''Tomichia cawstoni'' is a
species of very small
freshwater snail
Freshwater snails are gastropod mollusks which live in fresh water. There are many different families. They are found throughout the world in various habitats, ranging from ephemeral pools to the largest lakes, and from small seeps and springs ...
s which have a
gill and an
operculum,
gastropod
The gastropods (), commonly known as snails and slugs, belong to a large taxonomic class of invertebrates within the phylum Mollusca called Gastropoda ().
This class comprises snails and slugs from saltwater, from freshwater, and from land. T ...
mollusks or
micromollusk
A micromollusk is a shelled mollusk which is extremely small, even at full adult size. The word is usually, but not exclusively, applied to marine mollusks, although in addition, numerous species of land snails and freshwater mollusks also ...
s in the
family Tomichiidae.
Distribution
This species is
endemic to
South Africa.
The type locality is
Kokstad, KwaZulu-Natal,
Eastern Cape
The Eastern Cape is one of the provinces of South Africa. Its capital is Bhisho, but its two largest cities are East London and Gqeberha.
The second largest province in the country (at 168,966 km2) after Northern Cape, it was formed in ...
Province, South Africa.
[Brown D. S. (1994). ''Freshwater Snails of Africa and their Medical Importance''. Taylor & Francis. .]
Description
The width of the shell is 2.5 mm.; the height of the shell is 4.6 mm. Spire short, and flat sided. Whorls weakly convex.
Ecology
The natural
habitat for this species is
rivers in riverine forests, predominantly of freshwater in contrast to other species which inhabit ephemeral streams and rivers.
Threats
Species of the genus ''Tomichia'' are particularly susceptible to changes in their ecosystem, and thus species such as ''Tomichia cawstoni'' are greatly threatened by pollution and climatic changes (especially in the form of changes in rain cycles). In Kokstad, it is threatened by pollution and trampling from commercial cattle farming operations. All suitable locations for this species' inhabitance have since been found destroyed, restricting the species to the type locality.
References
External links
* Davis G. M. (1981). "Different modes of evolution and adaptive radiation in the Pomatiopsidae (Prosobranchia: Mesogastropoda)". ''
Malacologia'' 21
209262.
{{DEFAULTSORT:Tomichia Cawstoni
Endemic fauna of South Africa
Truncatelloidea
Gastropods described in 1939
Taxonomy articles created by Polbot