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Ancient Species of Eyeless Crustacean Found in Ocean Tunnel

Cave divers and scientists exploring the Tunnel de la Atlantida, the world’s longest submarine lava tube, on Lanzarote in the Canary Islands, have discovered previously unknown species, including an ancient form of eyeless crustacean.

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Picture of Speleonectes atlantida by Ulrike Strecker (Naturalanza)

The newly discovered species of crustacean was named Speleonectes atlantida, after the cave system it inhabits, deep under the Atlantic Ocean off the northwestern coast of Africa, according to research to be published in the Springer journal Marine Biodiversity.

Speleonectes is a species of Remipedia, a class of predatory crustaceans that instead of eyes “rely on long antennae which search the lightless void in all directions,” Springer says in a statement about the research.

“Like some type of science fiction monster, their head is equipped with powerful prehensile limbs and poisonous fangs.”

“Like some type of science fiction monster, their head is equipped with powerful prehensile limbs and poisonous fangs.”

The appearance and behavior of Remipedia, swimming though the complete darkness of submarine caves, constantly on the lookout for prey, has led to them being given names that sound menacing, Springer says. “There is the “Secret Club Bearer” (Cryptocorynetes) or the “Beautiful Hairy Sea Monster” (Kaloketos pilosus).”

Japanese Movie Monsters

“The names of some genera were inspired by Japanese movie monsters, for example, the “Swimming Mothra” (Pleomothra), the “Strong Godzilla” (Godzillius robustus) or the “Gnome Godzilla” (Godzilliognomus),” Springer’s statement adds.

The new species is morphologically similar to Speleonectes ondinae, a remipede that has been known from the same lava tube since 1985.

DNA comparisons proved that the lava tunnel harbors a second remipede species.

Divergence of the two species may have occurred after the formation of the six-kilometer [3.7-mile] lava tube during an eruption of the Monte Corona volcano some 20,000 years ago, researchers believe.

“Remipedia are among the most remarkable biological discoveries of the last 30 years,” Springer said.

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Divers in the submarine lava tube (cave system) in the Canary Islands.

Photo by Jill Heinerth

“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.”

Evolutionary Origins

The occurrence of these disjunct species continues to give rise to speculation about the evolutionary origins and history of Remipedia, Springer says.

“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, Springer explained, 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.

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Diver in the submarine lava tube in the Canary Islands.

Photo by Jill Heinerth

The research team consisted of scientists from Texas A&M University and Pennsylvania State University in the U.S., the University of Laguna in Spain, and the University of Veterinary Medicine Hannover and University of Hamburg, both in Germany.

The extensive results of the Atlantida Diving Expedition will be presented in a special issue of Marine Biodiversity, comprising seven articles, to be published in September 2009.