Gill ectoparasite assemblages of two non-native Cichla populations (Perciformes, Cichlidae) in Brazilian reservoirs

Abstract

The gills of 41 Cichla piquiti and 39 C. kelberi from Itaipu and Lajes reservoirs, respectively, Brazil, were examined to describe the ectoparasite assemblages of these two non-native peacock-bass populations. All ectoparasite species of the two studied hosts (C. piquiti and C. kelberi) were dominant, but Ascocotyle sp. (metacercariae) was the prevalent (58.53%) and most abundant helminth species in C. piquiti hosts, while Sciadicleithrum ergensi was the dominant species in C. kelberi hosts. Gill ectoparasites of C. piquiti and C. kelberi showed a typical pattern of overdispersion or aggregation, which is commonly reported for many other freshwater fishes. Ectoparasite prevalence and abundance did not vary between host sexes of the two Cichla populations. The prevalence and abundance of Ascocotyle sp. were positively correlated with C. piquiti standard length (SL), but only the abundance of S. ergensi showed a positive correlation with C. kelberi SL. Although environmental differences between reservoirs might also have influenced the results, we anticipated that the presence of a close congener in Itaipu reservoir and the lack of other Cichla species in Lajes reservoir were the key factors to explain the contrasts between C. piquiti and C. kelberi gill ectoparasites. Overall, our results suggest that the trend of parasite species loss through the invasion process may have contributed to the establishment of non-native C. piquiti and C. kelberi populations in Brazilian reservoirs.

Massive parasitism by Gussevia tucunarense (Platyhelminthes: Monogenea: Dactylogyridae) in fingerlings of bujurqui-tucunare cultured in the Peruvian Amazon

“…The results described herein are in accordance with Kritsky et al (1989) and Yamada et al (2011), who found the monogenean G. tucunarense parasitizing gills of two species of cichlid, C. ocellaris and C. kelberi respectively, being common the setting of this kind of monogenoide parasite in this (Kritsky et al 1989). Indeed, several studies report the parasitism of G. disparoides in gills of H. severus, C. amazonarum and C. ocellaris and all these fish species are currently being raised in confined environments in the Peruvian Amazon.…”

“…Several studies report the parasitism of neotropical cichlids by monogeneans belonging to Gussevia Kohn et Paperna, 1964(Kritsky et al 1989, Vidal-Martinez et al 2001, Yamada et al 2011, Mendoza-Franco et al 2010. For South America thirteen species of Gussevia have been described for eight species of cichlids (Kritsky et al 1986(Kritsky et al , 1989, evidencing a high specificity of Gussevia species parasitizing cichlids.…”

“…However, the results differ from our study where we found a prevalence of 100% and mean intensity of 50 and 100 parasites of G. tucunarense. A possible reason for the low levels of infestation reported by Yamada et al (2011) may be fact that the fish originate from nature.…”

“…Indeed, several studies report the parasitism of G. disparoides in gills of H. severus, C. amazonarum and C. ocellaris and all these fish species are currently being raised in confined environments in the Peruvian Amazon. Furthermore, in a study with C. kelberi, captured from the wild, Yamada et al (2011) found 18.42% of prevalence and mean intensity of 1 and 4 monogeneans of G. tucunarense. However, the results differ from our study where we found a prevalence of 100% and mean intensity of 50 and 100 parasites of G. tucunarense.…”

Parasite Community of Cichla kelberi (Perciformes, Cichlidae) in the Três Marias Reservoir, Minas Gerais, Brazil

“…(metacercariae) in peacock basses collected in the Itaipú Reservoir, State of Paraná. Yamada et al (2011) inventoried the ectoparasites S. ergensi, Gussevia tucunarense Kritsky, Thatcher, and Boeger, 1986, G. undulata and Ascocotyle sp. of peacock basses collected in the Lajes Reservoir, State of Rio de Janeiro.…”