Die verspreiding en habitats van Burnupia mooiensis in Suid–Afrika: (Walker 1912 [Gastropoda: Ancylidae])

Abstract

Burnupia mooiensis is reeds in 1912 vanaf eksemplare uit die Mooirivier, Potchefstroom beskryf en die oudste monster is in 1956 in die Nasionale Varswaterslakversameling (NVWSV) opgeneem. Op die oomblik is daar 14 spesies van Burnupia op rekord, maar tot dusver is die geografiese verspreiding en habitatvereistes van slegs twee spesies, naamlik B. capensis en B. stenochorias gepubliseer. Die geografiese verspreiding van die 224 monsters van B. mooiensis wat in die databasis van die NVWSV op rekord is en bepaalde aspekte van die vindplekke is ontleed, terwyl die voorkomsfrekwensie by verskillende watermassatipes, watertoestande en substrata in tabelle weergegee is. Data is statisties verwerk om habitatvereistes vas te stel. Die grootste persentasie monsters was afkomstig uit riviere (57.59%), asook uit spruite (18.30%) en die meerderheid is versamel in standhoudende habitats met klipperige substrata. Burnupia mooiensis is grootliks in die suidoostelike streke van Noordwes, sentrale streke van Gauteng en die suidwestelike streke van Mpumalanga versprei. In vergelyking hiermee strek die verspreiding van B. capensis en B. stenochorias oor 'n aansienlik wyer gebied. Die 14 spesies van Burnupia is oor 556 verskillende lokusse (0.0625°2) versprei en is derhalwe van die mees wyd verspreide varswaterslakgenusse in Suid-Afrika. In die lig van hul algemene voorkoms, grootliks sessiele, bentiese leefwyse en die feit dat hulle hoofsaaklik op epiliton voed, word aanbeveel dat die uitvoerbaarheid bevestig behoort te word om hulle as indikatorspesies van swaarmetaal-besoedeling in waterliggame in verskillende streke van Suid-Afrika te benutBurnupia mooiensis was already described in 1912 from specimens from the Mooi River, Potchefstroom while the oldest sample in the National Freshwater Snail Collection (NFSC) dates back to 1956. There are currently 14 species on record; however, to date the geographical distribution and habitat requirements of only two species were published. The geographical distribution of the 224 samples of B. mooiensis on record in the database of the NFSC and certain aspects of their sampling sites were analysed and the frequency of occurrence in different waterbodies, water conditions and substrata presented in tables. Data was statistically treated to determine habitat requirements. The largest percentage of samples came from rivers (57.59%), streams (18.30%) and the majority was collected in perennial habitats with stony substrata. Burnupia mooiensis is distributed mainly in the south-eastern areas of North-West, central areas of Gauteng and the south-western areas of Mpumalanga. In contrast to this, the distribution of B. capensis and B. stenochorias covers a much wider area, in spite of the fact that all three were already described by 1912 from sites in South Africa and that they share similar habitat requirements. The 14 species of Burnupia are spread over 556 different loci (0.0625°2) and therefore is one of the most widespread freshwater snail genera in South Africa. In view of its wide distribution, largely sessile, benthic lifestyle and the fact that they feed on epilithon, it is recommended that the feasibility to utilise them as bio-indicators of heavy metal pollution in waterbodies in different areas of South Africa be confirmed