SEASONAL VARIATIONS IN THE ABUNDANCE OF PENAEID PRAWN SEED IN RELATION TO ENVIRONMENTAL PARAMETERS IN THE SEED GROUNDS OF COCHIN BACKWATERS

Abstract

Early juveniles of Penaeus indicus, Metapenaues dobsoni and M. monoceros were collected from two centresin the shallow water areas in the Cochin backwaters where commercial seed collectors used to make their,prawn seed collections. A Quantitative Seed Sampler was used during premonsoon, monsoon andpostmonsoon period of 1988. The study enabled to understand the relative abundance and seasonal variationsof commercially important prawn seed of the above species. Of the total seed collected P. indicusformed 26%, M. dobsoni 59% and M. monoceros 15%. The seed exhibited considerable fluctuation inabundance through various seasons. Seventy per cent of the total seed of P. Indicus were collected duringpremonsoon period. But in the case of M. dobsoni, the highest percei>tage of 62 was obtained duringmonsoon period. The seed of M. monoceros had the maximum of 55% during monsoon period. Seedof P. indicus occurred at a maximum rate of 28/m' during April-May, that of M. dobsoni 20/m' and M.monoceros 7/m'during June to August. The relationship of the seed to the environment is also discussed