Cycleptus elongatusBlue Sucker

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Geographic Range

Blue suckers are widespread but rare throughout the Mississippi River basin in the United States. They are found from Pennsylvania to the Yellowstone and Missouri Rivers in central Montana, and in the Rio Grande River from Texas to Alabama. ("Status Report on Blue Sucker (Cycleptus elongatus), a Candidate Endangered or Threatened Species", 1993; Eitzmann, et al., 2007; "Species Profile: Minnesota Department of Natural Resources", 2012)

Habitat

Blue suckers inhabit main stems of major rivers and lower sections of main tributaries throughout their range. They are well adapted to strong currents and are found within riffles and rapidly flowing chutes. Blue suckers require gravel or rock bottoms with constantly flowing water that is relatively silt-free. ("Status Report on Blue Sucker (Cycleptus elongatus), a Candidate Endangered or Threatened Species", 1993; "Species Profile: Minnesota Department of Natural Resources", 2012)

  • Aquatic Biomes
  • benthic
  • rivers and streams
  • Range depth
    0.3 to 10 m
    0.98 to 32.81 ft

Physical Description

Blue suckers are olive in color with blue-black fins for the majority of the year. In the spawning season, they have blue-black fins, backs, and sides, and blue-white bellies. Blue suckers have long, compressed bodies, relatively small heads, subterminal mouths, and papillose lips. Dorsal fins are long and extend far down the length of the body. Dorsal fins are also falcate, meaning that the first several anterior rays of the dorsal fin are considerably longer than the posterior rays. This gives the appearance that the fin is pointed at the front and has a curved taper throughout the rest of the fin. The tail is deeply forked and has more than 24 rays. Adult blue suckers grow to be 76 to 102 cm long and typically weigh 1.8 to 4.5 kg. Blue suckers exhibit sexual dimorphism, with females larger than males by an average of 7 cm at comparable ages. ("Status Report on Blue Sucker (Cycleptus elongatus), a Candidate Endangered or Threatened Species", 1993; Daugherty, et al., 2008; "Species Profile: Minnesota Department of Natural Resources", 2012)

  • Sexual Dimorphism
  • female larger
  • Range mass
    1.8 to 4.5 kg
    3.96 to 9.91 lb
  • Average mass
    2.5 kg
    5.51 lb
  • Range length
    76 to 102 cm
    29.92 to 40.16 in

Development

Little is known about juvenile development in this species. It has been observed that spawning takes place in tributaries of the main stems of major rivers. Adults and juveniles segregate, with juveniles taking advantage of the slack waters in tributaries and backwaters. ("Status Report on Blue Sucker (Cycleptus elongatus), a Candidate Endangered or Threatened Species", 1993; Mestl, 2009; "Species Profile: Minnesota Department of Natural Resources", 2012)

Reproduction

Blue suckers spawn on sand, gravel and cobble substrates in tributaries at 0.3 to 3 m deep. They breed in the spring between April and June, at water temperatures around 10°C. ("Status Report on Blue Sucker (Cycleptus elongatus), a Candidate Endangered or Threatened Species", 1993; Eitzmann, et al., 2007; Yeager and Semmens, 1987)

Both male and female blue suckers reach sexual maturity at 3 to 4 years of age. Males develop small mating horns on their head, lips, and back during the spawning months. A female between 57 and 75 cm can produce anywhere from 150,000 to 250,000 eggs during the spawning season. ("Status Report on Blue Sucker (Cycleptus elongatus), a Candidate Endangered or Threatened Species", 1993; Yeager and Semmens, 1987)

  • Breeding interval
    Blue suckers breed annually.
  • Breeding season
    Blue suckers breed from April to June.
  • Range number of offspring
    150,000 to 250,000
  • Average age at sexual or reproductive maturity (female)
    3 years
  • Average age at sexual or reproductive maturity (male)
    3 years

Lifespan/Longevity

Blue suckers have a lifespan of 9 to 12 years in the wild. ("Status Report on Blue Sucker (Cycleptus elongatus), a Candidate Endangered or Threatened Species", 1993; Eitzmann, et al., 2007)

  • Range lifespan
    Status: wild
    9 to 12 years

Behavior

Little is known about blue sucker behavior. Observation in the wild is difficult due to swift currents and turbid waters that these fish inhabit. It it assumed that blue suckers hug the bottom of the main stem of river systems and wait for the current to bring food to them. ("Status Report on Blue Sucker (Cycleptus elongatus), a Candidate Endangered or Threatened Species", 1993; "Species Profile: Minnesota Department of Natural Resources", 2012)

  • Range territory size
    200 (high) km^2

Home Range

No published information is available on the home range of blue suckers. They have been known to migrate nearly 200 km to suitable spawning areas during and after the spawning season. ("Status Report on Blue Sucker (Cycleptus elongatus), a Candidate Endangered or Threatened Species", 1993; Eitzmann, et al., 2007; Yeager and Semmens, 1987)

Communication and Perception

Male and female blue suckers change coloration during the spawning season. Males also develop visible bumps on their heads during this time, so visual and tactile cues are likely important in blue sucker communication. ("Status Report on Blue Sucker (Cycleptus elongatus), a Candidate Endangered or Threatened Species", 1993; "Species Profile: Minnesota Department of Natural Resources", 2012; Yeager and Semmens, 1987)

Food Habits

Blue suckers are bottom feeders whose diet includes aquatic insects, insect larvae, crustaceans, plant material, and algae. ("Status Report on Blue Sucker (Cycleptus elongatus), a Candidate Endangered or Threatened Species", 1993; "Species Profile: Minnesota Department of Natural Resources", 2012)

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

Predation

Known predators of blue suckers include many game fish species common to the Mississippi river basin such as largemouth bass, northern pike, muskellunge, and walleye. ("Status Report on Blue Sucker (Cycleptus elongatus), a Candidate Endangered or Threatened Species", 1993; "Species Profile: Minnesota Department of Natural Resources", 2012; Sutton, 2009)

Ecosystem Roles

Blue suckers are predators and prey in the ecosystems they inhabit. ("Status Report on Blue Sucker (Cycleptus elongatus), a Candidate Endangered or Threatened Species", 1993)

Economic Importance for Humans: Positive

In the late 1800’s, nearly 2 million pounds of blue suckers were harvested from a 21-mile section of the Mississippi River for human consumption. More recently, their populations have not been large enough to consider harvesting them. ("Status Report on Blue Sucker (Cycleptus elongatus), a Candidate Endangered or Threatened Species", 1993)

  • Positive Impacts
  • food

Economic Importance for Humans: Negative

Blue suckers have no known negative economic impacts on humans. ("Status Report on Blue Sucker (Cycleptus elongatus), a Candidate Endangered or Threatened Species", 1993)

Conservation Status

Contributors

Ryan Acker (author), Minnesota State University, Mankato, Robert Sorensen (editor), Minnesota State University, Mankato, Catherine Kent (editor), Special Projects, Jeremy Wright (editor), University of Michigan-Ann Arbor.

Glossary

Nearctic

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

acoustic

uses sound to communicate

benthic

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.

carnivore

an animal that mainly eats meat

chemical

uses smells or other chemicals to communicate

detritivore

an animal that mainly eats decomposed plants and/or animals

detritus

particles of organic material from dead and decomposing organisms. Detritus is the result of the activity of decomposers (organisms that decompose organic material).

ectothermic

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

female parental care

parental care is carried out by females

fertilization

union of egg and spermatozoan

food

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

freshwater

mainly lives in water that is not salty.

herbivore

An animal that eats mainly plants or parts of plants.

insectivore

An animal that eats mainly insects or spiders.

iteroparous

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).

migratory

makes seasonal movements between breeding and wintering grounds

motile

having the capacity to move from one place to another.

natatorial

specialized for swimming

native range

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

omnivore

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

oviparous

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

polygynandrous

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

sexual

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

tactile

uses touch to communicate

temperate

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).

vibrations

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

visual

uses sight to communicate

References

Minnesota Department of Natural Resources. 2012. "Species Profile: Minnesota Department of Natural Resources" (On-line). Accessed February 08, 2012 at http://www.dnr.state.mn.us/rsg/profile.html?action=elementDetail&selectedElement=AFCJC04010.

U.S. Fish and Wildlife Service. Status Report on Blue Sucker (Cycleptus elongatus), a Candidate Endangered or Threatened Species. North Dakota State Office: Ecological Services. 1993.

Burr, B., J. Garvey. 2006. Ecology of larval blue sucker (Cycleptus elongatus) in the Mississippi River. Ecology of Freshwater Fish, 15: 291-300.

Daugherty, D., T. Bacula, M. Sutton. 2008. Reproductive Biology of Blue Sucker in a large Midwestern river. Applied Ichthyology, 24: 297-302.

Eitzmann, J., A. Makinster, C. Paukert. 2007. Distribution and growth of blue sucker in a Great Plains river, USA. Fisheries Management and Ecology, 14: 255-262. Accessed February 08, 2012 at http://web.missouri.edu/~paukertc/reprints/Blue%20sucker%20in%20Kansas%20River.pdf.

Mestl, G. 2010. Seasonal resource selection by blue suckers Cycleptus elongatus. Journal of Fish Biology, 76: 836-851.

Mestl, G. 2009. Seasonal use distributions and migrations of blue sucker in the Middle Missouri River, USA. Ecology of Freshwater Fish, 18: 437-444.

Sutton, M. 2009. Blue sucker stock characteristics in the Wabash River Indiana-Illinois, USA. Fisheries Managment and Ecology, 16: 21-27.

Yeager, B., K. Semmens. 1987. Early Development of the Blue Sucker, Cycleptus elongatus. Copeia, 2: 312-316. Accessed February 08, 2012 at http://www.jstor.org.ezp.lib.rochester.edu/stable/1445766.