2022 年 31 巻 p. 43-48
Alpheus dolichodactylus Ortmann, 1890 burrows muddy tidal flats, recorded from inshore coastal areas in central to southwestern Japan. Because of abrupt loss of habitats caused by human activities, the conservation status of the species is ranked as NT in the Japanese Red List. For example, the syntype of the species consists of 15 specimens from the Tokyo Bay, but there have been no records of the species since the original description from the Tokyo Bay and adjacent areas. In this study, we report on the occurrence of three specimens of A. dolichodactylus from small muddy tidal flat at the river mouth of the Heguri River in the Tatetama Bay, southern part of the Boso Peninsula, located at the outer part of the Tokyo Bay, represent the rediscovery of the species from the Tokyo Bay and adjacent areas by 129 years since the collection of the syntype. We also provide a description of the habitats where our specimens were collected. Maintenance of muddy substrate at estuarine areas will contribute to recovery of local population of the species.