The development rate of eggs and larvae of the hake, Merluccius merluccius (L.) and their distribution to the west of the British Isles

Abstract

An artificial fertilization of eggs of the hake (Merluccius merluccius (L.)) was carried out and the development of the eggs and larvae is described with particular emphasis on features of practical value for identification of specimens from the plankton. Eggs were incubated over a range of temperatures and the relationships between incubation temperature and the time to the end of three separate stages of development and to hatching are presented. The time from fertilization to hatching decreased from 220·5 h at 8·1°C to 69·2 h at 18·4°C. No eggs survived to hatch at incubation temperatures above 18·4°C while below 8·1°C embryonic development was still proceeding normally when the experiment was terminated. Eggs and larvae were usually taken in the plankton at the continental margin of the Celtic Plateau and werefound mostly in the upper 150 m of the water column.