Dr. Paul Sikkel examining the Marley parasite.
By Nathalia Holt | July 30, 2012
Once vibrant pockets of color, swarming with life, Caribbean coral reefs are in decline. Coral, a marine animal of seemingly infinite color, has fallen prey to bleaching and widespread disease. Since 1977, it’s estimated that 80% of the live coral in the Caribbean has deteriorated. Fish species in the Caribbean coral reefs have declined 5% a year for the past decade. These changes have been linked to climate change, overfishing, and other unknown pulls in the delicate balance that governs life in a coral reef. Research is grappling on one hand with the sheer diversity of life found in the Caribbean coral reef, while, at the same time, searching for answers to its decline. All in all, it’s a maddening time to be a marine biologist.
Dr. Paul Sikkel grew up on the beaches of Southern California, fascinated by reptiles, amphibians, and fishes. His passion for marine life began early, fueled by Wild Kingdom and The Undersea World of Jacques Cousteau, eventually cementing into a plan to pursue marine science. For a decade he watched hundreds, sometimes thousands of tiny parasites swirl around at his feet, never guessing that they would be the first new Caribbean parasite species described in over thirty years. The parasite was not only abundant but also exclusive to the Caribbean. He recently made news when, after discovering this new species of gnathiid, a fish parasite, he and his colleagues named the species Gnathia marleyi, in honor of Bob Marley. The response to naming a parasite after Bob Marley has been mixed. Several reporters have questioned the honor of having, as some have phrased it, ‘a blood-sucking parasite’ named after a legendary musician and activist.
Parasites, even when they can be directly linked to disease, don’t get much respect from biologists. This is surprising when you consider that parasitism is the mostcommon animal lifestyle. By definition, parasites are organisms that cause harm to their host. But they do so much more than this. Parasites are an important food source, bridging together species that would ordinarily not have contact with one another. This is especially pronounced in the Caribbean Sea, where each creature plays a vital role in the balance of survival.
A great example of the importance of parasites are the gnathiids, a family of isopod crustaceans. These tiny parasites, no bigger than a quarter, comprise, along with other parasite species, the vast majority of total life in Caribbean coral reefs. There are almost two hundred species worldwide, including the new Marley parasite. As abundant as these parasites are, we still have little information on their life cycle. In fact, the Marley parasite is the one of the few Caribbean gnathiids whose life cycle has been fully described. Sikkel explains this attention to detail by acknowledging the importance of Bob Marley, “We wanted to do the best job we could and make this the best piece of work we could produce, especially since it was named after Bob Marley.”
As an adult, the Marley parasite is harmless, but as juveniles they prey on those beautiful reef fish, sneaking up on them from behind coral rubble and attacking. In addition to sucking blood from colorful fish, they also provide a meal to cleaner fish. Paul describes their role as a “broker that brings the client and the cleaner together.” Without these creatures, the balance between species of the coral reef would be horribly altered. Importantly, these parasites also play a key, albeit not well understood, role in the transmission of disease. Similar to a mosquito or tick, they are capable of transmitting bacteria and viruses. These two factors, the balance of marine organisms and the spread of disease, are key to our investigation of the decline of reef communities in the Caribbean. Could understanding how one parasite influences these factors help preserve a delicate ecosystem?
Sikkel is an assistant professor at Arkansas State University. He brings the study of marine life to university students who might not otherwise see the ocean in their landlocked state. He travels the world researching marine ecology, studying gnathiids in the Caribbean and Australia, and tracing the lionfish invasion back to its origin in Guam and the Philippines. Wherever he is, he says his watch is set to Caribbean time, quoting another favorite musician, Jimmy Buffet, “I have a Caribbean soul I can barely control.” Naming the new parasite species after Bob Marley was done thoughtfully. Sikkel views it as “one professional (marine parasite ecologist) honoring another (Caribbean Reggae musician).”
It may not always be pretty, but parasites bring species together. They play a key role in the health of Caribbean coral reefs, one whose further understanding may inform new strategies to preserve this precious habitat. Bob Marley said, “The truth is, everyone is going to hurt you. You just got to find the ones worth suffering for.” The Marley parasite may be that very creature worth suffering for, an organism in need of unconditional love.