The Department of Natural Resources says anglers landed three fish with human-like teeth last month in southeast Michigan.
The DNR said three pacu reports were filed with their offices - two from Lake St. Clair and one from the Port Huron area.
The pacu fish have human-like teeth that are used for eating nuts and seeds and look somewhat similar to a native shad, the DNR said. FOX 2 reported on the pacu that was caught in Lake St. Clair in July. The fish, a relative of the piranha, also bears the undeserved nickname of the 'testicle-eating' fish.
The pacu is a popular aquarium fish imported from South America and is not native to the United States or Michigan. However, the DNR says that the fish is not considered invasive because they are not expected to survive the cold Michigan winters.
The problem with this fish is that it magnifies the problem of what people are doing with their pet fish once they can no longer keep them in an aquarium. The DNR said pacus are known to grow beyond the capacity of their tanks.
"Pet release is almost never humane. Pets released from confined, artificial environments are poorly equipped to fend off predators and may be unable to successfully forage for food or find shelter," said Nick Popoff, manager of the DNR's Aquatic Species and Regulatory Affairs Unit. "Those that do succeed in the wild can spread exotic diseases to native animals. In the worst-case scenario, released animals can thrive and reproduce, upsetting natural ecosystems to the degree that these former pets become invasive species."
Invasive or not, putting a non-native fish in Michigan lakes without a permit is illegal. That includes everything from the pacu to goldfish.
Paige Filice of Michigan State University works with a new statewide campaign to Reduce Invasive Pet and Plant Escapes (RIPPLE) to offer solutions for aquarium and pond owners. They advise anyone who has a pacu that has outgrown its tank to consider donating it or trading with a hobbyist, environmental learning center, an aquarium, or a zoo.
"You can also check with the pet store where you purchased the fish to see if they will take it back," Filice said.
The DNR said July is becoming a common month for pacus to be caught in Michigan lakes.