Summary
Physical Description
Ecology
Life History & Behaviour
Anatomy & Physiology
Evolution & Systematics
Biogeographic Distribution
Conservation & Threats
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Summary
Pinctada albina, Shark's Bay Shell, is a member of the genus Pinctada, which also contains Pinctada margaritifera (Black-lip oyster) and many other species of pearl oyster (Southgate & Lucas, 2008, Temkin, 2010). The genus Pinctada belongs to the phylum Mollusca, which encompasses a wide variety of animals, both aquatic and terrestrial (Ruppert et al., 2004). P. albina is small in size with grayish-green colouration on the exterior of the shell (Pearl Guide, 2011). Pearls found in P. albina are called Mabe pearls and are smaller and less spherical than normal pearls (Pear Guide, 2011).
External and internal views of a P. albina shell. Interior of the shell appear as shiny mother of pearl whilst exterior is grayish-green. The visceral mass, gills, mantle and other organs have been removed for sectioning and staining.
The distribution of P. albina varies depending on the literature source. Predominately found in Western Australia, the species may have a wider distribution through the Eastern Pacific and into South-east Asia (Encyclopedia of Life, Pearl Guide, 2011, Tenkin, 2010). Adults develop attached to the substrate by a specialised structure called a byssus that anchors them in place (Ruppert et al., 2004, Southgate & Lucas, 2008). Anchorage and the hard external shells surrounding the body of the animal mean that they can survive under a wide range of environmental and predatory stressors.
Worldwide distribution of P. albina. Populations mainly concentrated in Western Australia as displayed by the yellow marker, but specimens have been found around the Eastren Pacific (Image credit Discover Life, 2014)
Knowledge and literature pertaining to P. albina is sparse and widespread mostly due to the insignificant commercial value of the organism (Pearl Guide, 2011). A study of the morphological and feeding aspects was performed to help expand and consolidate the literature available on this particular species. Genus Pinctada shares many physiological characteristics with other Bivalves and so the imagery and study of the report may be applicable to a wide variety of Lamellibranchs. P. albina had not previously (in any found literature) been recorded as living in Moreton Bay, Queensland. It has been found to the north and south of the region and distribution within Moreton Bay has been assumed (O'Connor, 2002), but the discovery of these specimens on settlement plates confirms the distribution within Moreton Bay. |
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