Abstract
Inter-specific relations concerning three species of embiotocid fishes, Ditrema viridis, Ditrema temmincki and Neoditrema ransonneti, in the Zostera belt of Odawa Bay are discussed in the present paper. From the seasonal changes in fish fauna appearing in the Zostera belt, the utilization of the Zostera belt as a habitat of fishes was examined. D. viridis and d. temmincki are members of year-round residents and N. ransonneti is one of the seasonal residents. The O+ age group of D. viridis and D. temmincki have high probability to come into contact with other year-round residents, especially Rudarius ercodes, which occur frequently in the cath and are predominant in the Zostera belt. These fishes tend to reduce competition for the same food resources by6 means of different seasonal population fluctuation or segregation of microhabitat. The O+ age of N. ransonneti mainly use the Zostera belt as a spawning or nursery ground.
