Remipedia are among the most remarkable biological discoveries of the last 30 years. The first specimens of this crustacean group were discovered in 1979 during dives in a marine cave system on Grand Bahama in the Bahamas archipelago. Since then, 22 species of Remipedia have been discovered. The main distribution area of the cave-limited group extends from the Yucatan Peninsula in Mexico, through the northeastern Caribbean. However, two geographically isolated species inhabit caves in Western Australia and Lanzarote.
The occurrence of these disjunct species has continues to give rise to speculation about the evolutionary origins and history of Remipedia. Since it is assumed that the relatively small (largest specimens are up to four centimeters long) and eyeless cave-dwellers could not cross an entire ocean by actively swimming, there must be other reasons for their disjunct global distribution. It has therefore been suggested that Remipedia are a very ancient crustacean group, which was already widespread in the oceans of the Mesozoic, over 200 million years ago. For these reasons, remipedes are often considered as a primeval group of crustaceans.
According to this evolutionary scenario, the newly discovered species Speleonectes atlantida and the previously known species Speleonectes ondina, both occurring in the undersea lava tube on Lanzarote, would represent ancient relicts that became isolated from the main Caribbean group during the formation of the Atlantic Ocean.
|Contact: Joan Robinson|