New record of blunthead pufferfish, Sphoeroides pachygaster (Muller & Troschel, 1848) (Tetraodontiformes: Tetraodontidae) from Indian water along with DNA barcode and some biological aspects

565-572Blunthead pufferfish, Sphoeroides pachygaster (Muller and Troschel 1848) was recorded for the first time in Indian seas. A single female specimen of S. pachygaster was caught in bottom trawl operation at 263 – 310 m depth of the Eastern Arabian Sea. Morphometric and meristic description are presented in detail and compared with the pertinent records available elsewhere. The specimen collected was fully matured with Gonado Somatic Index (GSI) of 17.9 %. Gonad occupied two-third of the abdominal cavity, ova diameters ranged between 0.45 and 0.6 mm and the absolute fecundity estimated was 0.238 million eggs. Histological studies revealed that, this species performs single spawning strategy and it is the first information on the reproduction of S. pachygaster in India. Available reports on the occurrence of this species indicated distribution in the Mediterranean Sea, Atlantic, Indian and Pacific Oceans; however, the present record confirms its distribution in the Arabian Sea. Wide variations in the meristic counts among the specimens of this species collected from various locations are also discussed. Molecular analysis of the present specimen using Mitochondrial 16S rRNA gene sequences, confirmed the identity as S. pachygaster with intra specific divergence of 00.0 – 0.04 %. This report is the first well documented, confirmed record and re-description of S. pachygaster from the Indian Ocean, which documents a new addition to the family, Tetraodontidae of the Indian ichthyofauna