Fishery, biology and population dynamics of Parapenaeopsis stylifera at Calicut

Abstract

Results of the study based on the data collected at Calicut on the fishery and
biology of Parapenaeopsis stylifera for a period of five years from 1987 to 1992
are given. The average annual catch and catch per unit effort were 306 tons and
16.6 kg respectively. The peak landings were observed during October -January.
Shrimp formed 7.4% of the total trawl landings and 49.8% of the shrimp
catch was contributed by P.stylifera. The size range of female was 46-130mm
and in male, 51-110mm. Males outnumbered females in the total catch and the
difference was statistically significant. Mature females occured throughout the
season and the size at first maturity was 74.6 + 1.013 mm. The growth parameters,
L00, k and t0 were 132.03 mm, 0.1912 and 0.088 respectively for feamles
and 111.8 mm, 0.2065 and 0.398 respectively for males. Total average mortaility
rate was 6.41 (females) and 9.83 (males). Yield per recruit and cohort analysis
revealed that further increase in effort would affect the stock adversely.