Reproductive biology and morphology of eggs and larvae of Stiphodon percnopterygionus (Gobiidae: Sicydiinae) collected from Okinawa Island

Abstract

Reproductive biology and morphology of eggs and early larvae of the sicydiine goby Stiphodon percnopterygionus were investigated on Okinawa Island, southern Japan. Spawning season was estimated as being from May to December. Standard length at maturity was approximately 20 mm in both sexes, and batch fecundity was approximately 1000–10 000 per female. The egg masses, guarded by the male, were laid on the undersurface of stones in freshwater. The pyriform eggs had long- and short-axis diameters of 0.54–0.58 mm and 0.49–0.50 mm, respectively. Newly hatched larvae (1.20–1.32 mm notochord length: NL) were poorly developed, with large yolk sacs and unopened mouths. Three days after hatching (1.87–2.05 mm NL), eyes were fully pigmented and mouths were opened.