Spotfin chub (''Erimonax monachus'') is a species of freshwater

ray-finned fish Actinopterygii (; ), members of which are known as ray-finned fish or actinopterygians, is a class of bony fish that comprise over 50% of living vertebrate species. They are so called because of their lightly built fins made of webbings of sk ...

belonging to the

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

Leuciscidae Leuciscidae is a family of freshwater ray-finned fishes, formerly classified as a subfamily of the Cyprinidae, which contains the true minnows. Members of the Old World (OW) clade of minnows within this subfamily are known as European minnow ...

, the shiners, daces and minnows. It is the only species in the

monospecific genus In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unispe ...

''Erimonax''. This fish is endemic to the

Tennessee River The Tennessee River is a long river located in the Southern United States, southeastern United States in the Tennessee Valley. Flowing through the states of Tennessee, Alabama, Mississippi, and Kentucky, it begins at the confluence of Fren ...

watershed. Its other common names include turquoise shiner and chromium shiner.

Appearance and anatomy

Spotfin chub have an average length of .

Geographic distribution

The spotfin chub has a native range endemic to the Tennessee River drainage. This range includes five states:

Alabama Alabama ( ) is a U.S. state, state in the Southeastern United States, Southeastern and Deep South, Deep Southern regions of the United States. It borders Tennessee to the north, Georgia (U.S. state), Georgia to the east, Florida and the Gu ...

Georgia Georgia most commonly refers to: * Georgia (country), a country in the South Caucasus * Georgia (U.S. state), a state in the southeastern United States Georgia may also refer to: People and fictional characters * Georgia (name), a list of pe ...

North Carolina North Carolina ( ) is a U.S. state, state in the Southeastern United States, Southeastern region of the United States. It is bordered by Virginia to the north, the Atlantic Ocean to the east, South Carolina to the south, Georgia (U.S. stat ...

Virginia Virginia, officially the Commonwealth of Virginia, is a U.S. state, state in the Southeastern United States, Southeastern and Mid-Atlantic (United States), Mid-Atlantic regions of the United States between the East Coast of the United States ...

, and

Tennessee Tennessee (, ), officially the State of Tennessee, is a landlocked U.S. state, state in the Southeastern United States, Southeastern region of the United States. It borders Kentucky to the north, Virginia to the northeast, North Carolina t ...

. Current surveys show that spotfin chub has been extirpated from Alabama and Georgia.Yoichiro Kanno, Christina U. Schmidt, Steven B. Cook, Hayden T. Mattingly. 2012. Variation in microhabitat use of the threatened spotfin chub (''Erimonax monachus'') among stream sites and seasons. ''Ecology of Freshwater Fish'' 21: 363–374, The only remaining populations are confined to four tributaries along the Tennessee River: the Little Tennessee,

Emory Emory may refer to: Places * Emory, Texas, U.S. * Emory (crater), on the Moon * Emory Peak, in Texas, U.S. * Emory River, in Tennessee, U.S. Education * Emory and Henry College, or simply Emory, in Emory, Virginia, U.S. * Emory University, in Atl ...

Buffalo Buffalo most commonly refers to: * True buffalo or Bubalina, a subtribe of wild cattle, including most "Old World" buffalo, such as water buffalo * Bison, a genus of wild cattle, including the American buffalo * Buffalo, New York, a city in the n ...

, and Holston rivers. Many

anthropogenic Anthropogenic ("human" + "generating") is an adjective that may refer to: * Anthropogeny, the study of the origins of humanity Anthropogenic may also refer to things that have been generated by humans, as follows: * Human impact on the enviro ...

changes are the cause for such a large population decline. Major disturbances include dams,

sedimentation Sedimentation is the deposition of sediments. It takes place when particles in suspension settle out of the fluid in which they are entrained and come to rest against a barrier. This is due to their motion through the fluid in response to th ...

, introduction of

invasive species An invasive species is an introduced species that harms its new environment. Invasive species adversely affect habitats and bioregions, causing ecological, environmental, and/or economic damage. The term can also be used for native spec ...

, and wide-ranging fish kills. In 1957, a project aiming to enhance habitats for trout used ichthyocides to kill fish. By eliminating the competition, it was believed that trout would thrive.

Ecology

Spotfins are born predominately

benthic The benthic zone is the ecological region at the lowest level of a body of water such as an ocean, lake, or stream, including the sediment surface and some sub-surface layers. The name comes from the Ancient Greek word (), meaning "the depths". ...

insectivores A robber fly eating a hoverfly An insectivore is a carnivorous animal or plant which eats insects. An alternative term is entomophage, which can also refer to the human practice of eating insects. The first vertebrate insectivores wer ...

and become more open water as they mature. According to a study done with adult specimens from the Emory River, they prefer

midge A midge is any small fly, including species in several family (biology), families of non-mosquito nematoceran Diptera. Midges are found (seasonally or otherwise) on practically every land area outside permanently arid deserts and the frigid ...

black fly A black fly or blackfly (sometimes called a buffalo gnat, turkey gnat, or white socks) is any member of the family Simuliidae of the Culicomorpha infraorder. It is related to the Ceratopogonidae, Chironomidae, and Thaumaleidae. Over 2,200 s ...

, and

caddisfly The caddisflies (order Trichoptera) are a group of insects with aquatic larvae and terrestrial adults. There are approximately 14,500 described species, most of which can be divided into the suborders Integripalpia and Annulipalpia on the basis ...

larvae. Spotfins rely heavily on sight feeding. Food is a leading factor for microhabitat preferences, and microhabitats differ seasonally. Spotfins streamlined body and

eurythermal A eurytherm is an organism, often an endotherm, that can function at a wide range of ambient temperatures. To be considered a eurytherm, all stages of an organism's life cycle must be considered, including juvenile and larval stages. These wid ...

characteristics allows them to tolerate a wide range of habitats. During the summer and fall months, spotfins are most likely found in clear, warm water stretches of rivers that resemble run habitats. These runs consist of boulder/bedrock substrates with medium to moderate depth and velocity. However, during the winter they are most commonly found in pool habitats with a sandy substrate. Due to similar habitat requirements and desired prey they tend to compete with other minnow species. Their most common competitors of the genus ''

Cyprinella ''Cyprinella'' is a genus of freshwater ray-finned fish in the family Leuciscidae, the shiners, daces and minnows. They are known as the satinfin shiners. They are native to North America, and some are among the most common freshwater fish speci ...

'', primarily

whitetail shiners The whitetail shiner (''Cyprinella galactura'') is a species of freshwater ray-finned fish in the family Leuciscidae, the shiners, daces and minnows. It inhabits the Tennessee and Cumberland river drainages of Alabama, Mississippi, Georgia, Nort ...

(''Cyprinella galactura''), and the genus ''

Luxilus ''Luxilus'' is a genus of freshwater ray-finned fishes belonging to the family Leuciscidae, the shiners, daces and minnows. The species in this genus are found in North America. They are commonly known as highscale shiners. Species ''Luxilus' ...

'', such as the

warpaint shiner The warpaint shiner (''Coccotis coccogenis'') is a species of freshwater fish found in North America. It is common in the upper Tennessee River basin as well as in the Savannah River, the Santee River, and the New River in North Carolina. Adults ...

(''Luxilus coccogenis''). Humans are also competing for habitat. Flooding and sedimentation are both results of impounding water and harvesting

riparian A riparian zone or riparian area is the interface between land and a river or stream. In some regions, the terms riparian woodland, riparian forest, riparian buffer zone, riparian corridor, and riparian strip are used to characterize a ripar ...

vegetation.

Life history

They

spawn Spawn or spawning may refer to: * Spawning, the eggs and sperm of aquatic animals Arts, entertainment and media * Spawn (character), a fictional character in the comic series of the same name and in the associated franchise ** ''Spawn: Armageddon' ...

in areas with clean running water between May and August. The timing of spawning varies based on temperature and

photoperiod Photoperiod is the change of day length around the seasons. The rotation of the earth around its axis produces 24 hour changes in light (day) and dark (night) cycles on earth. The length of the light and dark in each phase varies across the season ...

. Breeding males' bodies will turn a metallic blue with their fins forming a white margin. Males will then select the site and deposit

milt Milt is the seminal fluid of fish, mollusks, and certain other water-dwelling animals. They reproduce by spraying this fluid which contains the sperm, onto roe (fish eggs). It can also refer to the sperm sacs or testes that contain the semen. ...

along the length of the crevice to attract the female. Spotfins spawn on stream bottoms where boulders create crevices. Females deposit their eggs in the crevice which is then fertilized by the male. Clutch size has been difficult to determine, but studies have shown the number to be in the low to mid hundreds per breeding pair. Any eggs not concealed by the crevice are quickly

cannibal Cannibalism is the act of consuming another individual of the same species as food. Cannibalism is a common ecology, ecological interaction in the animal kingdom and has been recorded in more than 1,500 species. Human cannibalism is also well ...

ized by either of the parents. Eggs have an incubation period of about six days. They grow rapidly as embryos while remaining benthic for approximately 30 days. Juveniles will then enter the water column and begin feeding on macroinvertebrates. After two years, most spotfin chub have reached sexual maturity. Spotfin chub have a lifespan of three years.

Current management

In 1977, spotfin chub became federally listed as threatened under the

Endangered Species Act The Endangered Species Act of 1973 (ESA; 16 U.S.C. § 1531 et seq.) is the primary law in the United States for protecting and conserving imperiled species. Designed to protect critically imperiled species from extinction as a "consequence of e ...

. Habitat loss, sedimentation, and dams have severely damaged the sustainability of its population. Sedimentation is detrimental to spotfin chub: a 2006 laboratory test done at the University of Georgia showed that densely suspended sediment levels in the water can result in a 15-fold decrease in growth rates of juveniles. Suspended sediment also damages gill tissues which impairs respiration and osmoregulatory patterns.Andrew B. Sutherland and Judy L. Meyer. 2007. Effects of increased suspended sediment on growth rate and gill condition of two southern Appalachian minnows. ''Environmental Biology of Fishes'' 80: 389–403, Organized efforts by many state, federal, and non-profit organizations have helped to sustain spotfin populations for many years. Non-invasive capture and relocation from species abundant locations to low

species abundance In ecology, local abundance is the relative representation of a species in a particular ecosystem. It is usually measured as the number of individuals found per sample. The ratio of abundance of one species to one or multiple other species livin ...

has helped to redistribute them to their once native ranges. Also, captive breeding efforts by Conservation Fisheries, Inc. and other organizations have increased knowledge of breeding patterns, life history, and microhabitat requirements.

References

External links

* {{Taxonbar, from=Q1384415 Taxa named by Edward Drinker Cope Fish described in 1868 Pogonichthyinae ESA threatened species