Commercial exploitation of lobsters from the Indian seas began in the 1950s. Annual landings have been declining from a peak of 4075 t in 1985 to 1364 t in 2002. Major fisheries were located on the north-west, south-west, and south-east coasts. Among the 12 species recorded, only four species of spiny lobsters (three littoral and one deep sea) and one species of slipper lobster are commercially important. At Kayalpattinam and Tharuvaikulam, on the south-east coast, lobster landings sharply declined for the gill-net fishery. Of the two species that contributed to the fishery, Panulirus ornatus and Panulirus homarus, the latter has been more affected owing to high vulnerability to fishing activities. Catch composition analysis of the trammel-net fishery showed that 35% of the landings consisted of P. homarus in the size range of 23-50 mm carapace length. On the north-west coast, the spiny lobster Panulirus polyphagus and the slipper lobster Thenus orientalis are incidentally caught in trawl nets. However, the fishery for T. orientalis in the waters off Mumbai lasted only up to 1994. Largescale exploitation of spawning females, which formed 60% of the total catch, might have been detrimental to the recruitment process resulting in rapid decline and total collapse of the fishery. Abundance of P. polyphagus reached its maximum during September, constituting 23% of the average annual landing during [1988][1989][1990][1991][1992][1993][1994][1995][1996][1997][1998][1999][2000][2001][2002]. A high exploitation ratio (>0.7) indicated over-fishing of the stock. Repeated spawning and high annual egg production are probably responsible for sustaining the stock, despite over-exploitation. Major problems confronting the resource management of the multi-gear and multispecies lobster fisheries in India are discussed. An operational project, involving fisher community, has been taken up for creating awareness of the need for sustainable exploitation of the resource. Regulatory measures, such as closure of the fishery during the peak of the breeding season, ban on trammel-net, mandatory release of egg-bearing lobsters, and establishment of lobster sanctuaries are suggested to the State Governments for implementation.

The morphometric relationships, carapace length vs total length (CL vs TL), carapace length vs weight (CL vs W), total length vs weight (TL vs W), carapace length vs carapace width (CL vs CW), carapace length vs length of third walking leg (CL vs III WL) and carapace length vs width of second abdomen (CL vs II ASW) were estimated for the Scalloped spiny lobster Panulirus homarus homarus fished from east and west coast of Tamilnadu. A total of 462 males and 350 females were measured for the study. Carapace length of lobsters ranged from 20.4 mm to 101.0 mm CL. The power function y=ax b was applied in all the relationships. The first derivative dY/dCL-abCL b-1 where Y is TL was used to study the growth tendency of TL in relation to CL. A negative allometry, b<1 was found for males which was also reflected in their decreasing growth rate of TL in relation to CL. The CL vs W relationship showed a general negative allometry, b<3 in both sexes. Size at the onset of sexual maturity in male was determined based on allometric growth of third pereopod. Slopes of regression of log transformed data showed positive allometric growth of third pereopod for males (b=1.17) compared to negative allometry in females (b=0.97). Females had (b=1.04) positive allometry in second abdomen width compared to negative allometry in males (b=0.934). However, their size at maturity could not be precisely predicted as the b value of the two regression lines of immature (1.09) and mature females (1.01) did not indicate any significant deviation from 1. The size at maturity of males (63.0 mm) was determined where the two regression lines of mature and immature specimens crossed. The results obtained in the present study support the predictions of resource allocation theory in crustaceans and demonstrate marked shifts in resource allocation through ontogeny in both sexes.

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