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Where When How Summer 2017 : Page 91

prey. Will fish on this side of the interna-tional date line adapt to better avoid be-coming a snack? Only time will tell. Another theory for their continuing success involves, of all things, parasites. As mentioned in our original lionfish article back in 2007, work on the parasites that infect lionfish was first initiated by Dr. Ann Barse from Maryland’s Salisbury State Uni-versity. She found that very few parasites were seen in the Atlantic population com-pared with what are found in native species. Her work is being continued by researchers in the Bahamas such as zoolo-gist Paul Sikkel. Like Barse, Sikkel is finding the gills — a prime location for parasites — amazingly clear compared with other native fish. The parasites that normally swarm all over a local species apparently aren’t going near the lionfish. The signifi-cance of this finding Sikkel describes as avoiding a kind of “tax” that fish have to pay whereby much of their energy gets di-verted from growth and reproduction into fighting the parasites. Not having to do that may well explain the abnormally large size of some of the captured lionfish and, though it is yet unknown, a suspected higher reproductive success rate than in their home range. The reproductive mode is also another factor that makes lionfish particularly good baby-making machines. Like most reef fish, they are broadcast spawners. Males engage in elaborate posturing de-signed both to intimidate rivals and im-press potential mates. This can go on for three or four days. If impressed by the dis-play, a willing female joins her suitor. The pair then begins a spawning dance where they circle each other face to face while slowly ascending. The actual deed happens just before reaching the surface, when the female expels a mucus ball containing thousands of eggs. As this “egg ball” floats to the surface, the male turns belly up and releases a cloud of sperm into it. Soon-after — in some cases after only a day — the eggs hatch into larvae, and the young eventually settle to hideouts along the seafloor. Just three months later the young are diminutive versions of their par-ents. And unlike other fish that mate only seasonally, lionfish mate year-round, en-suring a continuous supply. The combination of numbers and ap-petite are enough to make reef scientists and managers break out in a cold sweat. Diving as it should be Diving • Snorkelling • Instruction Tel: 649.946.5040 Visit the Turks & Caicos Islands at SUMMER 2017 • • • • • 91

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