Ichthyomyzon gagei

Geographic Range

Southern brook lampreys are found in the Mississippi River basin, the Tennessee River drainage, and Gulf of Mexico drainages. They inhabit freshwater temperate waters, mainly small streams during the larval stage and larger streams during the adult stage. They prefer shallow water and require a river bottom of gravel and smaller rocks to attach and spawn.

• Biogeographic Regions
• nearctic nearctic
  • native native

Habitat

Southern brook lampreys tend to live in swift flowing water but can also be found in the slower moving water, which is generally where the ammocoetes live. The Mississippi River basin is 3705 km long and has a large range of depth, width, and speed depending on the location. Southern brook lampreys typically stay in the smaller rivers and tributaries.

• Habitat Regions
• temperate temperate
• freshwater freshwater

• Aquatic Biomes
• rivers and streams

Physical Description

Southern brook lampreys have an eel-like body shape, a dorsal fin divided into two lobes but is not considered two separate fins. The mouth is a sucking disk filled with bicuspid teeth that distinguishes it from northern brook lampreys . Adults are a tannish or green color on their back and lighter yellow or white on the stomach, the fins are also lighter in color. The larval form lacks eyes and instead of an oral disc, the mouth is hood-like.

• Other Physical Features
• ectothermic ectothermic
• heterothermic heterothermic
• bilateral symmetry bilateral symmetry

• Sexual Dimorphism
• sexes alike

Development

Southern brook lampreys spend the majority of their lives as ammocoete larva that bury themselves in sandy river bottoms and feed on bacteria and algae floating in the sediment. The larval stage can change depending on the climate and surrounding conditions but generally ranges anywhere from 3 to 4 years. The transformation stage into an adult occurs over a 2 to 3 month period where it migrates to the faster portion of the stream. In the spring, the adult attaches itself to the gravel bottom where it spawns.

• Development - Life Cycle
• metamorphosis metamorphosis

Reproduction

Southern brook lampreys spawn in a group over a time period of less than a week. Five to 20 adults may build a nest of rocks, and several adults are needed complete the nests.

• Mating System
• polygynandrous (promiscuous) polygynandrous (promiscuous)

Within a few days after spawning, the adults die. The eggs hatch about 2 to 3 weeks after fertilization and grow into the larval form and stay that way for 3 to 4 years. For 2 to 3 months in the late summer or early fall the larvae metamorphose into adults. Females may carry and release anywhere from 1000 to 2000 eggs during the spawning period and the number of eggs fertilized depends on the number of males present.

• Key Reproductive Features
• seasonal breeding seasonal breeding
• sexual sexual
• fertilization fertilization
  • external external
• broadcast (group) spawning

Spawning southern brook lampreys build nests for the eggs, but the adults die after spawning.

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

Lifespan/Longevity

Southern brook lampreys need ideal conditions to survive different phases of their life, so they are hard to manage in captivity. In the wild, once fertilized, the eggs hatch in 2 to 3 weeks and the lampreys remain larvae for 3 to 4 years. Once they metamorphose into the adult phase, they spawn very fast because they only survive 2 to 26 days.

Behavior

As adults, southern brook lampreys have just a few days to reproduce and build a nest for their offspring. They spawn in large groups of 20 to 40 and the adults may work together to build nests.

• Key Behaviors
• motile motile
• migratory migratory

Communication and Perception

The adult form is the only mobile form. After metamorphosis, adults develop the ability to swim. Adults also have fully functioning eyes. Sight and touch are the two major forms of communication between species and interactions with the environment.

• Communication Channels
• visual visual
• tactile tactile

• Perception Channels
• visual visual
• tactile tactile

Food Habits

Southern brook lampreys are not parasites. The larval forms feed on algae and bacteria floating near their stationary location in gravel or sand. Adult southern brook lampreys do not feed, and rely on stored energy sources to survive a short time.

• Primary Diet
• herbivore herbivore
  • algivore
• detritivore detritivore

• Plant Foods
• algae

• Other Foods
• detritus detritus
• microbes

• Foraging Behavior
• filter-feeding filter-feeding

Predation

The larval form burrows into loose gravel or sand so it is hard to find by fish predators. The adult form attaches itself onto rocks in swift moving waters where it is also hard to find because of cryptic coloration. Their known predators include northern pike ( Esox lucius ), perch ( Perca fluviatilis ), and European chub ( Squalius cephalus ).

• Anti-predator Adaptations
• cryptic cryptic

Ecosystem Roles

The larval phase is the only phase that eats and filter feeds on nutrients from algae and bacteria. Southern brook lampreys are not predators.

Economic Importance for Humans: Positive

Although not a part of the diet for people in the United States, people in countries such as Sweden, Russia and South Korea consume lampreys and some consider it a delicacy. Southern brook lampreys are sold in bait shops to catch pike, perch and chub.

• Positive Impacts
• food food

Economic Importance for Humans: Negative

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

Conservation Status

IUCN Red List cites southern brook lampreys as a species of least concern throughout the United States.

Additional Links

Encyclopedia of Life

BioKIDS Critter Catalog

Contributors

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

References

Beamish, F., E. Thomas. 1984. Metamorphosis of the southern brook lamprey, Ichthyomyzon gagei . Copeia , 1984 (2): 502-515. Accessed July 11, 2011 at http://www.jstor.org/stable/1445205 .

Cochran, P., T. Pettinelli. 1987. "Northern and southern brook lampreys in Minnesota" (On-line pdf). Accessed July 11, 2011 at http://files.dnr.state.mn.us/eco/nongame/projects/consgrant_reports/1987/1987_cochran.pdf .

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 http://www.jstor.org/stable/1445782 .

Hammerson, G. 2010. " Ichthyomyzon gagei " (On-line). NatureServe Explorer. Accessed July 11, 2011 at http://www.natureserve.org/explorer/servlet/NatureServe?sourceTemplate=tabular_report.wmt&loadTemplate=species_RptComprehensive.wmt&selectedReport=RptComprehensive.wmt&summaryView=tabular_report.wmt&elKey=102239&paging=home&save=true&startIndex=1&nextStartIndex=1&reset=false&offPageSelectedElKey=102239&offPageSelectedElType=species&offPageYesNo=true&post_processes=&radiobutton=radiobutton&selectedIndexes=102239+gage .

Hassan-Williams, C., T. Bonner. 2007. " Ichthyomyzon gagei " (On-line). Accessed July 11, 2011 at http://www.bio.txstate.edu/~tbonner/txfishes/ichthyomyzon%20gagei.htm .

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 http://www.outdooralabama.com/fishing/freshwater/fish/other/lamprey/so/ .

Rainer, F. 2010. "Southern brook lamprey" (On-line). Accessed July 11, 2011 at http://www.fishbase.org/summary/speciessummary.php?id=2517 .

2011. "Ichthyomyzon gagei" (On-line). Accessed April 21, 2011 at http://www.dnr.state.mn.us/rsg/profile.html?action=elementDetail&selectedElement=AFBAA01040 .

2011. "Mississippi River Resource Page" (On-line). Accessed July 11, 2011 at http://www.mississippiriverresource.com/River/RiverFacts.php .