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- Title
Verspreiding van Burnupia capensis (Walker, 1912) en Burnupia stenochorias (Melvill & Ponsonby, 1903) (Gastropoda: Ancylidae) in Suid-Afrika.
- Authors
DE KOCK, K. N.; WOLMARANS, C. T.
- Abstract
The presence of Ancylidae in South Africa was established as early as 1848 but the first comprehensive study on this family was reported in 1923. This author came to the conclusion that extensive work still had to be done before it could be declared that knowledge pertaining to the South African representatives of this family could be considered as satisfactory. Another important contribution on South African Ancylidae was published in 1939. After a detailed morphological and histological study on Burnupia mooiensis three decades later the authors stated that the taxonomy of the Ancylidae still remained unsatisfactory, a view that was supported by authors as recently as 2002. The National Freshwater Snail Collection (NFSC) was established in 1956 but the oldest sample of Ancylidae on record dates back to 1954 and at present 14 species of Burnupia are represented in the database of the NFSC. This contribution deals with the geographical distribution and specific characteristics of the habitats of B. capensis and B. stenochorias the two most widespread species of this genus in South Africa. Very little is known of the conservation status of the Ancylidae of this country but some results pertaining to this subject are briefly discussed. Burnupia species are relatively inconspicuous organisms that are usually attached to solid objects on the substratum or aquatic vegetation and need to be specifically looked for during surveys. Personnel of government authorities and municipalities who made substantial contributions to the number of samples in the NFSC therefore received special training in sampling techniques during workshops. Identification of the specimens was largely based on shell and radula characteristics and on the location of the site of collection. Only samples of which the sampling sites could be located on the 1:250 000 topo cadastral map series of South Africa were considered for further analysis. Respectively 702 and 435 samples of B. capensis and B. stenochorias met this requirement. The loci (1/16 th square degrees) in which the collection sites of these species were located, were distributed in pre-selected intervals of mean annual air temperature and rainfall, as well as intervals of mean altitude, to illustrate the frequency of occurrence within specific intervals. A temperature index was calculated for all mollusc species in the database from their frequencies of occurrence within the selected intervals and the results used to rank them in order of their association with low to high climatic temperatures.…
- Subjects
SOUTH Africa; ANCYLIDAE; ZOOGEOGRAPHY; MOLLUSKS; HABITATS; WILDLIFE conservation
- Publication
Suid-Afrikaanse Tydskrif vir Natuurwetenskap en Tegnologie, 2009, Vol 28, Issue 3, p220
- ISSN
0254-3486
- Publication type
Article
- DOI
10.4102/satnt.v28i3.59