IUCN Red List cites southern brook lampreys as a species of least concern throughout the United States.
US Federal List: no special status
CITES: no special status
State of Michigan List: no special status
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 flavescens), and European chub (Squalius cephalus).
Known Predators:
Anti-predator Adaptations: cryptic
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.
Range mass: 1.05 to 4.25 g.
Average mass: 2.2 g.
Range length: 10 to 20 cm.
Average length: 16 cm.
Other Physical Features: ectothermic ; heterothermic ; bilateral symmetry
Sexual Dimorphism: sexes alike
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.
Typical lifespan
Status: wild: 1111 to 1507 days.
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.
Range elevation: 0 to 450 m.
Range depth: 0.9 to 61 m.
Habitat Regions: temperate ; freshwater
Aquatic Biomes: rivers and streams
Southern brook lampreys have a narrow geographic range in North America, living only in the Mississippi River basin, the Tennessee River drainage, and the 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 (Native )
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.
Plant Foods: algae
Other Foods: detritus ; microbes
Foraging Behavior: filter-feeding
Primary Diet: herbivore (Algivore); detritivore
The larval phase is the only phase that eats and filter feeds on nutrients from algae and bacteria. Southern brook lampreys are not predators.
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
There are no known negative economic effects on humans caused by southern brook lampreys.
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
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 ; tactile
Perception Channels: visual ; tactile
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)
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.
Breeding interval: 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: 1700.
Range age at sexual or reproductive maturity (female): 3 to 4 years.
Range age at sexual or reproductive maturity (male): 3 to 4 years.
Key Reproductive Features: seasonal breeding ; sexual ; fertilization (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)
The southern brook lamprey (Ichthyomyzon gagei) is a lamprey found in the Southern United States including Arkansas, Louisiana, Mississippi, Alabama, and Georgia. It is a jawless fish with a sucking mouth on one end of it (like a leech). It can appear to be a small eel, since it is rarely longer than one foot in length.
The southern brook lamprey occurs in slow moving rivers and streams from Florida to southern Mississippi, Georgia, and Arkansas along the Gulf Coast west to Oklahoma and Texas.[2] It ranges as far north as Minnesota and Wisconsin, and has been reported to occur in the Chattahoochee river system and the Conecuh River system in Alabama, the Sabine river system in Texas and Louisiana, the Illinois river system in Oklahoma, and the Neches River system in Texas. The southern brook lamprey was thought to be restricted to the southern United States; however, Becker observed southern brook lamprey in Wisconsin in 1983.[3] The southern brook lamprey has also been reported to occur as far north as the Spruce river and the Tamarac river in Wisconsin and Minnesota.[4] Unpublished findings have also shown that the southern brook lamprey inhabits tributaries of Choctawhatchee Bay and the Ochlockonee River system in Florida, the Chattahoochee river system in Georgia, and the Trinity and San Jacinto river systems in Texas.[5]
The diet of the southern brook lamprey changes as it undergoes metamorphosis during its life cycle from one phase to the next. The diet of larval southern brook lamprey consists mainly of organic detritus. Studies that focused on closely related lamprey species (I. fossor) found that the guts of larval lampreys contained 97.9% organic detritus, 2.12% algae, and 0.09% bacteria.[6] After metamorphosis into the adult phase, southern brook lampreys do not feed but rely on stored fat reserves accumulated during the larval stage for energy and nutrients. Studies have found that the digestive tract of the lamprey actually shrinks and becomes functionally useless as larval lampreys enter the adult stage. The southern brook lamprey encounters a wide range of predators in its natural habitat.[7] The eggs of adults are preyed on by various species of fish and crayfish.[8] Southern brook lampreys in the larval stage serve as prey for a wide range of fish and bird species.[8] Adult forms are preyed upon by larger fish species such as the Northern pike (E. lucius), perch species, the European chub (S. cephalus), and the mudpuppy (N. maculosus). The southern brook lamprey shares similar habitats and resources with many species of shiners (Notropis), the longnose dace (Rhinichthys cataractae), Johnny darters (Etheostoma nigrum), and mottled sculpins (Cottus bairdi).[9]
The creature's life cycle consists of two main stages: larval and adult. During the larval stage, the southern brook lamprey inhabits a distinct micro habitat involving relatively slow moving water and a sandy substrate.[7] The consistency of the substrate is vitally important to the Southern brook lamprey because during the larval stage, the lamprey burrows into the substrate using its oral disk as an anchor.[10] The southern brook lamprey secretes mucus from its body to form a tube leading to the entrance of the burrow and to provide support for the burrow.[10] The formation of this larval burrow relies on the composition and size of the substrate available. The combination of both small and large particles and coarse and fine sand grains allow the lamprey to construct a suitable burrow that allows enough water to flow through the burrow to ensure proper respiration.[10] The substrate in which larvae burrow must not contain too many fine silt and clay particles as this would inhibit respiration while too many particles of coarse sand would hinder proper burrow construction.[10] The larval stage is complete after approximately three years.[2] Following the larval stage, the southern brook lamprey undergoes metamorphosis into the adult form. Adults are found in crevices and cracks between large rocks in deeper, faster moving water than the habitat occupied during the larval stage.[9] After completing the metamorphosis to adults, southern brook lampreys come together in groups to spawn and, once spawning is complete, the adults die.[11] Spawning usually occurs between April and May and takes place in another distinct microhabitat consisting of shallow riffle areas with rocky substrate with a water temperature falling between 17 °C to 21 °C.[3] Fecundity of the southern brook lamprey averages between 800 and 2500 oocytes.[2] Human factors have been found to influence the lamprey's habitat. Southern brook lampreys have been recorded using shallow areas under bridges as spawning grounds, possibly to help conceal spawning aggregations from visual predators.
The southern brook lamprey is currently listed as a species of "least concern" in the United States by CN Red List.[12] It has also not been given any status regarding endangerment by the US Federal List or CITES.[12] Currently there are no conservation plans in action specific to the lamprey, nor laws or protected waterways aimed at conservation.[12] No evidence of biological factors has been found that would contribute to a decline in the abundance or the range of the creature; in fact, the biggest threat to the lamprey and closely related species is human-induced alteration of suitable microhabitats.[8] Habitat preservation and rehabilitation of affected microhabitats are essential.[8] Microhabitats used by the southern brook lamprey during all life stages must have a certain water temperature, substrate composition, and water quality to ensure successful habitation and spawning in these areas.[10]
The southern brook lamprey (Ichthyomyzon gagei) is a lamprey found in the Southern United States including Arkansas, Louisiana, Mississippi, Alabama, and Georgia. It is a jawless fish with a sucking mouth on one end of it (like a leech). It can appear to be a small eel, since it is rarely longer than one foot in length.
