Ichthyoplankton from the Vizhinjam coast

Abstract

This paper gives the results of ichthyoplankton studies in the nearshore waters of Vizhinjam conducted from April, 1981 to March, 1985. Studies on the composition, quantitative abundance and fluctuations of the fish eggs and larvae of Vizhinjam in relation to hydrography were the objectives of this investigation. The year 1982-'83 recorded the greatest number of eggs and larvae of commercially important fishes. The relative abundance and quantitative variations of eggs and larvae of 11 families were studied. Eggs and larvae of Carangidae formed the major component of ichthyoplankton community. Eggs and larvae of other groups like anchovies, sardines, mackerel, lizard fishes and ambassids were well represented. It was found that eggs and larval concentration of commercially important pelagic fishes was closely related to their spawning seasons observed by earlier workers. Thus mackerel and sardines recorded two spawning seasons. Anchovies and carangids showed extended breeding seasons; eel too recorded a definite breeding period. Larval forms of ambassids were recorded in different months within this period of study and hence it appears that they breed almost year round. The availability of eggs and larvae of marine fishes around Vizhinjam has shown that it is an ideal breeding and nursery ground.