Kudoa iwatai and two novel Kudoa spp., K. trachuri n. sp. and K. thunni n. sp. (Myxosporea: Multivalvulida), from daily consumed marine fish in western Japan

Abstract

Infection of marine fish by certain myxosporean species of the genus Kudoa results in unsightly cyst formation in the trunk muscle or post-mortem myoliquefaction, causing a great economic loss to aquaculture industries, capture fisheries, and fish dealers. In addition, consumers encountering unsightly Kudoa cysts in fish fillets believe them to be unknown foreign materials acquired during processing. To identify prevalent Kudoa spp. encountered in daily life by the Japanese population, fresh fish slices (sashimi) or fish fillets with whitish spots were collected during a 7-month period (May to December 2008) at local markets in the city of Yamaguchi, western Japan. Kudoa cysts were found in three Japanese seaperches (Lateolabrax japonicus), two black sea bream (Acanthopagrus schlegelii), two Japanese jack mackerel (Trachurus japonicus), and one albacore (Thunnus alalunga). Kudoa iwatai was identified in all the examined Japanese seaperch and black sea bream from Japan's Inland Sea, as assessed by morphology and genetic analysis of the 18S and 28S ribosomal RNA gene (rDNA). Kudoa trachuri n. sp. from two Japanese jack mackerel fished in the Japanese Sea off Nagasaki and Kudoa thunni n. sp. from one albacore fished in the Pacific Ocean had a spore, which was semiquadrate in shape in apical views and ovoid in lateral views, with four equal shell valves and drop-like polar capsules. Scanning electron microscopy revealed that these three Kudoa species had different types of small projections at the apex of each valve. The 18S and 28S rDNA sequences of K. trachuri n. sp. and K. thunni n. sp. were found to be closely related to those of Kudoa crumena; however, these sequences were distinct in each of the species, which additionally exhibited different morphological features.

Morphological and genetic characterization of Kudoa whippsi (Myxosporea: Multivalvulida) from Cheilodactylus zonatus in the western Pacific Ocean off Japan, and two new Kudoa spp. (K. akihitoi n. sp. and K. empressmichikoae n. sp.) from Acanthogobius hasta in the Sea of Ariake, Japan

“…Furthermore, the morphometrical variation of the small-sized myxospores of Kudoa spp. presents another problem requiring clarification for species differentiation (Matsukane et al 2011). Fortunately, rDNA nucleotide sequencing has dramatically improved our recognition of the species and systematics of Kudoa.…”

“…Kudoid cysts in the former individual contained 15 intact, well-grown plasmodia and 20 degenerated ones. The (Matsukane et al 2011;Kasai et al 2015). Therefore, this kudoid was not further investigated in the present study.…”

Kudoa spp. (Myxozoa, Multivalvulida) parasitizing fish caught in Aracaju, Sergipe, Brazil

“…In the case of parasites infecting B. marinus, the most similar species concerning general dimensions were K. grammatorcyni Adlard, Bryant, Whipps andKent, 2005 (ADLARD et al, 2005), K. leiostomi Overstreet, 1994 (DYKOVÁ et al, 1994), K. musculoliquefaciens Matsumoto, 1954(synonym: Chloromyxum musculoliquefaciens Egusa, 1986 and K. trachuri Matsukane, Sato, Tanaka, Kamata andSugita-Konichi, 2011 (MATSUKANE et al, 2011). In the case of K. grammatorcyni, the six polar capsules that it presents immediately separate the two forms.…”

Ultrastructure and phylogeny of Ceratomyxa diplodae (Myxosporea: Ceratomyxidae), from gall bladder of European seabass Dicentrarchus labrax

“…labracis Sitjà-Bobadilla &Álvarez-Pellitero, 1993, which infect the gall bladder (Álvarez-Pellitero & Sitjà-Bobadilla 1993b, Sitjà-Bobadilla & Álvarez-Pellitero 1993b. In the Indo-Pacific region, Kudoa iwatai Egusa & Shiomitsu, 1983 has also been reported infecting the muscle of D. labrax and is correlated with cases of food poisoning (Diamant et al 2005, Matsukane et al 2011, Suzuki et al 2012. Ceratomyxa spp.…”