Mimic Shiner

The mimic shiner (''Notropis volucellus') is a species of North American cyprinid freshwater fish in the genus '' Notropis''. The genus '' Notropis'' is commonly known as the eastern shiners. It is native to areas of the Hudson Bay drainage, Great Lakes drainage, much of the Mississippi River basin including areas of Tennessee, Virginia, North Carolina, and regions of the Gulf of Mexico extending from Mobile Bay to the drainage of Texas. However, this particular species can be found in other places such as the Atlantic Coast drainage in Connecticut and Housatonic rivers. This genus is usually characterized by almost all having a complete lateral line, 8 dorsal fin rays, a premaxillae protactile, and a silvery or speckled peritoneum. As the common name indicates, this species is difficult to classify in the wild because it looks similar to many other shiners. In fact, some even hypothesize that this species is actually a complexity of many cryptic species.Etnier, D.A. and W.C. Starnes. 2001. The Fishes of Tennessee. Knoxville: University of Tennessee Press. While this is the case, it is important to take more caution to not misidentify this species and to understand its impact on introduced areas.

The diet of ''N. volucellus'' consists of some terrestrial insects, small crustaceans, and midge pupae and larvae. Mimic shiners are reported to only live a total of three years, and are suspected to reach sexual maturity after one year. In lakes, fish spawn in large schools located over beds of aquatic plants.Moyle, P.B. 1973. Ecological Segregation Among Three Species of Minnows (Cyprinidae) in a Minnesota Lake. Transactions of the American Fisheries Society 102(4):794–805. When found in small streams ''N. volucellus'' are generally in clear pools over gravel substrate in moderate current but they can be seen along shorelines over gravel, sand, and mud substrates usually in slow to moderate current when found in large lakes.Hrabik, R. A. 1996. Taxonomic and distributional status of Notropis wickliffi in the Mississippi River drainage: a literature review. Long Term Resource Monitoring Program. Environmental Management Technical Center, Onalaska, Wisconsin, Special Report 96-S001: 15. The diet of ''N. volucellus'' consists mostly of ''Daphnia'' in early spring and late fall while mostly small crustaceans, filamentous algae, and small invertebrates when ''Daphnia'' is not as abundant in the summer.

This fish is suspected to have been introduced to many areas via bait bucket release. Because negative impacts of the introduction of this species have not been documented and because this species is not listed as threatened, there is not much immediate need for conservation efforts of this species.

Distribution

Historically, this species has been mostly found in the southern Hudson Bay drainage, Great Lakes drainage, and much of Mississippi River basin except in the northern Great Plains region and is oddly missing from many of its tributaries. The mimic shiner is also in Atlantic Coast drainage in Connecticut, Virginia, North Carolina, and Housatonic rivers along with the region of the Gulf of Mexico extending from Mobile Bay to the drainage of Texas.

However, currently this species can also be found in Susquehanna River,Cooper, E.L. 1983. ''Fishes of Pennsylvania and the Northeastern United States''. University Park: The Pennsylvania State University Press.Malick, R.W. 1978. The mimic shiner, Notropis volucellus (Cope), in the Susquehanna River drainage of Pennsylvania. Proceedings of the Pennsylvania Academy of Science 52:199-200. drainage in New York,Daniels, R.A., R. E. Morse, and B. R. Weatherwax. 2006. Fish, Conewango Creek, Allegheny River Drainage, New York, USA. Check List 2(1): 14-19
Potomac River,Stauffer, J.R., Jr., J.M. Boltz, and L.R. White. 1994. The Fishes of West Virginia. PA: West Virginia Department of Natural Resources, Academy of Natural Sciences of Philadelphia. East Branch of the Delaware River collected in 2002,Schmidt, R.E. and R. Jacobs. 2005. The Mimic Shiner, Notropis volucellus (Cope), in Connecticut. Northeastern Naturalist 12(3): 20325–330. Connecticut River drainage of Massachusetts,Schmidt, R.E. 1986. Zoogeography of the Northern Appalachians. pp. 137–159, In C.H. Hocutt and E.O. Wiley (Eds.). The Zoogeography of North American Freshwater Fishes. New York: John Wiley and Sons, Inc.Hartel, K.E., D.B. Halliwell, and A.E. Launer. 2002. Inland Fishes of Massachusetts. Lincoln: Massachusetts Audubon Society low altitude, Connecticut regions such as Westhill Pond, upper Nashua drainage of Massachusetts, Housatonic River drainage in Massachusetts.Halliwell, D.B. 1979. 1979 Massachusetts fish list. Fauna of Massachusetts Series #4, Massachusetts Division of Fish and Wildlife, Publication #11,348-15-1,000- 5-79-CR.

It is suspected that the disappearance of mimic shiners in some areas may be due to a change in hydraulic regimes due to fragmentation of landscapes along with urbanization and development. Due to fragmentation of the landscape near or around riverine ecosystems, there is less available vegetation along these areas. With less vegetation, a faster flow of water pours into streams and rivers and possibly causes erosion to its banks. This influx of water and higher velocity of flow could have negative impacts on this species that lives in areas that has a relatively slow to moderate current.

Ecology

''Notropis volucellus'' can generally be found in sandy pools of headwaters, creeks, clear small to large rivers, and in quiet areas of lakesPage, L. M., and B. M. Burr. 1991. A Field Guide to Freshwater Fishes of North America, north of Mexico. Boston: Houghton Mifflin Company. while avoiding small, headwater streams, and swampy and marshy areas. In small streams ''N. volucellus'' are in clear pools over gravel substrate in moderate current but they can be seen along shorelines over gravel, sand, and mud substrates usually in slow to moderate current when found in large lakes. When monitoring one most often will find mimic shiners near riffles in currentGilbert, C. R. and G. H. Burgess. 1980. Notropis volucellus (Cope), Mimic shiner. pp. 322 in D. S. Lee, et al. Atlas of North American Freshwater Fishes. N. C. State Mus. Nat. Hist., Raleigh. and often will find them schooling in mid-water or at the surface of water.Edwards, R. J. 1997. Ecological profiles for selected stream-dwelling Texas Freshwater Fishes. A report to the Texas Water Development Board. The Texas Water Development Board March 3, 1997:1-89.

Because this is a small fish, mimic shiners have many piscivorous predators that are bigger in size. Such predators include northern pike walleye, largemouth bass, black crappie, yellow perch, rock bass, and brown bullhead among others.Hanych, D.A, M.R. Ross, R.E. Magnien, and A.L. Suggars. 1983. Nocturnal Inshore Movement of the Mimic Shiner (Notropis volucellus): a Possible Predator Avoidance Behavior. Canadian Journal of Fisheries and Aquatic Sciences 40(7): 888-894.

The diet of ''N. volucellus'' consists mostly of ''Daphnia'' in early spring and late fall while mostly small crustaceans, filamentous algae, and small invertebrates when ''Daphnia'' is not as abundant in the summer. One study showed that ''Daphnia'' was present in 85% of all stomachs sampled and zooplankton (copepods and ''Chydorus'') was found in greater than 30% of stomach samples in August. Fish aged at 0 ate mostly ''Chydorus'', but in the summer were found to eat varying amounts of invertebrates like small leeches and some chironomids. At age 2, mimic shiners were found to eat other invertebrates than those stated after May while their diet consisted of 50-80% filamentous algae in September and early October but less than 50% at other times. In this study no other large fish populations, except for some centrarchids, were found that would compete for ''Daphnia'' as a food source.Gorski, P.R, R.C. Lathrop, S.D. Hill, and R.T. Herrin. 1999. Temporal Mercury Dynamics and Diet Composition in the Mimic Shiner. Transactions of the American Fisheries Society 128(4): 701-712

Due to pollution from humans, many fish have been observed to bioaccumulate mercury. While effects of bioaccumulation are mostly studied in the larger piscivores, they can also be observed in smaller prey such as the''Notropis volucellus''. A rise in mercury levels in water could cause the disappearance of mimic shiners in some areas.

Life history

Mimic shiners are reported to only live a total of three years. This species, at least documented in TN, reach sexual maturity after their first year of growth. Spawning of this species varies depending on different locations due to differences in seasons and temperature changes. In Minnesota and Wisconsin this occurs from May to AugustBecker, G.C. 1983. Fishes of Wisconsin. Madison: University of Madison Press. while in Alabama this event occurs from mid-April to early August.18. Oliver, J. R. 1986. Comparative reproductive biology of the Cahaba shiner, Notropis sp., and the mimic shiner, Notropis volucellus (Cope), from the Cahaba River drainage, Alabama. Master's thesis, Birmingham: Stamford University However, because males produce nuptial tubercles from late May to early October in Tennessee, it is suggested that ''Notropis volucellus'' have a longer breeding season than other areas which peak in the summer. In lakes, fish spawn in large schools located over beds of aquatic plants. In streams, however, spawning location has not yet been documented.Warren, L. W., Jr., B. M. Burr, S. J. Walsh, H. L. Bart, Jr., R. C. Cashner, D. A. Etnier, B. J. Freeman, B. R. Kuhajda, R. L. Mayden, H. W. Robison, S. T. Ross, and W. C. Starnes. 2000. Diversity, Distribution, and Conservation status of the native freshwater fishes of the southern United States. Fisheries 25(10):7-29. Clutch sizes increases per female with an increase in body size, ranging from 74 to 386 oocytes produced from body sizes ranging from .Coburn, M. M. 1986. Egg diameter variation in Eastern North American Minnows (Pisces: Cyprinidae): Correlation with Vertebral Number, Habitat, and Spawning Behavior. Ohio Journal of Science 86: 110-120. These fertilized eggs are demersal and adhesive.

Because spawning varies depending on varying seasons and temperature changes, it is not unimaginable to predict changes in spawning due to global temperature changes in the future. As of yet, there has not been much research regarding ''Notropis volucellus''. As stated before, human-caused development and deforestation around the areas alter current of streams and also alter turbidity. Also stated above, the mimic shiner breeds in areas that are clear, has little current, and contains vegetation. Changes in the hydraulic regime of the habitats mimic shiners live in could create unfavorable conditions to reproduce.

Current management

Some places do claim that this species has declined significantly in certain areas. The department of Natural Resources of Ohio state that the mimic shiner was once found all over Ohio, but it is now not as abundant in many places as it used to be.Mimic Shiner. Ohio.gov: Department of Natural Resources. http://www.dnr.state.oh.us/tabid/22427/Default.aspx In table 2 of a paper discussing effects of landscape change on fish abundances, the mimic shiner is also listed as intolerant to disturbances and thus has been decreasing in number.Kennen, J.G, M. Chang, B.H. Tracy. 2005. Effects of Landscape Change on Fish Assemblage Structure in a Rapidly Growing Metropolitan Area in North Carolina, USA. American Fisheries Society Symposium 47:39–52.

However, many other regions believe this fish to be invasive. The mimic shiner is suspected to have been introduced into many regions. The source is believed to be the spread via the sport of fishing. It is reported, though not commonly sold in stores as such, mimic shiners were used in vast quantities as bait in Wisconsin lake and were even used as a primary source for food for fishes at one hatchery.Scott, W.B., and E.J. Crossman. 1973. Freshwater fishes of Canada. Fisheries Research Board of Canada, Bulletin 184. Ottawa.

Not much is being done to protect this specific species nor are many groups focusing on the mimic shiner. This is not unusual seeing how it is not listed as needing protection according to the IUCN red list of threatened species the population of ''Notropis volucellus'' is stable and its conservation status is of least concern.''Notropis volucellus''(mimic shiner). International Union for Conservation of Nature and Natural Resources. Last updated February 2013. http://www.iucnredlist.org/search

While pollution and dams are a major problem or water ecosystems, this fish has not been reported to need assistance in respects to conservation. Instead of needing protection, they need to be prevented from being introduced into non-native areas. It is likely that they could cause disruption to their non-native introduced ranges due to competition for resources.

References

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{{Taxonbar, from=Q3762319

Notropis
Fish described in 1865
Freshwater fish of North America