On Tuesday, a popular aquarium fish with horrifically human-like teeth, has been pulled out of two separate bodies of water in Michigan, called a South American red-bellied pacu.

Weird Set of Teeth that Stands Out

According to Michigan Department of Natural Resources the red-bellied pacu, Piaractus brachypomus, is a popular aquarium fish imported from South America.

What makes tha red-bellied pacu different from other aquarium fish like trout, muskellege or northern pike, is its appearance. The strange animal sports a squarish set of teeth that look like they belong to humans.

Pacus Unloved by Pet Owners?

Being an aquarium fish, it is suspected that the reason why pacus are now found in at least 27 U.S. states is they are being freed or dumped by their aquarium pet owners to the lakes, ponds, or creeks, according to CNET.

Pacus are known to show significant growth, even beyond the size of their tanks. Because of these, most pet owners release them as they could not maintain or take care of the fish.

"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."

Despite Creepy Appearance, Pacus are Not Invasive

To be clear, pacus are not invasive species, at least in Michigan. Invasive species are defined as those that are not endemic to the area but can pose a threat to health, the environment as well as the economy.

While the risk is uncertain in he U.S., the presence of pacus in Michigan are not considered as a threat because they are tropical warm-water fish. This means that they are unlikely to thrive or survive in cold, Michigan winters.

Such is the case mention in The Blade article, though cases are rare, there have been reports of pacus showing up in St. Clair waters in the past, says Michigan Department of Natural Resources fisheries biologist Cleyo Harris from the Waterford Fisheries Station.