Fecundity and egg quality in two species of siganids (Siganus canaliculatus and Siganus fuscescens) from Lanuza Bay, Surigao del Sur, Philippines

Abstract

Siganus canaliculatus and Siganus fuscescens are two of the important yet highly exploited siganid aquatic resources in the Philippines. Only few studies for both species, especially for S. fuscescens, are available in the Philippine setting regarding its fecundity and egg quality. This study was conducted to provide information on the fecundity and egg quality of S. canaliculatus and S. fuscescens from Lanuza Bay, Surigao del Sur, Philippines. Fecundity was determined through gravimetric method in individual gonads. Fecundity range was determined to be 54,856 — 279,957 individual oocytes for S. canaliculatus and 7,397 — 563,722 for S. fuscescens. Fecundities of both species exhibited a weak to strong positive correlation to size, with higher correlation coefficient to standard length for S. canaliculatus and body weight for S. fuscescens. On the other hand, egg quality was determined through mean oocyte diameter, with diameters ranging from 176 — 426 ųm for S. canaliculatus and 171 — 500 pm for S. fuscescens. Mean oocyte diameters of both species exhibited weak positive correlation to size, but with a higher correlation coefficient on standard length. Regulating the capture of smaller-sized fishes and allowing them to grow would promote the increase in fecundity and egg quality of the species.