Abstract
Frequency observation on 5 essential movements of the reproductive behavior of an eleotrid goby, Odontobutis obscurus, was made in aquaria.The nesting male made a few characteristic movements (fanning, upside-down movement, and beating) before the female's entrance into his nest.After the entrance of a female in the nest, the male's beating disappeared;weaving, the upside-down movement, and quivering were observed frequently in the two sexes at prespawning and in spawning.Weaving and fanning by the egg-guarding male were frequent at the time immediately after the spawning as well as hatching of larvae.Dead eggs infected byaquatic fungi were not observed in the egg mass guarded by the male, in contrast with the unguarded egg mass.In addition, more dead eggs were dropped during 48 hr-experiment from the guarded egg mass than from that unguarded.It is suggested that the dead eggs were shaken out of the nest by such movements of the egg-guarding male as weaving and fanning, before the fungal infection spreads over the whole egg mass.
