Proteocephalid cestode infection in alien fish, Cichla piquiti Kullander and Ferreira, 2006 (Osteichthyes: Cichlidae), from Volta Grande reservoir, Minas Gerais, Brazil

Abstract

This work evaluates the variation of the parasitological indexes in 114 Cichla piquiti Kullander and Ferreira, 2006 (tucunaré) infected by two proteocephalid species (Cestoda) for the period of August 1999 to June 2001 in the Volta Grande reservoir, MG, Brazil. The relation between the parasitosis with rainfall and water quality (pH, electric conductivity, oxygen, chlorophyll, transparency and temperature) is discussed. Prevalence of Proteocephalus macrophallus (Diesing, 1850) and/or P. microscopicus (Woodland, 1935) Abiotic factors may favour the development of the species of the food chain that sustain the organisms in the diet of " tucunaré", but in this case, there was no correlation (P > 0.05) between the values of prevalence, mean intensity and mean abundance with the rainfall and water quality. At the same time, these organisms may constitute the intermediate hosts of cestodes. The time-course between the fish species development and the parasitosis manifestation in the definitive host can explain the lack of correlation between the parasitological indexes and abiotic factors. The predation on small fishes and cannibalism described for "tucunaré" might explain the high values of prevalence and intensity of infection. The results are also related to the exotic condition of the host in the reservoir.Keywords: Tucunare, alien fish, parasitism, Proteocephalidae, hydroelectric reservoir. Infecção por cestóides proteocefalídeos em peixe introduzido,Cichla piquiti (Osteichthyes: Cichlidae), no reservatório de Volta Grande, Minas Gerais, Brasil ResumoEste estudo avalia a variação nos índices parasitológicos de 114 espécimes de Cichla piquiti Kullander e Ferreira, 2006 (tucunaré) infectados por duas espécies de proteocefalídeos (Cestoda) entre agosto de 1999 e junho de 2001 no reservatório de Volta Grande, MG, Brasil. A relação entre a parasitose e os valores de pluviosidade e qualidade de água (pH, condutividade elétrica, oxigênio, clorofila, transparência e temperatura) é discutida. A prevalência de Proteocephalus macrophallus (Diesing, 1850) e/ou P. microscopicus (Woodland, 1935) foi 83,3%, intensidade média 110,8 e abundância média 100,7 durante todo o período. Prevalência de 100% foi observada em agosto e dezembro de 1999, abril e dezembro de 2000 e junho de 2001. As maiores intensidades médias foram 122,7 em outubro de 1999; 158,8 em dezembro de 1999; 96,4 em fevereiro de 2000; 400,7 em abril de 2000; 215,6 em outubro de 2000; e 136,4 em dezembro de 2000. Fatores abióticos podem favorecer o desenvolvimento de espécies que sustentam a alimentação do "tucunaré", mas, neste caso, não houve correlação (P > 0,05) entre os valores de prevalência, intensidade média e abundância média com a pluviosidade e qualidade de água no reservatório. Ao mesmo tempo, estes organismos podem constituir hospedeiros intermediários de cestóides. A relação entre o desenvolvimento da espécie hospedeira e Martins, ML. et al. 190 Braz. J. Biol., 69(1): [189][190][191][192][193][194][195] 2009 1993; Moravec, 2001). Scho...

Parasite diversity in Oxydoras niger (Osteichthyes: Doradidae) from the basin of Solimões River, Amazonas state, Brazil, and the relationship between monogenoidean and condition factor

“…These studies can indicate the fish food habit, as has been reported by Machado et al (1996), Takemoto et al (2004Takemoto et al ( , 2009 and Martins et al (2009). Piscivorous fish occupy the top of the food web and may present more chance of infection (Machado et al, 1996;Martins et al, 2009), while omnivorous fish present lower risks of infection by the fact that they are primary consumers in the food web (Feltran et al, 2004;Takemoto et al (2009).…”

“…Martins et al (2009) noticed that moderate infection rates by proteocephalidean cestodes have been registered in fish from several parts of the world, since this endohelminthes is distributed uniformly in several aquatic habitats . In that opportunity, Martins et al (2009) found high parasite load by Proteocephalus macrophallus (Diesing, 1850) Scholz, Chambrier, Prouza andRoyero 1996 andP. microscopicus Woodland, 1935 in Cichla piquiti Kullander and Ferreira, 2006 from the Volta Grande Reservoir, MG, Brazil.…”

“…A metacestode or procercoid develops in the body cavity of these crustaceans and the definitive host, a fish, becomes infected directly after consuming them (Scholz, 1999). Consequently, proteocephalidean infection in small fish by the ingestion of these crustaceans may contribute to improve the prevalence rate and the intensity of infection in the largest hosts as the fish of carnivorous habit (Martins et al, 2009). In the present study, the prevalence (3.7%) and mean intensity (1.0) of P. kuyukuyu was lower than that observed for P. macrophallus and P. microscopicus (83.3 and 110.8, respectively) in C. piquiti, a piscivorous fish from the Volta Grande Reservoir, MG (Martins et al, 2009).…”

“…Fish may present a great diversity of parasites which depend on the fish species, food habit, temperature, climate and rainfall (Martins et al, 2009;Takemoto et al, 2009). They act as a host for a large number of parasites with varied strategies in their life-cycle.…”

“…Consequently, studies on fish parasitology are needed to improve the knowledge of the relationships between host and parasites Takemoto et al, 2004Takemoto et al, , 2009Martins et al, 2009). These studies can indicate the fish food habit, as has been reported by Machado et al (1996), Takemoto et al (2004Takemoto et al ( , 2009 and Martins et al (2009).…”