A New Species of Mugilicola Parasitic on South African Elvers (Copepoda,Therodamasidae)

A new species of parasitic copepod belonging to the genus Mugilicola Tripathi, I960 (CYCLOPOIDA: THERODAMASIDAE) is described. The copepods were embedded in the buccal cavity of elvers of Anguilla mossambica caught in South African rivers.     

Polystomatidae (Monogenea) of southern African Anura: Polystoma channingi n.sp. parasitic in two closely related Cacosternum species

Polystoma channingi is described as a new species of polystomatid flatworm (Monogenea) parasitic in the urinary bladder of Cacosternum nanum in the Eastern Cape Province, South Africa. In a locality where C. nanum and C. boettgeri occur sympatrically the parasite has been found in both species. This finding of a Polystoma sp. in two closely related host species questions the strict host-specificity generally ascribed to the genus, but supports the hypothesis that host-specificity is determined by the oncomiracidium's ability to recognize the tadpole as a suitable host. This is the first polystome to be described from the genus Cacosternum and the ninth species of Polystoma from South Africa. The species is distinguished by its huge haptor and suckers relative to the body size. The haptor length/body length ratio of 0.38 is by far the largest for the known southern African polystomes. The prevalence of infection with P. channingi n.sp. was 25% for C. nanum and 40% for C. boettgeri, while the mean intensity of infections in adult frogs was 1.5 for C. boettgeri and 1.0 for C. nanum.     

Histochemical demonstration of the inhibitory effect of Nuvan and Neguvon on cholinesterase activity in Pseudodactylogyrus anguillae (Monogenea)

The nervous system of Pseudodactylogyrus anguillae, a gill parasite from European eel (Anguilla anguilla) is demonstrated histochemically using the acetylthiocholine iodide method. It was shown that the staining of the nervous system was reduced or eliminated due to the inhibitory effect of Nuvan® and Neguvon®.     

Impact of Prosopis (mesquite) invasion and clearing on vegetation species composition and diversity in semi-arid Nama-Karoo rangeland,South Africa

The Nama-Karoo biome occupies 28% of South Africa’s land area. Alien leguminous trees of the genus Prosopis have invaded large tracts of Nama-Karoo rangeland. We evaluated the impact of Prosopis invasion and clearing on vegetation species composition and diversity (alien and indigenous species richness and cover) in Nama-Karoo rangeland on two sheep farms in the Beaufort West district of the Western Cape province of South Africa. Our results suggest that Prosopis invasion and clearing can significantly change Nama-Karoo rangeland species composition. Invasion and clearing appear to have no effect on alien species richness. Invasion, however, increases alien species cover, while clearing restores it to pre-invasion levels. In contrast, invasion reduces indigenous species richness while clearing restores it to pre-invasion levels. Invasion appears to have no effect on indigenous species cover. This lack of effect appears to be the serendipitous result of a site-specific trade-off between a decline in cover of grasses that are negatively affected by Prosopis invasion and a concomitant increase in the cover of positively affected grasses. Clearing increases indigenous species cover to above pre-invasion levels. The higher than usual indigenous species cover after clearing could be a transient legacy of Prosopis soil nutrient enrichment.     

First record of predation by the alien invasive freshwater fish Micropterus salmoides L. (Centrarchidae) on migrating estuarine fishes in South Africa

This study presents results from stomach content analysis of 123 largemouth bass, Micropterus salmoides, sampled at the mouth of the fishway leading into a 3 m high weir at the tidal limit of the Kowie River, Eastern Cape Province (33°32‘39“S, 26°46‘ 52.3“E). Stomach contents from small (120–240 mm fork length, FL) and large (250–440mm FL) fish were analysed separately. Fish were the dominant prey item in small bass, followed by terrestrial insects and Potamonautes sp. In large bass, Potamonautes sp. dominated the stomach contents, while fish were less dominant and other prey items were considered incidental. Estuarine fish species, Monodactylus falciformis, and two species of the family Mugilidae, Mugil cephalus and Myxus capensis, were the most common fish prey in both size classes of M. salmoides. These results are the first evidence of the alien M. salmoides preying on these three indigenous estuarine species during their migration into fresh water.     

Disentangling the identities and distribution patterns of the introduced beachfleas Orchestia gammarellus and Platorchestia platensis (Crustacea: Amphipoda: Talitridae) in South Africa

Two introduced beachfleas, Orchestia gammarellus and Platorchestia platensis, have been recorded from South Africa, but have been misidentified by some earlier researchers and, prior to this study, each was also known from just a few, scattered observations, such that their true distributions remained obscure. We illustrate both species to clarify the features that identify and distinguish them and determine their true distributions by re-examining historical samples and by collecting new material from estuaries and lagoons along the west and south coasts of South Africa. Adult males of O. gammarellus have slender antennae and characteristic expanded, flattened, oar-like distal segments on pereopod 7. Adult males of P. platensis have the peduncle of antenna 2 strongly swollen and have bulbous, but not flattened, distal segments on pereopod 7. Both species occur under wrack and other debris along the banks of estuaries and sheltered lagoons. Orchestia gammarellus is found only along the south-west coast, in the Berg River Estuary, Langebaan Lagoon and the Diep River Estuary. Previous records from Knysna were misidentifications of P. platensis. Platorchestia platensis is found at one west coast site, Langebaan Lagoon, but is widely distributed from Cape Point eastwards to at least Algoa Bay. Both species share the same habitats as several other native beachfleas and competitive interactions between native and introduced species merit investigation.     

Species Richness and Abundance of Clinid Fish (Teleostei; Clinidae) in Intertidal Rock Pools

Factors affecting species richness and abundance of clinid fish(Fam. Clinidae)in 19 intertidal rock pools near Muizenberg, South Africa, were investigated. Some measure of cover is the most important predictor of clinid species richness, abundance and biomass. Intraspecific partitioning of habitat by Clinus superciliosus was observed, and apparently occurs in C. cottoides as well. Fish were observed to move between pools during high tides, and some individuals showed fidelity to particular pools. There is some evidence for suggesting that C. superciliosus might be a colonizing species.     

Endoparasites of the Siberian tiger (Panthera tigris altaica)

There have been few reports on the diversity and prevalence of parasitic fauna of the endangered Siberian tiger, which inhabits the territory of the Russian Far East. The present review attempts to summarize the information about the parasitic fauna of wild Siberian tigers, which includes 15 helminths and 3 protozoan species. The most prevalent parasitic species was found to be Toxocara cati, followed by Toxascaris leonina. Another commonly recorded Platyhelminth species is Paragonimus westermani, which causes a lethal infection of the lung parenchyma in Siberian tigers. However, the information about infections by this fluke in the Siberian tigers is scarce, although P. westermani infections pose a serious health hazard to tiger populations. The nematodes Aelurostrongylus abstrusus and Thominx aerophilus are found in Siberian tigers with an occurrence rate of 2.3% and 19%, respectively. The information on the parasitic infestations of captive populations of Siberian tigers is also presented along with the sources of infection and hazards for the wild tiger populations in their natural environment.     

Successful eradication of the European rabbit (Oryctolagus cuniculus) and house mouse (Mus musculus) from the island of Selvagem Grande (Macaronesian archipelago), in the Eastern Atlantic

The Portuguese island of Selvagem Grande (Great Salvage) in Macaronesia is an important seabird breeding station in the eastern Atlantic. Significant populations of Cory's shearwater Calonectris diomedea (Scopoli, 1769), Bulwer's petrel Bulweria bulweria (Jardine & Selby, 1828) and little shearwater Puffinus assimilis baroli (Bonaparte, 1857) are present, and white-faced storm-petrel Pelagodroma marina (Latham, 1790) and Madeiran storm-petrel Oceanodroma castro (Harcourt, 1851) populations are of global significance. Selvagem Grande also provides diverse habitats for an extensive flora, including 11 endemic species. The 270-ha island was also inhabited by two alien invasive mammals: the European rabbit Oryctolagus cuniculus (Linnaeus, 1758) and the house mouse Mus musculus (Linnaeus, 1758). Both are known to have had adverse impacts on breeding seabirds and island vegetation. In 2002, the Natural Park of Madeira conducted a program using brodifacoum bait formulations aimed at rabbit and mouse eradication. Approximately 17 000 individual baiting points were established on a 12.5 × 12.5 m grid. Baits were also applied by hand “seeding” on steep slopes and cliffs where bait stations could not be placed. Rabbits were removed after a month. However, mice persisted for considerably longer and strategic bait applications against them continued for a further six months. Subsequent assessments by trapping, bait takes and systematic observation of signs over three years, has confirmed the removal of both alien invasive species. This paper presents information on these operations, on measures adopted to mitigate adverse impacts of the eradication program on important vertebrate non-target species, including Berthelot's pipit Anthus berthelotii Bolle, 1862 and a species of gecko Tarentola bischoffi Joger, 1984 and on the initial response of the island's ecosystem to the eradication of rabbits and mice.     

A review of the Namaqua gecko,Pachydactylus namaquensis (Reptilia: Gekkonidae) from southern Africa,with the description of two new species

An analysis of morphological and allozyme variation in the Namaqua gecko, Pachydactylus namaquensis from southern Africa is presented. Three separately evolving lineages, well defined by morphology and allozyme variation, are identified. The isolated southern population, occurring on the southern escarpment and Cape Fold Mountains surrounding the western Little Karoo, is named P. kladamderma sp. nov., and is characterized by a slit-like ear opening, low number of granules bordering the mental (3-6) and mental and adjacent infralabials (513), the frequent (79%) occurence of the supralabial entering the nostril, and its drab brown base colouration. A northern population, occurring in southern Namibia and the Richtersveld is named P. haackei sp. nov., and is characterized by its more rounded or squared ear opening; high number of granules bordering the mental and adjacent infralabials (11-19), the general exclusion of the supralabial from the nostril (only 3.7% entry), and brighter, lighter colouration. It is further differentiated from P. kladaroderma on the basis of fixed differences at 11 allozyme loci. Both new species differ from P. namaquensis, which is mainly restricted to Little Namaqua- land, but is sympatric with P. haackei in the Lower Orange River region, by their more heterogenous dorsal scalation, smaller cloacal spurs, lack of spine-like tubercles on the lateral surfaces of the tail, and more fragile skin. The type locality of P. namaquensis is restricted to ‘the vicinity of Springbok, Little Namaqualand, Northern Cape Province, South Africa’.     

The status of habitat of great white and pink-backed pelicans in northeastern KwaZulu-Natal,South Africa: a review

Habitat change, mainly through the actions of humans, poses a threat to great white (Pelecanus onocrotalus) and pink-backed (P. rufescens) pelicans in northeastern KwaZulu-Natal, the southernmost distributions of these species on Africa’s eastern seaboard. This study assessed the relative importance and state of the potential pelican habitat in the northeastern KwaZulu-Natal region, focusing particularly on Lake St Lucia and the Phongolo River floodplain. Great white pelicans breed on islands in Lake St Lucia. Should these islands be lost through falling water levels or their becoming joined to mainland by deposits of silt, or by flooding, no suitable habitat for their breeding will remain in the region. By contrast, the pink-backed pelican nests in trees, and there appears to be plentiful alternative habitat. Lake St Lucia and, to a lesser extent, the Phongolo River floodplain, are important foraging areas for both pelican species. The hydrology of both these systems has been affected by human activities.     

Description of a new species of Afroedura (Loveridge) (Reptilia: Gekkonidae) from the south-western Cape

A new gekkonid species, Afroedura hawequensis, is described from the south-western Cape (South Africa). The three species groups recognized in the genus are discussed.     

The ant,Pachycondyla sennaarensis (Mayr) as an intermediate host for the poultry cestode,Raillietina tetragona (Molin)

The role of several species of ants as intermediate hosts for poultry cestodes in the Sudan was investigated by a search for cysticercoids in specimens from poultry houses in various localities in the country. Pachycondyla sennaarensis, Messor galla and Acantholepis sp. were the only species collected from the areas surveyed. All these ants were examined for cysticercoids of poultry tapeworms but only P. sennaarensis was found to carry cysticercoids, all of which were identical to those of the poultry cestode, Raillietina tetragona. This tapeworm was recovered from all chicks fed the cysticercoids obtained from P. sennaarensis. R. tetragona cysticercoids were present in 63.3% of the P. sennaarensis sampled with 1–40 cysticercoids per ant, which is the heaviest recorded infestation of an ant species with these cysticeroids.     

Morphological analysis of the reproductive activity of Curimatella lepidura (Characiformes: Curimatidae)

Curimatella lepidura, commonly known as the manjuba, belongs to the Curimatidae family. To assess the reproductive activity of this species, fish were collected from three sections of the São Francisco River: section 1 = the Três Marias reservoir (TMR), section 2 = the SFR immediately downstream of the TMR, and section 3 = the SFR 54 km downstream from the TMR after the confluence of the SFR with the Abaeté River. Fish were collected bimonthly from January to December 2012. From this, the gonadosomatic index (GSI), Fulton condition factor (K), gonadal maturation stages in females and males, and diameters of vitellogenic follicles were determined. That is, this study employed histological and histometrical techniques to study the ovaries and testes of collected fish. The Fulton condition factor was statistically higher in section 1 than in the other sections, indicating that C. lepidura presents better health conditions in this section. Fish in the maturation/mature gonadal stage were collected in the November/December and January/February bimesters, coinciding with high temperatures, a long photoperiod, and abundant rainfall in this region. The mean vitellogenic follicle diameter was statistically lowest for sections 2 and 3, with a better impact on reproduction than in section 1. Overall, the results show that C. lepidura has reproductive success in lentic environments, such as in section 1, the TMR.     

Phylogeography and genetic diversity of Psammophis schokari (Serpentes) in North Africa based on mitochondrial DNA sequences

The snake Psammophis schokari has a widespread distribution across North Africa, and in Morocco/Western Sahara is represented by three different morphotypes: striped, unicoloured and the Western-Sahara morph. ND4 mitochondrial DNA sequences from 28 specimens comprising 20 P. shokari, two P. aegyptius, one P. elegans, two P. sibilans, one P. condanarus and two outgroups were analysed. Within P. schokari we identified four genetic lineages (Morocco/Western Sahara, Mauritania, Algeria and Israel) with a genetic divergence ranging from 4-5%, less than that typically found between different species. Surprisingly, Moroccan/Western Sahara and Algerian lineages are the most divergent ones. This geographic substructuring may be due to severe climate changes in the Sahara desert between the Miocene and Pleistocene associated with expansion/contraction phases of this desert. Psammophis aegyptius is the sister-taxon of Psammophis schokari with a high level of genetic divergence between them (10.7%) supporting the recognition of P. aegyptius as a distinct species. The three Moroccan/Western Sahara colour morphotypes form one genetic lineage, indicating that colour pattern does not reflect a different phylogenetic history, and is probably an ecological adaptation to the local environment.     

Experimental Infection of Australian Freshwater Fish with Epizootic Haematopoietic Necrosis Virus (EHNV)

Abstract

The ranavirus, epizootic hematopoietic necrosis virus (EHNV), is endemic to southern Australia with natural outbreaks resulting in mass mortality events in wild Redfin Perch Perca fluviatilis (also known as Eurasian Perch) and less severe disease in farmed Rainbow Trout Oncorhynchus mykiss. To further investigate the host range for EHNV, 12 ecologically or economically important freshwater fish species from southeastern Australia were exposed experimentally to the virus. A bath-challenge model at 18 ± 3°C was employed with limited use of intraperitoneal inoculation to determine if a species was likely to be susceptible to EHNV. Of the species tested, Murray–Darling Rainbowfish Melanotaenia fluviatilis and Dewfish Tandanus tandanus (also known as Freshwater Catfish) were considered to be potentially susceptible species. EHNV was isolated from approximately 7% of surviving Eastern Mosquitofish Gambusia holbrooki, indicating this widespread alien fish species is a potential carrier. The infection of Silver Perch Bidyanus bidyanus and Macquarie Perch Macquaria australasica and the lack of infection in Murray Cod Maccullochella peelii peelii and Golden Perch Macquaria ambigua ambigua after exposure to EHNV via water confirmed earlier data from Langdon (1989). Five other species of native fish were potentially not susceptible to the virus or the fish were able to recover during the standard 35-d postchallenge observation period. Overall, it appeared that EHNV was less virulent in the present experimental model than in previous studies, but the reasons for this were not identified.

Received May 21, 2012; accepted November 1, 2012     

Some Parasitic Worms in Freshwater Fishes and Fish-Predators from the Transvaal,South Africa

This report concerns a collection of parasitic worms from South Africa, and contains a new species of monogenean, Gyrodactylus transvaalensis, six species of adult trematodes, including a new species of Phyllodistomum.P. van der waali, two metacercariae of the Family Clinostomidae and three of the Order Strigeida, as well as two species of cestodes, and larvae of the nematode genus Contracaecum. The adults of previously-known helminths are redescribed, with some remarks on their systematics and biology. Accompanying the material of the new gyrodactylid monogenean there is a specimen which is thought to be a giant of the new form, and this appears to be the first recorded suggestion of the occurrence of gigantism in the Monogenea, and in fact in any kind of helminth.