Perhaps more surprisingly, however, is that even for familiar habitats that, because of their accessibility and visibility, should have been well-sampled and well-described by now, biodiversity is remarkably underdescribed. A recent compilation of estimates, from leading invertebrate taxonomists, of underdescribed species in samples collected from some very familiar habitats reveals a startling reality (Table 1). Up to 99% of the organisms within a given taxon collected at a single site remain undescribed! In environments as easily reached as shallow tropical lagoons, coral reefs, and rocky shores, large numbers of even common species have no names. On the famous fishing grounds of Georges Bank (Massachusetts), almost one-third of the polychaete worms remain undescribed Ä worms that are one of the basic elements of the Bank's food chain [ Steimle, 1987]. In a tropical lagoon in New Guinea, the majority of brightly colored, highly conspicuous sea slugs are undescribed. It is probable, in fact, that in many familiar coastal systems it would be relatively easy to collect, within a short time, a large number of undescribed marine organisms, even to the surprise of many marine ecologists.
This compilation is merely illustrative; in fact, reliable estimates of the number of undescribed species for any taxon are often nearly impossible to obtain because it is the species descriptions that are published, not the lists of taxa for which there are no names.