Abstract
The occurrence patterns and feeding habits of the gobiid Tridentiger obscurus were investigated to clarify the habitat use in an urban seaside park constructed in the inner Tokyo Bay. Surveys were conducted using small seine nets and net cages on an artificial sandy beach, a tidal flat, and a seawall in Furuhama Park, Ota City, Tokyo. In total, 119 individuals（6.3-46.6 mm body length［BL］, mode of BL was 5.0-9.9 mm）were collected from the sandy beach; 89（6.2-42.6 mm, 10.0-14.9 mm）from the tidal flat; and 1,092（8.0-73.7 mm, 40.0-44.9 mm）from the seawall. On the sandy beach and tidal flat, the goby fed mainly on zooplankton by 11.0 mm BL, and thereafter on small benthic and epibenthic crustaceans in addition to the zooplankton as they grew. On the seawall, T. obscurus fed on small benthic and epibenthic crustaceans with no ontogenetic diet shift. These results revealed that T. obscurus would grow by taking different prey resources among multiple environments in the urban seaside park during their early life history, implying the need for comprehensive conservation of the various environments to protect the fish species.
https://ror.org/048nxq511 
