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Nonnative Freshwater Fish | |
Note: For a printable guide to some of these freshwater exotic fishes, see the Exotic Fish Identifier Sheet (546 kb; It is illegal to release any nonnative fish or any other nonnative organism into the waters of the state, but new exotic freshwater fishes seem to crop up almost annually in Florida. Anyone wanting to dispose of live exotic fish because they don't want them anymore, should give them to a friend or aquarium store, or euthanize them by lowering the temperature with ice or placing them in a plastic bag and freezing it. Not only is it illegal to release nonnative species in Florida, it is also inhumane since most will die shortly after being released, and those that don't may cause detrimental changes in our fish communities. One reason we have so many exotic fishes is that most of our aquatic habitats have been dramatically altered. For example, man-made canals in southeast Florida provide nearly ideal habitats for many of these fishes. Not only are these canals located in the warmest part of Florida, but large amounts of groundwater continuously flow into them keeping them warmer than they would otherwise be. Even though the presence of many exotic species might be viewed as being more symptomatic than problematic, the potential for these fishes to detrimentally affect native species is and has been a major concern to the Division of Freshwater Fisheries for more than 40 years. These concerns are based in the knowledge that: 1. Presence of exotic fish alters the natural energy flow through aquatic ecosystems. 2. They may compete or hybridize with native species. 3. Some, like the electric eel, piranha, and freshwater stingray, can be directly harmful to man. 4. They are unpredictable. And 5. They can be carriers of harmful parasites and diseases. In addition to the regulatory programs centered in the Fish and Wildlife Conservation Commission's (FWC) Division of Law Enforcement, the Division of Freshwater Fisheries has developed multifaceted programs focused on the prevention, assessment, and management of illegally introduced fishes. Prevention programs include public education, interagency coordination, and the elimination of new exotic fishes whenever possible. The main reason the Commission's primary focus is on prevention is that it is impractical, if not impossible for man to eliminate an exotic fish once it is reproducing in Florida's open waterways. For that reason, Florida maintains and enforces lists of conditional and prohibited aquatic animals. When an exotic fish is found to be reproducing in open waters, the Division of Freshwater Fisheries' (DFF) priority changes from one of prevention to one of assessment. Assessment is the primary responsibility of the DFF's Nonnative Fisheries Research Lab in Boca Raton. The objectives of this project include: 1. Documenting the occurrence and distribution of exotic fishes in Florida. 2. Defining their life histories, environmental limiting factors (e.g., lower lethal temperatures), and associations with native fishes. And 3. Developing fish management strategies to deal with these unwanted fishes. More can be learned about Florida's freshwater non-native fishes by clicking on some of the publications and reports that have been produced by this project. DFF's long-term goal is to eliminate illegally introduced fishes whenever and wherever possible, but when this is impossible our goal is to identify best management practices for these undesirable but no less available resources. One approach we use is to encourage people to fish consumptively for exotic fishes, such as the oscar and Mayan cichlid, which reduces their numbers and increases opportunities for recreation. Another management tool involves commercial harvesting extremely abundant exotic species such as the blue tilapia, which creates jobs and provides a source of low cost food. Regardless of the circumstances, one of the most controversial management practices that can be proposed today involves the legal introduction of an exotic fish. In Florida, legal introductions have been used primarily as biological controls for excessive growths of aquatic vegetation and overabundant forage fishes. The triploid grass carp, which is a functionally sterile fish, has been used in Florida to control aquatic vegetation for more than 20 years and the results have generally been viewed favorably. Specific permits are required and these can only be obtained when the triploid grass carp are to be used as biological controls for exotic aquatic plants. The butterfly peacock is the only reproducing exotic fish that was legally introduced, and this fish was released only after extensive research indicated it would be a beneficial addition. The objectives for introducing this fish were to convert an over-abundance of exotic forage fishes, especially the spotted tilapia, into a highly desirable urban sportfishery. The introduction of the butterfly peacock in 1984 has been extremely successful in that it has had no known detrimental effects, and it has generated millions of hours of fishing pleasure for thousands of anglers who spend more than $8 million a year to catch this fish! The DFF tested, then rejected the presupposition that every illegally introduced exotic fish represents an inherently catastrophic event. Based on decades of research, we have replaced this presupposition with one based on the historical fact that these fishes have real but less than catastrophic effects. The real effects of these fishes are cause for concern and DFF strongly believes everything practical should be done to prevent future illegal introductions. However, total prohibition of exotic fishes is unreasonable, just as it would be foolish to ignore them. Although not perfect, the existing combination of FWC regulations and programs provides us with a comprehensive and proven approach for dealing with the very serious and complicated problems created by exotic freshwater fishes in Florida. The exotic fishes displayed here are some of the most commonly encountered by anglers or those that have appeared prominently in media reports. Click here to view a complete list of exotic freshwater fishes collected by Commission fisheries scientists from Florida waters. For a printable guide to some of these freshwater exotic fishes, see the Exotic Fish Identifier Sheet (546 kb;
| Index By Common Name Airbreathing catfish 
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Our mission: Managing fish and wildlife resources for their long-term well-being and the benefit of people.
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