Freshwater Fishes of the Columbia Basin Return to Table of Contents Return to Species List

Introduced Fishes: Family Cyprinidae (Minnows, Carp)

Distribution of introduced minnow species
in the Columbia Basin
(RBCM Collections)

Carassius auratus (Linnaeus)	Goldfish
Carassius=European Crucian Carp auratus=gilded

The first account of Goldfish in British Columbia was in 1935 from a large pond in Salmon Arm, B.C. (Carl et al. 1967). Further collections made in 1941 by G.C. Carl noted that the Salmon Arm population had increased their numbers tremendously since 1935, and had become the dominant species. In the Columbia Basin, Goldfish populations are currently established in the warm waters of the lower Columbia River and Okanagan system. Most introductions of this Eastern Asian native come from illegal releases of aquarium fish and the distribution of Goldfish in British Columbia is continually subject to change.

Goldfish are an opportunistic long-lived species that are most successful in ponds and lakes with a large littoral zone and dense vegetation (Scott and Crossman 1973). Like many cyprinid species, Goldfish are an omnivorous species that feed on aquatic invertebrates and many types of aquatic vegetation. In the wild this species often reverts to an olive-brown colour as brightly pigmented individuals are easily picked by avian predators. Mature fish of both sexes usually congregate from April to August in shallow marshy areas to spawn. Breeding males develop tubercles on their operculum and pectoral fins, while females become noticeably rotund as their ovaries develop eggs (Wydoski and Whitney 1979). Larger females may deposit as many as 12,000 eggs, but most Goldfish found in British Columbia are smaller (<25 cm) and rarely produce more than 2,000 eggs a season. Females scatter sticky eggs among aquatic vegetation and are commonly accompanied by many males during egg deposition. The eggs develop without parental care and usually hatch in 5-10 days after fertilization, depending on water temperatures (Breder and Rosen 1966).

Goldfish are identified by the presence of a well-developed spine on the leading edge of the anal, and a long dorsal fin. The dorsal fin usually has 18 rays and extends onto the caudal peduncle. Goldfish lack the distinct corner mouth barbel of Carp (Cyprinus carpio) and have 31 or less scales arranged along the lateral line.

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Cyprinus carpio (Linnaeus)	Carp
Cyprinus=after island of Cyprus where Carp was first introduced in Europe carpio=Carp

Carp are native to temperate regions of Asia and are now widespread through Europe and North America. They most commonly inhabit shallow areas of lakes and streams and generally avoid swift waters. It is suspected that Carp were first noted in the Okanagan Valley in 1912 from populations planted in Washington State in 1882 as a food fish (Carl et al. 1967). The populations grew rapidly, and by 1934 7 Imperial Tons of Carp were removed from a trap set at the outlet of Okanagan Lake (McCrimmon 1968). In 1936, Dymond reported that Carp were not uncommon in Kalamalka, Woods and Shuswap lakes.

Carp forage for benthic crustaceans, aquatic insects, worms, algae and plant material. Males usually mature in their second year -- females mature in their third year. Spawning occurs in shallow water during the spring and summer when small groups containing one or more females and numerous males converge. Females release several batches of adhesive eggs while swimming through shallow water so that the eggs are distributed over a large area (Breder and Rosen 1966). Once females have finished depositing eggs they exit the spawning ground while males remain to spawn with other females. The eggs develop rapidly and usually hatch within four to seven days, depending on water temperature.

Carp are currently distributed in the lower Columbia (Arrow Lakes), lower Kootenay, Kettle (Christina Lake), and throughout the Okanagan system.

Carp can be identified by their long dorsal fin, heavy spines in front of the anal and dorsal fin, large immaculate scales and the presence of a conspicuous single barbel at the corner of their mouth.

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Tinca tinca (Linnaeus)	Tench
Tinca=Latin for Tench

Tench are slow-moving Carplike fish that are commonly introduced into ornamental ponds throughout Eurasia. Tench were first noted in British Columbia by G.C. Carl in 1941 from a lakeside pond near Osoyoos Lake, and several populations are now scattered through the Columbia Basin (RBCM collection records). It is likely that populations currently established in British Columbia originated from a series of small lakes near Spokane, Washington, where Tench were first introduced around 1895 (Carl et al. 1967). Habitat requirements of Tench are similar to that of Carp, and the two species are superficially similar, with Tench being the smaller of the two species. Spawning usually takes place during the early summer in weedy shallows when females deposit large numbers of small, rapidly developing eggs.

Tench are currently established above and below Okanagan Falls (Okanagan system), in Christina Lake (Kettle system) and in the Pend D' Oreille system above Waneta Dam.

Tench lack the long dorsal fin of Carp, and can be identified by their blocky head, dark fins, small immaculate scales and deep caudal peduncle.