In 1985, a lionfish was caught off the coast of Florida. Now they can be found not only in the Atlantic Ocean but also in the Gulf of Mexico and the Caribbean Sea. And they are continuing to move south. Lionfish are native to the Indian and western Pacific Oceans. So how did they end up in the Atlantic? Scientists believe some pet owners abandoned their unwanted lionfish and poured them into the sea. Little did they know the trouble their actions would cause. The Atlantic Ocean turned out to be a comfortable home for lionfish. Their venomous spines   protect them from sharks and other fish. Female lionfish can spawn   every few days, producing as many as 2 million eggs per year. Other big fish would have competed with lionfish for food. Bet overfishing has removed many of these large fish. As a result, the fish have eaten so much that they have grown to be more then three times the size of their cousins in the Pacific and Indian Oceans. "They eat mostly fish," says Stephanie Green, a scientist at Oregon State University. All that eating has caused great changes. Scientists have found that when lionfish are present somewhere, many other fish, which are small enough for them to eat, disappear. Some of the fish they eat are greatly missed in their habitats. For example, parrotfish eat certain plants off corals , which allows corals to grow better. But they are now disappearing due to lionfish. Scientists say lionfish are here to stay. But there are ways to deal with the problem. The key, says Green, is to keep lionfish numbers in check. In Florida, drivers can now go though a special training program and get certified  to catch lionfish in areas where fishing is not usually allowed. And a number of restaurants have added the fish to the menu. "It's going to be a long-term battle, but the missing sea species will come back someday," says Green. What can we learn about lionfish?
Its population is growing very quickly. All of them are almost the same size. They eat other big fish and even sharks Most of them have gathered in the Atlantic.