Natural spawning of greater amberjack (Seriola dumerili) kept in captivity in the Canary Islands

This paper describes results on sexual maturation and natural spawning of Seriola dumerili kept in captivity on Tenerife (Canary Islands). Wild fish captured at an average weight of 8 kg, spawned naturally and reaching an average weight of 25 kg, after 6 years in captivity in 500 m3 raceway tanks, under natural conditions of light and temperature and fed on low-value fish. Spawning took place between April and October, coinciding with the increase in temperature from 19 to 24 °C. A total of 14 million eggs were collected in 38 spawns, with an average of 61.75% fertilization and 16.49% hatching. The greatest number and highest fertilization and hatching rates of eggs were obtained in the month of July. The greater amberjack eggs with 1.121 ± 0.032 mm diameter, hatch within 34 to 45 h, producing larvae with an average length of 3.639 ± 0.012 mm, yolk sac volume of 0.097 ± 0.015 mm3, and oil globule diameter of 0.243 ± 0.001 mm.