Critter Catalog

What do they look like?

The bluntnose minnow is a very small silver fish, long and thin with a dark stripe from snout to tail. At the bottom of the tail the stripe becomes a dot. Upperparts are slightly olive while sides are bluish. The name "bluntnose" refers to the rather flat head and snout. During the breeding season, males become darker, with a silver bar behind the gill cover (opercle), and grow 16 bumps in three rows on their head.

• Other Physical Features
• bilateral symmetry

• Sexual Dimorphism
• male more colorful

• Range length

  11.0 (high) cm

  4.33 (high) in

Where do they live?

The bluntnose minnow is found only in the Nearctic region. They occur from southern Quebec and Manitoba south to Louisiana, west to the Mississipi River drainage (but not the Mississippi River itself).

• Biogeographic Regions
• nearctic
  • native

What kind of habitat do they need?

The bluntnose minnow is a freshwater fish that lives its entire life in the water. Bluntnose minnows prefer living in clear, rocky streams and creeks that are small to medium in size. They also occur in natural and man-made lakes.

• These animals are found in the following types of habitat
• temperate
• freshwater

• Aquatic Biomes
• lakes and ponds
• rivers and streams

How long do they live?

The maximimum recorded age for a bluntnose minnow is five years, this was probably a captive individual. In the wild, two years is a more realistic lifespan.

• Range lifespan
  Status: captivity

  5.0 (high) years

• Typical lifespan
  Status: wild

  2.0 (high) years

• Average lifespan
  Status: captivity

  5 years

  AnAge

How do they behave?

• Key Behaviors
• natatorial
• motile

How do they communicate with each other?

During breeding season the males use at least two methods of communication. First, their physical appearance changes (as described in the reproductive section). Second, males make a variety of pulsed sounds when acting aggresively with other males. It is not known if these sounds are also used in courtship or spawning.

Bluntnose minnows probably release chemicals called pheromones when they are alarmed.

• Perception Channels
• tactile
• chemical

What do they eat?

Bluntnose minnows eat algae, aquatic insect larvae, diatoms, and small crustaceans called entomostracans. Occasionally they will eat fish eggs or small fish.

• Primary Diet
• carnivore
  • eats eggs
  • eats non-insect arthropods
• omnivore

What eats them and how do they avoid being eaten?

This small fish is prey to many larger fish as well as many birds and reptiles. To avoid predators, minnows move fast, travel in groups called schools, or hide.

Like other minnows, these fish probably release a chemical called "alarm substance" when under attack. Scientists think the substance may be a distress signal that attracts other predatory fish who may interrupt the first predator and allow the minnow to escape.

The list below is only a sample of the species that eat minnows.

• Known Predators

  • black-crowned night herons (Nycticorax nycticorax)
  • great blue herons (Ardea herodias)
  • belted kingfishers (Megaceryle alcyon)
  • ring-billed gulls (Larus delawarensis)
  • common grackles (Quiscalus quiscula)
  • northern pike (Esox lucius)
  • largemouth bass (Micropterus salmoides)
  • snapping turtles (Chelydra serpentina)
  • painted turtles (Chrysemys picta)
  • northern water snakes (Nerodia sipedon)

What roles do they have in the ecosystem?

Bluntnose minnows serve an important role as prey for larger animals and as a predator on insect larvae

How do they interact with us?

Bluntnose minnows are commonly used for bait in the fishing industry. They are also used as a food source for raising larger sport fish, such as bass.

Are they endangered?

This is a very common fish. In fact, bluntnose minnows are probably the most abundant freshwater fish in the eastern United States.

• IUCN Red List

  Not Evaluated

• US Federal List

  No special status

• CITES

  No special status

• State of Michigan List

  No special status

Contributors

Cynthia Sims Parr (author), University of Michigan-Ann Arbor.

References

Chivers, D., G. Brown, R. Smith. 1996. Evolution of chemical alarm signals: attracting predators benefits alarm signal senders. American Naturalist, 148: 649-659.

Froese, R., D. Pauly, eds.. 2002. "Fishbase: Pimephales notatus" (On-line). Accessed 27 March 2002 at http://www.fishbase.org.

Johnson, C., D. Johnson. 2000. Sound Production in Pimephales notatus (Rafinesque) (Cyprinidae). Copeia, 2000(2): 567-571.

Page, L., B. Burr. 1991. A field guide to freshwater fishes. Boston: Houghton Mifflin.

State of Iowa DNR, 2001. "Bluntnose minnow card" (On-line). Accessed 27 March 2002 at http://www.state.ia.us/government/dnr/organiza/fwb/fish/iafish/minnow/card/bnm-card.htm.

USGS Great Lakes Science Center, 1982. "Atlas of the Spawning and Nursery Areas of Great Lakes Fishes" (On-line). Accessed 28 March 2002 at http://www.glsc.usgs.gov/information/atlas/volumes/volume13.pdf.