During parasitological surveys of freshwater fish from the Miranda River, Brazil, 199 Pygocentrus nattereri kner (Characidae) were caught. Two pentastomid families, Subtriquetridae Fain, 1961, represented by its single genus Subtriquetra Sambon, 1922, and Sebekidae Sambon, 1922, represented by three genera, were present. Free-living larvae of Subtriquetra subtriquetra (Diesing, 1835) were collected from the swim bladder. Encysted larvae of Alofia Giglioli, 1922 were found in the abdominal cavity, chambers of the heart, musculature, on the surface of the gonads and swim bladder. Some Alofia larvae were moving freely in the swim bladder. Larvae of Sebekia Sambon, 1922 were encysted in the musculature. Some larvae of Leiperia Sambon, 1922 were found encysted in the musculature and on the surface of the pyloric caeca, whereas others occurred free in the abdominal cavity. In some of the latter, the head was buried deep in the wall of the intestine, stomach or ovaries, whereas the rest of their body remained free. Infective pentastomid larvae were present throughout the year with an overall prevalence of 77%. Both prevalence and intensity were higher in members of the Sebekidae than in Su. subtriquetra, possibly due to the latter's mode of transmission and its high pathogenicity. No sex-related, statistically significant differences (p > 0.05) in prevalence or abundance were found. Fish weight and length had significant but weak positive correlations (r ≤ 0.27) with the abundance of pentastomid larvae, possibly reflecting an increased likelihood of prior exposure in older fish. Parasite abundance had no significant effect on host body condition (p ≥ 0.69). A higher prevalence and monthly mean abundance of pentastomids were seen in the dry season and might be due to increased host densities as habitats dry up. Pygocentrus nattereri represents a new intermediate host record for the genera Alofia, Leiperia and Subtriquetra.
Thirty-two specimens of the Nile crocodile, Crocodylus niloticus Laurenti (Reptilia: Crocodylidae), from the Kruger National Park, South Africa, and its vicinity were examined for pentastomid parasites during 1995 to 1999 and 2010 to 2011. Pentastomid parasites occurred throughout the year and were widespread in the study area with an overall prevalence of 97% and an overall mean abundance of 23.4 (0-81). Pentastome assemblages comprised six species in three sebekid genera: Alofia nilotici Riley et Huchzermeyer, 1995, A. simpsoni Riley, 1994, Leiperia cincinnalis Sambon, 1922, Sebekia cesarisi Giglioli in Sambon, 1922, S. minor (Wedl, 1861) and S. okavangoensis Riley et Huchzermeyer, 1995. The possible influence of host age, gender and geographic location (river system) on pentastome prevalence, abundance and species richness was investigated. Generally, neither host age, gender nor locality did affect infracommunities, likely because all hosts examined were adult or subadult and displayed comparable foraging behaviour, resulting in similar exposure pathways to fish intermediate hosts. Additionally, the longevity of pentastomids would contribute to accumulative infections as hosts mature. Structuring of pentastome assemblages was observed in as far as S. minor was the dominant species based on overall prevalence and abundance, followed by the equally common species S. cesarisi and L. cincinnalis. With an overall prevalence ranging from 34% to 41% and relatively low abundances, A. nilotici, A. simpsoni and S. okavangoensis form the rarer component of pentastome communities., Kerstin Junker, Frikkie Calitz, Danny Govender, Boris R. Krasnov, Joop Boomker., and Obsahuje bibliografii