Chrosomus cumberlandensis

Geographic Range

Blackside dace ( Phoxinus 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 nearctic
  • native native

Habitat

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 temperate
• freshwater freshwater

• Terrestrial Biomes
• forest forest

• Aquatic Biomes
• benthic benthic
• rivers and streams

Physical Description

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 ( Phoxinus 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).

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

• Sexual Dimorphism
• sexes colored or patterned differently
• male more colorful

Development

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.

Reproduction

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) 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).

• Key Reproductive Features
• iteroparous iteroparous
• seasonal breeding seasonal breeding
• gonochoric/gonochoristic/dioecious (sexes separate)
• sexual sexual
• fertilization fertilization
  • external external
• oviparous 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

Lifespan/Longevity

The lifespan of blackside dace is approximately 3 years (Etnier and Starnes, 1993).

Behavior

Little is known about the behavior of blackside dace.

• Key Behaviors
• natatorial natatorial
• motile motile
• sedentary sedentary
• social social

Home Range

Blackside dace are presumed to have a small home range. According to Detar, Jones, and Mattingly (2003), most of the 864 dace tagged with an elastomer injection stayed within the original site of capture with the exception of a few individuals migrating 600 to 1800 meters from the capture site and one individual with intertributary movement.

Communication and Perception

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 visual
• tactile tactile

• Perception Channels
• visual visual
• tactile tactile
• vibrations vibrations
• chemical chemical

Food Habits

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.

• Primary Diet
• herbivore herbivore
  • algivore

• Animal Foods
• insects

• Plant Foods
• algae

Predation

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.

Ecosystem Roles

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).

Economic Importance for Humans: Positive

Blackside dace have no economic value to humans.

Economic Importance for Humans: Negative

Mineral extraction is negatively impacted economically because mining companies cannot disturb streams containing blackside dace, which are then designated as Outstanding Resource Waters.

Conservation Status

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.

Additional Links

Encyclopedia of Life

Contributors

Mary Hejna (editor), University of Michigan-Ann Arbor.

Chris Isaac (author), Eastern Kentucky University, Sherry Harrel (editor, instructor), Eastern Kentucky University.

References

Biggins, R. 1988. Blackside Dace Recovery Plan . Atlanta, GA: U.S. Fish and Wildlife Service.

Detar, J., B. Jones, H. Mattingly. 2003. Factors affecting the distribution and recovery of the threatened blackside dace in Kentucky and Tennessee . Cookeville, TN: Tennessee Technological University.

Etnier, D., W. Starnes. 1993. The Fishes of Tennessee . Knoxville, TN: University of Tennessee Press.

Helfman, G., B. Collette, D. Facey. 1997. The Diversity of Fishes . Malden, MA: Blackwell Science, Inc..

Jones, B., H. Mattingly. 2003. "Building a predictive habitat model for the blackside dace, Phoxinus cumberlandensis" (On-line). Accessed November 01, 2005 at http://www.forestry.caf.wvu.edu/wvuafs/Colloquium/Post-web/abstracts.htm .

O'Bara, C. 1985. Status survey of the blackside dace Phoxinus cumberlandensis . Asheville, NC: U.S. Fish and Wildlife Service.

Starnes, W., L. Starnes. 1981. Biology of the blackside dace Phoxinus cumberlandensis . American Midland Naturalist , 106: 360-370.

2005. "NatureServe" (On-line). NatureServe Explorer: An online encyclopedia of life. Accessed August 30, 2005 at http://www.natureserve.org/explorer/servlet/NatureServe?searchName=Phoxinus+cumberlandensis .

U. S. Fish and Wildlife Service. 1991. "Species account for blackside dace ( Phoxinus cumberlandensis )" (On-line). Endangered and Threatened Species of the Southeastern United States (The Red Book) FWS Region 4. Accessed September 06, 2006 at http://www.fws.gov/endangered/i/e/sae2g.html .