THE RED LIONFISH, Pterois volitans has a striped complexion, feather-like pectoral and dorsal fins, making them a majestic addition to any marine aquarium. Packed full of personality, and with an explosive jaw, makes feeding times interesting. However, their venomous spines and tank-busting size (adults can reach around 50cm in length) mean these fish can prove tricky for even the most experienced aquarist. And in that lies the issue.
Many people have bought these fish thinking they could manage P. volitans’ size and feeding requirements (they prove stubborn when accepting any food that isn’t live), only to discover that they are too much to handle. Thinking there is no other option, some thoughtless hobbyists have released their fish into the water. This has led to P. volitans becoming a highly invasive species in the Caribbean. With no natural predators, the population has boomed to an unprecedented level. Living up to the concept that if a fish can fit in its mouth, it’s going to eat it, this alien has decimated local populations on the reefs. P. volitans are capable of eating fish much larger than that mouth appears. When a prey fish comes near the mouth of this predator, the Lionfish is able to extend its jaw a considerable amount and engulf the unsuspecting victim whole. Because of this, biodiversity on the reefs has declined greatly. It truly is a force to be reckoned with. Or so was thought for a long while.
There have been attempts to reduce the population of these predatory fish over the years. Some divers took to the water armed with spear guns, targeting these fish and collecting large quantities of them in small nets. However, this didn’t make a dint in the overall number. It seemed that this invasion was going to continue.
Then came a spark of ingenuity. If these fish had no natural predators, could we not make one? I don’t mean by playing God to create a whole new species in a lab, I mean training the other carnivorous species on the reef to eat the Lionfish. The Caribbean reefs are teeming with other, larger predators who, with some effort, could be trained to add something alien to their diet. P. volitans shares the waters with species of sharks; such as the Caribbean Reef Shark, the Nurse Shark, and Tiger Sharks, just to name a few. Along with these, there are many species of Moray Eels, such as the Green Moray Eel and the Spotted Moray Eel. If all the other predators on the reef could be taught to predate upon P. volitans, then this could go a long way to reducing the number. And that is exactly what some people are trying to do.
Once again armed with spear guns, divers have taken to the water. This time they aren’t removing the corpses. They are keeping them in the water and enticing predators to come and take a bite. This new method of control is proving promising. Videos have surfaced online showing different species of sharks and eels being fed Lionfish. If this behavioural adjustment is successful, then we could see a significant decrease in the numbers of P. volitans on Caribbean reefs. If this happens, then other species of reef fish can replenish their populations, creating a healthy and thriving reef once more.
The moral is: don’t dump a fish in your nearest water. Better yet, don’t buy it in the first place.