith length to
colliculum length variable, 2.5–3.3. Outer face markedly convex.
Coloration: Recently caught specimens often with brownish snout, dark dorsum and black papillae on head and
in lateral line.
Biology and distribution (Fig. 25). The 18 examined specimens were caught in bottom fishing gear at depths
of 440–850 m from off East Africa to Hawaii.
Remarks on variability. Saccogaster tuberculata is the most widely distributed species of the genus. It also
shows a remarkably high variation of certain characters, which however is not consistent enough to warrant
distinction of separate species. Particularly it appears that it is always single characters that make the distinction of
any given variation, which is not supported by any independent second character. Two specimens from Hawaii, the
northeastern-most occurrence of the species, show otoliths with a regularly curved dorsal rim (Fig. 18G), whereas
all others exhibit an undulating dorsal rim. The southwestern-most specimen, from off Madagascar, has a tight head
skin (vs. mostly loose) and a distinctly narrower interorbital width (3.4 % SL vs. 3.9–5.6 % SL). A specimen from
off New South Wales, Australia, has a single, feeble neuromast (Fig. 18E) and two specimens from off the
Solomon Islands show 2 and 3 neuromasts, respectively, all on the upper lip behind the eye. A few specimens from
off the Solomon Islands show dusky pigmentation on the posterior part of the body.
Parasaccogaster n.gen.
Type species: Saccogaster normae Cohen & Nielsen, 1972
Diagnosis. A genus of the subfamily Bythitinae (Cohen & Nielsen 1978) characterized by the following
combination of characters: Scales absent on head and body, head skin thick and loose; eyes sunk-in below
transparent skin-window; gill opening at level of or below dorsal margin of pectoral peduncle; head width 7.7–12.0
% SL, maxilla vertically expanded posteriorly; a median or a pair of small bony spines on frontals covered by skin
above and behind eyes; palatine teeth present; developed gill rakers on anterior arch 2–3, pseudobranchial
filaments 2; males with stalked intromittent organ; vertical fins joined, anal fin origin behind midpoint of fish,
pectoral fin radials slightly longer than high, peduncle adnate to body; pectoral fin rays 12–19; precaudal vertebrae
14–20.
Similarity. The most similar genera are Hastatobythites and Saccogaster. Parasaccogaster differs from both
genera by having thick skin with sunk-in eyes, pectoral peduncle adnate to body and gill opening ending at level
with or below dorsal margin of pectoral peduncle.
Etymology. Parasaccogaster refers to the similarity to Saccogaster.
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Key to species of Parasaccogaster
1 Nasal chamber black; vertebrae 45; anal fin rays 37; head width 12.0 % SL. . . . . . . . . . . . . . . . . . . . . . . . . . . . . melanomycter
- Nasal chamber not black; vertebrae 54–58; anal fin rays 49–54; head width 7.7–9.8 % SL . . . . . . . . . . . . . . . . . . . . . . . . . . . .2
2 Gill filaments on first gill arch short (1–2 times developed rakers); precaudal vertebrae 20; pectoral fin rays 12; strong ethmoi-
dal spine. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .rhamphidognatha
- Gill filaments on first gill arch long (4–5 times developed rakers); precaudal vertebrae 14–16; pectoral fin rays 17–19; no eth-
moidal spine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . normae
Parasaccogaster melanomycter (Cohen, 1981)
Figs. 19, 20, 26, Table 1, 2, 7
Saccogaster melanomycter Cohen 1981: 374, figs. 1–2 (type locality: Gairaca Bay, Caribbean Columbia).
Saccogaster melanomycter: Cohen 1987: 2; Nielsen et al. 1999: 110.
FIGURE 19. Parasaccogaster melanomycter, holotype, MCZ 47362, SL 66 mm (photo A. Williston).
Material examined (1 specimen, 66 mm SL). Holotype: MCZ 47362, 66 mm SL, female, Santa Maria, Gairaca
Bay (Encenada de Gayraca), Caribbean Columbia, coral reef, 8 m, 1968.
Diagnosis. Parasaccogaster melanomycter differs from the other two Parasaccogaster species by the sooty
black nasal chambers, few anal fin rays (37 vs. 49–54), few vertebrae (45 vs. 54–58) and a wider head (12.0 % SL
vs. 7.7–9.8 % SL). Also the following combination of characters is diagnostic: A pair of sub-dermal spines fused to
form a broad ridge on frontal just behind eyes, a small, median, sub-dermal, ethmoidal spine just in front of eyes
and an antero-ventrally directed spine at lower angle of preopercle (all spines covered by skin); three developed
rakers on anterior gill arch only slightly larger than the spiny knobs, gill filaments 7–8 times length of developed
rakers; pectoral peduncle slightly prolonged; palatines with several tooth rows; precaudal vertebrae 16 and total
vertebrae 45; fin rays in dorsal 74, anal 37, caudal 10 and pectoral 18.
Similarity. Parasaccogaster melanomycter differs from the two other species of the genus in the stouter body
shape, fewer vertebrae (45 vs 54–58), fewer anal fin rays (37 vs 49–54) and wider head ( 12.0 % SL vs 7.7–9.8 %
SL). Also the fusion of the paired frontal spines is not observed in any other species of the genera studied here.
Description. The principal meristic and morphometric characters are shown in Table 7. Body rather
compressed with pointed, slightly compressed head and tapering tail. Skin thick and opaque. Scales absent. Lateral
line continuous, originating above and anterior to upper angle of gill opening and descending to midline beyond
midpoint of body. Its course marked by narrow unpigmented line with widely spaced, small papillae; about 12 dark
papillae to level of vent and further posteriorly pale papillae difficult to count. Dorsal fin origin above middle of
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28 · Zootaxa 3579 © 2012 Magnolia Press
pectoral fin and anal fin origin well behind midpoint of fish. Pectoral fin reaching 1/3 to anal fin; pectoral peduncle
longer than broad and adnate to body. Anterior gill arch (Fig. 20D) with five low, spiny knobs on upper branch, one
slightly developed raker in angle and lower branch with two slightly developed rakers with a low knob in between
and followed by five partly united knobs, two shallow, likewise partly united knobs, and four well developed
separate knobs after a small break. Longest gill filaments about 2–3 three times length of developed rakers. Two
pseudobranchial filaments. Body cavity nearly filled with two distended ovaries packed with apparently
unfertilized eggs of about 1 mm in diameter.
Axial skeleton (from radiograph): Number of precaudal vertebrae 16. Anterior neural spine very short and
nos. 2–4 very long. Neural spines 2–8 much depressed and with blunt tips. Parapophyses developed on vertebrae
6–16. Pleural ribs on vertebrae 3–11.
Dentition: Palatines with rows of pointed teeth, inner row with larger teeth. Vomer with a boomerang-shaped
band of sharp-pointed teeth, inner row with larger teeth. Premaxillaries with a narrow band of granular teeth and an
inner row of enlarged, needle-like teeth. Dentaries with irregular row of small, slightly compressed teeth and an
inner row of larger, pointed teeth.
FIGURE 20. Parasaccogaster melanomycter, holotype: A—Lateral view of head. B—Lateral radiograph of head (photo A.
Williston). C—Dorsal view of head. D—Anterior right gill arch. E—and F—Lateral and dorsal views of head (CT photographs
A. Williston).
Head morphology (Fig. 20A–C, E–F): A pair of fused, sub-dermal spines on frontal plate above and just
behind eyes, a small, thin, compressed, sub-dermal, ethmoidal spine in midline of snout and broad, blunt, sub-
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dermal spine above eyes. Frontal plate with rough sub-dermal texture. Opercular spine pointed, covered by skin,
not reaching hind margin of operculum. Antero-ventrally directed spine at lower angle of preopercle below skin.
Anterior nostril placed close to upper lip, not tubular; posterior nostril twice as large as anterior nostril, positioned
at some distance from eye. Head pores: 1 supraorbital pore at tip of snout, 1 small posterior supraorbital pore above
base of opercular spine, 2 anterior infraorbital pores below and in front of eye, 2 anterior mandibular pores at tip of
jaw. Head with pointed snout, sunk-in eye covered by window of translucent skin, and many small, dark papillae
on occiput and cheeks. Upper jaw ends well behind eye with posterior part vertically expanded. Nasal chambers
sooty black about equal in size to orbit.
Otolith: Dissolved.
Coloration: Color light brown, darker dorsally and on caudal section. Dorsal and anal fins with narrow, pale rim.
Nasal chamber lined with sooty, black pigment, separated from eye by white area. Head papillae darker than skin color.
Biology and distribution (Fig. 26). Parasaccogaster melanomycter is only known from the holotype caught
at a depth of 8 m on a coral reef in Gairaca Bay, Caribbean Columbia. It is the only species of the three genera here
reviewed living on a shallow reef.
Parasaccogaster normae (Cohen & Nielsen, 1972)
Figs. 21, 22, 26, Tables 1, 2, 7
Saccogaster normae Cohen & Nielsen 1972: 463, figs. 1 and 6 (type locality: off northern Peru).
Saccogaster normae: Cohen 1987: 1; Nielsen et al. 1999: 110.
Material examined (6 specimens, 118–142 mm SL). Holotype: USNM 207356, female, 140 mm SL, off northern
Peru, 4°57’S, 81°23’W, R/V Anton Bruun, cr. 16, st. 625A, otter trawl, 118–133 m, 2 June 1966. Paratype: IM 421,
male, 138 mm SL, off northern Peru, 5°04’S, 80°24’W, R/V Lance, st. 76, 150 m, 7 May 1969. Non-types: UCR
1555-5 (male, 102 mm SL), UCR 1555-8 (female, 128 mm SL) and UCR 2072-21 (female, 118 mm SL), Peninsula
de Nicoya, Costa Rica, 9°44’N, 85°22’W, R/V Nautilus III, bottom trawl, 30 Oct. 1983. UCR 760-1, female, 142
mm SL, off Quepos, Puntarenos Prov., Costa Rica, 9°24’50’’N, 85°22’W, bottom trawl, 25 Mar. 1973.
Diagnosis. Parasaccogaster normae differs from the other two species of the genus by the gill filaments on
anterior arch being 4–5 times the length of the developed rakers and by the following combination of characters: A
pair of very small, subdermal, closely set spines on frontal plate above and behind eyes, no spine on ethmoid; 2–3
developed rakers on anterior arch not much longer than spiny knobs; gill filaments on anterior arch 4–5 times
length of developed rakers; palatines with 2–4 tooth rows; pectoral peduncle prolonged and adnate to body;
precaudal vertebrae 14–16 and total vertebrae 54–56; fin rays in dorsal 83–87, caudal 12–13, anal 51–54 and
pectoral 17–19.
FIGURE 21. Parasaccogaster normae, holotype, USNM 207356, SL140 mm, (from Cohen & Nielsen 1972).
Similarity. Parasaccogaster normae is most similar to P. rhamphidognatha with hidden opercular spine, nasal
chamber not black and distinctly more anal fin rays and vertebrae than found in S. melanomycter. Parasaccogaster
normae differs from P. rhamphidognatha by the longer gill filaments on anterior arch (4–5 times length of long
rakers vs. 1–3 times), more pectoral fin rays (17–19 vs. 12) and lack of an ethmoidal spine vs. spine present.
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30 · Zootaxa 3579 © 2012 Magnolia Press
Description. The principal meristic and morphometric characters are shown in Table 7. Head and body
elongate with tapering caudal part and blunt snout. Scales absent. Origin of lateral line dorsally above pectoral
peduncle and from above anus running in midline ending at base of caudal fin with 27 to ca. 40 small, dark
papillae. Dorsal fin origin above anterior part of pectoral fin and anal fin well behind midpoint of fish. Pectoral fin
ending far from halfway to anal fin and with prolonged peduncle. Anterior gill arch (Fig. 22E) with 3–4 small,
spiny knobs on upper branch, one a little longer raker in the angle and lower branch with two short rakers with a
knob in between followed by ca. ten spiny knobs. Long gill filaments 4–5 times length of developed rakers. Two
pseudobranchial filaments. Ovaries large, but no embryos observed.
Axial skeleton (from radiographs): Number of precaudal vertebrae 15–16. Anterior neural spine one fourth
length of second spine. Neural spines 2–4 long and depressed and with pointed tips, spines 5–10 with blunt tips and
nos. 5–8 depressed and with enlarged basal parts. Parapophyses developed on vertebrae 8–15, pleural ribs on
vertebrae 3–10 and epipleural ribs not observed.
Dentition: Palatines with 2–3 rows of pointed teeth, largest in inner row. Vomer boomerang-shaped and with
2–3 irregular rows of pointed teeth, largest in inner row. Premaxillaries with several irregular rows of pointed teeth
and a few fangs at symphysis. Dentaries with pointed teeth in irregular rows, largest in inner row.
Head morphology (Fig. 22A–B): Head profile slightly or not concave above eyes. Head with pair of very
small, sub-dermal, closely set spines on frontal plate above and behind eyes, no spine on ethmoid, broad, blunt,
sub-dermal spine above eyes, frontal plate with a median, bony ridge. Anterior nostril placed close to upper lip and
larger posterior nostril placed close to small eye. Head pores: 1 supraorbital pore at tip of snout, 2 anterior
infraorbital pores below and in front of eye, 1 anterior mandibular pore at tip of jaw. Head skin thick, loose. Head
with blunt snout, sunk-in eye covered by window of translucent skin. Upper jaw ends well behind eye with
posterior margin vertically expanded. Opercular spine hidden below thick skin. No subdermal preopercular spine.
Gill opening ending slightly below level of dorsal margin of pectoral peduncle.
FIGURE 22. Parasaccogaster normae: A—Lateral view of head (UCR 2072-21). B—Lateral radiograph of head (holotype,
USNM 207356, photo S. Raredon). C—Median view of right otolith (UCR 2072-21). D—Dorsal view of right otolith (UCR
2072-21). E—Anterior right gill arch (paratype, IM 421, from Cohen & Nielsen 1972).
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Otolith (Fig. 22C–D): Otolith elongate, thin; otolith length to height = 2.3, otolith height to thickness = 2.5.
Dorsal and ventral rims gently and regularly curved, smooth. Anterior and posterior tips pointed resulting in a
symmetrical outline of the otolith. Inner face slightly convex with centrally positioned, undivided oval, shallow
sulcus without anterior projection; otolith length to colliculum length = 2.5. Outer face nearly flat.
Coloration: Head and body chocolate brown with darker fins.
Biology and distribution (Fig. 26). A viviparous species living on the lower part of the continental shelf
(80–150 m). Four of the examined specimens are females with well developed eggs but apparently no embryos.
Sections of ripe testes show that the spermatozoans are arranged in spermatophores (Cohen and Nielsen 1972:
465). Known from off northern Peru and from the Pacific coasts of Costa Rica.
TABLE 7. Meristic and morphometric characters of Parasaccogaster melanomycter, P. normae and P. rhamphidognatha.
P.melanomycter HT
MCZ 47362 P. normae
6 specimens P. rhamphidognatha HT
LACM 44189-1
HT HT+PT+4 spms
Standard length 66 140 102–142 60
Meristic characters
Dorsal fin rays 74 87 83(86.2)87 77
Caudal fin rays 10 12 12(12.2)13 12
Anal fin rays 37 54 51(52.5)54 49
Pectoral fin rays 18 17 17(18.0)19 12
Pseudobranch. fil. 2 2 2 2
Precaudal vertebrae 16 15 14(15.0)16 20
Total vertebrae 45 55 54(55.5)56 58
Long rakers on
anterior gill arch 32–33 2–3
Ant. dorsal ray above vertebra no. 6 7 7 7
Ant. anal ray below dorsal fin ray no. 36 37(39.0)40 34
Ant. anal ray below vertebra no. 27 25 25 24
Morphometric characters in % SL
Head length 27.5 23.0 20.5(22.0)23.0 21.0
Head width 12.0 8.4(8.7)9.8 7.7
Depth origin anal fin 16.0 12.5 8.6(10.9)13.0 10.0
Body width 3.5(3.7 )3.9
Upper jaw 11.5 9.2(10.3)11.0 10.0
Posterior maxil. height 3.6 3.1(3.6)3.8 4.0
Dia. orbit 3.2 1.8 0.9(1.4)2.1 1.5
Interorbital width 5.5 4.7 3.7(4.2)4.1 4.0
Postorbital length - 15.5(15.9)17.0
Preanal length 64 63 55(60.0)62 55
Predorsal length 31.0 29.5 27.5(29.1)31.0 23.5
Base of pelvic fin to anal fin origin 38.5(41.5)43.5
Pectoral fin length 10.5 14.5 11.5(13.6)15.0
Pelvic length 11.0 9.6(10.9)12.0 6.2
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Parasaccogaster rhamphidognatha (Cohen, 1987)
Figs. 23, 24, 26, Tables 1, 2, 7
Saccogaster rhamphidognatha Cohen 1987: 1, fig. 1 (type locality: Gulf of Mexico).
Saccogaster rhamphidognatha: Nielsen et al. 1999: 109.
Material examined (1 specimen, 60 mm SL). Holotype: LACM 44189-1, male, 60 mm SL, Gulf of Mexico,
Mississippi delta, 29°13.5’N, 88°16.5’W, R/V Alaminos, st. 69A13-43, 210 m, 4–16 Oct. 1969.
Diagnosis. Parasaccogaster rhamphidognatha differs from the other two species of the genus by the antrorse,
hook-like projection at the postero-ventral angle of the maxillary, a median spine on frontals above and behind eyes
and the low number of pectoral fin rays (12). Also the following combination of characters is diagnostic: A strong,
ethmoidal spine; pectoral peduncle prolonged and adnate to body; 2–3 slightly developed rakers on anterior gill
arch; palatines with a single tooth row; gill filaments on anterior arch short, 1–2 times length of developed rakers;
precaudal vertebrae 20 and total vertebrae 58; fin rays in dorsal 77, anal 49 and pectoral 12.
Similarity. Parasaccogaster rhamphidognatha is most similar to P. norma e with hidden opercular spine, nasal
chamber not sooty black and distinctly more anal fin rays and vertebrae than found in P. melanomycter. P.
rhamphidognatha differs from P. normae by the shorter gill filaments on anterior arch (1–2 times length of long
rakers vs. 4–5 times), fewer pectoral fin rays (12 vs.17–19), presence of ethmoidal spine (vs. spine absent) and a
single median spine on frontal (vs. pair of small spines).
FIGURE 23. Parasaccogaster rhamphidognatha, holotype, LACM 44189-1, SL 60 mm (photo R. Feeney).
FIGURE 24. Parasaccogaster rhamphidognatha, holotype: A—Lateral view of head. B—Lateral radiograph of head (photo
R. Feeney). C—Dorsal view of head. D—Anterior right gill arch.
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Description. The principal meristic and morphometric characters are shown in Table 7. Head and body
elongate and compressed with blunt snout and tapering tail. Scales absent. Lateral line obsolete. Dorsal fin origin
above gill slit, anal fin origin well behind midpoint of fish and pectoral fins very short ending 1/5 to origin of anal
fin. Anterior gill arch with 2–3 flat, spiny plates on upper branch, a short, slightly prolonged raker in angle and
lower branch with 1–2 similar sized rakers followed by six spiny plates. Gill filaments short. Two pseudobranchial
filaments. The intromittent organ is provided with a 6 mm long penis indicating a ripe male.
Axial skeleton (from radiographs): Number of precaudal vertebrae 20. Anterior neural spine one third the
length of second spine. Neural spines gradually decreasing in length. Neural spines 6–8 with slightly blunt tips.
Tips of all other neural and haemal spines pointed. Parapophyses on vertebrae 4–20. Ribs obsolete.
Dentition: Palatines with small, pointed teeth in a single row. Vomer boomerang-shaped with band of small,
pointed teeth. Premaxillaries and vomer with an outer, narrow band of granular teeth and an inner row with larger,
needle-like teeth.
Head morphology: Head profile not concave above eyes. Head with single, strong, median, subdermal spine on
frontal plate above and behind eyes, a strong median, subdermal, ethmoidal spine in front of eyes and a broad,
blunt, sub-dermal spine above each eye. Anterior nostril placed close to upper lip, posterior nostril about three
times as large, lunate-shaped, placed at half way distance to small eye. Head pores: 1 supraorbital pore at tip of
snout, 2 anterior infraorbital pores below and in front of eye, 1 anterior mandibular pore at tip of jaw. Head skin
thick, loose. Head with blunt snout, sunk-in eye covered by window of translucent skin. Upper jaw ends well
behind eye with posterior margin strongly vertically expanded, somewhat hook-shaped. Flat opercular spine hidden
below thick skin. No subdermal preopercular spine. Gill opening ending at about level of dorsal margin of pectoral
peduncle.
Otoliths: Not extracted from unique holotype.
Coloration: Head and body pale. Vertical fins brownish distally.
Biology and distribution (Fig. 26). Parasaccogaster rhamphidognatha is only known from the holotype
caught at a depth of 210 m in the Gulf of Mexico.
FIGURE 25. Geographic distribution of Hastatobythites and Saccogaster in the Indo-West Pacific. Each marking may
represent more than one locality.
Geographical distribution
The bythitid genera Hastatobythites, Parasaccogaster and Saccogaster are mostly adapted to rocky bottom
environments on the deep shelf and continental rise from about 200 to 800 m and are caught in bottom trawls. The
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only exception is Parasaccogaster melanomycter, caught on a shallow reef off Caribbean Columbia. The four
specimens of the three new species described from northwestern Australia have been caught by a heavily armoured
bottom trawl—the Sherman sledge—indicating the potential of catching these perceived rare deep water bottom
living fishes.
The genus Saccogaster is the most widely distributed genus of the three (Fig. 25, 26), known throughout the
Indo- West Pacific (see Ekman 1953:11) and also with two species from the West Atlantic (Fig. 26) in the Gulf of
Mexico and off Brazil. There are no records from the East-Atlantic. Saccogaster contains one cosmopolitan Indo-
West Pacific species, S. tuberculata, and seven species with a geographically more restricted distribution pattern.
Of these, S. maculata has been recorded from the northern Indian Ocean and S. hawaii is assumed endemic to
Hawaii. The richest, seemingly endemic fauna is reported from off NW Australia with all three new species
described herein. The reason for such endemics is seen in the unusually wide and deeply subsided NW Australian
continental margin and its long effective plate tectonic isolation. However, the widely distributed S. tuberculata co-
occurs with these apparently endemic species both in Hawaii and NW Australia. Such wide distribution pattern is
interpreted as a result of a recent dispersal effect of this particular species postdating the evolution of the other
endemisms.
The genus Parasaccogaster is restricted to the tropical seas of the Americas (Fig. 26): Two species from the
tropical West Atlantic, including the only shallow water reef species, P. melanomycter, and one from the East
Pacific from off Peru to Costa Rica.
FIGURE 26. Geographic distribution of Parasaccogaster and Saccogaster in East Pacific and West Atlantic waters. Each
marking may represent more than one locality.
Fossil records
All fossil records related to the genus Saccogaster have been described from otoliths. Principally, bythitine otoliths
are difficult to distinguish on the generic level due to the rather reduced overall morphology with an undivided
sulcus, but otoliths of the genus Saccogaster are more elongate than those of most other genera occurring in the
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same habitat. The anteriorly projecting sulcus observed in S. horrida and S. tuberculata is not known from any
other bythitine otolith and is only paralleled in a few species of the genus Aphyonus of the Aphyonidae (see
Schwarzhans, 1981).
Three otolith-based fossil species have been referred to Saccogaster:
Saccogaster citreus Schwarzhans, 1980, from the Early to Middle Pliocene of New Zealand at Whangaimoana,
Lake Ferry, south coast of the North Island. This otolith very closely resembles the one from the recently described
Timorichthys disjunctus Nielsen & Schwarzhans, 2011 in all aspects including details of the outline and the flat
inner and convex outer face. The main difference is the larger, longer sulcus in the fossil species reflected in the
ratio otolith length : colliculum length of 2.4 (vs 3.5). Hence, S. citreus shall now be referred to as Timorichthys
citreus (Schwarzhans, 1980).
Saccogaster torpidus Schwarzhans, 1985, from the Late Eocene of South Australia at Blanche Point, Port
Willunga. This species represents the earliest record of the genus, and it is rather similar to some modern
Saccogaster otoliths in shape and proportions such as S. tuberculata, but without an anterior projection of the
sulcus. Saccogaster torpidus supports the recognition of bythitines as a group dating back well into early Tertiary
times.
Saccogaster vonderhochti Schwarzhans, 2010, from the Early to Middle Miocene of the North Sea Basin,
locations in Northern Germany. This species exhibits the anteriorly projecting sulcus similarly to the otoliths of the
recent S. horrida and S. tuberculata, differing from both by the inner face being about as convex as the outer face
(vs. nearly flat inner and markedly convex outer face). In terms of otolith shape S. vonderhochti is slightly more
elongate than S. horrida, but generally less elongate than S. tuberculata (otolith length : height = 1.8–2.1 vs. 1.7
and 2.0–2.2, respectively). This find supports a wider geographical distribution of the genus Saccogaster in the
past, bearing in mind, however, that the North Sea Basin was a warmer sea during the Miocene than it is today.
Acknowledgments
We wish to thank the following persons for providing data and/or material: D. Bray (NMV), W. Bussing (UCR), G.
Dally (NTM), H. Endo (BSKU), K. Conway (TCWC), S. Evseenko (IOM), R. Feeney (LACM), M. Goman
(NMV), K. Hartel (MCZ), A. Hay (AMS), E. Karmovskaya (IOM), H. Larson (NTM), Y. Machida (BSKU), M.
Macgrouther (AMS), J. Maclaine (BMNH), M.M. Mincarone (UFRJ), P.R. Møller (ZMUC), H.L. Prestridge
(TCWC), P. Pruvost (MNHN), S. Raredon (USNM), B. Russel (NTM), D.G. Smith (USNM), R. Thiel (ZMH), J.
Williams (USNM), A. Williston (MCZ). M. Krag (ZMUC), S.H. Nielsen (ZMUC) and N. Ioannou (ZMUC) took
the photos. A. Williston (MCZ) prepared the CT photographs of the head of Parasaccogaster melanomycter.
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