Below is the Map cowry, Cypraea mappa, found in the Indian Ocean and S. W. Pacific on coral reefs, shallow and deeper water. This snail is also known as Leporicypraea mappa. It is in the Cypraeiae (Cowry) family. It is economically important and collected for both food and it beautiful shell. The maximum length is 10 cm.
On the right is the Tiger cowry, Cypraea tigris. It is found in the Indian Ocean and the Western Pacific at depths of 10 - 40 metres, often near coral reefs or else on sand. It is much less abundant than formerly due to over collection (for its beauty) and dynamite fishing. The common name is rather strange as the shell is not striped but spotted.
Fully grown specimens can be up to 15 cm long, with the largest specimens found around Hawaii. The shell is highly polished. In life the mantle completely covers the shell only being withdrawn into the shell when the snail feels threatened.
The tiger cowry preys on corals and small invertebrates as an adult, but as a juvenile it eats algae. It is active at night, and stays concealed in crevices by day. The snail protects its eggs until they hatch out as larvae and drift off. It is preyed on by octopus.
It is used in Europe as a darning mushroom or egg. In Japan it is believed that clutching the shell during labour will ease the birth pains.
On the left, at the top is the Wonder cowry, Cypraea hesitata, also known as Umbilia hesitata. It can grow up to 12 cm long. Many individuals can have irregular brown spots or marks.
It is found off the South East Australian coast from 100 - 200 m deep, although around Tasmania it is found in shallower waters.
Mauritian cowry, also known as the Humpback cowry, the Chocolate cowry, and the Mourning cowry, Cypraea mauritiana, right, is found in the Western Indo-Pacific. The maximum size of a fully grown specimen is 13 cm. Its mantle is completely black, and it is normally found in exposed rocky habitats such as reefs or structures subject to wave wash between 2 - 50 m deep.
Mouse cowry, Cypraea mus, also known as Mura cypraea, right, is found in shallow waters, the intertidal zone, and in sea grass off Columbia and Venezuela. It feeds on algae and sponges.
Haliotidae (Abalone) family
There are over 200 described species of abalone. The shell has a low, spiral structure with multiple respiratory pores arranged along the outer edge. The respiratory pores are used to bring water to and from the gills. During reproduction sperm and eggs exit through the pores. Older pores are closed over as new pores open. There are usually from 4 - 10 open pores at any one time. The beautiful inner shell is used commercially for jewellery and decoration, and the flesh is eaten. Certain species of abalone have been farmed commercially since the 1950s.
On the right is the Staircase abalone or ridged ear abalone, Haliotis scalaris. This abalone may soon be farmed commercially off the west coast of Australia. In the wild it is found off the west and south-west Australian coast. A fully grown specimen can reach 11.5 cm in width. It inhabits the intertidal zone down to around 50 m deep, usually on rocks.