Crypsis and Defence
The focal feature of any cowrie is its shell. Made of CaCO3, it acts as a guard against predators, completely enclosing their soft body. Studies have shown that the thickness of the gastropod shell reflects a number of environmental influences, namely predation and unfavourable environments which inhibit their growth rate (Theodore, 1989). Gastropods that grow at high rates typically produce a larger and lighter shell, whilst species that are exposed to high temperatures and desiccation have a shell that is smaller and thicker, reducing predation intensity (Theodore, 1989).
L. vitellus is nocturnal, wedging themselves deep in crevices, under rocky and coral blocks during the day (Beesly et. al, 1996). The mantle plays an important role in their camouflage, extending across the entire surface of the shell. The mantle also assists in maintaining the quality of the shell by continuously depositing enamel onto the outer surface, whilst protecting the shell from abrasion (Archerd Shell Collection, 2014). This secondary shell layer is thin and transluscent, allowing the original shell colour to be visible in adult (Archerd Shell Collection, 2014).
|