Growth of larval pelagic fish in the South-East Atlantic from daily otolith rings in 1982/83 and 1983/84

Abstract

Larval growth was examined for pilchard, anchovy and round herring collected off South West Africa and from South Africa's Western Cape during the spawning seasons of 1982/83 and 1983/84. Rings on otoliths were validated as daily by examination of reared larvae. Larvae from 1982/83 were aged by ring counts on otoliths. It is demonstrated that the growth of larvae from 0,5 to 2,5 cm can be approximated as linear. A method is described for the calculation of daily growth rates from otolith increments. Daily growth rates over the most recent five days of life showed significant differences between months and stations and the differences may be correlated with temperature. Pilchard growth rates were more variable than those of anchovy. Back-calculated daily growth rates show that growth rate may change rapidly.