Paragonimus westermani and Some Rare Intestinal Trematodes Recovered from Raccoon Dogs (Nyctereutes procyonoides viverrinus) Introduced Recently on Yakushima Island, Japan

Abstract

ABSTRACT. Helminth parasites were collected from 9 raccoon dogs (Nyctereutes procyonoides viverrinus) and 2 Japanese weasels (Mustela itatsi sho) on Yakushima Island, Japan. The former carnivore was introduced to this World Natural Heritage Area presumably within the last two decades, expanding its population thence, although detailed process(es) of the introduction is unknown. The collected trematodes from raccoon dogs included the triploid form of Paragonimus westermani, Brachylaima tokudai, Maritrema eroliae, and Pseudocryptotropa sp. Simultaneously, Paragonimus ohirai was found in one weasel killed by a traffic accident. Although the triploid form of P. westermani and P. ohirai are known to be distributed in some river-mouth areas of Yakushima Island based on previous surveys on crab hosts, natural infection was detected for the first time in wild final hosts. Particularly, the raccoon dog infected with P. westermani was caught in a mountainous area, distant from human residence or river-mouth areas. Although it is possible that the infected raccoon dog moved from a river-mouth area endemic with P. westermani after infection, the alternative scenario remains to be pursued; the endemic area of this zoonosis is expanding along with the recent expansion of raccoon dogs or feral cats (Felis catus), that became prevalent recently on this island including the mountainous areas. Maritrema eroliae taking a variety of shorebirds as its natural final hosts, and a minute trematode, Pseudocryptotropa sp., taking unknown natural final host(s) were recorded for the first time in raccoon dogs.

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

“…In addition to the 5 trematode species reported in our previous study [38], 7 nematode and 3 acanthocephalan species from raccoon dogs, and 2 nematode and 1 acanthocephalan species from weasels were collected (Table 1). Raccoon dogs trapped in places other than Nagata and Seibu-rindo ( Fig.…”

“…Raccoon dogs trapped in places other than Nagata and Seibu-rindo ( Fig. 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.…”

“…In our previous work [38], we described 5 trematode species collected from raccoon dogs (Nyctereutes procyonoides viverrinus) and Japanese weasels (Mustela itatsi) on Yakushima Island, Kagoshima Prefecture, Japan. The collected trematodes included the triploid form of Paragonimus westermani, Paragonimus ohirai, Brachylaima tokudai, Maritrema eroliae, and Pseudocryptotropa sp.…”

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

“…68 (7): [689][690][691][692] 2006 In our previous works [10, 11], we described 5 trematode and 9 nematode species collected from raccoon dogs (Nyctereutes procyonoides viverrinus) and Japanese weasels (Mustela itatsi sho) on Yakushima Island, Kagoshima Prefecture, Japan. Parasitological surveys of invasive animals in a special ecosystem sometimes found scarcely known or unknown distribution of parasitic organisms maintained originally by native animal hosts [10][11][12]. Accordingly, parasitological surveys on culled animals will provide an alternative opportunity to collect information on the fauna and geographical distribution of symbiotic organisms in the native wildlife around us.…”