Hemibagrus menoda (Hamilton, 1822)

Hemibagrus menoda (Hamilton, 1822) View in CoL

( Fig. 14 View Fig )

Pimelodus menoda Hamilton, 1822: 203 , Pl. 1 Fig. 72 (type locality: Sharighat bazaar, 35 km NE of Sylhet on Sylhet – Shillong highway, Bangladesh; figure erroneously labelled Mugil corsula ; see Ng & Ferraris, 2000 for explanation).

Bagrus trachacanthus Valenciennes View in CoL , in Cuvier & Valenciennes, 1840: 419 (type locality: Bengal , India); Bleeker, 1853c: 56.

Bagrus corsula Valenciennes View in CoL , in Cuvier & Valenciennes, 1840: 408 (type locality: Sharighat bazaar, 35 km NE of Sylhet on Sylhet – Shillong highway, Bangladesh); Bleeker, 1853c: 56.

Macrones menoda - Günther, 1864: 74; Day, 1871: 706 (in part).

Macrones trachacanthus - Günther, 1864: 75.

Macrones corsula - Day, 1869: 307; 1878: 446, Pl. 100 Fig. 5 View Fig ; 1889: 153 (in part).

Pimelodus telgagra Day, 1871: 200 (not available, name published in synonymy)

Mystus menoda View in CoL - Shaw & Shebbeare, 1937: 92, Fig. 91; Hora, 1949: 72; Ataur Rahman, 1974: 7; 1989: 199, Fig. 119D; Venkateswarlu, 1976: 96; Jayaram & Singh, 1977: 263; Menon, 1977: 61; Venkateswarlu & Menon, 1979: 56; Datta Munshi & Srivastava, 1988: 238, Pl. 30 Fig. 1 View Fig ; Shrestha, 1994: 52, Fig. 80; Jayaram, 1999: 236 (in part); Jayaram & Sanyal, 2003:75 (in part); Hossain & Haque, 2005: 39; Khan, 2008: 32, Fig. 12 View Fig ; Shrestha, 2008: 150, Pl. 39 Fig. 130; Mohsin & Haque, 2009: 830.

Mystus (Mystus) menoda View in CoL - Jayaram, 1954: 546, Fig. 9 View Fig (in part); 1966: 446; Motwani et al., 1962: 21; Srivastava, 1968: 73, Fig. 46 View Fig ; 1992: 97, Fig. 64; Misra, 1976: 95 (in part); Shrestha, 1981: 157, Fig. 75.

Mystus (Mystus) menoda trachacanthus View in CoL - Jayaram, 1954: 546; 1966: 446.

Mystus (Mystus) punctatus View in CoL (in part) - Jayaram, 1954: 547.

Mystus corsula View in CoL - Qureshi, 1965: 41, Fig. 103.

Mystus menoda menoda View in CoL - Jayaram, 1977: 33, Fig. 25B View Fig (in part); Sen, 1985: 137, Fig. 75; 1992: 183, Fig. 60; Dutta et al., 1993: 26.

Mystus menoda trachacanthus View in CoL - Jayaram, 1977: 33; Yazdani et al., 1992: 231; Singh & Yazdani, 1993: 21.

Mystus trachacanthus View in CoL - Mo, 1991: 130.

Hemibagrus menoda View in CoL - Mo, 1991: 132; Ng & Ferraris, 2000: 130, Figs. 4 View Fig & 5 View Fig ; Ataur Rahman, 2005: 219, Fig. 158; Biswas et al., 2007: 64; Ferraris, 2007: 89; Vishwanath et al., 2007: 136; Siddiqui et al., 2007: 115; Saha & Bordoloi, 2009: 241; Mahanta et al., 2011: 346.

Mystus peguensis View in CoL (non Boulenger, 1894) - Mamnur Rashid et al., 1997: 137.

Material examined. — BANGLADESH: UMMZ 208726, 1 ex., 202.6 mm SL [neotype of Pimelodus menoda Hamilton, 1822 and Bagrus corsula Valenciennes , in Cuvier & Valenciennes, 1840; designated by Ng & Ferraris, 2000]), Surma (Meghna) drainage, Sharighat bazaar, 35 km NE of Sylhet on Sylhet –Shillong highway (said to be from Shari River).

INDIA: ANSP 85796 View Materials , 1 ex., 113.0 mm SL ; ZSI 426 , 1 ex., 167.2 mm SL, Bombay ; MNHN 1191 View Materials , 1 ex., 285.4 mm SL, Bengal [syntype of Bagrus trachacanthus ] ; RMNH 8791 View Materials , 1 ex., 184.6 mm SL, Assam .

Diagnosis. — Hemibagrus menoda differs from H. caveatus in having a pattern of dark spots arranged in vertical columns (vs. thin vertical lines and a midlateral line) along the sides of the body. It is distinguished from H. punctatus in having a smaller eye (12% HL vs. 14–16), and greyish (vs. reddish) fins in life, and from H. peguensis in having a rounded (vs. almost truncate) snout ( Fig. 12 View Fig ) and a broader, less deeply notched cleithral process (for about one quarter its maximum width vs. about one third its maximum width; Fig. 13 View Fig ).

Description. — Biometric and meristic data as in Table 7. General description as for genus. Head depressed and broad, body moderately compressed. Head length 32.7–33.5% SL; head depth 14.2–15.3% SL. Snout rounded. Eye diameter 12% HL. Dorsal profile rising evenly but not steeply from tip of snout to origin of dorsal fin, then sloping gently ventrally from there to end of caudal peduncle. Ventral profile horizontal to origin of anal fin, then sloping dorsally to end of caudal peduncle. Caudal-peduncle length 15.2–17.0% SL; caudal-peduncle depth 7.5–8.8% SL. Cleithral process broad, notched for about one quarter its maximum width. Adipose-fin base short, approximately as long as anal-fin base (13.0–15.8% SL); maximum height 3.8–4.5% SL. Adipose-fin origin separated from base of last dorsal-fin ray by distance of 14.2–14.9% SL. Dorsal spine stout, with 6–9 serrations on posterior edge. Pectoral spine stout, with 11–17 serrations on posterior edge. Anal-fin origin slightly posterior to adipose origin. Adpressed dorsal not reaching adipose fin. Caudal fin forked; distal margins of upper and lower lobes rounded. Maximum recorded size 285 mm SL.

Colour. — Preserved specimens have dorsal surface of head and body greyish-brown, gradually fading to dirty white on ventral surface. Lateral surface of body with about nine vertical columns of black spots, largest spots being those in middle of columns along lateral line. Dorsal, pectoral, pelvic and anal fins greyish brown, with scattered melanophores on fin rays and interradial membranes. Caudal fin greyish brown, with lighter hue along posterior edge, and on procurrent and outer principal caudal rays.

Distribution. — Hemibagrus menoda is known from the Ganges, Brahmaputra, Mahanadi and Godavari River drainages in Bangladesh and northern India ( Fig. 15 View Fig ).