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.

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We examined the food habits and ontogenetic trophic shifts of the Japanese common chiton, Acanthopleura japonica. Specimens were collected from the intertidal zone of Jogashima, Miura Peninsula, Kanagawa Prefecture, Japan. Based on gut content analysis of 18 specimens, red algae were found to be the most abundant food item（37.0%）, followed by green and brown algae（5.6% each）, bivalves（5.0%）, mites（2.6%）, and abundant abiogenic minerals（stone or rock debris）as non-food items. This gut content composition was inconsistent with that of another population from Amakusa, Kyushu, Japan; hence, the food habits of A. japonica would vary depending on habitat environments, suggesting they are non-selective omnivorous feeders. Individual variations of the gut contents did not correlate with the body length, indicating A. japonica has no ontogenetic trophic shift. Overall, we concluded that A. japonica is omnivorous without an ontogenetic trophic shift.

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There are two types of Kuroshio large meanders: the large meander west（LMW）, whose trough（the southernmost point）is located west of the Izu-Ogasawara Ridge, and the large meander east（LME）, whose trough is located on the ridge. We compared the characteristics of LMW and LME using accumulated Kuroshio path data. Comparing the five LMWs and three LMEs, the central latitude of the meanders of the LME was higher than that of the LMW, and the amplitude of the meanders of the LME was smaller than that of the LMW. Fitting the solution of the path equation to the Kuroshio path, the initial path direction of the LME was smaller than that of the LMW, but the characteristic velocities and meander wavelengths of the LME were not significantly different from those of the LMW. The difference in longitude between the LME and LMW troughs is due to the difference in separation longitude, not the difference in meander wavelength associated with the difference in characteristic velocity.

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