Geographic Range
The bluntnose minnow is widely distributed in small and medium-sized streams in North America. They occur from southern Quebec and Manitoba south to Louisiana, west to the Mississipi River drainage (but not the Mississippi River itself).(Froese and Pauly, 2002; State of Iowa DNR, 2001)
Habitat
Bluntnose minnows prefer clear, rocky streams and creeks that are small to medium in size. They also occur in natural and man-made lakes.
- Habitat Regions
- temperate
- freshwater
- Aquatic Biomes
- lakes and ponds
- rivers and streams
Physical Description
This is a very small silver fish, long and slender with a dark stripe from snout to tail. At the base of the tail the stripe becomes a dot. Upperparts are slightly olive while sides are bluish. The name "bluntnose" refers to the rather flat 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. (Page and Burr 1991; State of Iowa DNR, 2001)
- Other Physical Features
- bilateral symmetry
- Sexual Dimorphism
- male more colorful
Reproduction
During the spawning season, males' heads grow darker and their bodies become bluish. They also develop three rows of bumps, or tubercles on their heads. Females release masses of eggs which stick to the underside of rocks or floating logs. They are therefore sheltered while spawning. Depending on the temperature of the waters, eggs may hatch into fry in 8 to 14 days. (State of Iowa DNR, 2002; USGS, 1982)
- Key Reproductive Features
- fertilization
- oviparous
Males stay and guard the eggs and the fry. (USGS, 1982)
- Parental Investment
- male parental care
Lifespan/Longevity
The maximimum recorded age for a bluntnose minnow is five years. It is unclear whether this was a captive or wild individual. (Froese and Pauly, 2002)
Behavior
- Key Behaviors
- natatorial
- motile
Communication and Perception
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.
Food Habits
Bluntnose minnows eat algae, aquatic insect larvae, diatoms, and small crustaceans called entomostracans. Occasionally they will eat fish eggs or small fish. (State of Iowa DNR, 2001)
Predation
This small fish is prey to many larger fish as well as many birds and reptiles. To avoid them, minnows move fast, travel in schools, and hide.
A close relative, the fathead minnow ( Pimephales notatus ) gives off a chemical called "alarm substance" when under attack. Scientists think the substance may be a distress signal that attracts other predatory fish who interrupt the first predator, allowing the minnow to escape (Chivers et al., 1996)
The list below is only a sample of the species that eat minnows.
Ecosystem Roles
Bluntnose minnows serve an important role as prey for larger animals and as a predator on insect larvae.
Economic Importance for Humans: Positive
This fish is commonly used for bait in the fishing industry.
Conservation Status
This is a very common fish. In fact, bluntnose minnows are probably the most abundant freshwater fish in the eastern United States. (Page and Burr, 1991)
Additional Links
Contributors
Cynthia Sims Parr (author), University of Michigan-Ann Arbor.
- 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.
- native range
-
the area in which the animal is naturally found, the region in which it is endemic.
- 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).
- freshwater
-
mainly lives in water that is not salty.
- 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.
- fertilization
-
union of egg and spermatozoan
- external fertilization
-
fertilization takes place outside the female's body
- oviparous
-
reproduction in which eggs are released by the female; development of offspring occurs outside the mother's body.
- male parental care
-
parental care is carried out by males
- carnivore
-
an animal that mainly eats meat
- omnivore
-
an animal that mainly eats all kinds of things, including plants and animals
- natatorial
-
specialized for swimming
- motile
-
having the capacity to move from one place to another.
- tactile
-
uses touch to communicate
- chemical
-
uses smells or other chemicals to communicate
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 .