4 May 2026

This goldfish looks familiar. Someone didn’t want it or couldn’t keep it anymore so they dropped it off in the nearest waterway to let it “swim free.” Big mistake.

The goldfish above was found at Presque Isle State Park but I’ve seen them this big in Schenley Park’s Panther Hollow Lake. Goldfish are in the carp family (Cyprinidae) and live 12-20 years.

Awww, but it was so tiny when I bought it! Not anymore. During their long lifetime goldfish reach 6-10 inches in a tank but grow much bigger outdoors where they can weigh up to 4 pounds!

Your pet store goldfish after two years in the wild: ‘Call me Megalodon.’ [an extinct giant shark]

This goldfish isn’t supposed to be here. But someone released it, thinking they were being kind. Instead, they created an invasive problem that can last decades.

Goldfish grow massive in the wild, where they can turn lakes and waterways into murky messes, steal food from native fish, and wreck water quality.

If you can’t keep your fish, rehome it. Just don’t let it loose.

— Facebook Post for Invasive Species Week, 25 Feb 2025 by U.S. Fish and Wildlife Service

Goldfish are invasive in many states including Pennsylvania and Minnesota. This 4+ minute video shows what happens in the wild and provides answers for your unwanted goldfish problem.

Remember, if you have an unwanted goldfish it is illegal to drop it off outdoors. Rehome it (give it away), take it to a Pet Surrender Event, call a pet or aquarium supply store, or call a Nature Center for advice. Don’t put it outdoors!

p.s. Goldfish create lousy, murky water quality. I’ll bet they are part of the problem at Panther Hollow Lake.