A DIVERSITY OF TETRAODONTIFORMES (FAMILY: TETRAODONTIDAE, DIODONTIDAE) IN FISH BYCATCH OF TRAWL NET FISHERY OF CHENNAI COAST

Order Tetraodontiformes consist of ten families in which tetraodontidae (puffer fish)  consists of 28 genera 192 valid species and diodontidae (porcupine fish) consists of 7 genera 18 valid species. Among 192 species in tetraodontidae only two species in Lagocephalus has been eaten as food in several Malaysian region. As a mobile non-selective fishing gear, the bottom trawl net collects every organism in its path and the incidental capture of non-target species bycatch has become a major concern allied to trawling. In this study the contribution of tetraodontiformes in the bycatch of trawl net from Chennai coast was estimated. Sampling were done at Royapuram fishing harbour bimonthly from the period of June 2018 to January 2019.

In this present study 9 Species of puffer fish belonging to 4 genera and 3 species of porcupine fish from 2 genera has been collected and identified. Totally 328 specimens were collected between June 2018 and January 2019. The species in tetraodontidae are Canthigaster petersii  (Bianconi, 1854)- P1, Arothron hispidus (Linnaeus 1758)- P2, Torquigener brevipinnis  (Regan, 1903)- P3, Lagocephalus suezensis  (Clark & Gohar, 1953)- P4, Arothron stellatus  (Anonymous, 1798)- P5, Arothron immaculates ((Bloch and Schneider, 1801)- P6, Arothron reticularis  (Bloch & Schneider, 1801)- P7, Takifugu oblongus (Bloch, 1786)- P8, Chelonodon patoca  (Hamilton, 1822)- P9 and diodontidae species are Cyclichthys spilostylus  (Leis & Randall, 1982)- P10, Cyclichthys orbicularis  (Bloch, 1785)- P11, Diodon liturosus  Shaw, 1804- P12 (Fig.1). From the 12 species a single specimen of A. hispidus was collected at the month of July and L. suezensis shows the dominance in puffer fish group from the Chennai region with size ranging from 24.3 cm to 1.2 cm in length. Thus the minimum size of L. suezensis shows that trawl net operated in the Chennai region has very small mesh size in cod end. The number of fish (species richness) was maximum in the month of September and November while minimum in the month of July with occurrence of only L. suezensis and followed by January with three species of puffer fish.