Triacanthus nieuhofii Bleeker, 1852

Mohanty, Swarup Ranjan, Mohapatra, Anil & Mishra, Subhrendu Sekhar, 2018, First Record of Triacanthus nieuhofii Bleeker, 1852 (Tetraodontiformes: Triacanthidae) from Northern East Coast of India, Records of the Zoological Survey of India 118 (3) : -

Triacanthus nieuhofii Bleeker, 1852 (Silver tripodfish)

1852. Triacanthus nieuhofii Bleeker, Natuurk. Tijdschr. Ned. Indië , 3(3): 459 (Siboga, Sumatra, Indonesia).

Material examined: MARC /ZSI/F4932, 1 ex., 122 mm TL, Shankarpur fishing harbour, West Bengal, coll. by. Swarup R. Mohanty, Date of Collection. 08.07.2017 ; MARC /ZSI/ F5010, 1 ex., 62 mm SL, Digha Mohana, West Bengal, coll. by. Swarup R. Mohanty, Date of Collection. 10.07.2017 .

Diagnostic characters: Body moderately elongate and strongly compressed. Mouth relatively small, terminal in position. Body supported by a thick skin with small scales that can be visible clearly under magnifying glass. Head compressed as body, about 3.2-3.3 in standard length. Large eye about 2.7-3.0 in head length. Ventral surface of pelvis almost as wide anteriorly as posteriorly,not distinctly tapered to a point and basal one-fourth to one half of first dorsal fin spine much darker than the distal part directly indicate that genus is Triacanthus . In front of pectoral fin base a small slit like gill opening present. First dorsal fin has 5 dorsal spines, where 1 st dorsal spine larger and stronger than the other and second dorsal fin have 24 rays. Pelvic fin is having only single large spine like 1 st dorsal spine. Pectoral fin contains 14 branched rays. Caudal fin is deeply forked. Lateral line inconspicuous. Caudal peduncle gradually becomes narrow towards the caudal fin. Outline of head between base of first dorsal-fin spine and eyes somewhat convex in front of spine and then straight or slightly concave over eye.

Colour: Colour of the body silvery on lower half and dusky in upper half. Caudal fin, 2 nd dorsal fin and pectoral fins are yellowish in colour ( Figure 1 ). Basal part of the dorsal spine is darker than that of distal part. Spiny dorsal-fin membrane very dark between first and third spines and pale between third and fifth spines.

Distribution: Matsuura (2015) noted distribution of Triacanthus nieuhofii from Arabian Sea, Bay of Bengal, Andaman Sea, Indonesia, South China Sea, and northern Australia. However, its record from Bay of Bengal along east coast of India is reported from Tamil Nadu only recently ( Jeyasanta and Patterson, 2017). Present study extends the distributional range of the species to the Northern part of the east coast of India, from West Bengal coast.

Figures

Figure 1. Triacanthus nieuhofii Bleeker, 1852 collected from Shankarpur fishing harbour.