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Home -> Kingdom Animalia -> Phylum Chordata -> Subphylum Vertebrata -> Class Actinopterygii -> Order Perciformes -> Suborder Percoidei -> Family Percidae -> Species Etheostoma barbouri

Etheostoma barbouri
teardrop darter



2009/11/29 02:46:10.183 US/Eastern

By Dana Campbell

Kingdom: Animalia
Phylum: Chordata
Subphylum: Vertebrata
Class: Actinopterygii
Order: Perciformes
Suborder: Percoidei
Family: Percidae
Genus: Etheostoma
Species: Etheostoma barbouri

Geographic Range

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). (Kuehne and Small, 1971)

Biogeographic Regions:
nearctic (native ).

Habitat

Depth
0.33 to 2.66 m
(1.08 to 8.72 ft)


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). ("Tennessee Animal Biogeographic System Tabs", 12/2002; Flynn and Hoyt, 1979; Kuehne and Small, 1971)

These animals are found in the following types of habitat:
temperate ; freshwater .

Aquatic Biomes:
benthic ; rivers and streams.

Physical Description

Mass
2.70 g (high)
(0.1 oz)


Length
3 to 4.50 cm; avg. 4 cm
(1.18 to 1.77 in; avg. 1.57 in)


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. ("Tennessee Animal Biogeographic System Tabs", 12/2002; Flynn and Hoyt, 1979)

Some key physical features:
ectothermic ; heterothermic ; bilateral symmetry .

Development

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. (Flynn and Hoyt, 1979)

Reproduction

Breeding interval
Breeding occurs once yearly.

Breeding/spawning season
Spawning season is April through May depending on the time it takes for the gonads to develop(Flynn and Hoyt, 1979).

Number of offspring
17 to 48

Time to hatching
125 to 270 hours

Age at sexual or reproductive maturity (female)
1 years (average)

Age at sexual or reproductive maturity (male)
1 years (average)

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. (Flynn and Hoyt, 1979)

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. (Flynn and Hoyt, 1979)

Mating systems:
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. (Etnier and Starnes, 2001; Flynn and Hoyt, 1979; Page and Burr, 1982)

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. (Etnier and Starnes, 2001)

Parental investment:
pre-fertilization (provisioning, protecting: female); pre-hatching/birth (protecting: male).

Lifespan/Longevity

Average lifespan (wild)
2 years

Typical lifespan (wild)


Average lifespan (captivity)
2 years
[External Source: AnAge]


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). (Etnier and Starnes, 2001; Flynn and Hoyt, 1979)

Behavior

Males will defend their territory from other competing males, chasing them off.

Home Range

There is no information available on home range in this species.

Communication and Perception

Darters can produce a chemical, fright substance in the water to deter predators. (Etnier and Starnes, 2001)

Teardrop darters use their vision, tactile senses, and chemoreception to perceive their environment. (Etnier and Starnes, 2001)

Communicates with:
chemical .

Perception channels:
visual ; tactile ; chemical .

Food Habits

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. (Flynn and Hoyt, 1979)

Primary Diet:
carnivore (insectivore ).

Animal Foods:
insects; aquatic crustaceans.

Other Foods:
detritus .

Predation

Known predators

Besides being eaten by other teardrop darters, some predators include grass pickerel (Esox americanus), banded sculpin (Cottus carolinae), water snakes (Nerodia), snapping turtles (Chelydra serpentina), belted kingfishers (Megaceryle alcyon), and little green herons (Egretta caerulea). (Flynn and Hoyt, 1979)

Teardrop darters hide and rely on their agility to deter predators. (Flynn and Hoyt, 1979)

Anti-predator adaptations::
cryptic .

Ecosystem Roles

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). (Flynn and Hoyt, 1979)

Commensal or parasitic species (or larger taxonomic groups) that use this species as a host
  • Black spot parasites, Crassihpiala bulboglessa
  • Nematodes are found in the mesenteries of the body cavity.

Economic Importance for Humans: Negative

Teardrop darters have no negative impact on humans.

Economic Importance for Humans: Positive

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.

Ways that people benefit from these animals:
research and education.

Conservation Status

IUCN Red List: [link]:
Not Evaluated.

US Federal List: [link]:
No special status.

CITES: [link]:
No special status.

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. (Myers, 2002)

Other Comments

Etheostoma virgatum and Etheostoma obeyense are the closest relatives of teardrop darters. They seem to be allopatric species. (Kuehne and Small, 1971)

The teardrop darter was named after Professor Roger W. Barbour from the University of Kentucky. (Kuehne and Small, 1971)

For More Information

Find Etheostoma barbouri information at

Contributors

Tanya Dewey (editor), Animal Diversity Web, University of Michigan Museum of Zoology.

Dana Campbell (author), Eastern Kentucky University. Sherry Harrel (editor, instructor), Eastern Kentucky University.

References

12/2002. "Tennessee Animal Biogeographic System Tabs" (On-line). Accessed October 19, 2005 at fwie.fw.vt.edu/TN/TN00077.htm.

Etnier, D., W. Starnes. 2001. The Fishes of Tennessee.. Knoxville: The University of Tennessee Press.

Flynn, R., R. Hoyt. 1979. The life history of the teardrop darter. The American Midland Naturalist, 101: 127-141.

Kuehne, R., J. Small. 1971. Etheostoma barbouri, a new darter (Percidar, Etheostomatini) from the Green River with notes on the subgenus Catonotus.. Copeia: 18-26.

Myers, G. 2002. "Tennessee Wildlife Resources Agency" (On-line). Accessed November 22, 2005 at http://www.state.tn.us/tura/nong002.

Page, L., B. Burr. 1982. Three new species of darters (Percidae, Ethepstoma) of the subgenus Nanostoma from Kentucky and Tennessee.. Occ. Pap. Mus. Nat. Hist. Univ. Kans., 101: 1-20.

2009/11/29 02:46:12.639 US/Eastern

To cite this page: Campbell, D. and S. Harrel. 2006. "Etheostoma barbouri" (On-line), Animal Diversity Web. Accessed November 29, 2009 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Etheostoma_barbouri.html.

Disclaimer: The Animal Diversity Web is an educational resource written largely by and for college students. ADW doesn't cover all species in the world, nor does it include all the latest scientific information about organisms we describe. Though we edit our accounts for accuracy, we cannot guarantee all information in those accounts. While ADW staff and contributors provide references to books and websites that we believe are reputable, we cannot necessarily endorse the contents of references beyond our control.

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