image: A throng of yellow brittle stars cling to a gorgonian (a.k.a., sea fan). view more
Credit: Photographed by Alvaro Migotto. Courtesy of the Natural History Museum of Los Angeles County.
Coral Reefs, the Journal of the International Society for Reef Studies, has published online a study co-written by Dr. Gordon Hendler of the Natural History Museum of Los Angeles County (NHM) about an invasive species of brittle star, Ophiothela mirabilis. The species was previously restricted to Pacific waters, but surprisingly, growing populations have established themselves at distant points in the Atlantic. Its presence near Brazilian and Caribbean ports indicates that O. mirabilis could have been spread by shipping.
The marine animal is colorful and six-rayed. It clings in multitudes to corals and sponges and reproduces asexually, by splitting in two and regenerating severed body structures. The ability of one star to "clone" vast numbers of identical twins enormously increases the species capacity to proliferate and disperse.
The impact of the ophiothela brittle star remains to be seen. Like most marine invertebrates (except for commercially important species) we know little about its biology, so it is difficult to envision how it will affect the ecology of its new ocean. But further expansion of the range of Ophiothela could alter the appearance and the ecology of Atlantic coral reef habitats because ophiothelas, in multitudes, densely colonize gorgonians and sponges on Indo-West central Pacific and on tropical eastern Pacific reefs.
"I imagine that when my grandchildren learn to scuba dive," Hendler says, "Caribbean reefs will look very different than they do today, in part because many corals and sponges may be covered with a network of invasive yellow brittle stars."
Invasive species have a massive impact on our economy and our environment, causing over 100 billion dollars of damage in the U.S. alone, every year. Invasive echinoderm species are exceptional (invasive plants and insects are much more numerous). Probably the best known is the Japanese sea star (Asterias amurensis) that was native to the north Pacific and now damages fisheries in Tasmania and southern Australia. Notably, it is among the species that recently washed ashore in Oregon on Japanese Tsunami debris.
The paper was written by Dr. Hendler (NHM); A. E. Migotto (Centro de Biologia Marinha, Universidade de São Paulo, São Sebastião, Brazil); C. R. R. Ventura (Museu Nacional, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil); and L. Wilk (ReefNet Inc., Ontario, Canada).
About Echinoderms and the NHM Echinoderms Department:
Echinoderms are sea stars, sea urchins, sea cucumbers, brittle stars, feather stars, and related animals. For many millions of years, they have been among the most conspicuous and abundant oceanic organisms. People around the world have recognized their beauty and importance since ancient times.
Sea urchins and sea cucumbers valued as culinary delicacies are heavily fished, and sometimes seriously overfished. Quite the reverse, predatory sea stars with insatiable appetites can be impossible to control. Once described as "...a noble group designed to puzzle the biologist," echinoderms -- and the scientists who study them -- continue to unlock the mysteries of molecular genetics, genomics, evolution, and ecology.
NHM began to acquire specimens of echinoderms in the 1920s through its bygone Department of Marine Zoology. In 1985, the Museum became an internationally recognized center of echinoderm studies with the appointment of the first Echinoderms Curator, and with the accrual of major collections that elevated the Museum's holdings to the third largest in the United States.
About the Natural History Museum of Los Angeles County (NHM):
NHM serves nearly one million families and visitors annually, and is a national leader in research, exhibitions and education. The Museum was the first dedicated museum building in Los Angeles, opening its doors in 1913. It has amassed one of the world's most extensive and valuable collections of natural and cultural history — with more than 35 million objects, some as old as 4.5 billion years. The Natural History Family of Museums includes the NHM (Exposition Park), the Page Museum at the La Brea Tar Pits (Hancock Park/Mid-Wilshire), and the William S. Hart Park and Museum (Newhall, California).
NHM is located at 900 Exposition Blvd., Los Angeles, CA, 90007. For more information, visit NHM's website at www.nhm.org or call (213) 763-DINO.
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Journal
Coral Reefs