The monotypic genus Bovitrigla established by Fowler in 1938 accommodates B. acanthomoplate and is known from the Philippines and the South China Sea. A single specimen of B. acanthomoplate was collected from the Enshu-nada Sea off Shizuoka Prefecture, Japan. The species is characterized by having a long rostral spine, a long posttemporal spine and a postocular spine, which are the generic diagnostic characters. This record represents not only the first record from Japan but the northernmost record of this species. Comparing the Japanese specimen with ten specimens of this species collected from the South China Sea, we found the former differs in having the following characters: 52 lateral line scales vs. 54–57; snout length 47.5 % in HL vs. 42.5–46.4 %; and interorbital width 33.8 % in HL vs. 29.7–32.7 %. We redescribe this species in detail and give the new standard Japanese name, Minami-sokohobo for this species and Minami-sokohobo-zoku for the genus.
A new freshwater species with two new subspecies of the gobiid fish genus Rhinogobius is described from the Yaeyama Group of the Ryukyu Islands, Japan. One of the subspecies, Rhinogobius aonumai aonumai (29 specimens, 35.9–70.5 mm SL) known only from Iriomote-jima Island, is distinguished from all congeneric species-group taxa (species and subspecies) by having the following combination of features: 9–15 predorsal scales; 32–37 longitudinal scales; 11+15–17=26–28 vertebrae (mode 27); anteriormost two pterygiophores (proximal radials) of the second dorsal fin mounted over the neural spine of 10th vertebra; fifth segmented pelvic-fin ray divided into 3–4 (usually four) branches at the position where proximal-most segment of each branch alignes transversely; yellow-colored body in freshly-collected; no dark spot on first dorsal fin; caudal fin with vertical rows of dark spots or forming dark zigzag bands. The other subspecies, Rhinogobius aonumai ishigakiensis (12 specimens, 33.3–56.5 mm SL) known only from Ishigaki-jima Island, is distinguished from all congeneric species-group taxa by having the following combination of features: 10–14 predorsal scales; 33–38 longitudinal scales; 10+16–18=26–28 vertebrae (mode 27); anteriormost two pterygiophores (proximal radials) of the second dorsal fin mounted over the neural spine of 9th vertebra; fifth segmented pelvicfin ray divided into 2–3 (usually two) branches at the position where the proximal-most segment of each branch alignes transversely; yellow-colored body in freshly-collected; no dark spot on first dorsal fin; caudal fin with dark zigzag bands on the caudal fin.
Two new species of the genus Hynobius are described from the southern part of Hiroshima Prefecture, Japan. Hynobius akiensis was divided into three groups (Hiroshima-Ehime group, Higashihiroshima group, Northern Hiroshima group) based on morphological and molecular analyses; thus, the Hiroshima-Ehime and Higashihiroshima groups were described as Hynobius geiyoensis sp. nov. and Hynobius sumidai sp. nov., respectively. According to morphological comparisons, males of H. geiyoensis sp. nov. have significantly larger snout–vent length relative to those of males of the other two species, whereas members of H. sumidai sp. nov., unlike H. akinesis, have a distinct brownish–yellow stripe on the dorsal side of their tail. Following this description, the distribution area of H. akiensis has changed substantially; thus, the habitat status of this species or two new species should be reassessed for its conservation.
A new species of the genus Hynobius is described from the western part of Aichi Prefecture, Japan. Hynobius vandenburghi can be divided into two groups, the Aichi and Kinki groups, based on molecular and morphological analyses; thus, we described the Aichi group of H. vandenburghi as a new species, Hynobius owariensis sp. nov.. Morphological comparisons revealed that although male H. vandenburghi have distinct bright yellow lines on the dorsal and ventral sides of the tail, males of the new species do not. Additionally, in males, the new species usually has fewer costal folds between its adpressed limbs than are observed in H. vandenburghi. Other significant differences in several morphological characteristics were also found between H. vandenburghi and the new species, and results of discriminant analyses between the two species in both sexes suggested that they are separated in terms of morphological data. The new species is restricted in the western part of Aichi Prefecture, which is threatened with extinction by artificial development or reformation of well-drained paddy fields.
New distribution records of six species of Japanese Phygadeuontinae, Acrolyta spola Momoi, 1970 (from Tokunoshima Is.), Diatora lissonota (Viereck, 1912) (from Tokunoshima Is.), Mastrus oshimensis (Uchida, 1930) (from Honshu), Phygadeuon elongatus (Uchida, 1930) (from Honshu), P. yonedai Kusigemati, 1986 (from Honshu and Izuoshima Is.), and Theroscopus maruyamanus (Uchida, 1930) (from Honshu), are recorded. These species except A. spola and P. yonedai are re-described. In addition, P. akaashii Uchida, 1930 and T. fukuiyamensis (Uchida, 1936) are also re-described. Mastrus oshimensis and T. maruyamanus have only been recorded in the original description and these are the second record for both species.
Libelloides ramburi is an endangered species whose distribution in Kanagawa Prefecture is currently limited to a corner of the northern part of the prefecture. In this study, we report the results of the ecological survey conducted in 2020 and 2021. We newly observed that this species rested on dead herbal stems such as Japanese pampas grass in the nocturnal habitat. In addition to the preference for resting places of the L. ramburi (i.e., Japanese pampas grass in the early stage, rice grass in the latter half), we also found that the specie has the preference for the height of the resting position. In 2021, we marked 174 adults of L. ramburi for individual identification, of which 6 % were recaptured. The result suggests that adult members in the populations interchange rather frequently. The number of days to survive was as follows: male: 34 days, female: 24 days. The ratio of males was high in the early stage, but it was remarkably decreased in the later stage. Other new ecological knowledge are 1) Two species of spiders were recorded as predators of this species, 2) The average number of eggs in a mass was 60.4, 3) The majority of spawning targets were dead stems of alien plants, Solidago canadensis var. scabra (74 % of the total spawning targets).
I conducted a mammal fauna survey using a camera trap in Iryuda, Odawara City, Kanagawa Prefecture, from April 2020 to May 2021. Cameras set at 10 sites took a total of 2,500 photographs of eight species of middle to large mammals and unidentified species of Rodentia Muridae and Chiroptera. The most photographed species was Sus scrofa, followed by Paguma larvata, Nyctereutes procyonoides and Cervus nippon, in this order. In correlation analyses of relative abundance index (RAI) between eight taxa (seven species and Muridae) that were photographed at more than seven sites, the correlation between S. scrofa and C. nippon was especially high and the correlations between Mu. itatsi and Muridae, and between Me. anakuma and Muridae, were present. Several species pairs showed negative correlations, such as between Mu. itatsi and P. larvata. Correlations of RAI between species could partly reflect the similarity of habitats and strength of competition between species.
European earthworms Dendrobaena veneta veneta (Rosa, 1886) and Lumbricus terrestris Linnaeus, 1758 are new records for Japan found in vermi-compost and fishing bait supplies. Both were likely introduced via the USA some years earlier when much stock was shipped to meet Japanese composting needs.
Two large native worms are an Amynthas from Kumejima, Okinawa and a Metaphire from Lake Biwa, Shiga-ken both supported by mtDNA COI barcodes, and two new species are described. New 2016 Okinawa exotic reports are of small American lumbricid Bimastos parvus (Eisen, 1874) and confirming of Asian megascolecid Pithemera bicincta (Perrier, 1875).