Length frequency data for Amblyqaster sirm inhabiting
western coastal waters of Sri Lanka, obtained over a
period of 3 years were analysed , using the Compleat V' i ELEFAN . programme. The maximum value for asymptotic
length was estimated- to be 25.8 cm. The values for
growth coefficient varied from 1.10 to 1.48 during the
study period. The instantaneous . total. mortality
coefficieirt- ranged from 4.63,in 1985/86 to 6.75 in t 1986/87. The values for instantaneous;natural mortality
coefficient ranged from 2.0 to 2.4.: The exploitation I ratio was observed to be over 0.5 indicating that the
stock is being overexploited. In the recruitment
pattern, two pulses separated by a 2-4 month interval
was observed. The size at recruitment during 1986/87
period was estimated to be lower than those estimated
for previous two years probably due to the Use of larger
percentage of gill nets with lojwer mean selection t
lengths.