Two of the pterois species have developed themselves as a significant invasive species on the East Coast of the USA and the Caribbean, particularly in Florida. Pterois, or lionfish, are a genus of venomous marine fish originally found in the Indo-Pacific. Pterois, in particular the red and common lionfish, are native to tropical and subtropical regions stretching from Southern Japan to Australia. They are unique in the fact that they have developed a successful colonisation in a new open marine environment.
Lionfish are naturally aggressive predators and feed on smaller fish and invertebrates in their reef environment. They have venomous fin rays that make them particularly adept predators in Florida and, unfortunately, are also poisonous to humans. Lionfish venom can cause a variety of unpleasant symptoms, including diarrhoea, vomiting and in some cases heart failure and even death. Whilst this is not usual in adults, small children and the elderly are more at risk of an anaphylactic shock.
It is thought that Hurricane Andrew caused damage to an aquarium in Southern Florida and this may have been the original release for the lionfish into the Caribbean Sea. Lionfish in aquarium tanks are very difficult to keep as they can attack the other fish in the tank and also make cleaning the tank very difficult. It is thought people that had not understood the difficulties before purchasing lionfish have been releasing them into the ocean. Pterois can reproduce quickly, prey on the local reef life and have very few natural predators meaning that from these few original fish they have multiplied exponentially along the Florida coast. In addition to this their ability to survive in water with low salinity has led to recent fears that the fish could enter the estuaries of river networks in the near future.
There has been a succession of different strategies deployed since the mid 1990’s to handle the lionfish population explosion. A recent study suggests that over 25% of the population of pterois needs to be eradicated per month just to maintain the population at its current level. In Florida there are now sanctions in place to prevent the transport of lionfish into the state via the pet trade. In addition, there are teams of divers and hunters who go out and eradicate the fish where possible. A new craze for helping to decrease the population has been to serve them on fish restaurant menus, though this has taken a while to get going as they are particularly difficult to prepare. At present there is no hard and fast way of eradicating or controlling the population of lionfish.
Whilst lionfish are a menace in the wild in Florida, keeping pterois in aquarium tanks is still an attractive proposition. Lionfish require careful looking after and maintenance and are not recommended for the beginner. There are a few basic things to consider when keeping them. Firstly is to ensure that there are no fish or invertebrate smaller than itself as it will nearly always attack and prey on the smaller fish.
Lionfish require quite a large tank, available from most online retailers such as Swell UK, and as most are dusk and dawn hunters require plenty of caves to hide in during the day. Lionfish will not harm the corals in a tank so as a singular fish in a tank these fish can be beautiful pets.
By Chris Plum
Aquatics Specialist and Advisor