Three subspecies of Cottus carolinae are recognized (Page and Burr, 1991). The genus name Cottus is an old name for "Miller’s thumb", the common name of these fishes in Europe, and the species name carolinae is in honor of Miss Caroline Henry, a friend of the species’ describer (Etnier and Starnes, 1993).
Banded sculpins are cryptic in coloration and behavior. Their coloration mimics the stream substrate, which is a beneficial adaptation since they are primarily nocturnal ambush predators (Koczaja, et. al., 2005).
A study conducted by Koczaja, et al. (2005) in a Cumberland River Basin stream in Tennessee showed that the presence of adult banded sculpins affected the habitat preference of juvenile banded sculpins. Juveniles were more likely to use pool habitat in the absence of adults. Adults may represent a potential predator to juveniles and/or a competitor for refuges in pools. The study suggests that this is not likely a function of food availability since many prey items of small banded sculpins prefer the faster velocities of riffles. Adults showed preference for pool habitats. Predation risk from birds, mammals, and/or reptiles is the best explanation for the depth preference of adult banded sculpins. Despite their cryptic coloration, banded sculpins are susceptible to predation by piscivorous birds such as belted kingfishers and great blue herons. This risk is minimized by banded sculpins' use of deeper pool habitats. Large piscivorous fish, which inhabit deep pools, are the greatest predation risk to smaller sculpins (Koczaja, et. al., 2005).
Known Predators:
Anti-predator Adaptations: cryptic
Banded sculpins are bottom-dwellers with somewhat dorsally depressed bodies. Maximum total length is 18 centimeters (7.25 inches). The flattened body and large pectoral fins provide hydrodynamic adaptations to swift waters. These adaptations help the fish maintain position as it is pressed to the streambed by the overhead flow of water. Nonbuoyancy is acheived by the lack of a swimbladder (Etnier and Starnes, 1993). In general, sculpins have few or no scales. Ground color is most often rusty brown with four dark dorsal saddles (Etnier and Starnes, 1993). The last three saddles extend onto the sides as sharply defined bars (Page and Burr, 1991). The color of the body varies depending on the substrate and water clarity (Etnier and Starnes, 1993). The chin is mottled with dark pigment. The lateral line is complete, usually with 29 to 34 pores. There are 3 preopercular spines. The dorsal fins separate to the base (Page and Burr, 1991). The dorsal fin has 7 to 8 spines and 15 to 18 soft rays. The edge of the spinous dorsal fin is rust colored like the body but may be tinged with red in some spring habitats. The anal fin ray count is 12 to 14. Pectoral fin rays number 15 to 17 (Etnier and Starnes, 1993). There are 4 pelvic rays (Page and Burr, 1991). Principal caudal fin rays range from 10 to 12. Palantine teeth are well developed (Etnier and Starnes, 1993).
Range length: 18 (high) cm.
Other Physical Features: ectothermic ; heterothermic ; bilateral symmetry
Sexual Dimorphism: sexes colored or patterned differently
Maximum life span is estimated at 4 years (Etnier and Starnes, 1993).
Average lifespan
Status: wild: 4 years.
Typical lifespan
Status: wild: 2 to 3 years.
Average lifespan
Status: wild: 2 to 3 years.
Average lifespan
Status: captivity: 4 years.
Banded sculpins are freshwater fish that inhabit streams of all sizes, ranging from small streams to large upland rivers. Individuals of this species occupy clear, cool to warm water and are frequently found in springs and caves. They are found in various velocities of water but prefer the gravel and rubble of riffles where their dark and pale dorsal coloration camouflages them from potential predators (Koczaja, et al., 2005; Etnier and Starnes, 1993; NatureServe, 2005).
In a study conducted on a stream in the Cumberland River Basin, Tennessee on “size-specific habitat segregation and intraspecific interactions” affecting habitat choice in banded sculpins, adults were found almost exclusively in the pools, while young-of-the-year were almost always found in riffles, and juveniles were found in both habitat types. Young-of-the-year preferred shallow habitat, both alone and when in the presence of an adult. Juveniles preferred deep habitat when no adult was present but chose shallow habitat in the presence of an adult. An explanation for this habitat preference is that juveniles may see adult banded sculpins as potential predators and may compete for refuges in the pools. Since banded sculpins are reported to be nocturnal foragers and the study was conducted during the morning, the results of the study correspond to refuge habitat use, as opposed to feeding habitat use of banded sculpins (Koczaja, et al., 2005).
Habitat Regions: temperate ; freshwater
Aquatic Biomes: benthic ; rivers and streams
Other Habitat Features: caves
Cottus carolinae (banded sculpin) is distributed in fourteen states within the southeastern and midwestern United States. The species occupies upland streams within the Mississippi River basin from the New River drainage in West Virginia and Virginia, west to Ozark Mountain drainages in southern Missouri and Kansas, and from southern Indiana and Illinois, south to northern Arkansas, Alabama, and northeast Georgia (Page and Burr, 1991; NatureServe, 2005).
Biogeographic Regions: nearctic (Native )
Both adults and immature banded sculpins are invertivores and piscivores (NatureServe 2005). They are nocturnal feeders and make effective use of their cryptic coloration when they stalk or ambush prey. Young banded sculpins consume aquatic insect immatures, including caddisflies (especially hydropsychids), mayflies (Ephemeroptera), and midge larvae (Chironomidae). Adults prefer larger prey such as large stonefly nymphs (pteronarcids, perlids, and perlodids), other aquatic insects, crayfish (Astacoidea), salamanders, and small fish, especially other benthic riffle species such as darters (Etnier and Starnes, 1993).
In a study on the food habits of four benthic fish species (including banded sculpin, orangethroat darter (Etheostoma spectabile), logperch (Percina caprodes), and slender madtom (Noturus exilis)) from northwest Arkansas streams, chironomids comprised the greatest portion of the diet of banded sculpins in numbers, but crayfish were the most abundant item by volume. Indices used in the study indicated active selection for crayfish as prey. Some seasonal variation in diet was also observed. Small size classes of banded sculpins consumed large numbers of small prey, while large size classes fed on fewer but larger prey. The study showed banded sculpins to have a relatively narrow variation in diet. Banded sculpins and slender madtoms appeared to be the most seasonally opportunistic feeders of the species studied (Phillips and Kilambi, 1996).
In a study involving feeding periodicity of banded sculpins in the Little River of eastern Tennessee, behavioral observations and gut content analyses suggest that the species is primarily a nocturnal feeder. Mean weight of ingested food was greater at night than during the day. None of the sculpins collected at night had empty stomachs, but 53% of the sculpins collected during the day did (Greenberg and Holtzman, 1987).
Animal Foods: amphibians; fish; insects; aquatic crustaceans
Primary Diet: carnivore (Piscivore , Insectivore )
Banded sculpins are invertivores and piscivores, feeding primarily on aquatic insect larvae, crayfish, and small fish. They are considered benthic since they feed at the bottom of streams (NatureServe, 2005). As predators, they feed primarily at night by stalking or ambushing prey (Etnier and Starnes, 1993).
Banded sculpins are generally sensitive to pollution and are considered intolerant of water quality impairment. Due to their low tolerance for poor quality water, banded sculpins are used as indicators of stream health. The species has been incorporated into a metric used to calculate the Index of Biotic Integrity, which measures stream health based on the fish community (Kentucky Department for Environmental Protection - Division of Water, 2002).
There are no known adverse affects of the banded sculpin on humans.
Other than discussion of habitat, there is little discussion in the literature on the life cycle of banded sculpins. Small young inhabit quiet shallow areas and areas covered in detritus (Etnier and Starnes, 1993). Sometime between their first and second year of life, banded sculpins transition from shallow riffles to deeper, pool areas. This shift is attributed to a change in predation risk from piscivorous fish to avian and terrestrial predators (Koczaja, et al., 2005). A study by Craddock on Kentucky populations showed growth to be highly variable, with total lengths at ages 1 to 3 being 50 to 80 mm, 100 to 130 mm, and over 160 mm, respectively (Etnier and Starnes, 1993).
Banded sculpins are not listed by the United Sates Fish and Wildlife Service as threatened or endangered. There are no records for the banded sculpin on the CITES-listed species database. The species is not listed on the IUCN Red List of threatened species.
US Federal List: no special status
CITES: no special status
During the breeding season, males may become darkened or exhibit dark or red coloration in the spinous dorsal fin. These color changes are typical of mottled sculpins (Cottus bairdii) but may be absent or less pronounced in banded sculpins (Etnier and Starnes, 1993). Ground body color changes to match the substrate. For example, specimens from streams with chert gravel substrates may be brown, white, or pale green, while those from streams with other types of gravel may be the characteristic rusty brown with dark saddles (Etnier and Starnes, 1993). The literature reviewed does not comment on communication within the species, but it is likely that some visual cues are employed.
Communication Channels: visual
Perception Channels: visual ; tactile ; chemical
No information was found on the mating system of banded sculpins.
Spawning occurs beneath stones or other objects where the eggs are deposited in large clumps. This takes place in winter and early spring at temperatures between 9 and 14 degrees Celsius. Fecundity averages 475 ova per female. The male guards the nest. Most reproductive females are 2 or more years old (Etnier and Starnes, 1993; NatureServe, 2005).
Breeding interval: Breeding occurs once yearly.
Breeding season: Banded sculpins spawn in late winter or early spring.
Average number of offspring: 475.
Average age at sexual or reproductive maturity (female): 2 years.
Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; fertilization (External ); oviparous
Average number of offspring: 475.
Average age at sexual or reproductive maturity (male)
Sex: male: 730 days.
Average age at sexual or reproductive maturity (female)
Sex: female: 730 days.
After eggs are deposited, the male banded sculpin guards the nest (Etnier and Starnes, 1993).
Parental Investment: pre-hatching/birth (Protecting: Male)
The banded sculpin (Cottus carolinae) is a freshwater fish dwelling mostly in small to moderate sized streams in areas of swift current. Young and juvenile C. carolinae can mainly be found in pools, riffles, and other shallow habitats while adults tend to prefer deeper waters. C. carolinae primarily eats insects and insect larvae, but their large mouths enable them to eat prey nearly as large as themselves, including other sculpin.[2] To prevent predation, including by other fish, the color and pattern of the sculpin tends to match its environment. Most Cottus carolinae are mottled brown with dark vertical banding and usually reach about three inches in length. They have a broad head which rather quickly narrows into a slim body, giving them the appearance of a tadpole reaching adulthood.
Cottus carolinae has proven to be useful as a representative species for the effects of mining related impacts on fishing communities since it has been proven that their density is negatively correlated with higher metal concentrations from mining.[3] In other areas around the Cumberland Basin, as a benthic fish, the C. carolinae is in danger of increased siltation by area farming. Though the sculpin faces these threats, they are not yet on the list of endangered species.[4]
Cottus carolinae is a freshwater species dwelling within the United States. The wide-ranging species occurs in eastern North America west of the Appalachians and south of the Ohio River Valley.[5] The species lives as far south as the mountain streams of Alabama, but prefers the cooler streams of the mid to northern United States.[6]
Cottus carolinae usually inhabits streams and rivers with cool, running water. They are a benthic species and prefer stream beds made of sand bedrock, stones, or boulders. C. carolinae partake in size-specific habitat segregation, with the majority of adults in the pools of streams and rivers with the young-of-the-year inhabiting the riffles.[7] Most streams inhabited by the species are less than two meters deep with a velocity between 0.1 and 0.7 meters per second with a standard deviation of + or - .2 meters per second.[4]
The species is sometimes found in caves, but such individuals generally resemble the aboveground population and may only be occasional visitors.[8] An apparently cave-adapted individual that lacked pigmentation but had normal eye-size has been reported from a cave in West Virginia.[9] Other better-known cave-adapted (in both pigmentation and eyes) populations from Missouri were formerly included in this species, but recognized as a separate species, the grotto sculpin (C. specus), in 2013.[10]
The banded sculpin is intolerant to habitat changes, and has experienced some limitations due to the effects of pollution. The largest pollutant threat to Cottus carolinae habitat is siltation of rivers and streams. Additionally, water impurities such as mining-derived metals in areas of Missouri have posed a high enough threat to populations that numbers have dwindled in those areas.[2]
Cottus carolinae is primarily a nocturnal ambush predators and subsists largely off of a diet of insects and insect larvae, though they are opportunistic feeders and have been known to feed on one another,[11] as well as salamanders, other fish, plants, and detritus.[12] A large portion of their diet consists of mayflies, followed closely by fly larvae.[2] Because of their flexible feeding habits, diet of C. carolinae varies with habitat, and they consume invertebrates whose own presence is determined by the relative availability of food sources such as algae and detritus.[12]
The greatest risk of predation for larger C. carolinae is posed by piscivorous mammals, reptiles, and birds, which lead to the habitat shift from shallow riffles to deeper pools into adulthood.[7]
Their largest concern with respect to competition is for rock shelters with other species such as crayfish.[13] Individual fish have an average home range of 47 square meters.[14]
Mating and nesting for C. carolinae begins in early spring. Spawning is triggered by a spike in water temperature of about fifty degrees Fahrenheit. Though the temperature spike does not have to be maintained for continued spawning, it is necessary for spawning activation.[7] In preparation for the spawning period, some males will darken in coloration, though this is less common in Cottus carolinae and more common in other Cottus species', such as Cottus bairdii.
The spawning period for Cottus carolinae is short, lasting less than two weeks. Spawning occurs underneath stones or other objects and eggs are deposited in large clumps. Fecundity averages 465 ova per female. Once spawning is complete, males guard the nests until the eggs hatch.[5] Some very attentive males groom out bad eggs while eggs in the clutches of less attentive males are sometimes preyed upon by opportunistic bacteria and fungi. Most male Cottus carolinae begin reproduction at the age of two years or beyond, with females beginning to reproduce slightly sooner. The lifespan of Cottus carolinae averages four years.[15]
The United States Environmental Protection Agency has Cottus carolinae listed as intolerant to habitat destruction and intermediately intolerant to pollution. As a species that feeds and reproduces benthically, C. carolinae is more vulnerable to stream degradation that non-benthic species. Because of this pollution sensitive nature, the species is often used as an indicator of stream health.[16] Studies have shown that populations of C. carolinae decrease in the presence of silts, pollution, and disturbance and it has been shown in the past that C. carolinae densities are negatively correlated with water metal concentrations.[15] Though there is not a huge threat to the species from invasive species, excess trout introduction in some areas has reduced species numbers.
Currently, Cottus carolinae is not listed as threatened or endangered by the United States Fish and Wildlife Services, nor is it on the IUCN Red List. Though some studies have been done to determine the effects of siltation and mining-related metal concentrations, there are currently no large conservation efforts in place for Cottus carolinae due to its absence from any threatened or endangered species lists. In the future, human impact can be reduced by managing the effects of farming on siltation and devising a way to prevent run-off water containing mining-related metals from flowing into streams and rivers.
The banded sculpin (Cottus carolinae) is a freshwater fish dwelling mostly in small to moderate sized streams in areas of swift current. Young and juvenile C. carolinae can mainly be found in pools, riffles, and other shallow habitats while adults tend to prefer deeper waters. C. carolinae primarily eats insects and insect larvae, but their large mouths enable them to eat prey nearly as large as themselves, including other sculpin. To prevent predation, including by other fish, the color and pattern of the sculpin tends to match its environment. Most Cottus carolinae are mottled brown with dark vertical banding and usually reach about three inches in length. They have a broad head which rather quickly narrows into a slim body, giving them the appearance of a tadpole reaching adulthood.
Cottus carolinae has proven to be useful as a representative species for the effects of mining related impacts on fishing communities since it has been proven that their density is negatively correlated with higher metal concentrations from mining. In other areas around the Cumberland Basin, as a benthic fish, the C. carolinae is in danger of increased siltation by area farming. Though the sculpin faces these threats, they are not yet on the list of endangered species.
