This week’s blog focuses on one of the most well recognized marine fish. Not Nemo, but the lionfish, specifically the red lionfish (Pterois volitans). Lionfish belong to the Scorpaenidae family, which includes rockfishes and Scorpionfishes. This particular species is native to the Indo-Pacific, where they can be found in lagoons and reefs in waters up to 50 meters in depth. They feed mostly on other fishes, shrimps and some crabs. One unique feature of these fish is their large pectoral fins. You can see in the video below how the pectoral fins are splayed out perpendicular to the body when initiating a strike. According to fishbase, they use these fins to trap prey in a corner, stun it and swallow it, with the aid of suction. Like most Scorpaenidae, red lionfish are venomous at the dorsal spines. However, despite this they are a common species found in home aquariums.

One thing that I was not aware of until recently about this particular species of lionfish is its invasiveness. Although red lionfish are native to the Indo-Pacific oceans, they were first documented in the Atlantic Ocean in 2000 off the coast of North Carolina, although there were some earlier reports of them off the coast of Florida in the 1990’s. The cause of invasion is most likely through the aquarium industry, whether accidental or not. While some juvenile red lionfish may make their way up to the New York area due to the Gulf Stream, their range in the Atlantic seems to extend to Cape Hatteras, North Carolina, with cold temperatures limiting further range expansion. For instance, laboratory experiments have shown they do not feed below 16C. Despite this northern limitation on their range expansion, their numbers seem to be increasing off the southeast coast of the US and into the Bahamas. In fact, they seem to be the first invasive marine species to become established off the coast of Florida. Much research has been conducted on this recent invasion, with reports documenting their effect on the recruitment of native species, and their feeding ecology in the new habitat, which seems to be primarily fishes.

The recent invasion of red lionfish to the Atlantic Ocean is just one of many examples of non-ntaive species becoming established in a new habitat and affecting the ecosystem. Florida alone has seen the establishment of several freshwater, brackish water and terrestrial species (such as pythons in the Everglades). This recent invasion has already spawned new research and will most likely provide years of research to understand the ecology of invasive species.  Who knows maybe a comparison of feeding kinematics will be done to determine the evolution of suction feeding in response to varying ecology.

This is cross-posted with my personal blog.