A total of 23, 267 larval and juvenile fishes representing about 102 species was collected by monthly light-trap sampling on the rocky shore at Komi-nato, Boso Peninsula, central Japan, from February 1986 to January 1988. The highest number of species occurred in summer, in both 1986 and 1987, whereas the cooler seasons, characterised by lower water temperatures, the numbers of specimens caught and species represented fell. Species composition each month was dominated by a few species. Analyses of similarity indices between months indicated that the community composition of larval and juvenile fishes changed drastically in October and November. Based on developmental stages at the time of sampling and reproductive modes, the manner of utilization of the rocky area around the sampling site by larval and juvenile fishes was summarized as follows. Species were sorted into two groups based on the presence or absence of prelarvae, the former group comprising mainly species with demersal eggs (e.g., Atherion elymus, Eviota abax) or ovoviviparous reproduction (e.g., Sebastes hubbsi), and the latter species with pelagic eggs. The results indicated that the rocky shoreline was utilized as a spawning or parturient ground by the former group and for settlement by the latter.

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The distributions of five species of freshwater goby, Rhinogobius spp.(Rhinogobius sp.CB, OR, LD, DA and CO, according to recent morphological definitions) and R. fiumineus were surveyed at 264 points in 114 streams and rivers on the coastal area of Ise Bay, Japan. Rhinogobius sp.CB (cross-band type) was found in most of the rivers investigated, with R. sp.OR (orange type) occurring in many rivers on the Atsumi and Chita Peninsulas. The possibility of separate origins for the latter populations was discussed. Rhinogobius sp.LD (large-dark type) was found longer rivers flowing across the plains. Rhinogobius sp.DA (dark type) inhabited only a few rivers on the Shima Peninsula. In those rivers habitat segregation was observed between the former and R. flumineus. Rhinogobius sp.CO (cobalt type) occurred in rivers on the Kii Peninsula.

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