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Pisidium (Afropisidium) aslini Kuiper, 1983

Diagnostic features

The subgenus is diagnosed as follows: Shell small, oval. Surface finely striated, sculpture more pronounced around umbo. Hinge plate narrow, cardinal teeth straight. Ligament external, elevated over dorsal margin. Only one (exhalant) siphon present; inhalant opening merged with pedal slit due to loss of presiphonal suture; ventral pair of siphonal retractors well developed, placed at posterior end of pedal slit. Outer demibranch absent. Brood pouch localised dorsally, formed by 7 to 20 filaments (depending on size of animal). Lateral loop of nephridium clearly visible from dorsal side.

The species differs from other Australian Pisidium in having an exterior ligament exterior, an elongate, moderately convex shell which is sculptured with fine, dense striations. The shell reaches 2.5 mm in length.

Classification

Pisidium (Afropisidium) aslini Kuiper, 1983

Common name: Pea shell

Class Bivalvia  

Subclass Heteroconchia

Superorder Heterodonta

Order Cardiida

Superfamily Sphaeroidea

Family Sphaeriidae

Genus Pisidium Pfeiffer, 1821

Subgenus Afropisidium Kuiper,1962 (Type species: Pisidium lepus Kuiper, 1957 = Pisidium pirothi Jickeli, 1881).

Original name: Pisidium aslini Kuiper,1983. Kuiper.J. G. J. (1983). The Sphaeriidae of Australia. Basteria 47: 3-52.

Type locality: Left bank at junction of Moleside Creek, Glenelg River, Victoria.

Biology and ecology

Shallow burrower, suspension feeder. Inhabits creeks, is often associated with P. tasmanicum.(Korniushin, 2000).

Broods young.

Additional information on the biology and ecology of members of this family can be found in Fauna of Australia, vol. 5A, p. 355.

Distribution

Western Victoria and northern Tasmania.

Further reading

Korniushin, A. V. (2000). Review of the family Sphaeriidae (Mollusca: Bivalvia) of Australia, with the description of four new species. Records of the Australian Museum 52: 41-102.

Kuiper, J. G. J. (1983). The Sphaeriidae of Australia. Basteria 47: 3-52.

Lamprell, K. & Healy, J. (1998). Bivalves of Australia, volume 2. Leiden, Backhuys Publishers.