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. Kudoa are most commonly known and studied for the negative effects the genus has on commercial fishing and aquaculture industries.
Description 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. Each of these valves has a polar capsule. 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. Each Kudoa has two sporoplasm cells, one enclosed by the other. 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. There are approximately 100 described species of Kudoa which can be found in the Atlantic, Pacific, and Indian oceans.
Species
The following species are recognized in the genus Kudoa:
Kudoa aburakarei Li, Inoue, Tanaka, Zhang & Sato, 2020 Kudoa acentrogobia Li, Inoue, Tanaka, Zhang & Sato, 2020 Kudoa aequidens Casal, Matos, Matos & Azevedo, 2008 Kudoa ajurutellus Araújo-Neto, Cardim, Da Silva, Hamoy, Matos & Abrunhosa, 2020 Kudoa akihitoi Kasai, Setsuda & Sato, 2017 Kudoa alliaria Kovaleva, Shulman & Yakolev, 1979 Kudoa amamiensis Egusa & Nakajima, 1978 Kudoa amazonica Velasco, Sindeaux Neto, Videira, de Cássia Silva do Nascimento, Gonçalves & Matos, 2019 Kudoa anatolica Özer, Okkay, Gürkanlı, Çiftçi & Yurakhno, 2018 Kudoa azevedoi Mansour, Thabet, Chourabi, Harrath, Gtari, Omar & Hassine, 2013 Kudoa azoni Aseeva, 2004 Kudoa barracudai Abdel-Baki, Al-Quraishy, Omar & Mansour, 2016 Kudoa bengalensis Sarkar & Mazumder, 1983 Kudoa boopsi Kpatcha, Diebakate, Faye & Toguebaye, 1999 Kudoa bora Fujita, 1930 Kudoa borimiri Yurakhno, Slynko, Chinh, Ha & Whipps, 2022 Kudoa branchiata Joy, 1972 Kudoa camarguensis Pampoulie, Marques, Crivelli & Boucherau, 1999 Kudoa carcharhini Gleeson, Bennett & Adlard, 2010 Kudoa cascasia Sarkar & Chaudry, 1996 Kudoa caudata Kovaleva & Gaevskaya, 1983 Kudoa cerebralis Paperna & Zwerner, 1974 Kudoa chaetodoni Burger, Cribb & Adlard, 2007 Kudoa cheilodipteri Heiniger, Cribb & Adlard, 2013 Kudoa chilkaensis Tripathi, 1951 Kudoa ciliatae Lom, Rohde & Dyková, 1992 Kudoa clupeidae Hahn, 1917 Kudoa cookii Heiniger, Cribb & Adlard, 2013 Kudoa corniculata Li, Inoue, Zhang & Sato, 2022 Kudoa crenimugilis Abdel-Baki, Abdel-Haleem, Al-Quraishy, Azevedo & Mansour, 2018 Kudoa cruciformum Matsumoto, 1954 Kudoa crumena Iversen & van Meter, 1967 Kudoa cynoglossi Obiekezie & Lick, 1994 Kudoa dianae Dyková, Fajer & Fiala, 2002 Kudoa dicentrarchi Sitjà-Bobadilla & Alvarez-Pellitero, 1992 Kudoa empressmichikoae Kasai, Setsuda & Sato, 2017 Kudoa encrasicoli Iglesias, Rangel, Fernández-Vázquez, Santos & García-Estévez, 2022 Kudoa eugerres Casal, Soares, Rocha, Silva, Santos, Nascimento, Oliveira & Azevedo, 2019 Kudoa fujitai Li, Inoue, Zhang & Sato, 2020 Kudoa funduli Hahn, 1915 Kudoa grammatorcyni Adlard, Bryant, Whipps & Kent, 2005 Kudoa guangdongensis Li, Inoue, Tanaka, Zhang & Sato, 2020 Kudoa gunterae Burger & Adlard, 2009 Kudoa haridasae Sarkar & Ghosh, 1991 Kudoa hemiscylli Gleeson, Bennett & Adlard, 2010 Kudoa hexapunctata Yokoyama, Suzuki & Shirakashi, 2014 Kudoa hirsuta Li, Inoue, Zhang & Sato, 2022 Kudoa histolytica Pérard, 1928 Kudoa hypoepicardialis Blaylock, Bullard & Whipps, 2004 Kudoa igami Shirakashi, Yamane, Ishitani, Yanagida & Yokoyama, 2014 Kudoa igori Yurakhno, Slynko, Chinh, Ha & Whipps, 2022 Kudoa iidae Li, Inoue, Tanaka, Zhang & Sato, 2020 Kudoa inornata Dykova, de Buron, Fiala, Roumillat, 2009 Kudoa insolita Kovaleva, Shulman, & Yakovlev 1979 Kudoa intestinalis Maeno, Magasawa & Sorimachi, 1993 Kudoa islandica Kristmundsson & Freeman, 2014 Kudoa iwatai Egusa & Shiomitsu, 1983 Kudoa javaensis Yunus, Yustinasari, Natalia, Ghosh, Sakuma, Inoue & Sato, 2021 Kudoa kabatai Shulman & Kovalijova, 1979 Kudoa kenti Burger & Adlard, 2009 Kudoa konishiae Sakai, Kato, Sakaguchi, Setsuda & Sato, 2018 Kudoa lateolabracis Yokoyama, Whipps, Kent, Mizuno & Kawakami, 2004 Kudoa leiostomi Dyková, Lom & Overstreet, 1994 Kudoa lemniscati Miller & Adlard, 2012 Kudoa leptacanthae Heiniger & Adlard, 2012 Kudoa lethrini Burger, Cribb & Adlard, 2007 Kudoa longichorda Inoue, Kasai, Argamjav & Sato, 2022 Kudoa lunata Lom, Dyková & Lhotákova, 1983 Kudoa lutjanus Wang, Huang, Tsai, Cheng, Tsai, Chen, Chen, Chiu, Liaw, Chang & Chen, 2005 Kudoa megacapsula Yokoyama & Itoh, 2005 Kudoa miniauriculata Whitaker, Kent & Sakanari, 1996 Kudoa minithyrsites Whipps, Adlard, Bryant, Lester, Findlay & Kent, 2003 Kudoa mirabilis Naidenova & Gaevskaya, 1991 Kudoa monodactyli Gunter, Cribb, Whipps & Adlard, 2006 Kudoa muscularis Cheung, Nigrellu & Ruggieri, 1983 Kudoa musculoliquefaciens Matsumoto & Arai, 1954 Kudoa neothunni Arai & Matsumoto, 1953 Kudoa neurophila Grossel, Dyková, Handlinger & Munday, 2003 Kudoa niluferi Özer, Okkay, Gürkanlı, Çiftçi & Yurakhno, 2018 Kudoa nova Naidenova, 1975 Kudoa obicularis Azevedo, Rocha, Matos, Oliveira, Matos, Al-Quraishy & Casal, 2016 Kudoa ocellatus Da Silva, Da Silva, Lima, Matos, De Carvalho Sanches, Matos & Hamoy, 2022 Kudoa ogawai Yokoyama, Yanagida & Shirakashi, 2012 Kudoa ovivora Swearer & Robertson, 1999 Kudoa pagrusi Al Quraishy, Koura, Abdel-Baki, Bashtar, El Deed, Al Rasheid & Abdel Ghaffar, 2008 Kudoa paniformis Kabata & Whitaker, 1981 Kudoa paralichtys Cho & Kim, 2003 Kudoa paraquadricornis Burger & Adlard, 2009 Kudoa parathyrsites Kasai, Li, Mafie & Sato, 2016 Kudoa parvibulvosa Li, Inoue, Zhang & Sato, 2022 Kudoa pericardialis Nakajima & Egusa, 1978 Kudoa permulticapsula Whipps, Adlard, Bryant & Kent, 2003 Kudoa peruvianus Mateo Salas, 1972 Kudoa pleurogrammi Kasai, Li, Mafie & Sato, 2016 Kudoa prunusi Meng, Yokoyama, Shirakashi, Grabner, Ogawa, Ishimaru, Sawada & Murata, 2011 Kudoa quadratum Thélohan, 1895 Kudoa quadricornis Whipps, Adlard, Bryant & Kent, 2003 Kudoa quraishii Mansour, Harrath, Abd-Elkader, Alwasel, Abdel-Baki & Al Omar, 2014 Kudoa ramsayi Kalavati, Brickle & MacKenzie, 2000 Kudoa rayformis Shin, Shirakashi, Hamano, Kato, Lasso & Yokoyama, 2016 Kudoa rosenbuschi Gelormini, 1966 Kudoa rousseauxii Velasco, Eduard, Neto, Dias, Matos & Gonçalves, 2022 Kudoa saudiensis Mansour, Harrath, Abdel-Baki, Alwasel, Al-Quraishy & Al Omar, 2015 Kudoa schulmani Naidenova & Zaika, 1970 Kudoa sciaenae Teran, Llicán & Lugue, 1990 Kudoa scomberi Li, Sato, Tanaka, Ohnishi, Kamata & Sugita-Konishi, 2013 Kudoa scomberomori Adlard, Bryant, Whipps & Kent, 2005 Kudoa sebastea Aseeva, 2004 Kudoa septempunctata Matsukane, Sato, Tanaka, Kamata & Sugita-Konishi, 2010 Kudoa shiomitsui Egusa & Shiomitsu, 1983 Kudoa shkae Dyková, Lom & Overstreet, 1994 Kudoa sphyraeni Narasimhamurti & Kalavati, 1979 Kudoa stellula Yurakhno, 1991 Kudoa surabayaensis Yunus, Yustinasari, Natalia, Ghosh, Sakuma, Inoue & Sato, 2021 Kudoa tachysurae Sarkar & Mazumder, 1983 Kudoa tetraspora Narasimhamurti & Kalavati, 1979 Kudoa thalassomi Adlard, Bryant, Whipps & Kent, 2005 Kudoa thunni Matsukane, Sato, Tanaka, Kamata & Sugita-Konishi, 2011 Kudoa thyrsites Gilchrist, 1924 Kudoa trachuri Matsukane, Sato, Tanaka, Kamata & Sugita-Konishi, 2011 Kudoa trifolia Holzer, Blasco-Costa, Sarabeev, Ovcharenko & Balbuena, 2006 Kudoa unicapsula Yurakhno, Ovcharenko, Holzer, Sarabeev & Balbuena, 2007 Kudoa viseuensis Monteiro, Da Silva, Hamoy, Sanches & Matos, 2019 Kudoa whippsi Burger & Adlard, 2009 Kudoa yasai Cardim, Araújo-Neto, da Silva, Hamoy, Matos & Abrunhosa, 2020 Kudoa yasunagai Hsieh & Chen, 1984
Development In Myxozoan development, the Myxosporean life-stage develops inside a fish host, while the Actinosporean life-stage develops in an annelid host. 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. 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. Once attached to the fish, the gamete injects the sporoplasm cell into the fish. The sporoplast divides forming a fully-developed Myxosporean.
Diet Kudoa parasitize on marine and estuarine fish. 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. Most Kudoa are histozoic parasites, however, a few species are coelozoic. 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.
Implications for the fishing industry Kudoa are most well known for the economic loss they cause for the commercial fishing and aquaculture industries. 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. 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).
Some studies have found evidence to suggest that some species of Kudoa are linked to food-borne illness in humans.
References Encyclopedia of Life