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Southern brook lamprey

Ichthyomyzon gagei

What do they look like?

Southern brook lampreys have bodies shaped like eels. They have a fin along the top divided in two parts. Their mouth is a circle of teeth adapted for sucking that tells them apart from northern brook lampreys. They are light brown or green on their back and lighter yellow or white on their stomach. Their fins are lighter in color, too. Their larvae have no eyes and their mouths are shaped like a hood. ("Ichthyomyzon gagei", 2011; Hammerson, 2010; Mettee, et al., 2008; Rainer, 2010)

  • Sexual Dimorphism
  • sexes alike
  • Range mass
    1.05 to 4.25 g
    0.04 to 0.15 oz
  • Average mass
    2.2 g
    0.08 oz
  • Range length
    10 to 20 cm
    3.94 to 7.87 in
  • Average length
    16 cm
    6.30 in

Where do they live?

Southern brook lampreys are found in the Mississippi River basin, rivers that drain into the Tennessee River, and rivers that drain into the Gulf of Mexico. They live in freshwater streams. They are usually found in smaller streams as larvae and larger streams as adults. They like shallow water. They need a gravel or small rock river bottoms where they attach and later spawn. ("Ichthyomyzon gagei", 2011; "Mississippi River Resource Page", 2011)

What kind of habitat do they need?

Southern brook lampreys using live in quickly-moving water, but the larvae live in streams where the water moves more slowly. Southern brook lampreys are usually found in smaller rivers and tributaries. ("Ichthyomyzon gagei", 2011; "Mississippi River Resource Page", 2011)

  • Aquatic Biomes
  • rivers and streams
  • Range elevation
    0 to 450 m
    0.00 to 1476.38 ft
  • Range depth
    0.9 to 61 m
    2.95 to 200.13 ft

How do they grow?

Southern brook lampreys spend most of their lives as larvae, which are called ammocoetes. The larvae bury themselves in sandy river bottoms and eat floating bacteria and algae. They are usually larvae for 3 to 4 years. It takes them 2 to 3 months to transform into adults. During this time, they migrate to faster parts of the stream. In the spring, adults attach themselves to the gravel bottom where they lay their eggs. ("Ichthyomyzon gagei", 2011; Beamish and Thomas, 1984; Cochran and Pettinelli, 1987; Cochran, 1987)

How do they reproduce?

Southern brook lampreys mate and lay their eggs in less than one week. Somewhere between 5 and 20 adults work together to build a nest from rocks. (Cochran and Pettinelli, 1987; Mettee, et al., 2008)

The eggs take about 2 to 3 weeks to hatch. Then, southern brook lampreys spend 3 to 4 years as larvae. For 2 to 3 months in the late summer or early fall, the larvae transform into adults. Females release 1000 to 2000 eggs, and the males fertilize the eggs. Adults die a few days after females lay eggs. ("Ichthyomyzon gagei", 2011; Beamish and Thomas, 1984; Cochran and Pettinelli, 1987; Hassan-Williams and Bonner, 2007; Rainer, 2010)

  • How often does reproduction occur?
    Southern brook lampreys breed once in the spring and then die.
  • Breeding season
    Southern brook lampreys breed in the spring over a time period less than a week.
  • Range number of offspring
    1000 to 2500
  • Average number of offspring
  • Range age at sexual or reproductive maturity (female)
    3 to 4 years
  • Range age at sexual or reproductive maturity (male)
    3 to 4 years

Southern brook lampreys build nests for their eggs out of rocks, but die right after the females lay eggs. ("Ichthyomyzon gagei", 2011; Mettee, et al., 2008)

  • Parental Investment
  • pre-hatching/birth
    • provisioning
      • male
      • female
    • protecting
      • male
      • female

How long do they live?

Southern brook lampreys live 2 to 3 weeks as eggs, larvae for 3 to 4 years, and adults for 2 to 26 days. They are hard to raise in captivity. (Beamish and Thomas, 1984; Hassan-Williams and Bonner, 2007; Mettee, et al., 2008; Rainer, 2010)

  • Typical lifespan
    Status: wild
    1111 to 1507 days

How do they behave?

Adult southern brook lampreys have just a few days to reproduce and build a nest for their offspring. They form groups of 20 to 40 adults to release and fertilize their eggs. Adults may work together to build nests. (Cochran and Pettinelli, 1987; Cochran, 1987; Mettee, et al., 2008)

How do they communicate with each other?

Southern brook lampreys mostly communicate and understand their environment using their senses of sight and touch. Only adults have fully working eyes. ("Ichthyomyzon gagei", 2011)

What do they eat?

Southern brook lampreys are not parasites. The larvae eat algae and other bacteria floating near the spot they are stuck in the sand or gravel. Adult southern brook lampreys stay alive using energy they store when they are larvae, so they don't eat anything. ("Ichthyomyzon gagei", 2011; Hassan-Williams and Bonner, 2007; Mettee, et al., 2008; Rainer, 2010)

  • Plant Foods
  • algae

What eats them and how do they avoid being eaten?

Southern brook lamprey larvae burrow into sand or loose gravel, so they are difficult for predators to find. Adults attach themselves to rocks in swift-moving waters, and are also hard to find because they have camouflage coloring. They are eaten by northern pike, perch, and European chub. ("Ichthyomyzon gagei", 2011; Hammerson, 2010)

  • These animal colors help protect them
  • cryptic

What roles do they have in the ecosystem?

The larval phase is the only phase that eats and filter feeds on nutrients from algae and bacteria. Southern brook lampreys are not predators. ("Ichthyomyzon gagei", 2011; Mettee, et al., 2008; Rainer, 2010)

Do they cause problems?

There are no known negative economic effects on humans caused by southern brook lampreys.

How do they interact with us?

In Sweden, Russia and South Korea, lampreys are eaten by humans as food. They are also used as bait to catch pike, perch and chubs. (Hassan-Williams and Bonner, 2007; Rainer, 2010)

  • Ways that people benefit from these animals:
  • food

Are they endangered?

Southern brook lampreys are not threatened or endangered.


ryan oldsberg (author), Minnesota State University, Mankato, Robert Sorensen (editor), Minnesota State University, Mankato, Renee Mulcrone (editor), Special Projects, Catherine Kent (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.

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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.


having markings, coloration, shapes, or other features that cause an animal to be camouflaged in its natural environment; being difficult to see or otherwise detect.


an animal that mainly eats decomposed plants and/or animals


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


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


union of egg and spermatozoan


a method of feeding where small food particles are filtered from the surrounding water by various mechanisms. Used mainly by aquatic invertebrates, especially plankton, but also by baleen whales.


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.


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'.


A large change in the shape or structure of an animal that happens as the animal grows. In insects, "incomplete metamorphosis" is when young animals are similar to adults and change gradually into the adult form, and "complete metamorphosis" is when there is a profound change between larval and adult forms. Butterflies have complete metamorphosis, grasshoppers have incomplete metamorphosis.


makes seasonal movements between breeding and wintering grounds


having the capacity to move from one place to another.

native range

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


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


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).


uses sight to communicate


2011. "Ichthyomyzon gagei" (On-line). Accessed April 21, 2011 at

2011. "Mississippi River Resource Page" (On-line). Accessed July 11, 2011 at

Beamish, F., E. Thomas. 1984. Metamorphosis of the southern brook lamprey, Ichthyomyzon gagei. Copeia, 1984 (2): 502-515. Accessed July 11, 2011 at

Cochran, P. 1987. The southern brook lamprey (Ichthyomyzon gagei) in the St. Croix River drainage of Wisconsin and Minnesota. Copeia, 1987/2: 443-446. Accessed July 11, 2011 at

Cochran, P., T. Pettinelli. 1987. "Northern and southern brook lampreys in Minnesota" (On-line pdf). Accessed July 11, 2011 at

Hammerson, G. 2010. "Ichthyomyzon gagei" (On-line). NatureServe Explorer. Accessed July 11, 2011 at

Hassan-Williams, C., T. Bonner. 2007. "Ichthyomyzon gagei" (On-line). Accessed July 11, 2011 at

Mettee, M., P. O'Neil, J. Pierson. 2008. "Southern Brook Lamprey" (On-line). Fishes of Alabama and the Mobile Basin. Accessed July 11, 2011 at

Rainer, F. 2010. "Southern brook lamprey" (On-line). Accessed July 11, 2011 at

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oldsberg, r. 2013. "Ichthyomyzon gagei" (On-line), Animal Diversity Web. Accessed April 16, 2014 at

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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