ON THE FISHERY OF PENAEUS SIMISULCATUS AND ITS DISTRIBUTION IN RELATION TO DEPTH ALONG TINNEVELLY COAST, SOUTHERN INDIA

Abstract

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.