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.
