Beddomeia lodderae Petterd, 1889

Diagnostic features

Species of the B. hullii group are found in the northern half of Tasmania. Their shells are small (1.7-3.7 mm in length; most less than 3.5 mm), simple, ovate-conic to broadly conic, with a thin inner lip and no columellar bulge. The periphery of the last whorl of the shell is rounded, subangled or angled and, in other members of the group, the penis is simple.

The differences in shell morphology between the very similar taxa B. lodderae, B. waterhouseae and B. forthensis, show no significant differences in shell characters (although they differ anatomically), however there are some subtle differences. B. waterhouseae has a slightly thinner shell with the outer lip evenly curved into the suture, whereas in B. lodderae, it is slightly shouldered at the suture. In addition, the umbilicus is very narrowly open and the chink more distinct in B. waterhouseae and the inner lip is thinner and narrower. B. forthensis is smaller, thinner and has fewer whorls.

Classification

Beddomeia lodderae Petterd, 1889

Class Gastropoda

Infraclass Caenogastropoda

Order Littorinida

Suborder Rissoidina

Superfamily Truncatelloidea

Family Beddomeiidae

Genus Beddomeia Petterd, 1889

Original name: Beddomeia lodderae Petterd, 1889. In Petterd, W. F. (1889). Contributions for a systematic catalogue of the aquatic shells of Tasmania. Papers and Proceedings of the Royal Society of Tasmania 1888: 60-83.

Type locality: Upper Castra (Rivulet), Tasmania, ex W.F. Petterd.

Biology and ecology

Egg capsules are presumably 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

Known from the Upper Castra River, Tasmania.

Notes

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

This species is on the Tasmanian Threatened Species Protection Act 1995 as Vulnerable.

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.