Pisidium personatum Malm, 1855

Rassam, Hanane, Ghamizi, Mohamed, Benaissa, Hassan, Clewing, Catharina & Albrecht, Christian, 2021, The fingernail clams (Bivalvia: Veneroida: Sphaeriidae) of Morocco: Diversity, distribution and conservation status, Biodiversity Data Journal 9, pp. 73346-73346 : 73346

Pisidium personatum Malm, 1855

Ecological interactions

Native status

Autochtonous

Distribution

Europe, Asia and North Africa ( Kuiper 1983)

Notes

Shell dimensions: Mean length = 2.92 ± 0.7 mm; Mean height = 2.45 ± 0.6 mm; Mean width = 1.74 ± 0.88 mm.

Key features: Rounded shape, centrally located umbo, but not prominent. The presence of a raised callus in the hinge is a specific feature of the species (Fig. 8 ), lying between the lateral teeth and the ligament pit. The callus is mainly present in the right valve and may be absent in the left valve.

Remarks: Pisidium personatum may be confused with P. casertanum as both species share similar morphological features, but P. personatum can be easily identified from other species of Pisidium by the presence of a callus in the hinge plate between the ligament pit and the lateral teeth on both valves, although it is less marked on the left valve.

Figures

Figure 8. Pisidium personatum from Tessaout River a External view of the whole animal (left and right); b Dorsal view; c internal view of hinge plate of left and right valves.