Gyrodactylus spp. on African Clarias gariepinus: parasites who preferred co-speciation instead of host switching.
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| Year of publication | 2015 |
| Type | Conference abstract |
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| Description | Sharptooth catfish, Clarias gariepinus (Burchell, 1822), is widely distributed in Africa with the exception of Maghreb, Upper Guinea and Cape provinces of South Africa. On the African continent, C. gariepinus is currently known to be a host to seven species of the genus Gyrodactylus von Nordmann, 1832. During the period August 2011 – November 2014, several localities were sampled to establish gyrodactylid parasites diversity in the southern African region. In total 31 specimens of C. gariepinus were collected on several spots in South Africa (Flag-Boshielo Dam, Loskop Dam, Sand and Barota River in Limpopo Province; Mooi River and Barberspan Dam, North-West Prov.) and Zimbabwe (Zambezi River and Lake Kariba). The Gyrodactylus prevalence was noted to be 45%. Species identification based on opisthaptoral hard parts morphometry and nuclear rDNA ITS sequences identified the presence of 10 different Gyrodactylus species, of which four are currently known, i.e. G. alekosi Přikrylová, Blažek & Vanhove, 2012; G. gelnari Přikrylová, Blažek & Vanhove, 2012; G. rysavyi Ergens, 1973 and G. transvaalensis Prudhoe & Hussey, 1977. Present finding reveals unexpected Gyrodactylus species diversity and their wide distribution across different regions. Phylogenetic analyses based on the ITS rDNA sequences assisted in revealing interspecific relationships. Analysis of 18S rDNA revealed identical sequences for four species with distant geographical origin and which differ substantially in morpho-metrical characters. The observed species richness among one host seems to be a signal that co-evolution with intensive diversification occurred in this host-parasite system. |
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