Kudoa is a genus of Myxozoa and the only genus recognized within the monotypic family Kudoidae. There are approximately 100 species of Kudoa all of which parasitize on marine and estuarine fish.[1] Kudoa are most commonly known and studied for the negative effects the genus has on commercial fishing and aquaculture industries.[2]

Kudoa
Kudoa septempunctata - spores
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Cnidaria
Class: Myxosporea
Order: Multivalvulida
Family: Kudoidae
Meglitsch, 1960
Genus: Kudoa
Meglitsch, 1947
Synonyms
  • Hexacapsula Arai & Matsumoto, 1953
  • Pentacapsula Naidenova & Zaika, 1970
  • Septemcapsula Hsieh & Chen, 1984

Description

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The genus Kudoa is identified by the possession of four or more shell valves composed of a fragile membrane and arranged in a quadrate or stellate pattern. The maximum number of shell valves in any described Kudoa species is 13.[1] Each of these valves has a polar capsule.[3] The genus Kudoa was originally part of the genus Chloromyxum because of the distribution of their polar capsules, however, it was later determined to be a separate genus.[2] Each Kudoa has two sporoplasm cells, one enclosed by the other.[3] Most Kudoa are histozoic parasites, with a few species being described as coelzoic. Some taxonomists question whether these coelzoic organisms belong to a separate genus.[2] There are approximately 100 described species of Kudoa which can be found in the Atlantic, Pacific, and Indian oceans.[1]

Species

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Kudoa septempunctata in olive flounder (Paralichthys olivaceus) muscles.

The following species are recognized in the genus Kudoa:[4]

Development

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Summary of Myxozoan Life Cycle

In Myxozoan development, the Myxosporean life-stage develops inside a fish host, while the Actinosporean life-stage develops in an annelid host.[5] Fully-developed Myxospores are consumed by annelids and reproduce asexually via schzogony in the gut epithelium of worms. Gametes are formed in the gut of the worm and these gametes fuse together to create eight zygotes.[6] The zygotes become spores with three valves, 3 polar capsules, and a sporoplasm that are released in the worm's feces and attach to the surface of a fish host.[6] Once attached to the fish, the gamete injects the sporoplasm cell into the fish. The sporoplast divides forming a fully-developed Myxosporean.[6]

Diet

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Kudoa parasitize on marine and estuarine fish.[7] Kudoa typically feed on the skeletal muscle tissue, although some may feed on other parts of the body such as the central nervous system, heart, intestines, ovaries, or gills.[1] Most Kudoa are histozoic parasites, however, a few species are coelzoic.[1] The genus Kudoa attack a wide range of hosts, however, individual species only feed on specific hosts. Kudoa feed via pinocytosis across the host-parasite membrane. One species of Kudoa, K. thyrsites, are distributed worldwide and are believed to have been reported in over 20 different species of fish but it is possible that the species described as K. thyrsites is actually multiple different species.[7]

Implications for the fishing industry

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Kudoa are most well known for the economic loss they cause for the commercial fishing and aquaculture industries.[1] When Kudoa attach to hosts, they leave unsightly cysts that lower the price fish can be sold for at market. Kudoa also release proteolytic enzymes that degenerate muscle in fish to aid in their own growth and development, further decreasing the fish's value.[8] Some species in the genus Kudoa with the most notable effects of the commercial fishing and aquaculture industries are: K. musculoliquefaciens in Broadbill Swordfish (Xiphias gladius), K. thyrsites in Atlantic Salmon (Salmo salar), K. clupeidae in Atlantic Herring (Clupea harengus), K. septempunctata in Olive Flounder (Paralichthys olivaceus), K. thunni in Yellowfin Tuna (Thunnus albacares) and K. paniformis in Pacific Hake (Merluccius productus).[7][9][10]

Some studies have found evidence to suggest that some species of Kudoa are linked to food-borne illness in humans.[11]

References

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Encyclopedia of Life

  1. ^ a b c d e f Shin, Sang Phil; Shirakashi, Sho; Hamano, Shogo; Kato, Keitaro; Lasso, Lissette Trejos; Yokoyama, Hiroshi (May 2016). "Phylogenetic study of the genus Kudoa (Myxozoa: Multivalvulida) with a description of Kudoa rayformis sp. nov. from the trunk muscle of Pacific sierra Scomberomorus sierra". Molecular Phylogenetics and Evolution. 98: 337–345. doi:10.1016/j.ympev.2016.02.019. PMID 26947709.
  2. ^ a b c Moran, J.D.W; Whitaker, D.J; Kent, M.L (March 1999). "A review of the myxosporean genus Kudoa Meglitsch, 1947, and its impact on the international aquaculture industry and commercial fisheries". Aquaculture. 172 (1–2): 163–196. doi:10.1016/S0044-8486(98)00437-2.
  3. ^ a b Lom, Jiri; Dykova, Iva (2006-03-01). "Myxozoan genera: definition and notes on taxonomy, life-cycle terminology and pathogenic species". Folia Parasitologica. 53 (1): 1–36. doi:10.14411/fp.2006.001. PMID 16696428.
  4. ^ Eiras, Jorge Costa; Saraiva, Aurélia; Cruz, Cristina (February 2014). "Synopsis of the species of Kudoa Meglitsch, 1947 (Myxozoa: Myxosporea: Multivalvulida)". Systematic Parasitology. 87 (2): 153–180. doi:10.1007/s11230-013-9461-4. ISSN 0165-5752. PMID 24474038. S2CID 15664523.
  5. ^ Takeuchi, Fumihiko; Sekizuka, Tsuyoshi; Ogasawara, Yumiko; Yokoyama, Hiroshi; Kamikawa, Ryoma; Inagaki, Yuji; Nozaki, Tomoyoshi; Sugita-Konishi, Yoshiko; Ohnishi, Takahiro; Kuroda, Makoto (2015-07-06). Sun, Genlou (ed.). "The Mitochondrial Genomes of a Myxozoan Genus Kudoa Are Extremely Divergent in Metazoa". PLOS ONE. 10 (7): e0132030. Bibcode:2015PLoSO..1032030T. doi:10.1371/journal.pone.0132030. ISSN 1932-6203. PMC 4492933. PMID 26148004.
  6. ^ a b c Kent, Michael L.; Andree, Karl B.; Bartholomew, Jerri L.; El-Matbouli, Mansour; Desser, Sherwin S.; Devlin, Robert H.; Feist, Stephen W.; Hedrick, Ronald P.; Hoffmann, Rudolf W.; Khattra, Jaswinder; Hallett, Sascha L. (July 2001). "Recent Advances in Our Knowledge of the Myxozoa". The Journal of Eukaryotic Microbiology. 48 (4): 395–413. doi:10.1111/j.1550-7408.2001.tb00173.x. ISSN 1066-5234. PMID 11456316. S2CID 5518818.
  7. ^ a b c Moran, J.D.W; Whitaker, D.J; Kent, M.L (March 1999). "A review of the myxosporean genus Kudoa Meglitsch, 1947, and its impact on the international aquaculture industry and commercial fisheries". Aquaculture. 172 (1–2): 163–196. doi:10.1016/S0044-8486(98)00437-2.
  8. ^ Kristmundsson, Árni; Freeman, Mark Andrew (August 2014). "Negative effects of Kudoa islandica n. sp. (Myxosporea: Kudoidae) on aquaculture and wild fisheries in Iceland". International Journal for Parasitology: Parasites and Wildlife. 3 (2): 135–146. doi:10.1016/j.ijppaw.2014.06.001. PMC 4142268. PMID 25161912.
  9. ^ Jang, Yeoung-Hwan; Subramanian, Dharaneedharan; Won, Seung-Hwan; Heo, Moon-Soo (August 2017). "Immune response of olive flounder ( Paralichthys olivaceus ) infected with the myxosporean parasite Kudoa septempunctata". Fish & Shellfish Immunology. 67: 172–178. doi:10.1016/j.fsi.2017.06.019. PMID 28602738. S2CID 926387.
  10. ^ Bolin, Jessica A.; Cummins, Scott F.; Mitu, Shahida A.; Schoeman, David S.; Evans, Karen J.; Scales, Kylie L. (2021-06-11). "First report of Kudoa thunni and Kudoa musculoliquefaciens affecting the quality of commercially harvested yellowfin tuna and broadbill swordfish in Eastern Australia". Parasitology Research. 120 (7): 2493–2503. doi:10.1007/s00436-021-07206-8. ISSN 1432-1955. PMID 34115215. S2CID 235404099.
  11. ^ Kawai, T.; Sekizuka, T.; Yahata, Y.; Kuroda, M.; Kumeda, Y.; Iijima, Y.; Kamata, Y.; Sugita-Konishi, Y.; Ohnishi, T. (2012-04-15). "Identification of Kudoa septempunctata as the Causative Agent of Novel Food Poisoning Outbreaks in Japan by Consumption of Paralichthys olivaceus in Raw Fish". Clinical Infectious Diseases. 54 (8): 1046–1052. doi:10.1093/cid/cir1040. ISSN 1058-4838. PMID 22281845.