Temperature influence on the initial development of Sardinella brasiliensis larvae

Abstract

Temperature is a limiting factor to the development of fish eggs and larvae. The aim of this study was to define the optimal temperature for egg incubation, larval survival and development of Sardinella brasiliensis larvae. Eggs were obtained by natural spawn and collected after the blastopore enclosure. Fertilized eggs were incubated at 17, 20, 23, 26 29 or 32°C in beakers. Larval development (200 eggs L−1), hatching and survival rates (100 eggs L−1) and RNA/DNA ratio were evaluated. The best temperature for hatching was 28°C, the best survival rate was obtained at 24.7°C, and 100% of the larvae died at 18.4°C. The time of mouth opening (24 to 51 h) and moment of eye pigmentation (24 to 45 h) varied with temperature. No significant difference was found in the RNA/DNA ratio between the treatments, indicating the nutritional status of the larvae. The interval between 24.7 and 28°C resulted in a better hatching rate and larval survival. Water temperature affected the hatching rate, survival and morphometric development of S. brasiliensis larvae.