Spawning of the Silver Sea Bream, Sparus sarba, in Captivity

Spawning of the silver sea bream, Sparus sarba, in captivity was studied at ambient temperature and photoperiod during one breeding season. Broodstock were divided to two groups (A and B) of 6 and 7 individuals, respectively. They were caught in the sea and acclimatized to laboratory conditions for about seven months prior to spawning. Spawning lasted 65 days from April 8 to June 11 in group A, and 43 days from April 10 to May 22 in group B, within the temperature range between 13.5 and 21.3°C. Numbers of buoyant and sunken eggs, fertilization rate of buoyant eggs and percentage of abnormally developed eggs were estimated daily. There was no correlation between water temperature at spawning and viable hatch, and between spawning period and viable hatch, at the same incubation temperature in all cases. The total number of eggs released during the spawning period was estimated at 18.1 million in group A and 10.8 million in group B. Mean egg diameter tended to decrease during the spawning season along with increasing water temperature. Mean egg diameter ranged from 0.952 to 1.001 mm and from 0.962 to 1.015 mm in groups A and B, respectively.