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.
Pisidium (Afropisidium) aslini Kuiper, 1983
Common name: Pea shell
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.
Shallow burrower, suspension feeder. Inhabits creeks, is often associated with P. tasmanicum.(Korniushin, 2000).
Western Victoria and northern Tasmania.
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.