Collectors are usually interested in shells, and it is easy to forget that these once housed living animals.
Living Cowries
There are about 185 species of genus Cypraea alive today, and most of them live in tropical and sub-tropical waters, associated with coral reefs. They are nocturnal creatures that usually hide under dead coral during the day and come out to feed at night. When they are active the shell is covered by their ‘mantle’ (thin folds of tissue that protrude to cover the shell), and this mantle often provides very effective camouflage in dim light. (Watch a short video of a living cowry moving underwater.) Cowries have separate sexes, and the females usually remain with their eggs to protect them.
Collecting Cowries
Since more than half of the cowries live in shallow water it is possible to collect them with a minimum of equipment. Wading in the water at low tide, and searching under large slabs of dead coral will usually do the trick. During the daytime they will be safely tucked inside their shell, and just as the mantle provided camouflage throughout the night, the shell will blend in very well with the background. (Shell and mantle colours are different, providing the camouflage appropriate for the different conditions.)
Habitat Conservation
A single collector turning over slabs of dead coral and ferreting around under overhangs will do little damage to the habitat – provided the slabs are always returned to their original position, right side up! Careless collecting can do immense damage – it takes a long time for the communities of small creatures that live under rocks to establish themselves, and they play an important part in their ecosystem. Living coral should only be explored by snorkelling or scuba-diving, and local restrictions should be adhered to.
Species Conservation
Once again, an individual collector will do little harm to populations of any one species, provided he or she makes sure that there are a good number of specimens available and only takes one or two of these. It is frustrating to leave behind a rare shell, but if only one or two are found that’s how it should be! Females guarding eggs should always be left undisturbed, or at the very least, returned to their exact location – they are looking after the next generation.
Scientific Data
If the exact location and date of collection are recorded for each individual, then that shell (and the whole collection) can be of scientific value. (Without this information they are just old, maybe pretty, shells!) In addition to this basic information it is also a good idea to make a few field notes about such things as the state of the tide, nature of the habitat, and so on. These recordings are best done immediately after each collecting session, memory is a funny thing!
Main reference: 'The Living Cowries' by C.M.Burgess
Other articles by John Blatchford
 |
