Sucker-Minnow Identification Guide

Revised January 2000
Produced by the Washington Department of Fish and Wildlife, Angler Education Program. For more information or additional copies of this publication, please contact one of the following department offices:

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The 1993 classification of several new game fish species in Washington opened the door to new state record categories and opportunities. The six species listed here are described in this pamphlet to help anglers determine whether they may have a potential state record. Remember though, when you apply for a state record, a WDFW fisheries biologist must still verify the species and sign your application form.

References for all species are Freshwater Fishes of Canada, Scott and Crossman, 1973; and Inland Fishes of Washington, Wydoski and Whitney, 1979. Drawings are reproduced from Freshwater Fishes of Canada by permission of the authors.



Suckers are members of the Catostomidae family of fishes. Washington’s four species all have an elongated, roundish, "torpedo-shaped" body with a sub-terminal or ventral (on the bottom side) mouth. Mouth characteristics, mainly the amount of cleft (split) in the lower lip and arrangement of papillae (small nipple-like projections) on the upper lip, are the easiest way to distinguish between the four species. Coloration is often too variable to rely on. Location of capture can be helpful information. Fin ray and scale counts provide useful and reliable information, but are provided here only as a reference for biologists.


Bridgelip Sucker

Bridgelip SuckerIn Washington this species occurs in the Columbia River drainage, and is more common east of the Cascades. Maximum size forBridgelip Sucker adults is generally 12-14 inches, with occasional specimens to 17 inches reported. The back and top of the Bridgelip’s head are dark-brown to olive; the upper sides often somewhat mottled and paler brown; the lower sides, head below the eye, and belly are white to pale-yellow . Breeding males (in spring) develop a prominent orange stripe on the sides.

Distinguishing characteristics:

  • The lower lip is only slightly cleft (less than half-way); this distinguishes it from the Largescale and Longnose Suckers, which have almost completely-cleft lower lips.
  • The bottom of the lower lip has rounded lobes, the corners of the mouth have slight or indistinct notches, and the front of the upper lip has at least one row of distinct papillae. These characteristics distinguish the Bridgelip from the Mountain Sucker, which has similar geographic distribution and a partially-cleft lower lip, but almost flat lobes on the lower lip, distinct notches at the corners of the mouth, and no papillae on the front of the upper lip (both Bridgelip and Mountain have 2-5 total rows of papillae on the upper lip).
  • Rays: 11-14 in the dorsal fin, usually 11 or 12; 10-11 in pelvic fins; 17 in pectorals. Lateral line scales: 87-124, usually 88-99.


Largescale Sucker

Largescale SuckerThis common sucker is found throughout Washington. Maximum size is about 18 inches, with occasional individuals to 24 inches. As its name implies, the scales are larger than on any other Largescale Sucker Washington sucker species. Adults are dark and noticeably countershaded (dark above, lighter below, which provides a camouflaging effect). The back, upper sides to just below the lateral line, and head to just below the eye are bluegray to olive; the lower sides, lower part of the head, and belly are cream to white. A dark lateral band, below the lateral line, extends from the snout to the base of the tail. Countershading and the dark lateral band are more pronounced on breeding males (in spring).

Distinguishing characteristics:

  • The lower lip is almost completely cleft, which distinguishes it from the bridgelip and mountain suckers.
  • The longnose sucker has a similarly-cleft lower lip, but has a much longer snout overhanging the mouth.
  • Rays: 12-16 in the dorsal fin (usually 13-15); 9-12 in pelvic fins; 16-18 in pectorals. Lateral line scales: 62-83, increasing in size from head to tail.


Longnose Sucker

Longnose SuckerAlthough found most commonly in the Columbia River drainage, this sucker has a widespread distribution. Size range is about the same as for the Largescale Sucker; up to 17 or 18 inches, with occasional larger individuals. Adults are generally dark, with very noticeable countershading. The back, upper sides, and head below the eyes are dark olive with brassy reflections, or gray to almost black; lower sides of the head and body and the belly are cream to white. Breeding adults develop a bright red lateral stripe, more pronounced in males. Males in breeding dress may also have well-developed tubercles (small rounded lumps or wartlike growths) on the head and anal and tail fins.

Distinguishing characteristics:

  • The almost completely cleft lower lip readily distinguishes it from the Bridgelip and Mountain Suckers.
  • The longer, overhung snout, plus dorsal fin ray and lateral line scale counts set it apart from the Largescale Sucker.
  • Rays: 9-11 in the dorsal fin (compare to 12-16 in the Largescale); 9-11 in pelvic fins; 16-18 in pectorals. Lateral line scales: 91-120, usually 99- 108, small and crowded toward the head.


Mountain Sucker

Mountain SuckerThis small sucker enjoys a fairly wide distribution, is more common in the upper Columbia River drainage than elsewhere in Washington. Mountain SuckerIt prefers clear, cold mountain streams with sandy or gravelly bottoms. Maximum length is usually about eight inches. The back, head above the eyes, and sides to the lateral line are green, gray or brown, speckled with black, the lateral line not prominent. Lower surfaces of the head and body are pale yellow to white, with a dark green to black lateral band or dorsal blotches. As with other species, breeding individuals are more prominently colored, with an orange to deep red stripe on the side and darker fin rays.

Distinguishing characteristics:

  • The lower lip is only partially cleft, setting it apart from the Largescale and Longnose Suckers.
  • Unlike the Bridgelip Sucker, the front edge of the upper lip is almost smooth, with no papillae, and there are usually distinct notches at the corners at· the mouth.
  • Rays: 9-11 in the dorsal fin (compare to 11-14 in the Bridgelip); 9-10 in pelvic fins; usually 15 in pectorals. Lateral line scales: 60-108, usually 79-89, small and crowded toward the head.



Minnows are members of the Cyprinidae family, which includes carp, chubs, dace; and shiners. Cyprinids comprise the largest family of fishes in the world, with approximately 275 genera and 1,600 species worldwide. Although the cyprinids are wel1-represented in Washington, only the Northern Pikeminnow and Peamouth are classified as game fish. Common Carp are classified as "food" fish, and Grass Carp are protected.

Northern Pikeminnows and Peamouth have long, slender bodies with a single dorsal fin, deeply-forked tail, and somewhat similar mouth characteristics and body shape. Their geographic ranges overlap considerably, and they are even known to hybridize (crossbreed). Color is usually a reliable way to tell them apart, along with mouth characteristics and dorsal fin ray counts.


Northern Pikeminnow

Northern PikeminnowNorthern Pikeminnows are well distributed in Washington, being found in the Columbia River system, plus coastal and Puget Sound drainages. They are opportunistic feeders, but larger fish are highly piscivorous (eat other fish). Adult Northern Pikeminnows are considered serious predators of juvenile salmonids, especially in the Columbia River, and programs there are designed to control their numbers.

The Northern Pikeminnow’s mouth is terminal (at the end of the head) and large, extending back past the front edge of the eye. All fins are clear (no spots or coloration). Body coloration is usually dark green or greenish-brown above, lighter and often silvery on the sides, with a whitish belly. Spawning fish, especially males, take on a yellowish or yellow-orange color. Males also develop tubercles on the head, back and some fins during spawning. Rays: 9-10 in the dorsal fin.



PeamouthThis minnow is found in much the same waters as the Northern Pikeminnow, plus some marine or brackish environments. Peamouth are largely insectivorous, consuming a wide variety of aquatic and terrestrial insects and their larvae. They also feed on planktonic crustaceans, molluscs and occasionally small fish.

The mouth is slightly overhung by the snout (sub-terminal), and stops well short of the front edge of the eye (compare to the larger mouth in Northern Pikeminnows), with a small barbel at each corner. The color is generally silvery with a dark back and two distinct lateral bands. Areas of red or reddish-pink sometimes extend from around the mouth, along the cheek and opercle to the pectoral fin, and along the sides. Spawning fish of both sexes are highly-colored, with red lower lips and the lateral red stripes well developed; spawning males with a green back, females with a brownish back. Rays: always 8 in the dorsal fin.

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