Whether it was at a museum, doctor’s office or in your own home, at one time or another we have all enjoyed the experience of watching a fish gracefully swim back and forth in an aquarium. The ability to spy on the underwater world prompts many to keep a home aquarium.

Fish are often a great first pet for introducing children to the responsibility of caring for an animal. The requirements are fairly simple: food and a healthy habitat. 

But what should you do after Nemo has lost his charm or if you can no longer care for your finned friend? 

In this case, the expression, “If you love something, set it free” does NOT apply!

Any plant or animal not native to Texas is considered an exotic species. Most fish available for sale at pet shops are exotic and imported from outside of the United States. 

Every year, exotic fish are released into creeks and rivers because the owner may not be able to take the fish with them when they move, the fish has outgrown the aquarium, or the fish is unhealthy. 

Whatever the reason, releasing exotic fish into local waters is not a good idea, and it is illegal.

You may think little Bubbles will be happier swimming in the river, but even if the fish survives the initial stress and possible predators and diseases of its new environment, it also poses an immense threat to the plants and animals naturally living in the waterway. 

Exotic fish cause changes to the aquatic community through predation and competition with native species by infecting native fish with exotic parasites and by hybridizing with native fish.

The suckermouth catfish (also called plecostomus or armored catfish) is an exotic species that could pose a threat to the ecology of the upper Guadalupe River if a population becomes established. This common aquarium species is popular because of its ability to clean algae from your fish tank. However, its voracious appetite is far less charming when released into a waterway, because it can drastically reduce the amount of green plants, therefore knocking out the base of the food chain and affecting all other aquatic organisms. 

The suckermouth can also burrow into stream banks causing erosion and sedimentation. In addition, their large, thick scales make them very resistant to predation which allows the species to quickly dominate an area. 

The San Marcos River, which joins the Guadalupe River near Gonzales, is currently home to a growing population of suckermouth catfish, and substantial efforts are underway to reduce the numbers. Currently, there are no known occurrences of suckermouth catfish in Kerr County, but exotic fish like koi and goldfish have been observed in our waterways.

What can you do if you are no longer able to care for your aquarium fish? You could ask a local pet store to accept it, find someone to adopt the fish, or donate it to a school, professional office, museum or nursing home. 

If these options are not available, the fish should be euthanized. 

Please call UGRA for assistance with this or any other questions. 

If you catch an exotic fish in a creek or river, do not release it! Please report the species via email to UGRA — tbushnoe@ugra.org — and include a photo if possible.

Tara Bushnoe is the natural resources coordinator for the Upper Guadalupe River Authority. She can be reached by phone, 830-896-5445, or by email, tbushnoe@ugra.org.

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