Catostomus catostomus

Geographic Range

Longnose suckers, Catostomus catostomus, are found throughout northern continental United States, Canada and eastern Alaska. The northmost portion of the range is the Northwest Territories in Canada, at Kugluktuk. The range extends to the southern edge of the James Bay and includes areas north to Erik Cove. Their easternmost range is Labrador, Canada at the Labrador Sea. The range continues southward into the United States including the Great Lakes. These suckers inhabit the Great Lakes but are less common in Lake Erie. The southern range continues westward to the North Platte River, Nebraska. The westernmost part of the range is eastern Alaska at the headwaters of Little Nelchina River, near the Talkeetna Mountains.

Longnose suckers are also found in rivers of eastern Siberia. they have been introduced, through human activity, in the upper Colorado River drainage in Wyoming and Colorado, as well as in Finland. ("Catostomus catostomus", 2014; Robins, et al., 1991; Trautman, 1981)


Longnose suckers dwell in the benthic zone, averaging at a depth of 10 m, of freshwater rivers and lakes. Longnose suckers are sometimes found at a maximum depth of 182 m in the Great Lakes. These fish can also be found in brackish water near Arctic streams. They are common in both large-order and small-order streams. The temperatures of the water the fish usually inhabits are between 0°C to 15°C. They move to shallow, gravel-filled streams to spawn. In Lake Erie, longnose suckers inhabit deep and cool habitats, and only come to waters within 7.6 m depths in spring to mate. (Childress, et al., 2016; Robins, et al., 1991; Scott, 1967; Trautman, 1981)

  • Range depth
    7.6 to 182 m
    24.93 to 597.11 ft

Physical Description

Adult longnose suckers have a maximum length of 64 cm and a maximum mass of 3.3 kg. As adults, they have an average length of 22.5 cm and an average mass of 2.2 kg. The females are usually larger and heavier than the males.

Longnose suckers have a ventral – or inferior – mouth, with thick papillated lips flaring backwards. Their snouts overhang their mouth. They have large fins with small and numerous scales – up to 85 lateral line scales total. They have eleven soft rays in the dorsal fin and seven in the anal fins. The dorsal fins are usually 30.5 to 40.6 cm long, while the pelvic fins are 22.8 to 30.5 cm and the pectoral fins reach lengths of 40.6 to 45.7 cm.

Adults have an olive-brown or reddish-brown color along their dorsal side with silvery or yellowish color along their lateral side. Their ventral parts are milky white. These fish are ectothermic, which use heat acquired from the environment and behavioral adaptations to regulate their body temperature. During the breeding season, adult males will have a dark dorsal side with a lateral reddish stripe. Adult males have white tubercles on the rays of their anal and caudal fins as well as on their head during the breeding season. These tubercles are absent or weakly developed in females. The dorsal side of juvenile longnose suckerfish usually have a dark gray color with black dots. By the end of their first summer the juvenile fish can be between 4 and 7 cm long.

Longnose suckers are often confused with white suckers Catostomus commersonii. White suckers have a long slender body with light brown colored sides and a white belly. Longnose suckers sometimes hybridize with white suckers because they are so similar. White suckers differ by having shorter snouts and fewer later line scales. (Marrow, 1980; Robins, et al., 1991; Scott, 1967; Trautman, 1981)

  • Sexual Dimorphism
  • female larger
  • male more colorful
  • sexes shaped differently
  • Range mass
    3.3 (high) kg
    7.27 (high) lb
  • Average mass
    2.2 kg
    4.85 lb
  • Range length
    64 (high) cm
    25.20 (high) in
  • Average length
    22.5 cm
    8.86 in


In colder water temperatures, below 10°C, it takes 14 days for longnose sucker eggs to hatch. Above 10°C, it takes only seven days for eggs to hatch. On average, eggs hatch after 11 days. After they hatch, longnose suckers will stay in the gravel as sac fry for one to two weeks until they are able to move and feed themselves. As sac fry, their average length is 4.2 cm and they will grow 9.1 cm within their first year.

For the first year, juvenile longnose suckers feed mostly on zooplankton before switching to an omnivorous diet. The age of maturity varies depending on location but is usually two to three years for both males and females. Further north in their range, age of maturity is three years, while further south it is two years. Longnose suckers have indeterminate growth, meaning they keep growing throughout their lives. (Bailey, 1969; Harris, 1962; Stauffer, 1972)


Longnose sucker spawning occurs during daylight hours. Females swim into shallow streams or areas of lakes over gravel, and each female is surrounded by two to four males. The males use their pelvic fins to grasp the female while they vibrate to release both eggs and sperm at the same time. The spawning act lasts only for a few seconds but may occur up to 40 times per hour. This happens with multiple groups creating a mass spawning. Longnose suckers don’t build nests, but let their eggs fall into crevices in the gravel. Once the eggs are released, males and females separate to mate with others. This makes longnose suckers polygynandrous. ("Catostomus catostomus", 2014; Harris, 1962)

Around mid-April, longnose suckers seasonally migrate to a shallow stream or areas of lakes over gravel to spawn. They are iteroparous, breeding multiple times in their lives but only once a year, between May and June. When longnose suckers aren’t breeding during this time period, they are feeding. A single female can produce between 16,000 to 60,000 eggs averaging.

Longnose suckers that have migrated out of a lake to spawn return to the lake after a few days of spawning. River-resident longnose suckers may stay on or near the spawning area for the rest of the summer. During that time longnose suckers feed on large amounts of insects and algae. By October, all adult longnose suckers leave the spawning area and move downstream or to lakes to over-winter.

Eggs hatch on average 11 days post-spawning. In colder temperatures, the eggs hatch after 14 days while in warmer temperatures the eggs hatch after 7 days. Average weight for longnose suckers is 1.9 g and average length is about 4.2 cm at hatching. Young stay in the gravel as sac fry until they are one to two weeks old and can forage independently. The age of maturity for both males and females is between two to three years. ("Catostomus catostomus", 2014; Harris, 1962; Stauffer, 1972)

  • Breeding interval
    Longnose suckers breed once yearly
  • Breeding season
    Between May and July
  • Range number of offspring
    16,000 to 60,000
  • Average number of offspring
  • Range time to hatching
    7 to 14 days
  • Average time to hatching
    11 days
  • Average time to independence
    0 minutes
  • Range age at sexual or reproductive maturity (female)
    2 to 3 years
  • Range age at sexual or reproductive maturity (male)
    2 to 3 years

Longnose suckers have no parental investment beyond the act of spawning. Once the long suckers have mated, they don’t protect or care for the young in any way. (Page and Johnson, 1990)

  • Parental Investment
  • no parental involvement


The data regarding life expectancy for longnose suckers out in the wild are varied. Atanasov (2005) reported a life expectancy of 12 years, while another source references 19 years. Dean and Rickabaugh (2005) reported that a female survived 21 years in the wild. Therefore, the expected lifespan of longnose suckers out in the wild is between 12 to 19 years. However, the longest known lifespan for female longnose suckers is 21 years and has not been reported for males. Longnose suckers are rarely kept in captivity, but one specimen at Alaska Sea Life Center has lived in captivity for 20 years. The specimen died in 2018. (Atanasov, 2005; Dean and Rickabaugh, 2005; Hugg, 1996)

  • Range lifespan
    Status: wild
    21 (high) years
  • Range lifespan
    Status: captivity
    20 (low) years
  • Typical lifespan
    Status: wild
    12 to 19 years
  • Average lifespan
    Status: wild
    15 years


Around mid-April, adult longnose suckers will migrate to a shallow stream or shallow part of lakes to lay their eggs over gravel. The changing color of the males’ dorsal side, from an olive-brown to a reddish stripe, is the cue for the migration. Some spawn in consecutive years while others sometimes skip a year. Once adults reach the spawning site, males wait near the gravel until a female swims past them. Males crowd and grasp females, then vibrate to release both eggs and sperm. They mate multiple times per hour in multiple groups.

After spawning, some longnose suckers that have migrated out of lakes will return to the lake while river-resident suckers will stay near the spawning area for the rest of the summer. By October, all the adult longnose suckers leave the spawning area and move downstream or to lakes to over-winter. Longnose suckers don’t hibernate during the winter. They stay active all year.

Longnose suckers swim in small schools to avoid predators during breeding season. If longnose suckers are attacked and their epidermis is damaged it sends out pheromones alerting other longnose suckers, activating their flight instinct. They also rely on their acute hearing and lateral line system to detect and avoid predators. Juvenile and adult longnose suckers rely on their sense of taste to track their prey and then suck them up into their mouths.

Outside of the breeding season, longnose suckers are solitary. Adult and juvenile longnose suckers feed day and night but are more active during the day. Generally, longnose suckers don’t show aggression towards other longnose suckers or other fish of similar size. (Amoser and Ladich, 2005; "Catostomus catostomus", 2014; Edwards, 1983; Harris, 1962; LePage, 2014; Scott, 1967; Smith, 1977; Stauffer, 1972; Urry, et al., 2017)

Home Range

LePage (2014) reported that the maximum linear home range for longnose suckers is approximately 494 m with an average range of 107 m. LePage reported these linear home ranges for 50 individuals in the Elk River Watershed in British Columbia between June and October. Of the 50 individuals monitored, 17 were adult females, 1 was an unsexed juvenile, and 32 were adult males. From June to July, linear home ranges for adult males ranged between 88 and 302 m, while the range of the females was between 88 and 206 m. The linear home range of juveniles was 88 m. In mid-October, five tagged longnose suckers were monitored 494 m outside of the original monitoring location. They do not defend a territory. (Edwards, 1983; LePage, 2014)

Communication and Perception

Longnose suckers have a lateral line system. These organs are sensitive to vibrations in the water, which helps them find prey and avoid predators. Also, when their epidermis is damaged, these fish release alarm pheromones. Conspecifics smell this and initiate a flight response. Longnose suckers have relatively sensitive hearing with a frequency range of 100 to 1600 Hz. Juveniles usually rely on their sense of smell to detect predators. Both adult and juvenile longnose suckers mostly rely on their sense of taste to find their food.

These fish have good vision and can see in color. The changing color of the males, which happens between May and June, is their cue for returning to their breeding grounds. Males use their pelvic fins to grasp females while they vibrate to release both eggs and sperm at the same time. (Amoser and Ladich, 2005; Smith, 1977; Urry, et al., 2017; Weisel, 1962)

Food Habits

Adult longnose suckers are omnivores, feeding on benthic algae, mollusk,s and aquatic invertebrates – specifically the family Chironomidae (non-biting midges) and the genera Gammarus (crustaceans), Daphnia, and Cladocera (both zooplankton). Juvenile longnose suckers feed on plankton for the first year. They also feed on the eggs of lake whitefish (Coregonus clupeaformis) in whitefish spawning grounds in Lake Huron. The large lips of longnose suckers enable them to suck up food. (Nester and Poe, 1984; Scott, 1967)

  • Animal Foods
  • eggs
  • insects
  • mollusks
  • aquatic crustaceans
  • Plant Foods
  • algae


Adult and juvenile longnose suckers are preyed upon by larger predatory fish, such as largemouth bass Micropterus salmoides, walleye Sander vitreus, brook trout Salvelinus fontinalis, northern pike Esox lucius, muskellunges Esox masquinongy, burbot Lota lota and sea lamprey Petromyzon marinus.

In spawning season, adult longnose suckers are preyed upon by bald eagles Haliaeetus leucocephalus, herons (Family Ardeidae), commons loon Gavia immer, red-throated loons Gavia stellata, yellow-billed loons Gavia adamsii, osprey Pandion haliaetus, river otters Lontra canadensis, and bears Ursus. Longnose sucker eggs are sometimes eaten by white suckers Catostomus commersonii.

Longnose suckers, during their non-breeding season, use their hearing, lateral line, and their alarm pheromones to detect and escape predators. If longnose suckers are attacked and the epidermis is damaged it sends out pheromones alerting other longnose suckers, activating their flight instinct. During the breeding season, longnose suckers form small schools to avoid predators. The fish that are near the edge of the school act as lookouts. The rest of the schooling longnose suckers quickly reacts to the escape reaction of lookouts, partly due to sensing via their lateral line system. (Crait and Ben-David, 2006)

Ecosystem Roles

Longnose suckers feed on a variety of invertebrates and algae. Their consumption of invertebrates, algae and eggs is not influential enough to affect other fish species. They are prey to numerous fish, birds and mammals.

These suckers are host to a number of internal parasites. Protozoans Trichophrya catostomi infest the gill surface of longnose suckers, feeding on the tissue of the host. Protozoans in the genus Hexamita can infest the intestines of the longnose suckers, causing anorexia, emaciation, and abdominal distension. Protozoans Apiosoma piscicola are sessile and attach to the skin, gills, and fins of fish living in an environment. These parasites can cause decreased appetite, flashing, hyperplasia of infested gill tissues, and compromised osmoregulation and respiration. Trematodes Acolpenteron catostomi infect the kidneys of longnose suckers, causing damage to their renal collecting duct. Nematodes Philometra parasitize the body cavities, tissues and ovaries of longnose suckers. In their larval stage these roundworm parasites move to the bodies of longnose suckers. This movement can cause damage to skeletal joints, resulting in internal bleeding. Emaciation and lowered growth rates may also be a result from this parasite moving.

Externally, sea lampreys Petromyzon marinus have a suction-cup mouth ringed with sharp teeth. They attach to longnose suckers and feed on their blood, usually killing their hosts. Sea lamprey populations are a major problem in the upper Great Lakes, killing large numbers of longnose suckers and other fish. (Childress, et al., 2016; Crait and Ben-David, 2006; Hanek and Molnar, 2011; Heckmann and Ching, 1987; Nester and Poe, 1984)

Commensal/Parasitic Species

Economic Importance for Humans: Positive

Longnose suckers are a low-value gamefish and of minor value in commercial fisheries. People have used suckers for bait, dog food, and as food (sometimes as fillets called mullet). However, Becker (1976) stated that the flesh of longnose suckers has more flavor than other suckers and may be profitably canned in the future. This 1976 prediction may not have panned out. (Becker, 1976; "Catostomus catostomus", 2014)

  • Positive Impacts
  • food

Economic Importance for Humans: Negative

Longnose suckers have no negative economic impacts on humans. ("Catostomus catostomus", 2014)

Conservation Status

Longsnose suckers are a species of “Least Concern” on the IUCN Red List. Longnose suckers have no special status under the US Federal list or CITES list. They have no special status on the state of Michigan list. These suckers are threatened in Illinois and endangered in Ohio and Pennsylvania. They are considered a species of concern in Ohio, Massachusetts, and New York.

A consistent threat across their range is poor water quality. Water pollution – either from point sources like paper mills and municipal sewage outfalls or non-point sources like fertilizer runoff from residential lawns or agricultural fields – can harm these fish. In Pennsylvania, mine drainage has caused the population to suffer due to severe water acidification. A second threat is the introduction of invasive species, such as sea lampreys Petromyzon marinus in the Great Lakes. These parasitic lampreys are known to cause an imbalance in the Lake Michigan ecosystem. Dam construction is thought to have mixed effects on these suckers.

There was a petition to list one population of longnose suckers on the Federal list. Pennsylvania asked to list their population in a single river basin, believing their population of longnose suckers are different from others. The USFWS deemed that the population being considered is not distinct enough to be considered different from others at this time.

Conservation measures suggested for these suckers include monitoring populations for signs of range shifts due to increases in water temperature or local impacts to populations caused by expanding development. Other recommendations include continuing to collect baseline data on suckers and to set up stations for long-term water temperature monitoring. Consideration of longnose suckers for dam construction has also been suggested. Longnose suckers require cold, clear water, which leads to mixed success due to dam construction. The turbid conditions upstream may damage the population, but clear conditions downstream may make them a dominant species. (Anderson, 2007; "Catostomus catostomus", 2014; Cooper, 2007; Illinois Department of Natural Resources, 2018; New Hampshire Fish and Game Department, 2007)


Thomas Marshall (author), Radford University, Lauren Burroughs (editor), Radford University, Logan Platt (editor), Radford University, Karen Powers (editor), Radford University, Galen Burrell (editor), Special Projects.



living in the Nearctic biogeographic province, the northern part of the New World. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.

World Map


living in the northern part of the Old World. In otherwords, Europe and Asia and northern Africa.

World Map


uses sound to communicate


Referring to an animal that lives on or near the bottom of a body of water. Also an aquatic biome consisting of the ocean bottom below the pelagic and coastal zones. Bottom habitats in the very deepest oceans (below 9000 m) are sometimes referred to as the abyssal zone. see also oceanic vent.

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

brackish water

areas with salty water, usually in coastal marshes and estuaries.


an animal that mainly eats meat


uses smells or other chemicals to communicate

  1. active during the day, 2. lasting for one day.

animals which must use heat acquired from the environment and behavioral adaptations to regulate body temperature

external fertilization

fertilization takes place outside the female's body


union of egg and spermatozoan


A substance that provides both nutrients and energy to a living thing.


mainly lives in water that is not salty.


An animal that eats mainly plants or parts of plants.

indeterminate growth

Animals with indeterminate growth continue to grow throughout their lives.


An animal that eats mainly insects or spiders.


referring to animal species that have been transported to and established populations in regions outside of their natural range, usually through human action.


offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).


makes seasonal movements between breeding and wintering grounds


eats mollusks, members of Phylum Mollusca


having the capacity to move from one place to another.


specialized for swimming

native range

the area in which the animal is naturally found, the region in which it is endemic.


active during the night


an animal that mainly eats all kinds of things, including plants and animals


reproduction in which eggs are released by the female; development of offspring occurs outside the mother's body.


the kind of polygamy in which a female pairs with several males, each of which also pairs with several different females.

seasonal breeding

breeding is confined to a particular season


reproduction that includes combining the genetic contribution of two individuals, a male and a female


associates with others of its species; forms social groups.


lives alone


uses touch to communicate


that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).


movements of a hard surface that are produced by animals as signals to others


uses sight to communicate


2014. "Catostomus catostomus" (On-line). Accessed February 01, 2020 at

Amoser, S., F. Ladich. 2005. Are hearing sensitivities of freshwater fish adapted to the ambient noise in their habitats. Journal of Experimental Biology, 208: 3533-3542.

Anderson, R. 2007. "Endangered and Threatened Wildlife and Plants; 90-Day Finding on a Petition To List the Monongahela River Basin Population of the Longnose Sucker as Endangered" (On-line). Accessed April 02, 2020 at

Atanasov, A. 2005. The linear alometric relationship between total metabolic energy per life span and body mass of poikilothermic animals. Biosystems, 82: 137-142.

Bailey, M. 1969. Age, growth, and maturity of the longnose sucker Catostomus catostomus, of western Lake Superior. Journal of the Fisheries Research Board of Canada, 26/5: 1288-1298.

Becker, G. 1976. Environmental Status of the Lake Michigan Region: Inland Fishes of the Lake Michigan Basin. Argonne, Illinois: Argonne National Library.

Childress, E., R. Papke, P. McIntyre. 2016. Spawning success and early life history of longnose suckers in Great Lakes tributaries. Ecology of Freshwater Fish, 25/3: 292-404.

Childress, E., P. McIntyre. 2016. Life history traits and spawning behavior modulate ecosystem-level effects of nutrient subsidies from fish migrations. Ecosphere, 7/6: e01301. Accessed January 27, 2020 at

Cooper, E. 2007. "Longnose sucker (Catostomus catostomus)" (On-line). Accessed April 02, 2020 at

Crait, J., M. Ben-David. 2006. River otters in Yellowstone Lake depend on a declining cutthroat trout population. Journal of Mammalogy, 87/3: 485.

Dean, J., S. Rickabaugh. 2005. Comparison of Two Forms of Longnose Suckers on the Kenai National Wildlife Refuge, Alaska. Soldotna, Alaska: U.S. Fish and Wildlife Service.

Edwards, E. 1983. Habitat suitability index models: Longnose sucker. U.S. Fish and Wildlife Service Fort Collins Co Western Energy and Land Use Team, 10: 4.

Hanek, G., K. Molnar. 2011. Parasites of freshwater and anadromous fishes from Matamek River system, Quebec. Journal of the Fisheries Research Board of Canada, 31/6: 1135-1139.

Harris, H. 1962. Growth and reproduction of the longnose sucker, Catostomus catostomus (Forster), in Great Slave Lake. Journal of the Fisheries Research Board of Canada, 19/1: 113-126.

Hauser, W. 2014. Fishes of the Last Frontier: Life Histories, Biology, Ecology, and Management of Alaska's Fishes. Anchorage, Alaska: Publication Consultants.

Heckmann, R., H. Ching. 1987. Parasites of the cutthroat trout, Salmo clarki, and longnose sucker, Catostomus catostomus, from Yellowstone Lake, Wyoming. The Great Basin Naturalist, 47/2: 259-275.

Hugg, D. 1996. Freshwater and Estuarine Fishes of North America. Edgewater, Maryland: Life Science Software.

Illinois Department of Natural Resources, 2018. "Longnose sucker" (On-line). Accessed April 02, 2020 at

LePage, P. 2014. Life History of Dwarf Longnose Sucker (Catostomus catostomus) in the Elk River Watershed. Waterloo, Canada: University of Waterloo.

Mann, D., P. Cott, B. Hanna, A. Popper. 2007. Hearing in eight species of northern Canadian freshwater fishes. Journal of Fish Biology, 70/1: 109-120.

Marrow, J. 1980. The Freshwater Fishes of Alaska. Vancouver, British Columbia, Canada: Alaska Northwest Books.

McPhail, J. 2007. The Freshwater Fishes of British Columbia. Alberta, Canada: University of Alberta.

Nester, R., T. Poe. 1984. Predation on lake whitefish eggs by longnose suckers. Journal of Great Lakes Research, 10/3: 327-328.

New Hampshire Fish and Game Department, 2007. "Longnose sucker (Catostomus catostomus)" (On-line). Accessed April 02, 2020 at

Page, L., C. Johnson. 1990. Spawning in the creek chubsucker, Erimyzon oblongus, with a review of spawning behavior in suckers (Catostomidae). Environmental Biology of Fish, 27: 265-272.

Robins, C., R. Bailey, C. Bond, J. Brooker, E. Lachner, R. Lea, W. Scoot. 1991. "Catostomus catostomus" (On-line). NatureServe Explorer. Accessed January 27, 2020 at

Scott, W. 1967. Freshwater Fishes of Eastern Canada. Toronto, Ontario, Canada: University of Toronto Press.

Smith, R. 1977. Chemical communication as adaptation: Alarm substance of fish. Pp. 303-320 in D Müller-Schwarze, M Mozell, eds. Chemical Signals of Vertebrates. Boston, Massachusetts: Springer.

Stauffer, M. 1972. Age, growth, and downstream migration of juvenile rainbow trout in a Lake Michigan tributary. Transactions of the American Fisheries Society, 101/1: 18-28.

Trautman, M. 1981. The Fishes of Ohio. Columbus, Ohio: Ohio State University Press.

Urry, L., S. Wasserman, P. Minorsky, J. Reece, N. Campbell. 2017. Campbell Biology. New York, New York: Pearson Education.

Weisel, G. 1962. Comparative study of the digestive tract of a sucker, Catostomus catostomus, and a predaceous minnow, Ptychocheilus oregonense. The American Midland Naturalist, 68/2: 334-346.