Invasive Species | Fish and Invertebrates
Goldfish
Goldfish
(Carassius auratus)
French common name: Poisson rouge
A widely distributed aquarium pet, Goldfish are a freshwater fish that eat a wide variety of insects, crustaceans, and plant material allowing them to grow to many times their original size when released into the environment.
Description:
Goldfish are an easy-to-keep aquarium fish sold worldwide through the aquarium and pet industries. Originally from Asia, these small freshwater fish are thought to be the first foreign fish species introduced to North America. Through the pet trade, these fish have been transported across Canada where they are then introduced by humans into local waterbodies. In Fredericton, NB, Goldfish have been found in large numbers in stormwater ponds.
Problem:
Goldfish feed on native fish eggs, snails, aquatic plants, and small fish, competing with native fish species and growing rapidly to
take away habitat and food sources from native fish species. Goldfish feeding activity can also disturb the bottom of waterbodies, increasing the turbidity (or cloudiness) of water which prevents sunlight from reaching aquatic plants below.
Species identification:
Goldfish are a wide-bodied fish that vary in colour from the traditional bright orange to a more natural olive, gold, and white colour. They can grow up to 60 cm long and weigh between 100-300g in a lake or river environment (see below) and have scales on their body but not their head.
How it’s spread:
Goldfish have been primarily introduced into NB waterways as discarded pets when people dump their Goldfish and aquariums into local waterbodies or as pond “escapees” in severe flooding events. It is important to never dump your Goldfish or other aquatic pets/plants into local waterbodies as they can impact native species. Remember, Don’t Let it Loose! If you need to rehome your Goldfish, visit our program page for more information.