| Shadow bass | |
|---|---|
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Actinopterygii |
| Order: | Perciformes |
| Family: | Centrarchidae |
| Genus: | Ambloplites |
| Species: | A. ariommus |
| Binomial name | |
| Ambloplites ariommus Viosca, 1936 |
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The shadow bass (Ambloplites ariommus) is a species of freshwater fish in the sunfish family (Centrarchidae) of order Perciformes. It is native to Missouri, Arkansas, Louisiana, and Georgia.
A. ariommus reaches a maximum recorded overall length of 30 cm (12 in) and a maximum recorded weight of 820 g (1.8 lb).
Shadow bass Ambloplites ariommus (from here on shadow bass), is a member of the Centrarchids family or sunfish family and is closely related to the rock bass Ambloplites rupestris along with one more related species occurring naturally (Johnson et al. 2003). The shadow bass is native to the southeastern United States and is most common in Florida, Georgia, Louisiana, Mississippi, Alabama and two isolated populations in Arkansas and Missouri. The shadow bass inhabits small to medium size rivers and streams with permanent water flow and prefers cool water temperatures similar to smallmouth bass Microtperus dolomieu habitat. Management of the shadow bass was not conducted till the 1980s and still much management being done on shadow bass since most individuals value them below smallmouth bass, but with protection of pools and riffles with vegetated or bushy cover with substrates of gravel, mud, and sand (Roell et al. 2010).
Contents |
The shadow bass' native range includes the southeastern United States from the Apalchicola River drainage in Georgia to the lower Mississippi basin in Louisiana. The two isolated populations in the St. Francis, Black Arkansas Red and upper Ouachita River Drainages in Missouri and Arkansas in the Ozark regions (Roe et al. 2008). In Tennessee the Shadow bass can be found in most drainages south of the Tennessee River. Other river drainages that shadow bass inhabit are Blackwater and Chattahoochee rivers in southern Georgia and northern Florida. The apparent absence of shadow bass in Black Belt streams is probably the result of low stream flow and poor water-quality conditions during the late summer when temperatures are high. Channelization is a possible factor in the distribution of the shadow bass in Mississippi river systems but results from Mareska et al. 2000. research proved no difference in the distribution of shadow bass.
The shadow bass is a freshwater fish that inhabits a climate range of 38 degrees North and 29 degrees north in the United States. The shadow bass prefers slow-flowing water over substrates of silt-free mud, sand, gravel, and pebbles. Brushy and vegetated pools are preferred micro-habitat in most streams (Walsh and Harris 2004). Under cut banks and woody debris in small to medium sized rivers and streams are also preferred habitat. The quantitative diet of shadow bass consist mostly on small invertebrates mainly crayfish Order Decapoda when small less than three inches after three inches can begin feeding on small fish species such as darters, madtoms, and minnows (Roell et al. 2008). The main predator and competitor of the shadow bass is the smallmouth bass which inhabits the same micro-habitat and research was conducted by Walsh and Harris in 2004 on the introduction of rainbow trout Oncorhynchus mykiss in shadow bass habitat to measure competition between the species, the data showed no effect on shadow bass populations. Factors by humans that might attribute to population decline of the shadow bass channelization, sedimentation from logging, and habitat encroachment.
Not much research has been done on the life history of the shadow bass so reproductive age, clutch size, life span information is lacking and needs more research. The Shadow bass being a sunfish builds circular nest in the spring during the breeding season. The male shadow bass does the nest constructing, the females only obligation is to pick a suitable males nest and lay her eggs after that she departs. The male bass watches over the eggs till they hatch 3–5 days later.[1] The nests are often colonial, meaning several nest in one area. The preferred nesting sites are sandy pools with bushy vegetation. Average size for shadow bass is around 8 inches or 20 cm and an average weight of around a pound through the state record in Missouri is over 2 pounds (Mareska et al. 2000.) One trait of the shadow bass is its ability to change color to match its substrate background.
Current management
Through its range even for the two isolated population the shadow bass populations are not listed in any danger and the shadow bass is federally listed as G5 secure. Current management for the shadow bass in the case of the scenic rivers in Mississippi was to protects pools and prevent sediment pollution in areas of shadow bass populations (Mareska et al. 2000). Though in most places shadow bass are not consider a game fish and receive little management attention. In Missouri however, where shadow bass has a demand in the game fish market, biologists are conducing population studies and conducting estimates using mark and recapture methods and information for anglers to provide data to determine what if any angling restrictions need to apply to shadow bass fishing.
Management recommendations Recommended management options for shadow bass would be first to estimate the population size in a given area. Best option since the bass prefer deep pools in moving water would be to conduct angler surveys and ask questions on size weight and location of individuals caught. Seining and mark and recapture estimates are advised in areas where this is feasible; in deeper areas where boat access is accomplishable electroshocking would be a good way to gather data on population numbers. Recommended sampling time should be in early to mid spring before the breeding season to limit stress on the fish. Use sampling equipment best suited for the area. Research main option there could be a lot more data on life history and population sizes based on long term research to see fluctuation within a population and what factors attributed to the fluctuations and how to manage those factors.
Roell, J.R., R.J. DisStefano. 2010. Effects of a Conservative Rock Bass Length Limit on Angler Participation, Sport Fish Populations, and Crayfish Prey in a Missouri Ozark Stream. NORTH AMERICAN JOURNAL OF FISHERIES MANAGEMENT. 30:552-564.
Roe, K.J., R.L. Mayden, P.M. Harris. 2008. Systematics and Zoogeography of the Rock Basses (Centrarchidae: Ambloplites). American Society Ichthyologist herpetologist. 4:858-867.
Walsh, M.G., D.l. Harris. 2004. Characteristics of Smallmouth Bass (Micropterus dolomieu) and Shadow Bass (Ambloplites ariommus) Populations in an Ozark Stream Before and After Rainbow Trout Introduction. Journal of Freshwater Ecology.4:587-596.
Johnson, R.L. C.F. Cavenaugh. 2003. Genetic similarity of shadow and Ozark basses (Ambloplites) as determined by mitochondrial DNA analysis. Journal of the Arkansas Academy of Science. 57:206-208.
Mareska, J.F., D.C. Jackson. 2000. Use of shadow bass stock characteristics to evaluate natural and scenic waterways in Mississippi. Proceedings of the Annual Conference Southeastern Association of Fish and Wildlife Agencies. 54:167-178.