Juvenile Bird Acanthocephalans Recovered Incidentally from Raccoon Dogs (Nyctereutes procyonoides viverrinus) on Yakushima Island, Japan

Abstract

Helminth parasites were collected from 14 raccoon dogs (Nyctereutes procyonoides viverrinus) and 2 Japanese weasels (Mustela itatsi sho) on Yakushima Island, Kagoshima Prefecture (Kyushu), Japan. In addition to trematodes and nematodes reported separately, everted cystacanths of 3 bird acanthocephalans (Mediorhynchus robustus in 5 animals, Porrorchis leibyi in 2 animals, and Sphaerirostris lanceoides in 1 animal) were collected from the raccoon dogs introduced recently on this World Natural Heritage Area. A cystacanth of P. leibyi was collected also from a weasel indigenous to this island that were killed by traffic accidents. Recovery of everted cystacanths of M. robustus from the intestine of raccoon dogs was remarkably frequent (36%), suggesting that this acanthocephalan should be highly prevalent in passerine hosts on Yakushima Island, and the animals might vigorously take insect hosts or paratenic hosts. Furthermore, the present report is the second on M. robustus after its first record in Japan (Aichi Prefecture, Honshu) as M. garruli from a Eurasian jay (Garrulus glandarius japonicus) by Yamaguti in 1939. Porrorchis leibyi has never been recorded in Japan.

Mitochondrial DNA dataset suggest that the genus Sphaerirostris Golvan, 1956 is a synonym of the genus Centrorhynchus Lühe, 1911

“…The morphology and morphometrics of our specimens are almost identical with the descriptions of the cystacanths of S. lanceoides by Sato et al . (2005, 2006), Torracca et al . (2010) and Kang and Li (2018), including the size and morphology of the trunk and proboscis, the number of the longitudinal rows of proboscis hooks and the hooks per longitudinal row (Fig.…”

“…The specimens were identified as the cystacanths of S. lanceoides using morphological characters and genetic data ( cox 1 sequences) according to Sato et al . (2005, 2006), Torracca et al . (2010), and Kang and Li (2018).…”

“…The specimens of S. lanceoides (Petrochenko, 1949) were isolated from the intestine of the Indian pond heron Ardeola grayii (Sykes) (Ciconiiformes: Ardeidae) in the district Swabi (34°07 ′ 07.23 ′′ N, 72°36 ′ 32.38 ′′ E), Khyber Pakhtunkhwa Province, Pakistan, and then stored in 75% ethanol at −20°C for molecular studies. The specimens were identified as the cystacanths of S. lanceoides using morphological characters and genetic data (cox1 sequences) according to Sato et al (2005Sato et al ( , 2006, Torracca et al (2010), and Kang and Li (2018).…”

Nematodes from Raccoon Dogs (<i>Nyctereutes procyonoides viverrinus</i>) Introduced Recently on Yakushima Island, Japan

“…1) harbored no trematodes, and thus no more data of trematodes was added to the previous study [38], which reported trematode parasites in these hosts collected in Nagata and Seibu-rindo. Taxonomical details of acanthocephalans are reported separately [37].…”

“…Parasitological surveys of alien animals in a new ecosystem sometimes found scarcely known or unknown distribution of parasitic organisms maintained originally by native animal hosts [35,37,38,40]. This is partly ascribed to the abundant supply of animal materials for examination, and year-round collection of animals which enables the collection of information on parasites showing seasonal changes in prevalence.…”