| Trispot darter | |
|---|---|
| Conservation status | |
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Actinopterygii |
| Order: | Perciformes |
| Family: | Percidae |
| Genus: | Etheostoma |
| Species: | E. trisella |
| Binomial name | |
| Etheostoma trisella Bailey & Richards, 1963 |
|
The trispot darter (Etheostoma trisella) is a species of fish in the Percidae family. It is endemic to the United States.
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The monitoring plan for Etheostoma trisella will have to take place in two areas because it requires two separate but interconnected habitats. When not breeding, E. trisella occupies the peripheral zones of the main river where there are slow moving water and silt gravel substrate with vegetation cover. The breeding habitat is much warmer water, and usually clayed bottom substrate with heavy vegetation seepage.[1] The trispot darter is native in the Conasauga River and its tributaries in northern Georgia and southeast Tennessee. The main food source of Etheostoma trisella in this habitat is nymphs and larvae.[1] The trispot darters spawn around January through March, with the males showing brilliant colors of skin pigment. The skin color is thought to actually aid in attracting mates. Egg clutch numbers vary from 50-300 eggs per female.[2] The average length of Etheostoma trisella is 35 mm. SL and is somewhat short lived with an average life span around 2.5 years.[3] The management plan should be that the species should be treated as threatened or even justified by endangered. E. trisella uses a vulnerable habitat and can be harmfully affected by human activity so implementing a large scale management may be risky to the species. Management efforts can be somewhat isolated, which is good news because it decreases the chances of altering another darters niche in its ecosystem. The management will have to consider the spawning factors in as well for management of Etheostoma trisella which include substrate, water temperature, stress factors, and of course sex ratios.
The trispot darter Etheostoma trisella is endemic to the Conasauga river and its tributaries[1] The Conasauga River is located in northern Georgia and southern Tennessee. The species were thought to be extinct from the historical range for 7 years until 1967 a specimen was found in north Georgia. The historical range was in the Alabama River system and as far south as Coosa river, and in Georgia rivers you could find the darter. The species also was found in a reservoir at lake Weiss .The recent efforts to find the darter has not been very successful and now is only located in the Conasauga.[1] The reason for the decline in distribution is hypothesized to be due to human impact and development. The silt in water effects the clutch of eggs survival ad water temperature is vital for breeding for E. trisella. The Conasauga River offers the critical undisturbed habitat for the species.[2]
The majority of the species diet that accounts for 70 % of the diet is chironomidae larvae. The second most abundant source of food that accounts of 19% is ephemeroptera nymphs. The calculations of diet were measured by examining the stomach of E. trisella.[2] The species co exist with several other species in their habitat such as; Campostoma anomalum, Fundulus stellifer, and Etheostoma coosa. The only real competitor to E. trisella is E. coosa because of the mouth size and body length to be a threat for food and space. The main natural predators of the species are from the genius Mycropterus.[3] The abiotic factor, water temperature has to be warmer around spawning are maturity rate for example the water at 12 degrees C is best for egg maturation, another factor is water velocity because the species live in the peripheral zones of the main river where water runs slower. Also E. trisella like a silty substrate for egg laying. These factors are believed to cause micro-distribution.
The average length of Etheostoma trisella is 35 mm. SL and is somewhat short lived with an average life span around 2.5 years.[3] The micro-habitats that it needs are slow moving water with a silty substrate with cover when it is spawning. Etheostoma trisella uses the substrate as a nesting mature to hide the eggs as they mature. The other habitat is more of a main river stream with some cover shade. The clutch size varies from water based on water temperature. The clutch number is anywhere from 56 to 154 eggs per female. It has been known that some species of darter can have clutch sized of 292 developing eggs so this can also contribute to a limiting factor.[4] The human influence can affect this species life history vary easily because of the needs for spawning. If humans impacted the substrate of water temperature it would be detrimental to E. trisella
The human impacts must be reduced to ensure the future of E. etheostoma. One thing that should be done is that there should be no industrial or agricultural runoff allowed in trispot habitat due to the case of it might raise water temperatures and stop reproduction. The local agencies need to get together and set aside habitat for them since they are very interdependent of their environment. The loss of habitat is the number one reason for decline of the fish anyways.[5] The universities of Tennessee, Georgia, Alabama need to get together and use collaborative management to create a plan of action to submit to the agencies ,since these schools have collected all the data on the species. The management plan needs to happen fast because the species is listed as vulnerable, is still on decline. A human induced negative could also be at hand here with the Micropterus. The state agencies could have liberal fishing regulations on areas where the two species overlap to take some stress off of Etheostoma trisella. The scientific world needs to keep the balance of ecosystems to promote a balance of flora and fauna, which even a small vertebrate like a darter can affect an entire niche.
Gimenez Dixon, M. 1996. Etheostoma trisella. 2006 IUCN Red List of Threatened Species. Downloaded on 4 August 2007.
size and egg size darter.Ecology of freshwater fish 19:322-332