Capture based aquaculture of mud spiny lobster, Panulirus polyphagus (Herbst, 1793) in open sea floating net cages off Veraval, north-west coast of India

Abstract

Capture based aquaculture (CBA) of the mud spiny lobster, Panulirus polyphagus was conducted in two cylindrical floating net cages of 6 m diameter and 4.5 m depth, made of HDPE sapphire netting of 18 mm mesh size. The cages were installed at a depth of 8 m, about 900 m away from the shore off Prabhas Patan, Veraval, India. Live lobsters were collected from lobster fishing centres of Veraval and Mahua regions of Gujarat and segregated into two groups: animals weighing 80-120 g (Group-1) and animals weighing < 80 g (Group-2). One thousand numbers of sub-adults of Group-1 with initial body weight of 99.75 ± 8.4 g, were stocked in Cage-1 and 1500 juveniles of Group-2 with initial body weight of 46.44 ± 8.8 g were stocked in Cage-2. The lobsters were fed twice daily with trash fish @ 8 % of the body weight by tray feeding. After the culture period of 90 days, no significant difference (p > 0.05) was observed in the survival rate (overall survival = 93.7 %) whereas, juvenile lobsters in Cage-2 showed weight increase of 1.49 g d-1 and specific growth rates of 1.51 % d-1 which was significantly higher (p < 0.05) than the weight increase of 1.17 g d-1 and specific growth rates of 0.80 % d-1 recorded from Cage-1. Results suggest that P. polyphagus has potential for capture based aquaculture in sea cage culture systems along Gujarat coast.