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Gilt darter

Percina evides

What do they look like?

Gilt darters are medium-sized for darters, but small compared to a lot of other fish. They are about 6.35 cm long. They are dark olive on the top or back, and brightly colored bronze on their belly. They have 5 to 8 dark bands that run across their back and down their sides. They have 10 to 13 spines along their top front fin. The spines are orange on the tips and connected by dark skin. Their tail fins are much lighter or colorless. Most of their other fins are orange closer to the body and colorless at the end. Males and females look different during the breeding season. ("Minnesota Department of Natural Resources", 2011; Dickson, 2008; Eddy and Surber, 1947; Phillips, et al., 1982)

  • Sexual Dimorphism
  • sexes colored or patterned differently
  • male more colorful
  • Range length
    5.08 to 7.62 cm
    2.00 to 3.00 in

Where do they live?

Gilt darters live North America from eastern Minnesota to western New York, south to northern Arkansas, Mississippi, Alabama, and Georgia. The area where they live is shrinking because of erosion, buildup of silt and sediment, man-made changes to the way the river flows, and pollution. ("NatureServe", 2010)

What kind of habitat do they need?

Gilt darters live in freshwater streams and rivers that are pretty clear. Their streams and rivers are 20 to 100 m wide, and flow year-round at about 0.5 to 1.2 m/sec. Gilt darters travel between different depths depending on season. In spring and early summer, they scatter and fertilize their eggs in fast-moving rocky spots of rivers. Afterwards, they move to deeper water and places with gravel bottoms, where they stay for the rest of the year. ("Minnesota Department of Natural Resources", 2011; Hatch, 2004)

  • These animals are found in the following types of habitat
  • temperate
  • Aquatic Biomes
  • rivers and streams

How do they grow?

Females release hundreds of yellow or orange eggs which the males fertilize. The eggs measure are 1.1 to 1.4 mm across, and get hard when they are let out into the water. Eggs hatch in 8 to 10 days, when the water temperature is about 20°C. The fish larvae are 4.0 to 4.8 mm long. They become juvenile, or young, gilt darters about 1 week later. (Hatch, 2004)

How do they reproduce?

Males start to look and act different at the start of the breeding season. Their upper body turns dark blue-green and their underbellies become iridescent yellow or orange. Their sides get dark blotches and the fins turn blue on the side closer to their body. Males compete for females by marking off a territory around rocks in fast-flowing parts of the stream. They get very aggressive towards rivals. They defend their territories by chasing, tail-beating, confident body posturing, and rapid color changing. Females are pursued if they enter territory of a male. If she is interested, the female poses a certain way and communicates by touch. Females decide a location to disperse her eggs, and males fertilize them in the water. Both males and females push down on the river bottom to bury their eggs. Females mate with more than one male. (Dickson, 2008; Hatch, 2004)

Gilt darters breed once a year in the summer, when the water is 17°C or warmer. Grown-up females lay 132 to 762 eggs, and 247 on average. Eggs take about 8 to 10 days to grow into larvae. Males can mate when they are 11 to 13 months old, and females when they are 22 to 23 months old. (Hatch, 2004)

  • How often does reproduction occur?
    Gilt darters breed once a year.
  • Breeding season
    Gilt darters breed from June to early July.
  • Range number of offspring
    132 to 762
  • Average number of offspring
    247
  • Range time to hatching
    8 to 10 days
  • Range age at sexual or reproductive maturity (female)
    22 to 23 months
  • Range age at sexual or reproductive maturity (male)
    11 to 13 months

Gilt darters don't protect or care for their young after they scatter and fertilize the eggs.

  • Parental Investment
  • pre-fertilization
    • provisioning
    • protecting
      • female

How long do they live?

Gilt darters have a lifespan of 2 to 3 years in the wild. Occasionally, some can live for 4 years. Less than 1 in 10 1-year-old gill darters lives to be 3 years old. (Hatch, 2004)

  • Range lifespan
    Status: wild
    4 (high) years
  • Range lifespan
    Status: captivity
    4 (high) years
  • Typical lifespan
    Status: wild
    2 to 3 years
  • Typical lifespan
    Status: captivity
    2 to 3 years

How do they behave?

Compared to other darters, gilt darters can move around a lot in the water. They have a small gas bladder, which is a special organ that helps them move in the water. This means they swim around more than other darters. Darters get the name from using their fins to "dart" around, but gilt darters swim more than they dart. (Dickson, 2008; Phillips, et al., 1982)

Home Range

Scientists don't know the normal size of home range for gilt darters. (Phillips, et al., 1982)

How do they communicate with each other?

Like all fish, gilt darters have a sensory organ running from their head to tail called a lateral line. It helps them sense water currents and vibrations. Gilt darters use their eyes, internal ears, and lateral line to get information about their environment. (Eddy and Surber, 1947)

What do they eat?

Gilt darters eat mostly larvae of insects that live in the water. They find their prey mostly by sight, and feed in early or in the middle of the day. There is a lot of food available from April through August, but this goes down a lot in September. Because the amount of prey available goes up and down so much, their diet changes depending on what is available. Gilt darters eat a lot of mayflies, caddisflies and other flies. They also eat midges and black fly larvae. Young gilt darters eat more caddisflies in their first 2 months than when they are adults. Before breeding, they eat more mayflies than anything else. ("NatureServe", 2010; Hatch, 2004)

  • Animal Foods
  • insects

What eats them and how do they avoid being eaten?

The fast-flowing waters where gilt darters live are excellent safe zones from predators. All darters do a good job of avoiding predators by staying at the bottom of the river or stream. Gilt darters can also get away from a lot of predators because they can swim and change directions quickly. They are probably eaten by fish-eating fish. (Hatch, 2004; Shiels, 2011)

What roles do they have in the ecosystem?

Gilt darters may help limit the number of insects that are pests to humans. They are likely prey for various other fish. They also play an important role in mussel reproduction as hosts for numerous species of mussel larvae called glochidia, including rabbitsfoot mussels. (Shiels, 2011)

  • Ecosystem Impact
  • creates habitat
Commensal or parasitic species (or larger taxonomic groups) that use this species as a host

Do they cause problems?

There are no known negative impacts of gilt darters on humans. (Froese, 2010)

How do they interact with us?

Gilt darters are sensitive to changes in their habitat, and often used by scientists to measure the health of their environment. ("Minnesota Department of Natural Resources", 2011)

  • Ways that people benefit from these animals:
  • research and education

Are they endangered?

Gilt darters live throughout the Midwest and northeastern United States. In some places where they live, they are a species of special concern because their numbers have decreased a lot in the past 50 years. When humans build dams, sediment and silt builds up in the rivers and they get cloudy, which buries the places where they breed and makes it harder for them to see their prey. They don't have any special status from the U.S. Fish and Wildlife Service. ("Minnesota Department of Natural Resources", 2011)

Some more information...

The scientific name for gilt darters used in Minnesota before 1955 was Hadropterus evides. (Hatch, 2004)

Contributors

Steve Sveine (author), Minnesota State University, Mankato, Robert Sorensen (editor), Minnesota State University, Mankato, John Berini (editor), Animal Diversity Web Staff, Catherine Kent (editor), Special Projects.

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

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.

carnivore

an animal that mainly eats meat

chemical

uses smells or other chemicals to communicate

ectothermic

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

fertilization

union of egg and spermatozoan

heterothermic

animals that have little or no ability to regulate their body temperature, body temperatures fluctuate with the temperature of their environment, often referred to as 'cold-blooded'.

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).

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.

polyandrous

Referring to a mating system in which a female mates with several males during one breeding season (compare polygynous).

seasonal breeding

breeding is confined to a particular season

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

2011. "Minnesota Department of Natural Resources" (On-line). Accessed April 28, 2011 at http://www.dnr.state.mn.us/rsg/profile.html?action=elementDetail&selectedElement=AFCQC04090.

2010. "NatureServe" (On-line). Accessed April 28, 2011 at http://www.natureserve.org/explorer/servlet/NatureServe?searchName=Percina+evides+.

Dickson, T. 2008. The Great Minnesota Fish Book. Minneapolis: The University of Minnesota Press.

Eddy, S., T. Surber. 1947. Northern Fishes. Minneapolis: The University of Minnesota Press.

Froese, R. 2010. "FishBase" (On-line). Percina evides. Accessed April 28, 2011 at http://www.fishbase.org/Summary/SpeciesSummary.php?ID=3493&AT=gilt+darter.

Hatch, J. 2004. "Gilt darter" (On-line). Accessed April 28, 2011 at http://hatch.cehd.umn.edu/research/fish/fishes/gilt_darter.html.

Phillips, G., W. Schmid, J. Underhill. 1982. Fishes of the Minnesota region. Minneapolis: The University of Minnesota Press.

Shiels, . 2011. "Pennsylvania Fish and Boat Commission" (On-line). Pennsylvania's Dynamic Darters. Accessed May 01, 2011 at http://www.fish.state.pa.us/education/catalog/darters.html.

 
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Sveine, S. 2012. "Percina evides" (On-line), Animal Diversity Web. Accessed April 23, 2014 at http://www.biokids.umich.edu/accounts/Percina_evides/

BioKIDS is sponsored in part by the Interagency Education Research Initiative. It is a partnership of the University of Michigan School of Education, University of Michigan Museum of Zoology, and the Detroit Public Schools. This material is based upon work supported by the National Science Foundation under Grant DRL-0628151.
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