Protozoan and metazoan parasites of Nile tilapia Oreochromis niloticus cultured in Brazil

Abstract

Objective. This study describes the parasitic fauna and relative condition factor (Kn) in Nile tilapia Oreochromis niloticus L. (Cichlidae) from fish farms in the State of Amapá. Material and methods. 123 fish from four fish farms in the state of Amapá, Brazil were necropsied for parasitological and Kn analysis. Results. 64.2% of the examined fish, had the gills infected with Cichlidogyrus tilapiae Paperna, 1960 (Monogenoidea: Dactylogyridae); Ichthyophthirius multifiliis Fouquet, 1876 (Protozoa: Ciliophora), Trichodina Ehrenberg, 1830 and Paratrichodina africana Kazubski & El-Tantawy, 1986 (Protozoa: Trichodinidae). The highest prevalence found corresponded to Monogenoidea C. tilapiae while the lowest corresponded to Trichodinidae. However, I. multifiliis was the parasite that presented the greatest intensity and abundance. The differences found in the infection rates of the different fish farms due to causes further discussed. The parasitism did not influence the relative condition factor (Kn) of fish. This was the first record of P. africana in Brazil and occurred in the Eastern Amazon. Conclusions. In Brazil, Lamproglena sp. is an emerging parasite in the Southern and Southeastern regions, but this crustacean was not found in the Nile tilapia in the State of Amapá. The parasitic infections in Nile tilapia farmed in Brazil are caused by protozoan, monogenoidea, crustacea and digenea species, and the regional differences on their prevalence and intensity rates are discussed in this study.

Parasites of native Cichlidae populations and invasive Oreochromis niloticus (Linnaeus, 1758) in tributary of Amazonas River (Brazil)

“…The low acquisition of exotic parasites by the rich fauna of native cichlids species was expected, since our recent studies (PANTOJA et al, 2012) …”

“…In contrast, C. tilapiae, the only species of helminth parasitizing this invasive fish in the region of this study, was not competent to invade any of the 16 species of native cichlids, fish ecologically similar. However, in Brazilian fish farms, O. niloticus has been parasitized by C. tilapiae and by C. sclerosus, besides other species still unidentified (PANTOJA et al, 2012), possibly the C. longicornis. Thus, the results of this fish introduction in Brazilian fish farms do not reflect what occurs in the natural environment; it indicates loss of monogenoideans species with the translocation of this tilapia from other regions of Brazil to the studied area.…”

“…In this same region, for this tilapia from fish farms, it was reported high levels of infection caused by C. tilapiae associated with low parasitism by Trichodina sp. (probably T. centrostrigeata), P. africana and I. multifiliis (PANTOJA et al, 2012), indicating that infections caused by ciliates were secondary. Fish with acute and subacute infection become more susceptible (TAVARES-DIAS et al, 2001) to infections by opportunistic species of protozoa showed in this study.…”

“…However, it has not been investigated yet the impacts of introducing Nile tilapia on the fauna of parasites in native ichthyofauna of this natural ecosystem with important species of scientific and applied interest. However, the introduction of trichodinids Paratrichodina africana (PANTOJA et al, 2012 was reported recently for O. niloticus farmed in this same region of Brazil.…”

Paratrichodina africana (Ciliophora: Trichodinidae) of wild and cultured Nile tilapia in the Northern Brazil

“…The authors allocated the species to the genus Paratrichodina due to the presence of two important features: the straight blade, in line with the radius of the adhesive disc and the absence of incision at the base of the blade, where the central part of the neighbouring denticle could enter. Later, the species was reported in Oreochromis mossambicus in West Bengal, India by Mitra and Bandyopadhyay (2006) and in O. niloticus in Northern Brazil by Pantoja et al (2012).…”