The documentation of the distribution and magnitude of biodiversity is an essential task for any program involving sustainable development and should be a fundamental part of each region’s development (Mittermeier et al. 1998). Since coastal ecosystems are responsible for a large proportion of fish and shellfish yields, the evaluation and conservation of their biodiversity should protect their productivity. Practical conservation depends on obtaining reliable information about the distribution and abundance of the organisms present in each ecosystem or habitat. Recently, invertebrates have been attracting attention regarding their importance in terms of conservation and monitoring (New 1998). Despite their ecologica