Quality of pejerrey (Odontesthes bonariensis) eggs and larvae in captivity throughout spawning season

Abstract

The aim of this work was to assess the quality of pejerrey eggs and larvae throughout its spawning season. Fertilized eggs were taken on September, October, November, and December from a captive broodstock. The egg diameter, yolk diameter, and oil droplets area decreased along the spawning season, with higher values in September. Fertilization and hatching rates decreased throughout this period, with highest values in September (88.0%; 55.2%) and the lowest values on December (43.0%; 25.2%). The larvae hatched from eggs obtained on October were the heaviest and longest (1.57 mg; 8.24 mm). The survival rate at 30 days post hatching (dph) was similar in larvae from September and October eggs (66.1%; 62.9%) with a sharp decrease in larvae from November and December eggs (22.4%; 23.3%). Furthermore, the highest body weight (15.1 mg) and total length (15.25 mm) at 30 dph were obtained in larvae from October eggs. The results obtained showed that overall eggs quality was better at the beginning of the spawning period, influencing the larvae performance.