Summary

Did you know?

The name "bifrenatus" comes from two latin words: "bi" means two and "frenatus" means bridle. Smith (1985) suggested the name may come from the stripes on the side of the head that resemble a horse's bridle.

State Ranking Justification

The abundance and range of Bridle Shiner in New York has moderately declined (NYS DEC 2015). Historically, this species was found in 16 of the 18 watersheds in New York (Carlson et al. 2016, NYS DEC 2015). The population remains stable in northern New York with a slow expansion in one of the watersheds. However, declines in abundance and range, some significant, are noted in western and central New York. It has not been confirmed in one of these watersheds since the 1920s. In addition, this species had not been collected from the Lower Hudson River watershed in over 25 years (Carlson et al. 2016).

Long-term Trends

Bridle Shiner historically occurred in 16 of the 18 New York watersheds. It has not been found in the Erie-Niagara watershed with a voucher since the 1920s; there is one unconfirmed report from 1960 (Carlson et al. 2016). The population appears to be stable in northern New York (NYS DEC 2015) with the range slowly expanding in the Raquette River watershed (Carlson et al. 2016). Declines are noted in the western and central parts of the state, as well as the Lower Hudson River watershed (NYS DEC 2015). Specimens have not been found west of Sodus Bay during recent surveys and this species has not been found in the Lower Hudson watershed in the last 25 years (Carlson et al. 2016).

Conservation and Management

Threats

Any activity which might lead to water contamination, siltation, warming of waterways, or the alteration of natural hydrology could directly and indirectly impact aquatic habitats and Bridle Shiner populations. Such threats might include roadway and agricultural runoff, industrial pollution, dams, bridge construction and maintenance, logging activities, and development near aquatic habitats (NYS DEC 2005). In addition, siltation decreases the amount of sunlight that reaches aquatic plants (EPA 2005) and lowers the quality of habitats needed for a variety of aquatic species (NYS DEC 2005). Point source pollution, such as effluents from municipal and industrial facilities, contribute to the degradation and pollution of aquatic habitats (EPA 2022, NYS DEC 2005, Mahar and Landry 2013, Strayer et al. 2004).
Altering natural waterflow can degrade habitat and restrict species movement. Dams directly restrict or impede species movement, alter the flow of water, change the water temperature, and contribute to sedimentation (NYS DEC 2005, Zaidel et al. 2021).
While modern day agricultural and silvicultural practices are an important aspect of the New York State economy, it is important to consider the effects on ecosystems and species. As these practices move closer to rivers, the natural riparian buffers are often removed. Riparian buffers maintain stream temperature and slow or prevent runoff of sediments from upland soil disturbances. Furthermore, they slow or reduce runoff from farm fields and pastures, such as contaminants from pesticides, fertilizers, manure, and sludge, into waterways (EPA 2005, NYS DEC 2005, Souza et al. 2020). Excessive fertilizer use can lead to algal blooms that can be deadly to aquatic life and overgrazing of livestock in fields could introduce pathogens, oxygen-demanding organics and solids, and invasive species to aquatic ecosystems (EPA 2005).
Approximately 10% of introduced, non-native species could have an impact on the health of ecosystems (McCormick et al. 2009). Invasive plants tend to outcompete native plants and can change natural processes (NYS DEC 2005). There is an increased risk of runoff and erosion when these plants are along streams and rivers. Aquatic invasive plants and animals can alter the water chemistry, change the nutrient regime, or decrease the dissolved oxygen levels. Introduced fish can alter trophic relationships resulting in a change in native fish populations and decreased water quality (McCormick et al. 2009).
Climate change is another threat that is likely to have lasting effects on aquatic systems. Irregular weather patterns can cause extreme drought, flooding, and temperature fluctuations. Heat waves are expected to be more intense (Frankson et al. 2022). The Northeast Region of the United States is expected to experience an increase in precipitation, more frequent storms, and higher than normal temperatures (EPA 2016, EPA 2022). Precipitation is expected to increase 10% to 15% in southern New York and 15 to 20% in northern New York by 2050 (Frankson et al. 2022). Extreme flooding can cause widespread erosion and runoff with added risk of contamination if flooding occurs at remediation sites, industrial sites, or wastewater treatment facilities (EPA 2016, EPA 2022). Temperature increases can significantly alter ecosystems. As water temperatures rise, the amount of dissolved oxygen decreases and evaporation increases, potentially lowering lake and stream levels (EPA 2022). Any combination of these events could change species distributions (EPA 2022) and those that cannot adapt or migrate may be extirpated from some areas (NYS DEC 2005).

Conservation Strategies and Management Practices

Protect water quality and reduce contamination and hydrological alteration (such as agricultural or road runoff, shoreline development, and damming) (NYS DEC 2005). Protect stream quality by maintaining both a riparian buffer that includes herbaceous and/or woody vegetation along the shoreline, and a significant forested buffer. These buffers reduce sediment and contaminant runoff (EPA 2005, NYS DEC 2005, Souza et al. 2020), provide shade, regulate temperature, and provide organic matter to animals (Hughes and Vadas 2021). Riparian zones with herbaceous and woody vegetation have high “indicator scores” for macroinvertebrates and fishes (Hughes and Vadas 2021).
Remove barriers to maintain or restore natural flow to waterways. Where removal is not possible, research alternatives that allow flow above and below a barrier.
In general, avoid stream crossings. If crossings are unavoidable, use Best Management Practices (BMP) to minimize disturbance to streams. Time periods of disturbance when water flow is low or normal, and install stream-crossing structures at a right angle to the stream (Watershed Agricultural Council Forestry Program 2018). Temporary methods to reduce runoff include water bars, gravel, geotextile fabric, rubber belt deflectors, open top culverts, straw bales, silt fencing, control blankets, and straw wattles (Watershed Agricultural Council Forestry Program 2018). Restore the disturbed area with native species as soon as possible. Areas that have been logged may also need ruts to be smoothed to reduce surface runoff (Watershed Agricultural Council Forestry Program 2018). Hughes and Vadas (2021) suggest that Best Management Practices may need to be applied to entire stream lengths and catchments to fully restore an aquatic ecosystem. If this is not possible, restore or manage a larger area around the directly disturbed area.
In general, tailor agricultural management plans to local conditions (e.g., soils, slope, land use). Often these plans aim to reduce pollution and increase farm productivity, but incentives could also be used to encourage sustainable farming practices. Proper management typically reduces runoff by 20-90% (EPA 2005). Consider using Integrated Pest Management (IPM) as an alternative to pesticide use. If pesticides and fertilizers are used, they should only be applied when needed, in the proper amount, and timed appropriately. In addition, rotate livestock to avoid overgrazing and to allow for vegetation regrowth. If needed, provide alternative water sources and shade to keep animals out of sensitive areas (EPA 2005).
Invasive species management can be time consuming and costly. Reduce the likelihood of non-native species being introduced into waterways. Boat-washing stations at boat launches can reduce transport of invasive plants and animals to new waterbodies. Educate anglers about the risk of releasing unused baitfish. If vulnerable species are present, consider a baitfish ban. Mechanical removal of some invasive plants may be needed in some rivers and streams. The use of pesticides to remove invasives can have a negative effect on ecosystems (McCormick et al. 2009) and should be a last resort to control invasive species.
Climate change is a global challenge. However, there are local actions that can help mitigate extreme weather events. Industrial and municipal infrastructure should be improved or replaced to be more resilient to flooding events (EPA 2016, NYS Comptroller 2023). Some suggested actions include installing or improving pumps to remove floodwater from facilities and installing protective structures, such as floodwalls. Ensure that existing bridges, dams, levees, seawalls, retaining walls, and wind barriers are prepared for extreme weather (NYS Comptroller 2023). Decrease runoff and erosion severity by installing large culverts, planting vegetation along riverbanks, and protecting and restoring wetlands (EPA 2016, NYS Comptroller 2023).

Research Needs

Additional research is needed on the general biology of this species to aid in better conservation decision-making.

Habitat

Habitat

Bridle Shiners are found in quiet, warm waters near the shores of lakes, ponds, and slow-moving areas of streams and rivers with submerged aquatic vegetation. The substrates are typically sandy gravel, silt, mud, or organic debris (Smith 1985). Spawning occurs in openings of quiet waters that are approximately 0.6 m deep and near vegetation, typically with watermilfoils (Myriophyllum) and green algae (Chara) (Smith 1985, Massachusetts Division of Fisheries and Wildlife 2015).

Associated Ecological Communities

• Confined river (guide)
  The aquatic community of relatively large, fast flowing sections of streams with a moderate to gentle gradient.
• Oligotrophic dimictic lake (guide)
  The aquatic community of a nutrient-poor lake that typically occurs in a deep, steeply-banked basin. These lakes are dimictic: they have two periods of mixing or turnover (spring and fall), they are thermally stratified in the summer, and they freeze over and become inversely stratified in the winter.
• Unconfined river (guide)
  The aquatic community of large, quiet, base level sections of streams with a very low gradient.
• Winter-stratified monomictic lake (guide)
  The aquatic community of a large, shallow lake that has only one period of mixing each year because it is very shallow in relation to its size, and is completely exposed to winds. These lakes typically never become thermally stratified in the summer, and are only stratified in the winter when they freeze over, and become inversely stratified (coldest water at the surface). They are eutrophic to mesotrophic.

Associated Species

• Iowa Darter (Etheostoma exile) (guide)
• Pugnose Shiner (Notropis anogenus)
• Blackchin Shiner (Notropis heterodon) (guide)
• Blacknose Shiner (Notropis heterolepis) (guide)

Range

New York State Distribution

Bridle Shiner is native to 16 of the 18 New York watersheds: Erie-Niagara, Ontario, Genesee, Oswego, St. Lawrence, Oswegatchie, Raquette River, Champlain, Chemung, Susquehanna, Delaware, Upper Hudson, Mohawk, Lower Hudson, Newark Bay, and Long Island. It has not been reported with a voucher specimen from the Erie-Niagara watershed since the early 1920s. While it is assumed that this species in native to Long Island, it is unable to disperse in saltwater and a has a limited range in the watershed. If it was introduced, it happened over a century ago (Carlson et al. 2016).

Global Distribution

The Bridle Shiner range includes the Lake Ontario basin and St. Lawrence River drainage, southern Quebec, eastern Ontario, and New York; Atlantic Slope drainages from southern Maine south to the James River drainage of Virginia (apparently extirpated from the Potomac and Rappahannock river drainages). This species is also known from the Neuse River drainage in eastern North Carolina (probably extirpated there and also in the Chowan River drainage) and the Santee River drainage in South Carolina (Burkhead and Jenkins 1991). The range has been significantly reduced in Massachusetts, New Jersey, Pennsylvania, Maryland, and, apparently, also in the Carolinas and elsewhere.

Best Places to See

• St. Lawrence River (St. Lawrence County)

Identification Comments

Identifying Characteristics

Bridle Shiner is a small, slender-bodied fish that is typically about 2 inches in length. Eyes are large compared to the overall size. There is an even black stripe that extends from the nose to the base of the tail. The lateral line is incomplete and ends before the dorsal area. There are seven anal rays and 4-4 pharyngeal teeth. The caudal (tail) fin is somewhat forked with somewhat rounded pointed lobes. Coloring is considered transparent yellow above the midlateral stripe and silver-white below. Breeding males are brighter yellow, especially along the lateral line. Females are more pale dorsally than males and are silvery-white below the lateral line. Dorsal and caudal fins have a slight yellow tint in both sexes. Scales are large with dark outline in the predorsal area. The dark outline is more pronounced in breeding males (Smith 1985).

Characters Most Useful for Identification

The most useful identification characteristics of the Bridle Shiner are the large eyes, the dark stripe from the tip of the nose to the base of the tail, and seven anal rays (Smith 1985).

Best Life Stage for Proper Identification

Adult.

Behavior

During spawning, the males chase the females. The male bumps the snout of the female and along the side of her body before spawning. The female lays a few eggs at time. It doesn't appear that territories are defended on a regular basis. The young stay in the vegetation after hatching. Eventually they form small schools and as time progresses the juveniles can be found in schools of 100 or more fish. They join the adult schools after they reach approximately 22 mm (Smith 1985).

Diet

Bridle Shiners only feed during the day. Their main diet consists of insects. Crustaceans, amphipods, water mites, mollusks, and plant material were also found in significant quantities in stomachs. Plankton is also consumed on or near vegetation (Smith 1985).

Best Time to See

Spawning occurs late May to late July or early August in quiet, shallow areas with aquatic vegetation, such as Myriophyllum or Chara (Smith 1985, Massachusetts Division of Fisheries and Wildlife 2015). Eggs sink and attach to submerged vegetation. Young remain in the vegetation in the spawning area for about a year (Massachusetts Division of Fisheries and Wildlife 2015).

Similar Species

• Pugnose Shiner (Notropis anogenus)
  Pugnose Shiner has a very small, nearly vertical mouth while the Bridle Shiner has a terminal, oblique mouth (Smith 1985).
• Ironcolor Shiner (Notropis chalybaeus)
  The inside of the Ironcolor Shiner's mouth is pigmented (Smith 1985).
• Blackchin Shiner (Notropis heterodon) (guide)
  Blackchin Shiner has a pigmented chin; the Bridle Shiner does not. In addition, the Blackchin Shiner has eight anal rays instead of seven (Smith 1985).
• Blacknose Shiner (Notropis heterolepis) (guide)
  The Blacknose Shiner has eight anal rays and "crescentic marks" in the lateral line (Smith 1985).
• Swallowtail Shiner (Notropis procne) (guide)
  Swallowtail Shiner has an interrupted midlateral stripe behind the eye. The midlateral stripe on the Bridle Shiner continues to the snout and the center of the upper lip (Smith 1985).

Bridle Shiner Images

Taxonomy

Bridle Shiner
Notropis bifrenatus (Cope, 1867)

• Kingdom Animalia
  • Phylum Craniata
    • Class Actinopterygii (Ray-finned Fishes)
      • Order Cypriniformes (Minnows and Suckers)
        • Family Cyprinidae (minnows and carps)

Additional Resources

References

Burkhead, N. M., and R. E. Jenkins. 1991. Fishes. Pages 321-409 in K. Terwilliger (coordinator). Virginia's Endangered Species: Proceedings of a Symposium. McDonald and Woodward Publishing Company, Blacksburg, Virginia.

Carlson, Douglas M., Robert A. Daniels, and Jeremy J. Wright. 2016. Atlas of Inland Fishes of New York. New York State Museum Record 7. The New York State Education Department and Department of Environmental Conservation. Albany, New York.

Environmental Protection Agency (EPA). 2005. Protecting water quality from agricultural runoff. https://www.epa.gov/sites/default/files/2015-09/documents/ag_runoff_fact_sheet.pdf.

Environmental Protection Agency (EPA). 2016. Adapting to climate change northeast. https://www.epa.gov/sites/default/files/2016-07/documents/northeast_fact_sheet.pdf.

Environmental Protection Agency (EPA). 2022. Region 2 climate adaptation implementation plan. https://www.epa.gov/system/files/documents/2022-10/bh508-R02%20Climate%20Adaptation%20Implementation%20Plan%209.19.2022%20HQ%20OP%20Copy.pdf

Frankson, R., Kunkel, K.E., Champion, S.M., Stewart, B.C., Sweet, W, DeGaetano, A.T., & Spaccio, J. (2022). New York State Climate Summary 2022. National Oceanic and Atmospheric Administration National Centers for Environmental Information. https://statesummaries.ncics.org/chapter/ny/

Hughes, Robert M., and Robert L. Vadas Jr. 2021. Agricultural Effects on Streams and Rivers: A Western USA Focus. Water 13, no. 14: 1901. https://doi.org/10.3390/w13141901

Mahar, Amy and Jenny Landry. 2013. New York State Department of Environmental Conservation species status assessment for Lasmigona subviridis (Green Floater).

Massachusetts Division of Fisheries and Wildlife. 2015. Massachusetts Division of Fisheries and Wildlife [web application]. Massachusetts Division of Fisheries and Wildlife, Westborough, Massachusetts. Available www.mass.gov/nhesp. (Accessed: July 26, 2021).

McCormick, Frank H., Glen C. Contreras, and Sherri L. Johnson. 2009. "Effects of nonindigenous invasive species on water quality and quantity." A dynamic invasive species research vision: opportunities and priorities 29 (2009): 111-120.

New York Natural Heritage Program. 2024. New York Natural Heritage Program Databases. Albany, NY.

New York State Comptroller. 2023. New York's local governments adapting to climate change: challenges, solutions, and costs. https://www.osc.state.ny.us/files/local-government/publications/pdf/climate-change-2023.pdf

New York State Department of Environmental Conservation. 2005. A strategy for conserving New York's fish and wildlife resources. Final submission draft.

New York State Department of Environmental Conservation. 2015. New York's Wildlife Action Plan: Fishes. Albany, NY.

Smith, C.L. 1985. The Inland Fishes of New York State. New York State Department of Environmental Conservation. Albany, NY. 522pp.

Souza, Francine N., Rodolfo Mariano, Tassio Moreia, and Sofia Campiolo. 2020. Influence of the landscape in different scales on the EPT community (Ephemeroptera, Plecoptera and Trichoptera) in the Atlantic Forest region. Environmental monitoring and assessment 129: 391-391.

Strayer, David L., J.A. Dowling, W.R. Haag, T.L. King, J.B. Layzer, T.J. Newton and S.J. Nichols. 2004. Changing perspectives on Pearly Mussels, North America's most Imperiled Animals. BioScience 54:429-439.

Watershed Agricultural Council Forestry Program. 2018. New York State forestry voluntary best management practices for water quality. http://nysbmpguidelines.com/. Accessed on June 20, 2023.

Zaidel, Peter A., A. H. Roy, K. M. Houle, B. Lambert, B. H. Letcher, K. H. Nislow, C. Smith. 2021. Impacts of small dams on stream temperature. Ecological indicators 120:6-11.

About This Guide

This guide was authored by: Shaw, Hollie Y.

Information for this guide was last updated on: September 27, 2023

Please cite this page as:
New York Natural Heritage Program. 2024. Online Conservation Guide for Notropis bifrenatus. Available from: https://guides.nynhp.org/bridle-shiner/. Accessed April 27, 2024.