1977 年 24 巻 3 号 p. 182-192
Fish fauna in the Zostera zone in Shimoda Bay and Nabeta Cove was studied by monthly sampling with a small beam trawl during March 1973 to March 1974.Sampling was made also in the sandy bottom of Nabeta Cove.A total of 135 species (13 orders, 58 families) were collected, i.e., 106 species (11 orders, 50 families) in the Zostera zone of Shimoda Bay, 84 species (10 orders, 39 families) in the Zostera zone of Nabeta Cove, and 60 species (10 orders, 34 families) in the sandy bottom of Nabeta Cove.Analysis of species composition revealed a slight difference between the Zostera zone of Shimoda Bay and that of Nabeta Cove, and a considerable difference between the Zostera zone and the sandy bottom in Nabeta Cove.The significant effect of Kuroshio Current on the fish fauna and the abundant appearance of rocky shore fishes were also noticed in these areas
The percentage of both the number of species and that of individuals among yearround resident, seasonal resident, seasonal transient, and casual species was nearly the same between the Zostera zone of Shimoda Bay and that of Nabeta Cove, but it was fairly different between the Zostera zone and the sandy bottom in Nabeta Cove.
The number of species and the total number of individuals collected in the Zostera zone showed a different seasonal change between Shimoda Bay and Nabeta Cove.This seems due to the difference of embayment degree between the two bays.The number of individuals obtained suggested that the Zostera zone has a higher population density than the sandy bottom.