On the fishery of Penaeus simisulcatus and its Distribution in relation to depth along Tinnevelly coast, southern India

Studies on the total landings in relation to the effort expended in the fishery indicate that off Tinnevelly coast the resource of Penaeus semisulcatus, the mainsta\ of the local prawn fishery, is underexploited. Breeding and recruitment into the fishery though take place more or less round the year, the breeding is more intense during July-October, December and February and the recruitment during November and February. P. semisulcatus is fished from three grounds along this coast, namely off Pattanamarudur-Tuticorin, Punnaikkayal and Manappad, ranging lespectively in depth from 0 to 2 m, 8 to 20 m and 15 to 30 m. From the size distribution, the juveniles appear to prefer shallow waters whereas the adults to prefer deeper areas. The mean sizes of males and females in the shallow-water fishery are found to be 89.1 mm and 90.5 mm, respectively. But the dominant modes of males and females in the fishery at Punnaikkayal varied respectively between 110 mm and 150 mm and 120 mm and 180 mm and at Manappad between 140 mm and 160 mm and 160 mm and 210 mm. That the prawns in maturing stages are found thus always in the deeper fishing grounds, and never in the shallow-water fisheries, indicate that the species move to the deeper waters for breeding