A new species of the Asian schilbid catfish genus Clupisoma from Myanmar, with a redescription of Clupisoma prateri Hora (Osteichthyes: Siluriformes: Schilbidae)
Author
Ferraris, Carl J.
Author
Jr
text
Zootaxa
2004
437
1
10
journal article
10.5281/zenodo.157339
8e462501-5d0a-4cf4-a0d3-82785fa46103
11755326
157339
BBEAA4C0-966C-47F3-B94B-277F8D24A37C
Clupisoma prateri
Hora, 1937
(
Fig. 2
)
Clupisoma prateri
Hora, 1937
: 671
, figs. 2b, 3b, 6 (
type
locality:
Burma
).
Holotype
: ASB Dup Cat. no. 219 [housed at ZSI]).
Material examined
. All specimens from
Myanmar
:
AMNH
7808 (
1, 161 mm
SL), Monywa;
BMNH
1889.2.1.2411–2 (
2, 132–133 mm
SL), Moulmein;
BMNH
1889.2.1.2462 (
1, 110 mm
SL), Irrawaddy;
BMNH
1891.11.30.184 (
1, 116 mm
SL), Sittang River;
CAS
88898 (
2, 123–124 mm
SL),
USNM
372157 (
1, 188 mm
SL), Yangon market;
CAS
88908 (
1, 122 mm
SL), NyaungU market;
CAS
94939 (
1, 146 mm
SL), Mandalay market;
NRM
31186 (
2, 178–180 mm
SL), Shweli River;
NRM
31187 (
9, 92– 187 mm
SL), Moulmein;
NRM
31190 (
5, 70–91 mm
SL), Rangoon;
NRM
31189 (
1, 123 mm
SL), Kyondo;
USNM
372495 (
2, 178–184 mm
SL),
Thanlyin
market.
Diagnosis
. A species of
Clupisoma
in which the pectoral spine extends at least to the base of the pelvic fin, the abdomen is markedly keeled from the level of the pectoralfin origin to the anus, pectoral fin with 12 or 13 segmented rays, anal fin with 37 to 41 branched rays, and first gill arch with at least 20 rakers. The body is silvery, except for a dorsal greenish band that extends only slightly ventral of the middorsal line of the body.
Description
. (based primarily on NRM 31187) Body elongate, compressed; depth at dorsal origin nearly
5 in
SL and approximately equal to HL; dorsal profile of body slightly convex, nearly horizontal posterior of dorsal fin, straight between dorsalfin origin and snout; abdomen sharply keeled from level of pectoralfin origin to vent; vent located just anterior to analfin origin. Lateral line complete, straight, with short branches extending obliquely above and, mostly, below for entire length. Vertebral column with 48 to 50 vertebrae and 13 or 14 ribs.
FIGURE 2.
Clupisoma prateri
Hora, 1937
, CAS 88908 (122 mm SL).
Head nearly
5 in
SL; compressed posteriorly, nearly as high as wide at middle of eye; opercular opening broad, extending from level of lateral line to anterior of isthmus, opercular membranes not connected to isthmus; posterolateral margin of operculum with posteriorly directed, fleshy lobe; tip of lobe rounded.
Snout acutely rounded in lateral view, in dorsal view, snout margin trilobed, lobes not well defined; anterior naris located on anterior margin of snout; naris round and directed anteriorly, narial opening surrounded by reflexed skin; posterior naris an elongated slit, located slightly posterodorsal and medial to anterior naris, naris nearly transversely oriented, but medial end somewhat posterior of anterior end; anterior narial margin with convex flap of skin that often covers narial opening; nares large, width of posterior naris greater than that of internarial distance.
Eye ventrolaterally placed, but also visible from dorsal view; eye positioned somewhat below middle of head, middle of pupil ventral to level of anterior naris; eye covered laterally with adipose tissue, with ovoid, vertically elongated opening.
Mouth subterminal, upper jaw overhangs lower jaw; mouth opening small, completely anterior to anterior orbital margin; premaxillary tooth plate arched, teeth slender and conical, in two or three irregular rows medially, as many as five rows laterally; upper jaw teeth exposed when mouth is closed. Tooth plate on lower jaw crescentic, teeth slender, conical and somewhat larger than premaxillary teeth, in several rows near symphysis, reduced to one row laterally. Palatal tooth patch elongate, ovoid, not reaching to midline; teeth conical, smaller than those of premaxilla. Teeth in five or six irregular rows. Accessory tooth patches absent from upper jaw and palate.
Gill rakers: 20 to 25 on lateral face of first arch (5 to 8 on dorsal limb and 15 to 18 on lower limb).
Barbel in four pairs, all barbels rest in shallow groove in skin, at least basally. Nasal barbel small, threadlike; extending from lateral margin of posterior naris to level of pupil. Maxillary barbel extends from posterior of anterior naris to tip of adpressed pelvic fin; mental barbels in two pairs, barbel bases originate in transverse row at level of posterior naris; inner mental barbel extends to level of pectoral spine origin, outer mental barbels slightly shorter.
Dorsal fin located in anterior onethird of SL, fin base short, about equal to snout length and about 1/2 of length of dorsal spine; fin much smaller than pectoral fin; dorsal fin with spinelet, slender spine and seven branched rays; spine with fine roughened ridge anteriorly, and with fine retrorse serrations on distal half of posterior margin; fin margin regressive, nearly straight; length of last ray less than onehalf that of first. Dorsal fin rays: II,7. Adipose fin tiny, located above posterior quarter of analfin base; absent is some specimens.
Caudal fin deeply forked, lobes pointed and symmetrical; outer principal rays somewhat less than 3 times length of middle rays. Principal caudal fin rays: i,7,8,i.
Analfin origin located just anterior to level of middle of SL; analfin base long, about 3 times in SL. Fin margin slightly concave anteriorly, nearly straight posteriorly; posterior rays shortest. Last ray without membranous connection to caudal peduncle. Analfin rays: iv–v, 37–41.
Pelvic fin moderate in size, its length about equal to length of dorsalfin spine; fin origin about one dorsalfin base length posterior to posterior insertion of dorsal fin; adpressed fin just shy of analfin origin. Pelvicfin rays: i, 5.
Pectoral fin large, triangular, first branched ray longest. Pectoralfin spine long, stout, adpressed fin extends to past level of dorsal fin base, and past pelvicfin origin; spine with fine roughened ridge anteriorly, and with fine retrorse serrations on distal half of posterior margin. Pectoralfin rays: I, 12–13.
Coloration
. Body greenish above, silvery below. Anteriorly, green extends to lateral line, for most of body greenish area limited to dorsum. Head dark dorsal to level of orbit, silvery laterally and ventrally; snout margin pale. Ventral surface of head and abdomen pale. Dorsal fin pale dusky anteriorly, posterior rays pale. Adipose fin pale. Caudal fin mostly pale, fin margin with broad dusky band. Anal and pelvic fins pale. Pectoral fin dusky on basal part of anterior rays, posterior rays and fin margin pale. Maxillary barbel dusky basally, other barbels pale.
Distribution
. Found widely distributed in the lower and middle reaches of the Irrawaddy River, the lower reaches of the Salween River, and the Bago and Sittang rivers of
Myanmar
.
Remarks
.
Hora (1937: 672–673)
distinguished
Clupisoma prateri
from
Clupisoma garua
on the basis of seven characters: “nasal barbels extend considerably beyond the front margin of the eye; maxillary barbel extend to about the middle of pelvics and sometimes to the commencement of the anal fin; mandibular barbels extend to the hind border of operculum; pectorals extend beyond pelvicfin origin; anal with about 40 to 44 rays; whole of dorsal fin considerably in advance of pelvics; and abdominal edge keeled throughout in front of vent.” Although Hora stated that the specimens he examined were not in good condition, the characters he observed fit well with those found in the specimens examined here from the lower Irrawaddy basin and nearby rivers. Therefore, even in the absence of a direct examination of the
holotype
, there is no doubt that the lower Irrawaddy specimens are
Clupisoma prateri
.
Characters that separate this species from
Clupisoma roosae
, the only other species in
Myanmar
, are summarized in
Table 1
as well as the Remarks section of that species.
Clupisoma prateri
is distinguished from all other congeners by the extent of the midventral abdominal keel, which extends from just posterior of the isthmus to the vent.
In the original description of
Clupisoma prateri
the
holotype
is listed with two different catalog numbers. In the caption for figure 6 and in the table on page 673, the number is listed as "Dup. Cat. No. 219," but in the text on page 673 it is listed as Duplicate Catalogue No. 213.
Menon and Yazdani (1968)
cite the catalog number as ASB Dup. Cat. No. 219 [housed at ZSI], which they presumably verified against the specimen and is, therefore, used herein.
Comparative material examined
.
Clupisoma garua:
All
specimens from
India
:
BMNH
1889.2.1.2443–2447 (
8, 73–145 mm
SL), Calcutta;
BMNH
1858.8.15.127 (
1, 128 mm
SL), Ganges; SU 34839 (
11, 109–167 mm
SL),
Hugli
River, Calcutta; SU 14579 (
1, 179 mm
SL) Megna River, Bengal;
NRM
40588 (
2, 232–248 mm
SL), Dibrugarh Market;
NRM
40599 (
1, 106 mm
SL), Dibrugarh Market.
Clupisoma sinensis
: CAS 93282 (
1, 166 mm
SL),
Laos
, Nam Theun; CAS 68201 (
2, 164–174 mm
SL),
Thailand
, Mukdahan Market.