Johnius coitor (Hamilton, 1822)

Hanafi, Norhafiz, Chen, Meng-Hsien, Chang, Chih-Wei, Chao, Ning Labbish & Seah, Ying Giat, 2024, Taxonomic review of the genus Johnius (Perciformes: Sciaenidae) from East Malaysian waters, with comments on newly recorded Johnius species, Zootaxa 5550 (1), pp. 85-117 : 100

Johnius coitor (Hamilton, 1822)

(Common name: Coitor croaker)

( Fig. 9 , Table 6 )

Bola coitor Hamilton, 1822: 75 (type locality: Ganges River as far as Kanpur and Jumna River at Angra and at Visakhapatum, India. No types known.

Johnius coitor (Hamilton, 1822) : Sasaki, 2000: 621; Sasaki, 2001: 3144; Mohamad Faisal, 2009: 98.

Material examined. Non-types: NMMB-P37096 (3, 109.25 to 136.62 mm SL), Sibu , Sarawak, Malaysia, 12 March 2017 ; NMMB-P33374 (121.72 mm SL), Pasar Tamu Sri Aman , Sarawak, Malaysia, 19 November 2019 .

Diagnosis. A species of Johnius with the following combination of characters: snout steep, obtusely pointed; mouth small, inferior; small eye, 12 to 16% of HL; gill rakers moderately long, slender, about 1/2 to 2/3 length of gill filaments at angle of arch, 9 to 11 on lower limb of first gill arch; second anal spine length long, stiff, about 35 to 40% of HL; and scales moderately small, 7 to 9 scale rows above lateral line.

Distribution. Eastern Indian Ocean, western Pacific; Bay of Bengal ( India and Bangladesh) and to eastern Australia.

Remarks. Johnius coitor is rare, endemic species and only distributed in the East Malaysia waters, concisely at the Sibu site collection. In previous, Sasaki (2001) has mentioned the species distribution recorded in the Borneo and Malay Peninsula, but no types are known. Thus, this study gives the first clear baseline information based on voucher specimen, genetic information and morphological measurement in detailed. In addition, it also available collected at one site at the Sarawak states, which based on our observation collected at freshwater river which caught in the ~ 120 km upstream at Rajang River. This is might due to this species much prefer riverine ecological factor such as sandy and muddy habitat with the highly freshwater intrusion for their life preference. However, this study needs to provide in detail with the environmental and biological evidence as supporting data.

Figures

FIGURE 9. Photographs of the comparative materials. Johnius coitor: NMMB-P 37096, non-type, 136 mm SL, Sibu fish landing port, Sarawak, Malaysia, 12 March 2017.