Smalleye Shiner (Notropois buccula) and Sharpnose Shiner (Notropis oxyrhynchus)
Two tiny fish join our list of endangered species in the Brazos River basin. The Notropois buccula, more commonly known as the smalleye shiner and the Notropis oxyrhynchus, known as the sharpnose shiner, both were listed as endangered in 2014.
The smalleye shiner and the sharpnose shiner both were listed as endangered by the U.S. Fish and Wildlife Service in August 2014 under the Endangered Species Act. The main threat facing both is habitat loss and fragmentation. Reductions in streamflow caused by droughts, water impoundments, and depletion of the water table from water wells and irrigation can also lead to habitat loss for both these small types of fish.
Current Range Map
The smalleye shiner is native to the Brazos River. Historically, it was found in the lower Brazos River as far south as Hempstead. The sharpnose shiner, however historically was found within the Brazos, Wichita, and Colorado rivers.
Both are now found only in segments of the upper Brazos River system upstream of Possum Kingdom Lake.
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Commercial or Environmental Importance
According to Matthews and Zimmerman (1990), the smallnose shiner species is potentially vulnerable to extinction in the event of global warming. There is no information at this time regarding the sharpnose shiner.
The smallnose shiner is commonly found in and on the edge of river channels with moderate depth, this fish can survive in isolated pools for a period of time. This species has a high thermal, low dissolved oxygen, and high salinity tolerances.
Meanwhile, the sharpnose shiner prefers mainstream rivers, sometimes entering smaller tributaries. It tends to avoid swifter currents and greater depths during periods of elevated discharge.
The smalleye shiner will release its eggs and sperm into the water where fertilization occurs. These semi-buoyant eggs will drift in the water for one to two days before hatching. Once the eggs hatch and become juvenile fish, they will move to margins of the river where the stream is slower, and food is more abundant. Once adults, their diet will mainly consist of invertebrates, but sometimes, they enjoy plants and pieces of decomposed materials.
The sharpnose shiner lives up to two years, and no substantial migration movements have been discovered. They eat aquatic and terrestrial insects, plants and sand.
Both species are estimated to need at least 171 miles of continuous free-flowing riverine habitat to complete all life stages.
The sharpnose shiner and the smalleye shiner both experience breeding seasons beginning in April and often continuing through September.
Ongoing Research/Conservation Efforts
Populations have likely become extinct in the Brazos River between Possum Kingdom Lake and the city of Waco. However, they both appear stable in the upper portion of the Brazos River. Much of the area upstream of Possum Kingdom Lake has been designated as critical habitat for the species.
For more information, visit:
- Durham, B.W. 2007. Reproductive ecology, habitat associations, and populaton dynamics of two imperiled cyprinids in a great plains river. Ph.D. Dissertation, Texas Tech University, Lubbock.
- Gilbert, C.R. 1980. Notropis buccula (Cross), Smalleye shiner. pp. 242 in D. S. Lee et al., Atlas of North American Freshwater Fishes. N. C. State Mus. Nat. Hist., Raleigh, i-r+854 pp.
- Marks, D.E. 1999. Life History Characteristics of the sharpnose shiner (Notropis oxyrhynchus) and the smalleye shiner (Notropis buccula) in the Brazos River, Texas. Ph.D. Dissertation, Texas Tech University, Lubbock.
- Marks, D. E., G. R. Wilde, K. G. Ostrand and Philip J. Zwank. 2001. Foods of the smalleye shiner and sharpnose shiner in the upper Brazos River, Texas. Texas Journal of Science, 53(4):327-334.
- Matthews, W.J., and E.G. Zimmerman. 1990. Potential effects of global warming on native fishes of the Southern Great Plains and the Southwest. Fisheries 15(6):26-32.
- Moss, R.W. and K.B. Mayes. 1993. Current status of Notropis buccula and Notropis oxyrhyncus in Texas. River studies report 8, Texas Parks and Wildlife Department, Austin, TX. 125 pp.
- Ostrand, K.G., and G.R. Wilde. 2001. Temperature, dissolved oxygen, and salinity tolerance of five prairie stream fishes and their role in explaining fish assemblage patterns. Trans. Amer. Fish. Soc. 130:742-749.
- Page, L.M., and B.M. Burr. 1991. A Field Guide to Freshwater Fishes of North America, north of Mexico. Houghton Mifflin Company, Boston. 432 pp.
Read more about the other endangered species of interest here.