A first experience of Patagonian sprat Sprattus fuegensis spawning in captivity: Adult acclimation, egg and larval measurements

Abstract

Relevant traits of eggs and larvae of Patagonian sprat (Sprattus fuegensis), obtained from adult reproduction in captivity conditions, were studied. Temperature for adult acclimation and for incubation of eggs and larvae was not controlled; however it ranged with a mean of 13 ± 2 °C. Adult sprat maintained in cylindrical ponds of 2000-L spawned spontaneously at the first night after catch, probably due to catch stress. The eggs were spherical with a diameter ranging between 0.89 and 1.06 mm (mean 1.00 ± 0.05 mm, n= 54). The larvae hatched between the fourth and fifth day after spawning and their size varied between 2.83 and 4.11 mm long (mean 3.56 ± 0.34 mm, n= 39). The yolk sac reached a volume of between 0.11 and 0.22 mm³ (mean 0.18 ± 0.033 mm³, n= 32) and was exhausted by the third day post hatching (dph). Larval growth only occurred during the endogenous feeding period (efp) and survival did not exceed 6 dph, probably due to inappropriate conditions for feeding and growth.