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Tennessee Wildlife Resources Agency (2002) has teardrop darters listed in non-game species in need of management. They are otherwise not listed as threatened or endangered.
US Federal List: no special status
CITES: no special status
The age of teardrop darters can be detected by size or annulus formation. The maximum life span reported is two and a half years (Etnier and Starnes, 2001). Females rarely live to two years of age (Flynn and Hoyt, 1979).
Typical lifespan
Status: wild: 2.5 (high) years.
Average lifespan
Status: wild: 2 years.
Average lifespan
Status: captivity: 2 years.
Teardrop darters are found in the freshwater aquatic drainage of the Green River in the temperate region of Kentucky and Tennessee. They are located in small to medium upland streams that are 2nd, 3rd, and 4th order tributaries. Adults are mostly collected in areas less than 0.66 meters deep and sometimes in pools of up to 1 meter deep and rarely seen in riffles (Kuehne and Small, 1971). Fry on the other hand have been found to occupy slow riffles and just below them (Flynn and Hoyt, 1971). They are flat rock bottom dwellers in low density of vegetative cover along sandy banks. Adults inhabit water with temperatures ranging from 21 to 27 degrees Celsius, whereas, eggs and larvae are found in water temperatures below 15 degrees Celsius (Tennessee Animal Biogeographic System Tabs, 2002).
Range depth: .33 to 2.66 m.
Average depth: .66 m.
Habitat Regions: temperate ; freshwater
Aquatic Biomes: benthic ; rivers and streams
Teardrop darters are an endemic species of the middle and upper portions of the Green River system in Kentucky and Tennessee from 38ºN to 36ºN (Kuehne and Small, 1971).
Biogeographic Regions: nearctic (Native )
Teardrop darters are carnivores. Their diet throughout life includes many different aquatic macroinvertebrates and occasionally detritus. Some of the most important food items for teardrop darters are the larval and adult stages of Diptera, Ephemeroptera larva, and Copepoda adults.
Animal Foods: insects; aquatic crustaceans
Other Foods: detritus
Primary Diet: carnivore (Insectivore )
The carnivorous diet, small body size, and short life span are the major factors in the teardrop darters' ecosystem roles. They are found to share the same area with the spottail darters (Etheostoma squamiceps).
Commensal/Parasitic Species:
Teardrop darters contribute to the diversity and enhance the beauty of the Green River basin. Teardrop darters could potentially have a greater importance to humans not currently understood.
Positive Impacts: research and education
Teardrop darters have no negative impact on humans.
Eggs develop in 15 to 22 days depending on temperature. Fry can be found starting in late May with a standard length of 15 mm. Age can be determined by their scale annuli. Teardrop darters are divided into three age groups. After one year they reach a standard length of 31.9 mm and grow to 47.1 mm after reaching two years of age.
Darters can produce a chemical, fright substance in the water to deter predators.
Teardrop darters use their vision, tactile senses, and chemoreception to perceive their environment.
Communication Channels: chemical
Perception Channels: visual ; tactile ; chemical
Etheostoma virgatum and Etheostoma obeyense are the closest relatives of teardrop darters. They seem to be allopatric species.
The teardrop darter was named after Professor Roger W. Barbour from the University of Kentucky.
Teardrop darters are divided into three age classes with a standard length of about 3 cm, 4 cm, and 4.5 cm. They are considered fully mature at 4.5 cm and weighing about 2.7 grams. They are bar checked darters and can be distinguished from the others by a darker sub orbital pigment bar, nine preoperculomandibular pores and less infraorbital and lateral line pores (Flynn and Hoyt, 1979). The Tennessee Animal Biogeography System website describes them as a slender fish having an incomplete lateral line with a count of 41 to 46 scales, 8 to 9 dorsal spines with dorsal ray counts of 12 to 14, and 2 anal spines with 8 to 9 anal rays. Teardrop darters are yellow with hints of orange, a dark head with a black bar by the eye, and black blotches on the body. They have dots on the caudal, anal, and second dorsal fins but the first dorsal fin is stripped and the pelvic fin is white to match the breast and belly.
Range mass: 2.7 (high) g.
Range length: 3 to 4.5 cm.
Average length: 4 cm.
Other Physical Features: ectothermic ; heterothermic ; bilateral symmetry
Sexual Dimorphism: sexes alike
Besides being eaten by other teardrop darters, some predators include grass pickerel (Esox americanus americanus), banded sculpin (Cottus carolinae), water snakes (Nerodia), snapping turtles (Chelydra serpentina), belted kingfishers (Megaceryle alcyon), and little green herons (Egretta caerulea).
Teardrop darters hide and rely on their agility to deter predators.
Known Predators:
Anti-predator Adaptations: cryptic
In teardrop darters, the sexes do not differ in appearance although males show a darkening through spawning season and after. Flynn and Hoyt (1979) also observed that there were no breeding tubercles, but females did have some inflammation in the genital papillae during spawning.
Males clear out areas underneath the rock with just enough room for the fish to fit with a fanning of their tail. One the nest site is ready, males will chase females into the site by bumping them. Both males and females invert their body during spawning.
Mating System: polygynous
Spawning season is April through May depending on the time it takes for the gonads to develop (Flynn and Hoyt, 1979). Each female lays 17 to 48 eggs (Flynn and Hoyt, 1979) underneath a flat stone monolayer with several using the same nest site (Page et al. 1982), and as many as 70 in one spot. Sexual maturity is complete at the end of the first year. Kuehne and Small (1971) describe reproduction as having a high resilience because the population can double in under fifteen months. Males have a yellowish growth on the dorsal fin in breeding season resembling an egg thought to compel females to lay eggs because females tend to select spots where others have deposited eggs earlier.
Breeding interval: Breeding occurs once yearly.
Breeding season: Spawning season is April through May depending on the time it takes for the gonads to develop(Flynn and Hoyt, 1979).
Range number of offspring: 17 to 48.
Range gestation period: 125 to 270 hours.
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
Males have been observed guarding nests (Etnier and Starnes, 2001). It is not clear whether males are protecting young or just waiting for another mating opportunity since females prefer to lay eggs in established sites. Males have been observed eating fry.
Parental Investment: pre-fertilization (Provisioning, Protecting: Female); pre-hatching/birth (Protecting: Male)
Etheostoma barbouri és una espècie de peix de la família dels pèrcids i de l'ordre dels perciformes.
Els mascles poden assolir els 6 cm de longitud total.[2]
Es troba als Estats Units: Tennessee i Kentucky.[2]
Etheostoma barbouri és una espècie de peix de la família dels pèrcids i de l'ordre dels perciformes.
The teardrop darter (Etheostoma barbouri) is a species of freshwater ray-finned fish, a darter from the subfamily Etheostomatinae, part of the family Percidae, which also contains the perches, ruffes and pikeperches. It is endemic to the eastern United States. It is only found in Kentucky and Tennessee, where it occurs in the middle to upper reaches of the Green River drainage. It inhabits small rivers and creeks and rocky pools where it feeds on the larvae of blackflies and midges, immature stages of caddisflies and mayflies, and cladocerans and copepods. This species can reach a length of 6 cm (2.4 in), though most only reach about 4.2 cm (1.7 in).[3] This species creates nests in which the females deposit their eggs and these are guarded by the male and have been found to contain between 40 and 80 eggs.[1] The teardrop darter was first formally described by Robert A. Kuehne and James W. Small Jr. in 1971 with the type locality given as Brush Creek, a tributary of the Green River, 2.7 miles north of Liberty, Casey County, Kentucky.[4] The specific name honours Professor Roger W. Barbour (1919-1993) in recognition of his contribution to the knowledge of Kentucky's vertebrate fauna.[5]
The teardrop darter (Etheostoma barbouri) is a species of freshwater ray-finned fish, a darter from the subfamily Etheostomatinae, part of the family Percidae, which also contains the perches, ruffes and pikeperches. It is endemic to the eastern United States. It is only found in Kentucky and Tennessee, where it occurs in the middle to upper reaches of the Green River drainage. It inhabits small rivers and creeks and rocky pools where it feeds on the larvae of blackflies and midges, immature stages of caddisflies and mayflies, and cladocerans and copepods. This species can reach a length of 6 cm (2.4 in), though most only reach about 4.2 cm (1.7 in). This species creates nests in which the females deposit their eggs and these are guarded by the male and have been found to contain between 40 and 80 eggs. The teardrop darter was first formally described by Robert A. Kuehne and James W. Small Jr. in 1971 with the type locality given as Brush Creek, a tributary of the Green River, 2.7 miles north of Liberty, Casey County, Kentucky. The specific name honours Professor Roger W. Barbour (1919-1993) in recognition of his contribution to the knowledge of Kentucky's vertebrate fauna.
Etheostoma barbouri es una especie de peces de la familia Percidae en el orden de los Perciformes.
Los machos pueden llegar alcanzar los 6 cm de longitud total.[1]
Se encuentra en los Estados Unidos: Tennessee y Kentucky.
Etheostoma barbouri Etheostoma generoko animalia da. Arrainen barruko Percidae familian sailkatzen da.
Etheostoma barbouri Etheostoma generoko animalia da. Arrainen barruko Percidae familian sailkatzen da.
Etheostoma barbouri is een straalvinnige vissensoort uit de familie van de echte baarzen (Percidae).[1] De wetenschappelijke naam van de soort is voor het eerst geldig gepubliceerd in 1971 door Kuehne & Small.
Bronnen, noten en/of referenties
巴氏鏢鱸為輻鰭魚綱鱸形目鱸亞目河鱸科的其中一種，分布於美國田納西州及肯塔基州的Green河流域，體長可達6公分，棲息在沿石底質的水塘、溪流，屬肉食性，以水生昆蟲為食。
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