Blood Fluke Infection of Cultured Tiger Puffer <i>Takifugu rubripes</i> Imported from China to Japan

Abstract

ABSTRACT-Monthly samplings of tiger puffer Takifugu rubripes, which had been cultured in China and later introduced to a farm in Kagawa Prefecture, Japan, in May 2005, were conducted over a four-month period commencing in June 2005. Blood flukes were found in the visceral vascular system with the highest number being 162 worms/fish, and their eggs accumulated in the visceral organs. The parasite was classified within the genus Psettarium based on the unique male reproductive system, and tentatively designated as Psettarium sp. TPC (= tiger puffer from China). Molecular analyses, using the ITS2 rDNA gene indicated that the blood flukes of tiger puffer from two other sources (cultured in China and subsequently in the Kyushu area, and cultured in China only) were also Psettarium sp. TPC. This suggests that the infection cycle of Psettarium sp. TPC has been established in China. On the other hand, no evidence was found that its life cycle is complete in Japanese waters. Similar blood flukes were collected in 1993 from postspawned tiger puffer caught in a set-net in Wakasa Bay, Fukui Prefecture and maintained there for several months. This parasite was differentiated from Psettarium sp. TPC by the presence of 5-6 rows of pre-oral spines and designated as Psettarium sp. TPJ (= tiger puffer from Japan).

A complex of the blood fluke genus Psettarium (Digenea: Aporocotylidae) infecting tetraodontiform fishes of east Queensland waters

“…The eggs of P. hawaiensis and P. nolani were noted to be accumulating in visceral organs, the liver in the case of P. hawaiensis and the intestinal wall in P. nolani [5,7]. Eggs of P. sinense, as well as those of the putative Psettarium species from aquacultured Japanese tiger puffer, Takifugu rubripes (Temminck & Schlegel), have also been noted in visceral organs of infected hosts, causing significant pathology and mortality in aquacultured puffer stocks [9][10][11][12]. The standard life-cycle paradigm of aporocotylids involves eggs released into the bloodstream and travelling to the gills, where the miracidial larvae hatch and exit the host.…”

Identification of Blood Flukes Infecting Tiger Puffer <i>Takifugu rubripes</i>

“…Since tiger puffer is extensively cultured both in et al (2003); 'Sanguinicolid sp. ' of Lockyer et al (2003) and Holzer et al Psettarium sinense (Liu, 1997) (Ogawa et al, 2007) Paradeontacylix sinensis Liu, 1997, Psettarium sp. TPC Ogawa, Nagano, Akai, Sugita & Hall, 2007 Psettarium pulchellum Yong, Cutmore, Bray, Miller, Semarariana, Palm & Cribb, 2016 Psettarium japonicum sensu Yamaguti, 1938 Japan and China and blood fluke infection is a serious threat to the culture industry, it is necessary to accurately identify the causative species among the three species described here.…”

“…The method of preparing permanent slide specimens for Psettarium sp. TPC and Psettarium TPJ were described in Ogawa et al (2007); the worms were flattened, fixed in AFA and stained with HH or alum carmine, dehydrated and mounted in Canada balsam. The same method was applied to the newly collected specimens from Dailian.…”

Diseases of cultured marine fishes caused by Platyhelminthes (Monogenea, Digenea, Cestoda)

“…For example, 50% to more than 80% of juvenile greater amberjack were lost in one month due to P. grandispinus and P. kampachi infection in Japan (Ogawa and Fukudome, 1994) and more than half of Japanese pufferfish were killed by an unidentified Psettarium (Aporocotylidae) (designated as Psettarium sp. TPC) within 3 months after puffers were introduced from China (Ogawa et al 2007).…”

“…Psettarium sp. TPC infected the visceral vascular system of farmed Japanese pufferfish, unlike the above cases of Paradeontacylix and Cardicola , which infect the heart and gill blood vessels of host fish (Ogawa et al 2007). Eggs accumulated in visceral organs such as the spleen, liver, testis, intestine and less frequently the gills.…”