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

Abstract

<i>Siganus canaliculatus</i> and <i>Siganus fuscescens</i> are two of the important yet highly exploited siganid aquatic resources in the Philippines. Only few studies for both species, especially for <i>S. fuscescens,</i> 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 <i>S. canaliculatus</i> and <i>S. fuscescens</i> 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 <i>S. canaliculatus</i> and 7,397 — 563,722 for <i>S. fuscescens.</i> Fecundities of both species exhibited a weak to strong positive correlation to size, with higher correlation coefficient to standard length for <i>S. canaliculatus</i> and body weight for <i>S. fuscescens</i>. 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 <i>S. fuscescens.</i> 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.