Two specimens (116.0–119.1 mm SL) of an epigonid fish, Epigonus fragilis (Jordan & Jordan, 1922), were caught by set net (ca. 40 m depth) from Sagami Bay, Japan. These specimens represent the first records of the species from the bay and the second report from Japan. The species has been previously reported mainly from deep-water around the seamounts in the central North Pacific. Its occurrence in coastal waters, including the present study, is considered to be rare. One specimen (119.1 mm SL) of was female with a great number of mature eggs, indicating that E. fragilis spawns off the Pacific coast of Japan. The species has been known as a member of the Epigonus pandionis group and characterized by the following combination of characters: dorsal fin rays VII-I, 10; pectoral fin rays 17 or rarely 18; gill rakers 25–27; vertebrae 10 + 15; pyloric caeca 7 or 8; pored lateralline scales 46–49 + 3 or 4; pungent opercular spine absent; maxillary mustache-like process absent; lingual teeth absent; small conical teeth on lower jaw; pair of ribs present on last abdominal vertebra; tubercle on inner symphysis of lower jaw absent; orbital diameter 13.0–15.2% SL; and pectoral-fin length 22.8–26.1% SL.

View full abstract

Two new freshwater species of the gobiid fish genus Rhinogobius, R. yaima and R. yonezawai, are described based on specimens from swift streams in the Ryukyu Islands, Japan. Rhinogobius yaima (16 specimens, 30.2–66.2 mm SL) is distinguished from all congeneric species by the following combination of features: 40–43 longitudinal scales; 10+16=26 vertebrae; head depressed, body and caudal peduncle elongate; first dorsal fin low in males, not extending posteriorly to second dorsal fin; fifth pelvic-fin segmented ray usually divided into five branches at its first (most proximal) segmenting point; pectoral-fin base and prepelvic area naked; belly with small cycloid scales except for a narrow area around ventral midline; a distinct orange oval spot on pectoral-fin base; two orange stripes on temporal region, reaching posteriorly to below origin of second dorsal fin; four vertical rows of orange dots on caudal fin in males; a pair of black blotches at caudal-fin base in females when alive or freshly collected. Rhinogobius yonezawai (17 specimens, 45.8–75.2 mm SL) differs from all congeners by the following combination of features: 35–39 longitudinal scales; 10+16=26 vertebrae; first dorsal fin in males high and falcate, non-filamentous, extending posteriorly to second dorsal-fin; fifth pelvic-fin segmented ray divided into four branches; pectoral-fin base and prepelvic area naked; belly with small cycloid scales except for a narrow area around ventral midline or around anterior half of ventral midline; a distinct black oval spot on pectoral-fin base; two orange stripes on temporal region, reaching posteriorly to below first dorsal fin; six to eight vertical red or orange lines on caudal fin in males; a black bifurcated blotch posteriorly at caudal-fin base in females when alive or freshly collected.

View full abstract

Taxonomic and zoogeographic notes on twelve genera of Japanese Cryptinae are reported. Twelve new species, Aritranis kuro sp. nov., Buathra nipponica sp. nov., Cryptus daidaigaster sp. nov., Glabridorsum japonicum sp. nov., Gotra elegans sp. nov., Hoplocryptus ashoroensis sp. nov., H. ezoensis sp. nov., H. intermedius sp. nov., H. japonicus sp. nov., H. maculatus sp. nov., H. toshimensis sp. nov. and Trychosis breviterebratus sp. nov. are described. Two species, Hylophasma luica Sheng, Li & Wang, 2019 and Picardiella melanoleuca (Gravenhorst, 1829) are newly recorded from Japan. The former is also a new record of the genus Hylophasma Townes, 1970 from Japan. Agrothereutes minousubae Nakanishi, 1965 is newly recorded from Honshu and Shikoku. Male of Caenocryptoides convergens Momoi, 1966 is described for the first time. Cryptus dianae is newly recorded from Honshu. Gambrus homonae Sonan, 1930 (comb. rev.) is redescribed including new description of males and new distribution data from Honshu and Izu-oshima Is., Hachijojima Is. And Tsushima Is. Hoplocryptus pini is redescribed including new description of males and new distribution data from Miyakejima Is., Shikoku, Kyushu and Yakushima Is. The second specimen of Hoplocryptus sumiyona Uchida, 1956 is recorded from Tokunoshima Is. Keys to Japanese species of the genera Caenocryptoides Uchida, 1936, Cryptus Fabricius, 1804, Gambrus, Gotra Cameron, 1902, Hoplocryptus Thomson, 1873, Picardiella Lichtenstein, 1920 and Trychosis Förster, 1869 are provided.

View full abstract

The authors investigated illustrations of the order Hymenoptera in historical manuscripts entitled “Yoshida-Ô-Chûfu (Part 1)” deposited in the Nagoya City Museum, which were made by OSHIO Goro (1830–1894) as copies of original in 1889, and is composed of 133 illustrations (including habitus of insects, except for nests, cocoon, prey and others). The original was made by YOSHIDA Takanori, who had a cognomen Heikuro with a pseudonym of Jyakusô-an (1805–1869) in the 1800s. Out of these, we identified 30 species from 33 illustrations in the part. Many illustrations are precisely illustlated in good quality, which makes it possible to identify each illustration at the generic or specific level. However, the arrangement of illustrated insects does not have regularity based on a phylogenetic or classified viewpoint like the Western natural history which existed at that time. From the constitution of the species, we can read about fauna and the habitat environment of Hymenoptera in Owari and Mikawa territories in around the 1800s.

View full abstract

Atsugi Children’s Wood Park is located in Nakaogino, Atsugi, Kanagawa Prefecture. Since 2015, two alien species, African clawed frogs (Xenopus laevis) and American bullfrogs (Lithobates catesbeianus), have been found in ponds and waterways that were newly created in this park, an area previously occupied by disused rice-fields. These new ponds are important habitats for several rare endemic species, including two odonatans, the Siberian winter damselfly (Sympecma paedisca) and the Four-spotted chaser dragonfly (Libellula quadrimaculata). The primary threat posed by the two alien frog species is considered to be predation, and we therefore examined the stomach contents of individual frogs trapped in this park. The results indicate that the diet of Xenopus laevis is dominated by aquatic arthropods, especially larval Odonata, although a Japanese Eight-barbel loach (Lefua echigonia), an Endangered IB species in the Red data book of Kanagawa Prefecture, was also identified. Lithobates catesbeianus, on the other hand, preyed on various arthropods, more than half of which were terrestrial species. However, L. catesbeianus fed less frequently on aquatic species than X. laevis, larval odonatans were again dominant among its aquatic prey. The predation pressure exerted by the two alien species on Sympecma paedisca and Libellula quadrimaculata could not be determined decisively in this study, given the number of sampled individuals and the limited sampling-period. However, as the artificial ponds are small, with few places to escape from predators, the alien species could be threat to any vertebrate or invertebrate living there. The invasion of alien species into newly built ponds in the Atsugi Children’s Wood Park has continued, despite continued monitoring. Active control of alien species is crucial for conservation of rare endemic species in this area.

View full abstract

Influence of scabies infection to body size variation of raccoon dog Nyctereutes procyonoides was investigated around Kanagawa Prefecture, Japan. Seasonal changes in body weight are recognized, with a tendency to increase in winter and decrease in summer. Such tendency is not seen in individuals suffering from scabies. Since some individuals without scabies infection was smaller in body weight than some scabies-infected individuals in summer, direct cause of death in scabies infected individuals may not be extreme starvation. Difference of body weight between individuals with/without scabies infection in winter suggest that direct cause of death in scabies infected individuals are freeze to death due to low fat accumulation in winter. In the correlation test among the measurement items indicating morphological sizes, significant correlations were found between all measurement pairs, but correlations were weak. These correlation patterns may not be affected by morphological distortion caused by scabies. Small correlation between size indicating measurements in raccoon dog can be one of the important morphological characteristics in this species.

View full abstract