Lampetra appendixAmerican brook lamprey

Geographic Range

American brook lamprey, Lampetra appendix, are limited on the northern end to Ontario and Quebec in Canada, south to North Carolina, Alabama, and Mississippi in the United States. The eastern limit is the east coast, from North Carolina to as far north as New Hampshire. The western limit is from Arkansas to Minnesota. (Hammerson, 2012)


American brook lamprey larvae typically reside in soft sediments within shallow, slow moving, fresh water streams. A suitable speed of water movement is roughly 5 centimeters per second, while depths are frequently less than 50 centimeters. The soft sediment often consists of fine sand and silt, although coarse sand and gravel are sometimes present in small amounts.

Adult habitats are typically gravel-sand riffles, creeks, or small to medium rivers with a strong water flow. (Mundahl, et al., 2006)

  • Aquatic Biomes
  • benthic
  • lakes and ponds
  • rivers and streams
  • Range depth
    0.5 (high) m
    1.64 (high) ft

Physical Description

Larval American brook lamprey, also called an ammocoete, hatch at about 2.6mm, but will continue to grow until metamorphosis, averaging 38mm at age 1. It is dark brown on the dorsal and lateral surfaces, and yellow-brown on the ventral surface.

Adult American brook lamprey are approximately 10.3 - 21.7cm long, 2.8 - 16.2g wet, with gray to black coloration on the dorsal and dorsal-lateral surfaces, and tan to gray white on the ventral and ventral-lateral surfaces. No distinction exists between male and female individuals.

Eggs are sphere shaped, adhesive, and sink to the bottom of the water. Color can range from pale yellow to light green.

As is characteristic with lampreys, this species has cartilage, as opposed to bones, does not possess jaws, scales, or paired fins, and has one nostril and seven pairs of rounded gill slits. This species possesses a dorsal fin, distinctly separated into two parts and with a black stripe at its base, a mouth disk narrower than the head, and teeth in a cluster pattern on the oral disc, as opposed to in rows. The caudal fin is simple and rounded. ("American Brook Lamprey", 2016; Page and Burr, 2016; "Lampetra appendix (DeKay); AMERICAN BROOK LAMPREY.", 2017)

  • Sexual Dimorphism
  • sexes alike
  • Range mass
    2.8 to 16.2 g
    0.10 to 0.57 oz
  • Range length
    10.3 to 21.7 cm
    4.06 to 8.54 in


American brook lamprey larvae hatch in the late spring to early summer, 20 to 22 days after eggs are fertilized. American brook Lamprey begin to undergo metamorphosis in the late summer, after a minimum of 4.5 years in the larval stage, but perhaps after more years. During metamorphosis, the filter feeding mechanisms become suction disks with teeth, and the eyes become fully functional. Metamorphosis is complete in the spring, when adults will begin breeding. ("American Brook Lamprey", 2008; Page and Burr, 2016)


Female American brook lamprey build nests, typically around 16cm in diameter, and use their oral disc to attach to a rock at the upstream end of their nesting site. The male uses his oral disk to attach to the female's head, then wraps his tail around her body so that their urogenital regions are in close proximity. The male contracts his body to assist the female in extrusion of the eggs. Both individuals vibrate vigorously for some seconds before releasing their gametes, serving to partially bury the fertilized eggs.

Multiple adult pairs may congregate to one location when spawning, with a record of 14 spawning lampreys found in one nest. (Page and Burr, 2016)

American brook lamprey larvae at a minimum of 4.5 years of age begin metamorphosis in late summer, and are fully developed adults and begin to spawn in spring, dying soon after. Per female, more than 1600 eggs are laid in nests in gravel-sand riffles or small to medium rivers, and then may run with the strong flow of the water. With the proper conditions, eggs hatch in 20 to 22 days, producing the larval lamprey. ("American Brook Lamprey", 2016; Hammerson, 2012; Page and Burr, 2016; "Lampetra appendix (DeKay); AMERICAN BROOK LAMPREY.", 2017)

  • Breeding interval
    American brook lamprey are semelparous, breeding once after metamorphosis.
  • Breeding season
    American brook lamprey spawn in the spring, with specific times ranging from late March to early June, dependent upon geographic location.
  • Average number of offspring
  • Range age at sexual or reproductive maturity (female)
    5 (low) years
  • Range age at sexual or reproductive maturity (male)
    5 (low) years

Parental involvement ceases after reproduction. When larvae hatch from eggs, parents are often deceased. ("American Brook Lamprey", 2016)


American brook lamprey spend at least 4.5 years in the larval stage before beginning metamorphosis, although they may wait longer. Adults do not feed, existing solely to spawn, and will die approximately six months after metamorphosis. (Eschmeyer, et al., 2017)

  • Average lifespan
    Status: wild
    5 years


American brook lamprey larvae bury themselves in soft sediment, exposing their heads to filter feed. After 4.5 years or more, larvae begin to undergo metamorphosis, and once complete the adults do not feed, existing solely to spawn. (Page and Burr, 2016)

Communication and Perception

Larval American brook lampreys can detect light and dark through eye spots, which develop into fully functional eyes during metamorphosis. An amount of chemo-sensory ability is afforded by the lone nostril. ("American Brook Lamprey", 2008)

Food Habits

American brook lamprey larvae feed by burying all of their body besides their head, and filtering organic material from the water, consuming a diet largely consisting of diatoms and detritus. Diatoms, however, contribute little to the diet and remain largely undigested, and larval lamprey have been observed healthily consuming diets composed entirely of detritus.

The adult stage lamprey do not feed. (Mundahl, et al., 2005)

  • Plant Foods
  • algae


Larval and adult American brook lamprey can easily become prey for muskellunge, walleyes, and smallmouth bass. The burying behavior demonstrated by larvae of this species may exist as one mechanism to help combat predation. (Eschmeyer, et al., 2017; Mundahl, et al., 2006)

Economic Importance for Humans: Positive

Ammocoetes, the larval stage of American brook lamprey, were sold extensively as bait in Canada in the mid 20th century. (Page and Burr, 2016)

Conservation Status

While not currently listed by conservation sites, American brook lamprey populations have been reduced or even eliminated from a significant number of streams. The most significant losses are those at the edges of their range.

The major source of concern for American brook lamprey populations is alterations of streams and waterways which served as habitat. This includes removal of suitable spawning area, as well those alterations that affect detritus availability, including production and processing of detritus, as well as delivery of detritus. (Mundahl, et al., 2005; Mundahl, et al., 2006)

Other Comments

American brook lamprey are also known as Lampetra appendix, Lampetra appendix, Petromyzon lamottenii, and Lampetra appendix (Eschmeyer, et al., 2017)


Curtis Gaul (author), Minnesota State University Mankato, Robert Sorensen (editor), Minnesota State University, Mankato, Tanya Dewey (editor), University of Michigan-Ann Arbor.



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


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.


uses smells or other chemicals to communicate


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).


a period of time when growth or development is suspended in insects and other invertebrates, it can usually only be ended the appropriate environmental stimulus.


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


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.


mainly lives in water that is not salty.


An animal that eats mainly plants or parts of plants.

induced ovulation

ovulation is stimulated by the act of copulation (does not occur spontaneously)


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.


Having one mate at a time.


having the capacity to move from one place to another.


specialized for swimming

native range

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


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


remains in the same area


offspring are all produced in a single group (litter, clutch, etc.), after which the parent usually dies. Semelparous organisms often only live through a single season/year (or other periodic change in conditions) but may live for many seasons. In both cases reproduction occurs as a single investment of energy in offspring, with no future chance for investment in reproduction.


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).


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


uses sight to communicate

young precocial

young are relatively well-developed when born


Illinois Department of Natural Resources. American Brook Lamprey. Biodiversity of Illinois. 2016. Accessed February 13, 2017 at

Massachusetts Division of Fisheries & Wildlife. American Brook Lamprey. Natural Heritage Endangered Species Program. 2008. Accessed April 19, 2017 at

University of Michigan Museum of Zoology. 2017. "Lampetra appendix (DeKay); AMERICAN BROOK LAMPREY." (On-line). U-M Library Digital Collections. Accessed February 13, 2017 at

Eschmeyer, W., R. Fricke, R. van der Laan. 2017. "Catalog of Fishes" (On-line). California Academy of Sciences. Accessed April 05, 2017 at

Hammerson, G. 2012. "NatureServe Explorer" (On-line). Accessed February 13, 2017 at

Mundahl, N., C. Erickson, M. Johnston, G. Sayeed, S. Taubel. 2005. Diet, feeding rate, and assimilation efficiency of American brook lamprey. Environmental Biology of Fishes, 72: 67-72. Accessed February 13, 2017 at

Mundahl, N., G. Sayeed, S. Taubel, C. Erickson, A. Zalatel, J. Cousins. 2006. Densities and Habitat of American Brook Lamprey (Lampetra appendix) Larvae in Minnesota. The American Midland Naturalist, 156/1: 11-22. Accessed February 13, 2017 at;2.

Page, L., B. Burr. 2016. "Lethenteron Appenidx, American brook lamprey" (On-line). Fishbase. Accessed April 05, 2017 at