Thryssa hamiltonii (Gray, 1835)

Zainal Abidin, Danial Hariz, Lavoué, Sébastien, Mohd Abu Hassan Alshari, Norli Fauzani, Mohd. Nor, Siti Azizah, A. Rahim, Masazurah & Mohammed Akib, Noor Adelyna, 2021, Ichthyofauna of Sungai Merbok Mangrove Forest Reserve, northwest Peninsular Malaysia, and its adjacent marine waters, Check List 17 (2), pp. 601-631 : 615

Thryssa hamiltonii (Gray, 1835)

Material examined. MALAYSIA • 2, 145– 166 mm TL; Kedah State, Kuala Kedah, Kuala Muda Whispering Market ; 05.578°N, 100.341°E; 6 Dec. 2018; Danial H. Zainal Abidin, Norli F.M.A.H. Alshari leg.; USMFC (82) 00041 . • 2, 97– 168 mm TL; Kedah State, Merbok, Pompang Sungai Merbok ; 05.664°N, 100.381°E; 6 Dec. 2018; Danial H. Zainal Abidin, Norli F.M.A.H. Alshari leg.; USMFC (82) 00043 .

Identification. A relatively large species of anchovy (maximum TL about 250 mm); body elongated, compressed and keeled from isthmus to anus; large mouth, its corner behind the eye; anal fin long with 3 unbranched and 35–37 branched fin rays; less gill rakers 12–14 (on first gill arch); maxilla moderately long, reaching to edge of gill cover; prepelvic scutes 16–19; post-pelvic scutes 8–9; body silvery with a conspicuous black blotch behind upper part of gill opening; no silver longitudinal stripe; pigment lines along dorsum ( Whitehead et al. 1988).

Thryssa hamiltonii can be easily distinguished from other species of Thryssa occurring in Merbok river estuary by its moderately long maxilla reaching to edge of gill cover. Thryssa hamiltonii is a predominantly coastal marine species occasionally caught in brackish ecosystems of this region; it is an economically important species. Otherwise, widely distributed in the Indo-West Pacific region ( Whitehead et al. 1988).