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Beddomeia launcestonensis (Johnston, 1879)

Diagnostic features

Species of the B. launcestonensis group are of medium size for the genus (2.0-4.2 mm in length), and rather globular. Their penis is simple. Found in the mid north and north eastern parts of Tasmania.

 Beddomeia launcestonensis differs from other members of this group in shell having a thicker, wider inner lip; female genital system with smaller bursa copulatrix, seminal receptacle at ventral edge of bursa copulatrix (rest at posterior edge) and simple ventral channel; male genital system with elongate, pyriform prostate gland; pallial cavity with hypobranchial gland usually having irregular ridges.

Classification

Beddomeia launcestonensis (Johnston, 1879)

Class Gastropoda

Subclass Caenogastropoda

Order Littorinimorpha

Superfamily Truncatelloidea

Family Tateidae

Genus Beddomeia Petterd, 1889

Original name: Amnicola launcestonensis Johnston, 1879. Johnston, R. M. (1879). Further notes on the fresh-water shells of Tasmania (with a description of a new species). Papers and Proceedings of the Royal Society of Tasmania 1879, 19-29.

Type locality: First Basin, Launceston, Tasmania.

Biology and ecology

Under large stones and rock slabs in deeper parts of the river. The white egg capsules are laid on the undersides of rocks and are like those of other species of Beddomeia - dome-shaped, with broad attachment base, covered with minute, mainly white sand grains and other fragments and containing a single egg. Development direct..

Distribution

This species is known only from a small part of the South Esk River between the First Basin and the Trevallyn Dam (Karen Richards pers. comm.).

Notes

All species of Beddomeia are geographically isolated and have restricted ranges.

This species is on the Tasmanian Threatened species list of Invertebrate Animals as Endangered.

Further reading

Ponder, W. F., Clark, G. A., Miller, A. C. & Toluzzi, A. (1993). On a major radiation of freshwater snails in Tasmania and eastern Victoria: a preliminary overview of the Beddomeia group (Mollusca: Gastropoda: Hydrobiidae). Invertebrate Taxonomy 7: 501-750.