The callichirid ghost shrimp Grynaminna tamakii Poore, 2000 was heretofore known only by the original description. The type series consisted of specimens from the south of Shimabara Peninsula, Nagasaki Prefecture, although it was noted that the species occurred also at Hayasaki Inlet on Oyano Island, Kami-Amakusa, Kumamoto Prefecture. In this study, we report on this rarely collected species on the basis of 28 specimens from the western coasts of Kyushu, Kagoshima Bay and Tanega-shima Island, adding new locality records since the original description. Most of the examined specimens were collected from the lower intertidal zone of sand or muddy sand flats at low tide by using yabby pump. The identification was confirmed by genetic analysis using the mitochondrial 16S rRNA gene in comparison with the sequences registered in the GenBank database combined with morphological comparison. The living coloration of the species is first documented. A brief note on biology of the species is also given.

We conducted laboratory experiments to examine the predation effects on larvae of two Japanese native dragonfly species by the North American invasive crayfish Procambarus clarkii. We put a larval individual of either Trigomphus interruptus or Coenagrionidae spp. in experimental aquaria, and after 24 hours we added an individual of P. clarkii of two different body size groups; small size group: total length (TL)<50 mm and large size group: TL>60 mm. After seven days, we observed whether the larval individuals of the dragonflies survived or not. We confirmed the severe predation on both of the two taxa of dragonfly larvae by P. clarkii. In T. interruptus, the survival rate was significantly lower compared to the control group (i.e., no crayfish) both in the small and large size groups. In Coenagrionidae spp., the survival rate of larvae in the small size group was significantly lower than the control group. In the large size group of P. clarkii, predation on the dragonfly larvae was also observed, but there was no significant difference compared to the control group. These results indicate that P. clarkii especially in small size can have a marked negative effect on dragonfly larvae through severe predation, if P. clarkii invades the habitats of dragonfly larvae.

A little-known alpheid shrimp, Bermudacaris britayevi Anker, Poddoubtchenko & Marin, 2006, is reported on the basis of a specimen collected from Nagannu Island, Ryukyu Islands, southwestern Japan. This species so far has only been known from Vietnam and Guam Island. Therefore, the present material represents the first record of this species from Japanese waters, and expands the distributional range 1,000 km to the north. We also refer to the fact that both chelae were similar in shape, instead of asymmetrical as shown in the previous study.

A mangrove sesarmid crab, Leptarma aurifrons (Li, Shih, & Ng, 2019), is reported from Japan for the first time based on a male specimen collected from Ishigaki Island, Ryukyu Archipelago. The present specimen extends the geographical range of the species to the northeast. A brief description of L. aurifrons is provided on the basis of the present specimen. Leptarma aurifrons is the third species of the genus recorded from Japan.