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Beddomeia mesibovi Ponder and Clark, 1993

Diagnostic features

Species in the B. bellii group are small to medium-sized (2.3-3.0 mm in length), ovate-conic to ovate and usually have a columellar swelling. The penis is simple (as in B. belli and B protuberata) or with a lenticular brown gland in the middle. Species in this group are restricted to north western Tasmania.

This species is one of five species that form a very distinct and apomorphic group, the other species being B. topsiae, B. salmonis, B, gibba and B. [1] [2]fultoni. All but one (B. [1] [2]fultoni) have a columellar fold on the rather broadly conic to ovate-conic shell, but the most distinctive feature is the presence of a large brown gland on the convex part of the medial section of the penis. B. mesibovi can be distinguished from the other members of the subgroup by the ventral channel of the capsule gland lacking an anterior vestibule and having a terminal genital opening.

Classification

Beddomeia mesibovi Ponder and Clark, 1993

Class Gastropoda

Subclass Caenogastropoda

Order Littorinimorpha

Superfamily Truncatelloidea

Family Tateidae

Genus Beddomeia Petterd, 1889

Original name: Beddomeia mesibovi Ponder and Clark, 1993 in Ponder, W.F., Clark, G.A., Miller, A. & 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.

Type locality: Small stream S of Arthur River near Kanunnah Bridge, Tasmania.

Biology and ecology

On leaf litter and moss and under wood and rocks in streams. Egg capsules like those of other Beddomeia species (Karen Richards pers. comm.) -  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 only known from a small stream south of Arthur River near Kanunnah Bridge, Tasmania.

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 Rare (small population at risk).

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.