Diversity of metazoan parasites of the Mozambique tilapia, <i>Oreochromis mossambicus</i> (Peters, 1852), as indicators of pollution in the Limpopo and Olifants River systems

Abstract

Aquatic systems are affected by a variety of anthropogenic activities that decrease water quality through the introduction of organic and inorganic pollutants. To investigate the relationship between fish parasite communities and water quality, metazoan parasites were examined in 140 specimens of the Mozambique tilapia (Oreochromis mossambicus) sampled in three lakes in the Limpopo Province, namely the Luphephe-Nwanedi Dams (regarded as unpolluted), the Flag Boshielo Dam (regarded as moderately polluted) and a return water dam on a mine site (regarded as polluted). The monogenean parasites Cichlidogyrus halli, digenean larval stages of Clinostomum and Diplostomum spp. and a gryporynchid cestode were found in or on O. mossambicus in all the sampled sites. The distribution of monogeneans (Cichlidogyrus sclerosus, Cichlidogyrus dossoui, Cichlidogyrus tilapiae, Scutogyrus longicornis and three Enterogyrus spp.), metacercarial stages of two digeneans (Neascus and Acanthostomum spp.) and nematodes (an unidentified nematode, Contracaecum sp., Paracamallanus cyathopharynx and Procamallanus laevionchus) was limited to the unpolluted and moderately polluted lakes. Larval stages of Diplostomum sp. were present in O. mossambicus collected from the unpolluted and polluted sites. The variability of the calculated infection indices (prevalence, mean abundance and mean intensity) and the parameters of species richness and diversity suggest that the structure of parasite communities are affected by the pollution levels of the water. The unpolluted reference site had the highest species richness and the highest overall parasite abundance values.

Seasonal occurrence of some larval stages of endoparasites in three cyprinids from the Nwanedi-Luphephe dams, the Limpopo River System, South Africa

“…During the entire course of the survey, levels of the selected physico-chemical parameters measured were relatively low and within permissible TWQR range. This agrees with previous studies from the Nwanedi-Luphephe dams, chacterizing them as essentially unpolluted due to little urban development, absence of intensive agricultural, industrial and mining activities in the area (Oberholster et al, 2009;Madanire-Moyo et al, 2012). The infective stages are considered highly sensitive to adverse water conditions, therefore, their presence or absence may serve as an indication of the status of the water body (Tieri et al, 2006).…”

“…and Contracaecum larvae were previously recorded from L. marequensis as well as from other fi sh species in South Africa (Olivier et al, 2009;Smit & Luus-Powell, 2011;Madanire-Moyo et al, 2012). A high prevalence and intensity of infection of the two parasites were also recorded in B. trimaculatus in this study.…”

A brief history of freshwater fish parasitology in southern Africa

“…Professor Olivier is mostly involved in acarology, but sometimes also collaborates on copepod parasites, e.g. van As et al (1999) and helminths (Olivier et al 2009;Madanire-Moyo et al 2010, 2012a. Smit and Luus-Powell (2012) report on the metazoan endoparasites of Schilbe intermedius.…”

Assessment of Heavy Metal Pollution and Fish Parasites as Biological Indicators at Arabian Gulf off Dammam Coast, Saudi Arabia

“…J. Zool. Res., 11 (5): 198-206, 2015 being highly sensitive either in their physiological response to aquatic contaminants or in their ability to accumulate particular toxins in a dose-time dependent manner (Madanire-Moyo et al, 2012;Perez-I-Garcia et al, 2015).…”