Hemibagrus peguensis (BOULENGER, 1894)

SynonymsTop ↑

Macrones peguensis Boulenger, 1894; Mystus peguensis (Boulenger, 1894)

Etymology

Hemibagrus: from the Greek hemi, meaning ‘half’ and the generic name Bagrus.

Classification

Order: Siluriformes Family: Bagridae

Distribution

Occurs throughout much of Myanmar in the Irrawaddy (aka Ayeyarwady), Bago and Sittaung (aka Sittang) river drainages plus the Chindwin basin, Manipur state, northeastern India.

Type locality is ‘Sittang River near Toungoo, Myanmar’.

Maximum Standard Length

The largest officially-recorded specimen measured 286 mm.

Diet

Probably a predator feeding on crustaceans and smaller fishes, although there should be no need to use such live foods in captivity.

NotesTop ↑

This species has been widely confused with the congener H. menoda in the past and is sometimes referred to as ‘Sittang mystus’, but seems virtually unknown in the aquarium hobby.

Hemibagrus has been divided into a number of putative species groups which may or may not represent monophyletic assemblages, and following a major review by Ng and Kottelat (2013) H. peguensis is included in the H. menoda group.

Members of this assemblage can be told apart from other congeners by possession of 44–46 vertebrae, an adipose-fin with a relatively short base (< 20 % SL), a colour pattern comprising either distinct black spots arranged in vertical columns or irregular black vertical lines running along the flanks, and normally a reddish or orangish caudal-fin in life.

Currently valid members are H. caveatus, H. menoda, H. peguensis and H. punctatus.

H. peguensis can be told part from H. caveatus by possession of dark spots arranged in vertical columns (vs. thin vertical lines and a midlateral line) on the flanks

It’s distinguished from H. menoda by its almost truncate (vs. rounded) snout and narrower cleithral process which is notched for about one third of its maximum width (vs. about one quarter), and from H. punctatus in having a longer adipose-fin base (14.2–19.3 % SL vs. 10.1–13.2) and a smaller eye (11–14 % HL vs. 14–16).

The genus Hemibagrus currently contains 40 nominal species which are distributed east of the Godavari River system in India and south of the Changjiang (Yangtze) drainage in China, with Southeast Asia a particular centre of diversity.

Many species are important food fishes and some are cultured for the purpose, or for sport angling.

Hemibagrus has previously been considered synonymous with Mystus but following Ng and Kottelat (2013) members can be diagnosed by their moderate to large adult size and strongly-depressed head shape with the interorbital region normally flat or slighly convex.

The grouping also shares a number of characters with the genera Sperata and Bagrus, and these three can be separated from other bagrids by the following: mesethmoid highly depressed (vs. not highly depressed), prominent (vs. reduced) dorsoposterior laminar extension of the mesethmoid, the first infraorbital with (vs. lacking) a posterolateral spine, enlarged (vs. moderate or small) premaxilla, and the metapterygoid with a long, free posterior margin (vs. contacting quadrate and hyomandibular).

Hemibagrus can be told apart from Sperata by possession of a a relatively short and slender (vs. enlarged and elongate) interneural and by absence (vs. presence) of a concave surface in the posterior portion of the posttemporal in which lies a portion of the swimbladder.

It’s distinguished from Bagrus by possession of 7, very rarely 8 (vs. 8-10) soft dorsal-fin rays.

References

1. Boulenger, G. A., 1894 - Annals and Magazine of Natural History (Series 6) v. 14 (no. 81): 196
   Description of a new siluroid fish from Burma.
2. Ferraris, C. J., Jr., 2007 - Zootaxa 1418: 1-628
   Checklist of catfishes, recent and fossil (Osteichthyes: Siluriformes), and catalogue of siluriform primary types.
3. Ng, H. H. and C. J., Jr. Ferraris, 2000 - Proceedings of the California Academy of Sciences 52(11): 125-142
   A review of the genus Hemibagrus in southern Asia, with descriptions of two new species.
4. Ng, H. H. and M. Kottelat, 2013 - The Raffles Bulletin of Zoology 61(1): 205-291
   Revision of the Asian catfish genus Hemibagrus Bleeker, 1862 (Teleostei: Siluriformes: Bagridae).
5. Ng, H. H., S. Wirjoatmodjo and R. K. Hadiaty, 2001 - The Raffles Bulletin of Zoology 49(2): 359-361
   Hemibagrus caveatus, a new species of bagrid catfish (Teleostei: Siluriformes) from northern Sumatra.