They become “monsters”: Why you should never throw a goldfish in lakes and rivers

What would you do if you have a goldfish -those that abound in the fish tanks at home- and you want to get rid of it?

Do you fire him in the bathroom? Do you take it to a nearby pond, river, or swamp? If that’s what you’re thinking, stop! and read this note first, as you could create a “monster”, according to experts.

In recent years, these friendly animals known as Carassius auratus have become a real problem for local species of swamps, lakes and rivers from all over the world.

And it is that in a wild environment they can reach the size of a soccer ball and weigh up to 2 kg.

If the size was not enough, the problem with these invasive species is that they are a threat to local ecosystems.

In fact, The Minnesota authorities have called on citizens not to release these fish -considered an invasive species- in the state’s lakes and rivers, after several giant specimens were found in Lake Kelle.

Part by part

On first place, These species native to China are carnivorous. They feed on the eggs laid by local fish, which in turn feed on the mosquito larvae in the water (thus being natural insecticides).

In addition, to search for food they use a technique that consists of shaking the ground.

Which brings us to second problem; by lifting the mud from the bottom, it causes previously buried nutrients to float, activating an excessive growth of algae.

In addition, this type of carp fish can bring diseases unknown to the native fish population.

Long distance

In a study conducted a few years ago in Australia in which they followed 15 goldfish for a year, they were able to determine how these species migrate.

“We discovered that these fish can migrate from the canals (where they are left by their owners) to the river and from there to the marsh system where they lay their eggs,” the research noted.

This means that in a year they can travel a distance of more than 230 kilometers.

Another detail of these creatures is that they breed like rabbits.

Furthermore, lfish tanks in homes limit their growth, but once you let them loose, we can see what happens.


But that is not all. Experts also warn of the consequences of dumping water from fish tanks into rivers and lakes.

Diseases and parasites accumulate in these stagnant waters, posing a threat to local species.

Now, Do you want to get rid of your goldfish?

Experts recommend two options: take it to an aquarium or “human euthanize it by putting it in the freezer.”

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