Reproductive biology of the whipfin silverbiddy gerres filamentosus cuvier, 1829 from the parangipettai waters (se coast of india)

Abstract

The developmental stages of the whipfin silverbiddy Gerres filamentosus go nads were recorded macroscopically and microscopically. Histological sections of gonads characterized seven stages of ovary and four stages of testes in G. filamentosus. Ova diameter in G. filamentosus ranged between 12.0 and 501.8 µm. The composite histograms based on the diameters of all oocytes at successive stages of maturation showed three modes in ovaries at stages III, IV, V & VI. Most of the fully ripe ovaries characterized three batches of matured eggs showing that G. filamentosus spawns three successive batches within the same prolonged spawning season. Indication of previous spawning was ascertained by the ruptured ovarian follicles and resorbing ovulated ova and atretic ovarian follicles observed during October-February. The silverbiddy males reach maturity at 143.8 mm, while the females at 136.6 mm total length. The annual fecundity varied from 121,700 to 2,062,278 while batch fecundity varied from 171,596 to 740,844 oocytes.