Johnius sp.

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 : 624

Johnius sp.

Material examined. MALAYSIA • 4, 105– 109 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 (48) 00002 . • 6, 104– 123 mm; Kedah State, Kuala Kedah, Kuala Muda Whispering Market ; 05.578°N, 100.341°E; 19 Mar. 2019; Danial H. Zainal Abidin, Norli F.M.A.H. Alshari leg.; USMFC (48) 00008 .

Identification. Body elongated, laterally compressed; mouth inferior; snout blunted; no barbel on chin; anterior portion of dorsal fin with VIII or IX spines; posterior portion of dorsal fin with I spine and 25 or 26 branched rays; anal fin with seven branched rays; scale rows above lateral line to origin of dorsal fin 6 or 7; scale rows below lateral line to origin of anal fin 9; scales on upper part of body and head ctenoid; first gill arch with about 12 gill rakers on lower limb; caudal fin pointed; body light brown with pectoral and anal fins cream.

This unidentified species can be distinguished from J. belangerii by its pectoral and anal fins cream (vs. blackish in J. belangerii ) and caudal fin pointed (vs. S-shaped in J. belangerii ). Using the identification key by Carpenter and Niem (2001a), we are unable to assign this species to any described species due to the difficulty to identify some species of the genus Johnius . Johnius sp. could be either Johnius carouna (Cuvier, 1830) or Johnius coitor (Hamilton, 1822) , two species recorded around this region, or a different species, morphologically similar to them.