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Also, a series of “U-shaped greenish blotches” alternate along its side with thin, narrow, orange markings (Missouri Department of Conservation). The Niangua darter can be distinguished from other darters by the presence of two small, black spots at the base of its tail fin. Without these spots, the Niangua darter is nearly identical to many other darters. This is because the coloration displayed by the Niangua darter is quite comparable to that of other darters. However, these identifying spots are not apparent in breeding males. This can be attributed to the spawning behavior that they exhibit, clearing possible spawning areas with its tail. During this process, the scales along the bottom side of the tale, including the dots, simply wear off. They do, however, grow back and reappear at the end of the breeding season. The Niangua darter’s closest known relative is the arrow darter, which can be found in eastern Kentucky and northern Tennessee. Not surprisingly, it lacks the distinctive black tail spots of the Niangua (Missouri Department of Conservation). The two species never cross paths during their lifetimes, and therefore there is no confusion in identifying between the two very similar-looking species. Darters are an important part of any stream ecosystem. They generally play the crucial role of secondary consumers, comprising most of their diet of soft-bodied animals that feed mainly on photosynthetic organisms. With its slender snout, the Niangua darter probes crevices in rock and gravel for aquatic insect larvae, crustaceans and snails (USFWS). Also, it is known to predate upon the nymphs of stoneflies and mayflies (Missouri Department of Conservation). The population of Niangua darters has been declining since the 1940s, according to the United States Fish and Wildlife Service. This can be attributed to the introduction of rock bass and spotted bass for game fishing in the darter’s territory. The darter has to compete with the highly predacious bass species for nutrients, as well as territory. Because of this threat and others, the state of Missouri has placed the Niangua darter on the endangered species list, signifying that “the prospects for survival of the species within the state are in immediate jeopardy.” Also, the fish is now listed as threatened on a national level. Despite the small numbers remaining in its population, the Niangua darter is still doing well in at least some of its native territory. The darter is so endangered from extinction that it can only be found in 11 counties of the entire world: Benton, Cedar, Dade, Dallas, Greene, Hickory, Miller, Osage, Polk, St. Clair, and Webster (United States Geological Survey). All of these counties fall within the watersheds of either the Osage or Niangua river basin. In these areas, the Niangua darter lives mostly in clear upland creeks, but is also found in some small to medium-sized rivers. The darter was historically widespread and abundant in these rivers and streams (Magers). They require continuously flowing waters with slight to moderate currents and silt-free gravel or rock bottoms. Typically, these waters are the drainage from hilly areas (MDC). The most common types of bottom material found in streams containing the Niangua darter are chert and dolomite (MDC). Mating season for most stream fish species is from late March to early June. The Niangua darter is not an exception to this, although most of its breeding is done in mid-April. Throughout most of the year, they are found in shallow pools, margins, and stream runs. During breeding though, they move into shallow gravel runs. The males change to bright colors and clear out areas for spawning with their tales. Breeding males are brilliantly colored, exhibiting an orange to red bottom-sides as well as series of blue and green bars along their sides (Northern Prairie Wildlife Research Center). To spawn, males generally follow the females into shallow riffles where they may engage in threat displays with other males. This is common among fishes and has been observed in many species. Also during this time, males exhibit somewhat of a change in color. Along with the differences in color previously mentioned, they oftentimes lose the distinguishing dots found at the base of the tail. This is due to the clearing out of area with the tail. All markings do return to normal as soon as spawning has taken place. The darter is a secondary consumer and can often times be found searching around in cracks of rocks for aquatic insect larva to eat. It also consumes small crustaceans, snails, and nymphs of stoneflies and mayflies. Also, and unfortunately for the darter, it is a food source for almost all fish species larger than it is. Most fish naturally predate upon other species of fish and comprise a decent portion of their diet this way. Without the darter fulfilling this vital link in the food chain, the ecology of the stream system would be largely obsolete. According to the U.S. Fish and Wildlife service and the Missouri Department of Conservation, construction has wreaked havoc on the darter’s habitat, driving it from much of its range. Actions of people have created barriers in its habitat, fragmented its range, and thus blocked escape from streams that become polluted or altered. Highway and bridge constructions straighten and widen streams, eliminating the small pools in which darters live. Construction and other streamside activities such as clearing brush and gravel dredging has also increased erosion and added silt to the streams, disrupting the fish's habitat. Other threats include exotic predatory fish such as spotted bass and rock bass, which were introduced for game fishing in the 1940s. Since then they have spread throughout much of the darter's range, driving it out of some parts. There are, nonetheless, many other colorful darters that use the same habitat as the Niangua darter. This is what makes biologists believe that it is a good indicator species of stream quality. The Niangua darter seems to be very sensitive to water quality where it lives. It cannot live in silted streams, and needs purely gravel or rock bottom material (USGS). Also, because of its small range of habitats, it is a good indicator of how man has affected areas of the streams where it lives. Construction along riverbanks has been a major problem for the darter and is thought to be the driving force toward its extinction. Along with the construction, there are many other reasons that the quality of habitat that the darter lives in is depleting. The unrestricted removal of gravel is an example of this. When gravel is removed from a stream, the effects are grave on the local animal species, especially those that are highly sensitive to the amount of silt in the water. This can be especially dangerous for the darter’s survival during breeding season when their appearance is a primary factor for reproduction. Aside from gravel removal, poor land management and pollution also play roles in the breakdown of the water quality where the darter is found (Missouri Department of Conservation). Right now, research is being done to see how we can help save this species of fish. There are not any programs that focused on helping it recover, but that will undoubtedly come in the near future. The focus of government agencies is simply to learn more about how we can help the darter and to educate those individuals who can help (USFWS). It is also being monitored by many private organizations. There are things that individuals can do to help save the Niangua darter that have been found through this research. An important factor to the darter’s health is its environment, so in order to help the fish, we must undo the damage that has been done to its habitat. Replanting stream edges is a great start. Also, better land management could prove very beneficial to the further duration of the species. Dredging, channeling, making culverts and all other stream altering methods are disruptive to the darter’s habitat that can be easily avoided. Also, grazing cattle should be kept away from stream banks where the darter lives. If at all possible, there should be a different water source for them to drink from. By having cattle trampling along the banks, the land is eroded at a much quicker pace than would naturally occur, thus the water quality is deleted and having cattle trampling along the banks puts silt put into the water. As previously mentioned, the darter is a vital link in the ecosystem and all efforts should be made to keep a healthy population surviving within our waters. It is not only important on the organism level, but also to the general population. It serves us as well as its fellow biological species. By being a measure of water quality, it aids us in many ways. It provides a simple way to calculate the attributes of the waters in which it lives. Our government has noticed how important the Niangua darter is and is taking action to help save the species. Now it is our turn as citizens to do all that we can to insure that the species will continue to live and thrive in the river systems of the Niangua and Osage basins. Hopefully one day we will be able to say that the Niangua darter can be found in more territory than it ever had before. Bibliography: 1. Status of Listed and Recovery Plan Development. (On-line) http://www.greatplains.org/npresource/distr/others/recoprog/states/species/ethenian.htm 2. U.S. Fish and Wildlife Service. November 1997. (On-line) http://www.fws.gov/r3pao/eco_serv/endangrd/fishes/niang_fc.html 3. Watershed Management Planning. (On-line) http://www.ctic.purdue.edu/KYW/TipsAndHints/ConcernsEffects.html 4. Center for Agricultural, Resource and Environmental Systems. University of Missouri, Columbia. April 06, 1999. (On-line) http://www.cares.missouri.edu/cares/projects/GA.html 5. Major Issues and Findings: Fish Communities. U.S. Geological Survey. (On-line) http://water.usgs.gov/pubs/circ1158/circ1158.4F.html 6. Pesticides: Endangered Species Program Update. U.S. Department of Agriculture. (On-line) http://www.mda.state.mo.us/d7m.htm 7. Endangered Species Guidesheet. (On-line) http://www.conservation.state.mo.us/nathis/endanger/darter/ 8. Biotic Communities. (On-line) http://www.conservation.state.mo.us/fish/watershed/pomme/biotic/330bctxt.htm 9. Missouri Department of Conservation: Wildlife Diversity Report, July 1994-June 1995. (On-line) http://www.conservation.state.mo.us/nathis/wilddiv/95div1.html#DARTER 10. Status of Listed Species and Recovery Plan Development: Niangua Darter. Northern Prairie Wildlife Research Center. http://www.npwrc.usgs.gov/resource/distr/others/recoprog/states/species/ethenian.htm 11. Pomme de Terre River Watershed Inventory and Assessment. 1999. (On-line) http://www.conservation.state.mo.us/fish/watershed/pomme/contents/330cotxt.htm 12. Missouri Fish and Wildlife Information System: DARTER, NIANGUA. 08/19/98 (On-line) http://www.conservation.state.mo.us/nathis/mofwis/detail/0100064.HTM 13. Species Summary for Etheostoma nianguae: Niangua darter. Page, L.M. and B.M. Burr,1991. (On-line) http://www.fishbase.org/Summary/SpeciesSummary.cfm?ID=3444 14. All Outdoors - 3. Conservation Incentives Make Stream Management Attractive. 12/15/95 (On-line) http://www.conservation.state.mo.us/news/out/1995/out12155.html 15. Magers, Vince. Ichthyology’s Golden Age. Missouri Conversationist, Volume 60, Number 9, Sept 1999. http://www.conservation.state.mo.us/conmag/1999/09/6.html Word Count: 1617
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