Johnius heterolepis Bleeker, 1873

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 : 104

Johnius heterolepis Bleeker, 1873

(Common name: Heterolepis croaker)

( Fig. 10 , Table 7 )

Johnius heterolepis Bleeker, 1873: 456 (type locality: Sarawak and Sabah, Borneo.) Syntype: RMNH 6042 (2)

Johnius heterolepis Bleeker, 1873 : Sasaki, 1992: 193; Sasaki, 2000: 621; Sasaki, 2001: 3145; Mohamad Faisal, 2009: 98; Atan et al. 2010: 195.

Material examined. Non-types: NMMB-P37090 (4, 77.95 to 117.86 mm SL), Sarikei , Sarawak, Malaysia, 14 March 2017 ; NMMB-P23664 (119.81 mm SL) , NMMB-P21541 (2, 104.94 to 128.85 mm SL) , NMMB-P21711 (125.93 mm SL) , NMMB-P23665 (3, 103.17 to 138.95 mm SL) , NMMB-P23656 (8, 102.43 to 123.8 mm SL), Pantai Remis , Perak, Malaysia, 4–6 June 2014 ; NMMB-P34749 (10, 90.32 to 119.07 mm SL) , NMMB-P34751 (15, 105 to 113.9 mm SL), Bako , Sarawak, Malaysia, 17 March 2017 ; NMMB-P34750 (10, 81.24 to 101.56 mm SL), Goebilt , Sarawak, Malaysia, 17 March 2017 ; NMMB-P35556 (6, 90.3 to 112.64 mm SL), Betangor , Sarawak, Malaysia, 14 March 2017 ; NMMB-P23657 (2, 103.81 to 127.65 mm SL), Tanjung Gemok , Pahang, Malaysia, 10 June 2014 ; NMMB-P21527 (2, 103.14 to 127.33 mm SL), Tanjung Piandang , Perak, Malaysia, 3 June 2014 ; NMMB-P34748 (10, 91.9 to 112.84 mm SL), Bintulu , Sarawak, Malaysia, 9 March 2017 ; NMMB-P23658 (7, 91.34 to 112.68 mm SL), Kuala Kedah, Kedah, Malaysia, 3 June 2014 ; NMMB-P21537 (120.15 mm SL), Bagan Panchor , Perak, Malaysia, 5 June 2014 .

Diagnosis. A species of Johnius with the following combination of characters: snout steep, obtusely pointed; mouth small, inferior; moderate eye, 20 to 29% of HL; gill rakers moderately slender, about 1/2 length of gill filaments at angle of arch, 9 to 11 on lower limb of first gill arch; second anal spine length short, slender, about 25 to 34% of HL; and scales larges, 5 to 6 scale rows above lateral line ( Hanafi et al., 2022).

Distribution. Western Pacific; Gulf of Thailand, Malaysia and Indonesia.

Remarks. Johnius heterolepis can be distinguished from most similar sympatric congener species, J. sasakii , by the snout pointed (snout blunt in sasakii ) and the gill raker slender and count more higher (9 to 11 in heterolepis vs short, stiff, 8 to 10 in sasakii ). Johnius heterolepis also is a common species, dominant and abundant especially concentrated in Sarawak states. It was collected at several sites of the Goebilt, Sarikei, and Bintulu.

Figures

FIGURE 10. Photographs of the comparative materials. Johnius heterolepis NMMB-P 37090, 78 mm SL, Sarikei, Sarawak, Malaysia, 14 March 2017.