Goldfish

Identification & Biology
Latin Name : Carassius auratus
Category : Fish
Description :
  • Deep elongated body with a large head and eyes
  • Small mouth
  • Long dorsal (back) fin, which is longer than the head
  • Large scales on body but none on head
  • Ranges in colour from gold to olive-green to white
  • Adults are on average 15-20 cm long and weigh 100-300 grams

 

The Goldfish is a freshwater species that is a commonly kept as an aquarium pet or an ornamental fish for ponds. They are often intentionally released into bodies of water by pet owners, or they can escape from outdoor ponds. They are omnivorous fish; they eat a variety of aquatic plants, detritus, crustaceans worms, small insects, and snails. They commonly travel in schools. Goldfish spawn in the spring and females can produce up to 40,000 eggs per year.

Goldfish can be sometimes confused with other members of the family Cyprinidae (ex. Minnows and carps). Goldfish can distinguished from carp species by their lack of barbels, their dorsal (back) fin being longer than their head, and their hard and serrated spine near the front end of the dorsal and anal fins.

Look Alikes
Habitat

Due to their popularity in aquariums and ponds, Goldfish have been introduced worldwide. Self-sustaining populations of Goldfish have established in British Columbia in the lower mainland, southern Interior, and southern Vancouver Island. They commonly inhabit rivers, lakes, ponds, lagoons, and ditches with cold, slow-flowing water and aquatic vegetation. They can tolerate a large range of temperature and oxygen levels, and are unaffected by ice cover.

Impact & Risks
  • Goldfish may outcompete native fish species for food and prey on native fish species.
  • They stir up mud and other matter when they feed, which affects the turbidity of the water and affects growth of aquatic plants.
  • They can carry diseases such as koi herpesvirus that can harm native fish populations.
Prevention & Mitigation
  • Do not possess, breed, ship or release Goldfish.
  • Use of live bait in B.C. is prohibited.
  • Do not release aquarium fish into the wild.
  • Properly  clean,  drain,  dry  your boat and equipment before entering a new water body.
  • CLEAN  off all plant parts, animals, and mud from boat and equipment (e.g. boots, waders, fishing gear). Use a power wash station if available
  • DRAIN  onto land all items that can hold water (e.g. buckets, wells, bilge, and ballast)
  • DRY  all items completely before launching into another body of water
  • Report Goldfish, or any other invasive species via the ReportInvasives phone app, that is available from the provincial website: gov.bc.ca/invasive-species

 

Primary source for information: Goldfish Invasive Species Alert – Government of British Columbia

Okanagan Distribution

Priority Level Definitions

Watch For - Poses a significant threat (very high risk) and does NOT presently occur in the region OR is relatively new to the region and is very limited in extent.
High - High risk/impact; limited population with significant potential to spread in the region.
Medium - Medium risk/impact; limited distribution – broader population distribution with potential to spread further in a region.
Low - Low risk/impact; may be widespread or not, may be of concern in specific situations with certain high values – e.g. specific agriculture crops. Some species may be treated primarily with biological control agents.