Blackside dace are listed by the United States Fish and Wildlife Services as Threatened, and are protected under the Endangered Species Act.
Habitat degradation caused by strip mining and logging practices seem to be the leading cause of the decline in numbers of blackside dace. Blackside dace occur in the coalfields of southeastern Kentucky and inhabit headwater streams where these activities have the most impact.
Through the pre-mine permitting process, state and federal agencies restrict or highly regulate mining activities that are to occur in watersheds containing blackside dace.
US Federal List: threatened
CITES: no special status
IUCN Red List of Threatened Species: vulnerable
Jones and Mattingly (2003) have noted a negative correlation between blackside dace and both redbreast sunfish and largemouth bass abundance that may be due to a predator-prey interaction.
Known Predators:
Blackside dace have an incomplete lateral line with 66 to 81 lateral line scales (Etnier and Starnes, 1993). Anal fin ray count is 8 to 9 and pectoral fin rays range from 14 to 16 (Etnier and Starnes, 1993). Adults range from 50 to 65 mm during the end of the second and third summers and can reach a maximum length of 76 mm (Etnier and Starnes, 1993). Adults have a single black lateral stripe or two stripes converging on the caudal peduncle, a green/gold dorsum with black speckling and a pale to brilliant scarlet belly (Biggins, 1988; Etnier and Starnes, 1993). The fins are often bright yellow with metallic silver surrounding the base of the pelvic and pectoral fins (Biggins, 1988). The yellowish fins seem to be associated with the breeding season (Etnier and Starnes, 1993). The male is more colorful and can be distuingished from the female by having a golden dorsum and well developed tubercles on the pectoral fins during the breeding season (Etnier and Starnes, 1993).
A similar species that can be found in the same watershed as blackside dace is southern redbelly dace (Chrosomus erythrogaster). Blackside dace are differentiated from southern redbelly dace by a single black lateral stripe or two stripes that converge on the caudal peduncle, where southern redbelly dace have two parallel lateral stripes (Etnier and Starnes, 1993).
Juvenile blackside dace can be confused with juvenile creek chub (Semotilus atromaculatus) and juvenile blacknose dace (Rhinichthys atratulus) (Etnier and Starnes, 1993). Creek chub are more robust and have only 51 to 54 lateral line scales, and blacknose dace are differentiated by having a frenum (Etnier and Starnes, 1993).
Range length: 76 (high) mm.
Other Physical Features: ectothermic ; heterothermic ; bilateral symmetry
Sexual Dimorphism: sexes colored or patterned differently; male more colorful
The lifespan of blackside dace is approximately 3 years (Etnier and Starnes, 1993).
Average lifespan
Status: captivity: 4 years.
Blackside dace inhabit small to medium sized streams 2.1 to 4.6 meters in width, with moderate gradient, and rarely exceeding 21 degrees Celsius (70 degrees Fahrenheit) (Biggins, 1988). According to O’Bara (1985), blackside dace occur in only moderate gradient streams that have a 60:40 riffle-pool ratio. Substrate in these streams consists of cobble-gravel in riffles and bedrock-boulder-silt in pools (O’Bara, 1985). Starnes and Starnes (1981) note that these fish are generally associated with undercut stream banks and large rocks, and they are usually found in drainages with well-vegetated watersheds and riparian zones. The riparian vegetation generally associated with blackside dace habitat includes woody species such as eastern hemlock (Tsuga canadensis), giant rhododendron (Rhododendron maximum), ironwood (Carpinus caroliniana), river birch (Betula nigra), and American sycamore (Platanus occidentalis) (O’Bara, 1985). Canopy cover at stream sections that support blackside dace is usually over 70 percent (O’Bara, 1985).
Habitat Regions: temperate ; freshwater
Terrestrial Biomes: forest
Aquatic Biomes: benthic ; rivers and streams
Blackside dace (Chrosomus cumberlandensis) are found in approximately 40 tributaries of the Cumberland River in Pulaski, Laurel, McCreary, Whitley, Knox, Bell, Harlan, and Letcher counties in Kentucky, and Scott, Campbell, and Claiborne counties in Tennessee (NatureServe, 2005) and have been recently discovered in the upper Clinch River drainage in Lee County, Virginia (Pinder, M.J., personal communication). A survey of 168 upper Cumberland River streams, by Starnes and Starnes (1981) found the species to occur in 27 different drainages. A survey by O’Bara (1985) found blackside dace in 30 of 193 upper Cumberland River drainages.
Biogeographic Regions: nearctic (Native )
Blackside dace feed on algae attached on the stream substrate and potentially beneath banks of the stream (Etnier and Starnes, 1993). According to Etnier and Starnes (1993) blackside dace feed on insect larvae during the winter when algae is less abundant.
Animal Foods: insects
Plant Foods: algae
Primary Diet: herbivore (Algivore)
Blackside dace are primary consumers, feeding mainly on algae. They serve as a food source for carnivores, particularly larger fishes, and may occasionally themselves be predators on aquatic insect larvae (USFWS, 1991).
Blackside dace have no economic value to humans.
Mineral extraction is negatively impacted economically because mining companies cannot disturb streams containing blackside dace, which are then designated as Outstanding Resource Waters.
Little is known about the early development of blackside dace. A life span of three years is typical, with fry growing to about 30 mm by the first fall of life and reaching sexual maturity by their first spring (Etnier and Starnes 1993). During the second and third year, total lengths average 50 to 60 mm, with a maximum total length of 76 mm (Etnier and Starnes, 1993). Size ranges are broken into three age classes, which include the following: Age 0: 30 to 39 mm, Age I: 40 to 59 mm, and Age II: 60 to 79 mm (O’Bara, 1985). Biologists use the age classes to determine if blackside dace populations are reproducing and viable.
Blackside dace use vision, hearing and chemoreception. In addition, they use their lateral line system to detect vibrations in the water, which may help them avoid predators (Helfman et al., 1997).
Little is known about intraspecific communication in blackside dace.
Communication Channels: visual ; tactile
Perception Channels: visual ; tactile ; vibrations ; chemical
Little is known about the mating systems of blackside dace. Spawning occurs during the spring, from April to June. Males gather in small groups during spawning and several males fertilize the eggs of each female as she deposits them (USFWS, 1991).
Mating System: polygynandrous (promiscuous)
Blackside dace spawn from April through June, but the majority of spawning occurs during May (Starnes and Starnes, 1981). During spawning, males develop tubercles and both males and females develop brilliant colors (Etnier and Starnes, 1993). Spawning typically occurs over silt-free gravel in the nests of other cyprinid fish, but presumably riffle areas are used when these nests are not present (Etnier and Starnes, 1993). Females deposit an average of 1,540 ova during spawning (O’Bara, 1985).
Breeding interval: Blackside dace spawn once a year.
Breeding season: Blackside dace spawn each April through June.
Average number of offspring: 1540.
Average age at sexual or reproductive maturity (female): 1 years.
Average age at sexual or reproductive maturity (male): 1 years.
Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; fertilization (External ); oviparous
Little is known about parental investment in blackside dace. Once the eggs are fertilized and deposited, there is no further parental involvement.
Parental Investment: no parental involvement; pre-fertilization (Provisioning, Protecting: Female)
The blackside dace (Chrosomus cumberlandensis)[4] is a species of ray-finned fish in the family Cyprinidae. It is endemic to the Cumberland River drainage in Kentucky and Tennessee as well as the Powell River drainage in Virginia in the United States. It is a federally listed threatened species.[2][3]
This fish is 50 to 65 millimetres (2.0 to 2.6 in) in length. It is olive green in color with black speckling and a black stripe. During the breeding season in April through July the stripe becomes a deeper black, there are red areas on the upper parts, and the fins become yellow.[5]
This fish is found in 105 streams in Kentucky and Tennessee, but many of these populations are very small, with under 10 individuals. The species has been found in western Virginia, but these populations may have been introduced by people[5] or represent undescribed species.[1]
The fish lives in cool, clear streams with rocky substrates and overhanging vegetation. It is schooling and lives under banks and rock formations. Other fish in the habitat include the common creek chub (Semotilus atromaculatus), white sucker (Catostomus commersoni), stoneroller (Campostoma anomalum), and stripetail darter (Etheostoma kennicotti). The dace eats algae and sometimes insects. It lives 2–3 years and becomes sexually mature in its first year.[6] The female lays an average of 1540 eggs.[7]
The species is threatened by the loss and degradation of its habitat. The rocky riverbed substrates in which it spawns are degraded by erosion and sedimentation, which are increased by human activities such as runoff pipes from septic tanks, and trash being dumped into streams. Several populations have been extirpated by these processes.[6]
In 2007 a large scale die-off of aquatic life, including blackside dace, occurred in the Acorn Fork in Kentucky. Scientists from the U.S. Geological Survey and the U.S. Fish and Wildlife Service concluded that the most likely cause was a spill of hydraulic fracturing fluid from nearby natural gas wells. The results of a joint study indicated that the spill caused a spike in acidity, as well as toxic concentrations of heavy metals.[8][9]
The blackside dace (Chrosomus cumberlandensis) is a species of ray-finned fish in the family Cyprinidae. It is endemic to the Cumberland River drainage in Kentucky and Tennessee as well as the Powell River drainage in Virginia in the United States. It is a federally listed threatened species.
