FAMILY CYPRINIDAE
The Family Cyprinidae is the largest family of vertebrate animals, with an estimated 2010 species worldwide (Nelson, 1994). In biomass and species diversity, minnows are the dominant group of fishes in nearly all of North America’s temperate zone watersheds.
The ecological importance of minnows is also great. Minnows are the most common prey of piscivorous fishes in temperate North America. They are the most important single food resource for most of our freshwater game and commercial fish species. The species composition and diversity of minnows in a water body can provide a good indication of the type and quality of habitat. Unlike most other groups of fish in our area, many of our minnow species have relatively narrow habitat requirements, and show partitioning of habitat by water velocity, depth, substrate type, feeding and spawning habits, and habitat. Ten of our native species of minnows have been subject to detailed studies of at least some aspects of their biology in Manitoba. There are also limited data available for three additional native species. In some of these species, significant differences in biology between Manitoba populations and those to the south have been shown. Fourteen of our 26 native species of minnows reach their northern or northwestern limit of distribution in Manitoba, and it is reasonable to expect that there would be significant differences in the biology of species in near-limiting environments. Finally, detection of changes in distribution of these species could provide indications of the ecological effects of climate change.
Minnows display a wider array of feeding and habitat adaptations than suckers, and this is reflected in the large number of genera and species in the family. Manitoba alone has 14 native genera containing 26 native species of minnows.
In addition, there are two genera and two species of introduced exotics established in the province. One of these, the common carp, was introduced in Manitoba in 1886, making it the oldest introduced fish species in the province. For all these reasons, our minnows should receive a good deal more attention than they have to date.
Minnows are closely related to the suckers, and, like them, lack teeth in their jaws. Instead, as in the suckers, the fifth or pharyngeal arches, at the back of the gill chamber, have one or more rows of strong teeth that function in food processing. In comparison to suckers, minnow pharyngeal teeth are fewer in number, more heavily constructed, and widely spaced, often in two or more rows, and do not oppose a bony branchial organ in the roof of the pharynx.
As a group, minnows can be distinguished from all other Manitoba freshwater fishes by a combination of the following characters. The jaws are toothless. There are no fleshy expansions of the lips and no adipose fin. The distance from the origin of the anal fin to the middle of the base of the caudal fin is more than half the distance from the origin of the anal fin to the rear margin of the operculum. Carp and goldfish also have a spine at the leading edge of the dorsal and anal fins, and the carp has both maxillary and terminal barbels on the upper jaw.
All native species of minnows in our area belong to the subfamily Leuciscinae, which is distributed across North America and Eurasia, north of India, and Southeast Asia. Our two introduced species, the carp and goldfish, both belong to the subfamily Cyprininae, which is native to all of Eurasia, including the Indian subcontinent and Africa.
Note: The red shiner, Cyprinella lutrensis, has not been found in the wild in the Hudson Bay Drainage, but it does appear occasionally in the tropical aquarium trade in Winnipeg, either misidentified as “Asian rainbow barbs” or in shipments of goldfish. The red shiner is native in the Missouri River in North Dakota and is a favoured bait species in the United States (Stewart et al., 2001). This is an invasive species that has caused the extirpation of populations of native cyprinids in a number of locations where it was introduced in the western United States (Moyle, 1976). The possible introduction of this species into Manitoba should be guarded against and prevented if possible.
KEY TO THE MINNOWS FOUND IN MANITOBA AND ADJACENT AREAS OF THE HUDSON BAY DRAINAGE
1A Dorsal fin long, with more than 11 soft rays and a spine at its leading edge. A spine also present at the leading edge of the anal fin.
go to choice 2
1B Dorsal fin short, with fewer than 11 soft rays and no spine at the leading edge of dorsal and anal fins.
go to choice 3
2A (1A) Upper jaw with 2 barbels on each side. Pharyngeal teeth broad, flat-crowned, and molar-like, in 3 rows. common carp, Cyprinus carpio page 69
INTRODUCED
2B No barbels on upper jaw. Pharyngeal teeth slender, with rounded crowns, in 1 row.
goldfish, carassius auratus page 65
INTRODUCED
3A (1B) Lower jaw with a cartilaginous cutting edge. Intestine long, and looped in a spiral pattern over the ventral surface of the swim bladder.
go to choice 4
3B Lower jaw without a cartilaginous ridge. Intestine may be long and have extra loops, but not in a spiral pattern over the ventral surface of the swim bladder.
go to choice 5
4A (3A) Usually 39–46 scale rows around the body just in front of the dorsal fin. Usually 49–55 lateral line scales. central stoneroller, Campostoma anomalum page 63
OTTER TAIL RIVER (RED RIVER DRAINAGE), USA
4B Usually 31–36 scale rows around the body just in front of the dorsal fin. Usually 43–47 lateral line scales.
largescale stoneroller, Campostoma oligolepis page 64
FOREST RIVER (RED RIVER DRAINAGE), USA
5A (3B) A slender barbel present at the posterior tip of the upper jaw.
go to choice 6
5B Barbel either absent or forward of posterior tip of upper jaw, and often tiny and difficult to see.
go to choice 12
6A (5A) Groove separating upper lip from snout is interrupted across midline of snout.
genus Rhinichthys, go to choice 7
6B Groove separating upper lip from snout is continuous across midline.
go to choice 8
7A (6A) Snout projects beyond tip of lower jaw by a distance equal to or greater than that from tip of lower jaw to angle of mouth.
longnose dace, Rhinichthys cataractae page 106
7B Snout projects beyond tip of lower jaw by less than the distance from tip of lower jaw to angle of mouth. western blacknose dace, Rhinichthys obtusus page 108
8A (6B) Well-developed dark lateral band that extends onto the head is present and visible even on faded preserved specimens. Note: In lake chub, Couesius p...
