An Analysis of Variation in Australian Specimens of Pinctada albina (Lamarck) (Lamellibranchia)

Abstract

An analysis is made of variation in Australian specimens of Pinctada albina (Lamarck). Eight characters are investigated, and it is shown that these characters fall into two well-defined and unrelated groups.

In one group lie those characters which modify shape of shell. They are shown to vary with ecological conditions but not geographically.

In the other group lie those characters which modify colour and size of shell. Their variations are not ecological but are interpreted as geographical discontinuities, or clines, dividing the species into eastern and western subspecies.

Shark Bay is selected as designated typical locality for Pinctada albina (Lamarck) ; and P. albina albina (Lamarck) and P. a. sugillata (Reeve) respectively are the valid names for the western and eastern subspecies.