It seems like we see these stories every few years, but it’s worth talking about when the topic comes up: do not, under any circumstances, release any pet fish into the wild. Doing so causes a massive disruption to the entire ecosystem.
If you need proof of this, just look at what the fisheries managers in Canada pulled out of Lake Ontario recently. These massive goldfish have torn up habitat that’s historically been used by spawning pike – a fish that’s actually native to Canada. Goldfish are a relative of the common carp, and share many of the same characteristics, including eating up vegetation that other fish rely on.
You can read more about what happens when pet fish are released here.