AGE AND GROWTH OF SPINY LOBSTER PANULIRUS POLYPHAGUS (HERBST) OF BOMBAY WATERS

Age and growth of spiny lobster Panulirus polyphagus (Herbst) has been determined based on length-freque ncy method. Growth during the first 3 years is identical in both sexes; 85 mm in the I year, 145 mm in II year and 205 mm in III year. Thereafter the males grow faster than females; measuring 265 mm by the end of IV year, 315 mm by the end of V year and 355 mm by the end of VI yisar. Females measure 255 mm, 290 mm, 320 mm, 345 mm and 365 mm respectively by the end of successive years IV to VIII. The frequency of moult­ ing is more and the intermoult period shorter in juveniles; with advance in age, the intermoult period lengthens and the number of moulting reduces. The length incrwnent per moult is nearly constant over the juvenile and adult phases. Six to seven broods appear to be recruited annually to the fishery. The peak period of recruitment, of very small-sized juveniles, is November-Dece mber. The growth does not conform with the general growth pattern of fishes, but follows the pat­ tern common to crustaceans. Values of growth parameters by von Bertalanffy's growth equation are: L„ == 537 mm, K = 0.2000 and t,, = 0.6037 for males and L„ == 443 mm, K = 0.2231 and t„ - 0.1985 for females.