A histological evaluation of pansteatitis-affected Mozambique tilapia, Oreochromis mossambicus (Peters 1852), from different geographical locations in South Africa.

Pansteatitis is the leading cause for the decline in Nile crocodile populations and the sporadic mortality of fish in the Olifants River System, South Africa. To determine the prevalence of this disease in lentic systems, Mozambique tilapia, Oreochromis mossambicus, were collected from Lake Loskop, Lake Flag Boshielo, Phalaborwa Barrage and Lake Luphephe-Nwanedi. The former three impoundments are located within the main stem of the Olifants River, while the latter, which is geographically isolated and situated in the Limpopo River System, served as a reference site. Mesenteric adipose, liver, serosa of the swim bladder, gill and the skeletal muscle of fish sampled were examined for gross and microscopic evidence of pansteatitis. Microscopically observed changes were used to statistically compare pansteatitis prevalence between samples and sites. Based on histopathological evaluation, the adipose tissue in the liver, swim bladder serosa and coelom from severely debilitated individuals showed the most significant pathological changes. Lesions indicative of steatitis were observed in fish collected from Lake Loskop (75%), Lake Flag Boshielo (22%) and Lake Luphephe-Nwanedi (15%). Further investigation is warranted to understand the pervasiveness and mechanisms driving pathological changes of pansteatitis at Lake Flag Boshielo, Phalaborwa Barrage and Lake Luphephe-Nwanedi.

Expanded description of Lamproglena cleopatra Humes, 1957 (Lernaeidae: Copepoda) from Labeo spp. (Cyprinidae) with a key to species of Lamproglena von Nordmann, 1832.

The occurrence of the copepod Lamproglena cleopatra Humes, 1957, parasitising freshwater fishes in the Limpopo River System is presented, along with new morphological data. This crustacean was originally described parasitising a cyprinid (Labeo forskalii Rüppell) from the River Nile, Egypt. During 2014-2015 crustacean samples were collected from the gills of three cyprinid fish species, Labeo rosae Steindachner from Flag Boshielo Dam, Labeo molybdinus Du Plessis from Nwanedi-Luphephe Dam in South Africa, and Labeo ruddi Boulenger from the River Bubye in Zimbabwe. The specimens from the present study were morphologically similar regardless of the host, but exhibited some morphometric intraspecific differences in comparison with the type-specimen from Egypt. A description of L. cleopatra copepodid III stage and a taxonomic key to Lamproglena spp. is provided.

Screening for Hepatozoon parasites in gerbils and potential predators in South Africa.

Samples of gerbils and their potential predators were screened for the presence of Hepatozoon parasites (Apicomplexa: Adeleorina) using both microscopic examination and sequencing of partial 18S rRNA sequences. Positive samples were compared to published sequences in a phylogenetic framework. The results indicate that genets can be infected with Hepatozoon felis. A Cape fox was infected with Hepatozoon canis, whereas the sequence from an infected rodent fell within a group of parasites primarily recovered from other rodents and snakes.