The production structure of demersal fish assemblages in sandy shallow areas of Sagami Bay

Seasonal changes in the structure and composition of the demersal fish assemblages along the coastal area of Sagami Bay, Japan, were examined based on data collected from bottom trawl surveys in 2002-2004. Species diversity and abundance of fish assemblages increased in spring and summer compared to other seasons. Cluster analysis indicated that samples belonging to clusters, which infauna feeding Sasaushinoshita, Heteromycteris japonica, dominated and in which the number of species and abundance were low, occupied over 80% of all lots. Another commonly observed cluster was dominated by the nekton and epifauna feeding Sabihaze, Sagamia genetonema, and was observed primarily in May-June. The feeding habits of fish assemblages were compared with data for the same area from 30 years ago, and similarities in seasonal patterns of production structure were examined.