Reproductive Ecology of the Gobiid Fish Eviota abax at Nobeoka, Japan, with Notes on Geographic Variation

Abstract

The reproductive behavior and spawning cycle of the gobiid fish Eviota abax were observed in a rocky tide pool at Nobeoka, Miyazaki, Japan. Both sexes maintained nonterritorial, overlapping home ranges. The spawnings took place at the low tide of neap to spring tidal periods. Matings varied in each spawning cycle, but males did not simultaneously mate with multiple females. Males were larger than females in the spawning pairs. After spawning, only the male guarded the egg mass. Although separated by 900 km, the basic patterns of reproductive ecology were similar at Nobeoka to those reported earlier for this specie,s from Kominato, Chiba, Japan; nest entrances were smaller at Nobeoka than at Kominato, and larger males kept their home ranges longer at Nobeoka.