FISHERY AND BIOLOGY OF PENAEID PRAWNS AT HARNAII, MAHARASHTRA

Abstract

Penaeid prawn fishery at Harnaii in Ratnagiri District of Maharashtra
was investigated during fishing seasons of 2002-03 and 2003-04 from mechanized
(MLD) and hand operated trawlers (HT). During the two years, MLD
contributed 86% and HT 14% to the average annual penaeid prawn catch of
2,242 t. The '?atch showed two peaks, a major during October-December and
a minor during April-May in both the gears but abundance of the individual
species differed.
P. stylifera, M. affinis, S. crassicornis, M. brevicornis, P. merguiensis and
M. dobsoni mainly constituted the fishery and their species composition,
seasonal abundance, annual size distribution and monthly mean size were
investigated. Biological studies on food, size at maturity, spawning period,
sex-ratio and juvenile abundance were carried out to ·explain temporal
abundance of the species in the fishery. Among the species P. stylifera, M.
affinis and S. crassicornis exhibited distinct seasonality with two spawning
peaks, one in pre-monsoon and the other in post monsoon period to produce
two discrete broods while P. merguiensis despite two spawning peaks
exhibited a single dominant brood. M. brevicornis showed monsoon and postmonsoon
spawning while M. dobsoni showed only post-monsoon spawning.
Migrations between nearshore and offshore waters resulted in mixing of the
broods and they remained inseparable in the catch.
Keywords: penaeid prawn fishery, biology, spawning seasons, recruit
abundance.