ABSTRACT

Cichla monoculus (Spix & Agassiz, 1831) has long been erroneously termed C. ocellaris, so all species recorded in Brazilian Central Amazonia of C. ocellarisshould actually correspond to C. monoculus. This fact together with the lack of parasitic studies in this species, led to record the Monogenoidea species that parasitize C. monoculus from six floodplain lakes in the Brazilian Amazon for the first time. Thirty eight specimens of C. monoculus from five floodplain lakes of the Solimões River and one of the Purus River, Brazil during March to December 2012, were captured and necropsied. A total of 1665 specimens of Monogenoidea were collected. The prevalence of infection was 89%. Ten species belonging to three genera were identified: Gussevia sp., Gussevia arilla Kritsky, Thatcher & Boeger, 1986, Gussevia longihaptor Mizelle & Kritsky, 1969, Gussevia tucunarense Kritsky, Thatcher & Boeger, 1986, Gussevia undulata Kritsky, Thatcher & Boeger, 1986, Sciadicleithrum sp., Sciadicleithrum ergensi Kritsky, Thatcher & Boeger, 1989, Sciadicleithrum umbilicum Kritsky, Thatcher & Boeger, 1989, Sciadicleithrum uncinatum Kritsky, Thatcher & Boeger, 1989 and Tucunarella cichlae Mendoza-Franco, Scholz & Rozkosná, 2010. The Monogenoidea fauna was composed of three main species, four secondary and three satellites. Gussevia undulata had the highest coefficient of dominance within the whole parasite community. There was a significant positive correlation (p < 0.05) between the standard length of C. monoculus and the abundance of parasites and also a positive correlation between the host standard length and Monogenoidea species richness.

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