The plasticity of parental care behavior has been reported in several species of substrate-spawning fish, where females show parental care when males disappear, even in species where males typically provide parental care. In this study, we investigated the plasticity of sex roles in egg-caring behavior in the monogamous goby, Lubricogobius exiguus , where pair dissolution occurs relatively frequently. When both sexes cohabited...

In this study, we investigated mating system and mate choice of the triplefin blenny Enneapterygius etheostoma on a rocky reef at Banda, Tateyama Bay, Chiba, Japan, from 21 May to 19 July 2020. The larger males maintained a territory, while the smaller ones joined reproduction as a sneaker. The females visited the territorial males to spawn. The mating success of each territorial male was evaluated by the number of females the...

Cryptobenthic reef fish (CRF), which are benthic reef fish with body lengths of less than 50 mm, generally exhibit life history characteristics, such as a short lifespan, early maturation, high mortality, and microhabitat specialization. In this study, we investigated breeding season and population fluctuation patterns of a gobiid CRF fish Lubricogobius exiguus . At our field study site, the breeding season of L. exiguus exten...

Larvae and juveniles of three species in the family Gobiidae are described based on laboratory-reared material: Bathygobius fuscus to post-settlement, Bathygobius cyclopterus to 2 days old, and Bathygobius petrophilus to just after hatching. Newly hatched larvae of these species are distinguishable from each other by the melanophore arrangements on the dorsal region of the trunk, ventrally near the tip of the tail, and along t...

Some teleost fishes change their sex, and some of these fishes have specific gonads known as “ovotestes,” that is, gonads containing both ovarian and testicular tissues. In this study, we revealed the gonadal transformation process and cell dynamics during the female‐to‐male sex change in the harlequin sandsmelt, Parapercis pulchella (Pinguipetidae), in which females possess ovotestes. Histological observations revealed that a...

We investigated reproductive behavior and sexual patterns in two odacid fish—Rainbow cale Heteroscarus acroptilus and Herring cale Olisthops cyanomelas—inhabiting temperate reefs in Australia on the basis of underwater observations and histological studies. The males of both species established a territory and continuously courted females they encountered in the territory. The males and females went up in the water column to r...

Of the ca . 500 known hermaphroditic fish species, bidirectional sex change and simultaneous hermaphroditism are currently known in 69 and 57 species, respectively. Both bidirectional sex change and simultaneous hermaphroditism are predicted to evolve when mating opportunities are limited, such as in cases of low‐density distribution and low mobility of individuals. However, the plasticity of sex is adaptive in obtaining matin...

Fewer than 1% of vertebrate species are hermaphroditic, and essentially all of these are fishes. Four types of hermaphroditism are known in fishes: simultaneous (or synchronous) hermaphroditism (SH), protandry (male-to-female sex change; PA), protogyny (female-to-male sex change; PG), and bidirectional sex change (BS or reversed sex change in protogynous species). Here we present an annotated list of hermaphroditic fish specie...