The sharpnose shiner (''Notropis oxyrhynchus'') is a species of freshwater

ray-finned fish Actinopterygii (; ), members of which are known as ray-finned fish or actinopterygians, is a class of bony fish that comprise over 50% of living vertebrate species. They are so called because of their lightly built fins made of webbings of sk ...

in the

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

Leuciscidae Leuciscidae is a family of freshwater ray-finned fishes, formerly classified as a subfamily of the Cyprinidae, which contains the true minnows. Members of the Old World (OW) clade of minnows within this subfamily are known as European minnow ...

, the shiners, daces and minnows. It is

endemic Endemism is the state of a species being found only in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also foun ...

Texas Texas ( , ; or ) is the most populous U.S. state, state in the South Central United States, South Central region of the United States. It borders Louisiana to the east, Arkansas to the northeast, Oklahoma to the north, New Mexico to the we ...

in the United States, where it is limited to the upper

Brazos River The Brazos River ( , ), called the ''Río de los Brazos de Dios'' (translated as "The River of the Arms of God") by early Spanish explorers, is the 14th-longest river in the United States at from its headwater source at the head of Blackwater ...

basin.Species Assessment and Listing Priority Assessment Form: ''Notropis oxyrhynchus''.
USFWS. April 15, 2011. In 2013 it became a candidate for federal listing as an

endangered species An endangered species is a species that is very likely to become extinct in the near future, either worldwide or in a particular political jurisdiction. Endangered species may be at risk due to factors such as habitat loss, poaching, inv ...

of the United States.

Description

This is a slender minnow generally measuring 3 to 5 centimeters in length at maturity, but it is known to reach 9.5 centimeters.Froese, R. and D. Pauly. (Eds.
''Notropis oxyrhynchus''.
FishBase. 2011. It is silver with a faint line extending from the

gill A gill () is a respiration organ, respiratory organ that many aquatic ecosystem, aquatic organisms use to extract dissolved oxygen from water and to excrete carbon dioxide. The gills of some species, such as hermit crabs, have adapted to allow r ...

s to the tail. The snout is pointed.

Distribution

Today the fish occurs mainly in the upper Brazos River system above

Possum Kingdom Lake Possum Kingdom Lake (popularly known as P.K.), is a reservoir on the Brazos River located primarily in Palo Pinto County, TX, Palo Pinto County Texas. It was the first water supply reservoir constructed in the Brazos River basin. The lake has ...

, it is rarely observed below this

reservoir A reservoir (; ) is an enlarged lake behind a dam, usually built to water storage, store fresh water, often doubling for hydroelectric power generation. Reservoirs are created by controlling a watercourse that drains an existing body of wa ...

and may be

extirpated Local extinction, also extirpation, is the termination of a species (or other taxon) in a chosen geographic area of study, though it still exists elsewhere. Local extinctions are contrasted with global extinctions. Local extinctions mark a chan ...

from most or all of the tributaries in the lower river system. Populations are extirpated from the

Wichita River The Wichita River ( ) is a river of Northwest Texas that is part of the Red River of the South, Red River drainage basin, watershed. Rising in northeastern Knox County, Texas, Knox County at the confluence of its North and South Forks, the river ...

, which represented nearly 70% of the known former range of the species. In the upper Brazos it is still a common species.

Biology

This

freshwater fish Freshwater fish are fish species that spend some or all of their lives in bodies of fresh water such as rivers, lakes, ponds and inland wetlands, where the salinity is less than 1.05%. These environments differ from marine habitats in many wa ...

inhabits medium and large rivers,

channels Channel, channels, channeling, etc., may refer to: Geography * Channel (geography), a landform consisting of the outline (banks) of the path of a narrow body of water. Australia * Channel Country, region of outback Australia in Queensland and pa ...

, and pools. It can be found in shallow, turbid waters over sand and mud substrates. The fish feeds on aquatic and terrestrial invertebrates, including

flies Flies are insects of the Order (biology), order Diptera, the name being derived from the Ancient Greek, Greek δι- ''di-'' "two", and πτερόν ''pteron'' "wing". Insects of this order use only a single pair of wings to fly, the hindwin ...

caddisflies The caddisflies (order Trichoptera) are a group of insects with aquatic larvae and terrestrial adults. There are approximately 14,500 described species, most of which can be divided into the suborders Integripalpia and Annulipalpia on the basis ...

, bugs,

beetle Beetles are insects that form the Taxonomic rank, order Coleoptera (), in the superorder Holometabola. Their front pair of wings are hardened into wing-cases, elytra, distinguishing them from most other insects. The Coleoptera, with about 40 ...

s, odonates, and

ostracod Ostracods, or ostracodes, are a Class (biology), class of the crustacean, Crustacea (class Ostracoda), sometimes known as seed shrimp. Some 33,000 species (only 13,000 of which are extant taxon, extant) have been identified,Brandão, S.N.; Antoni ...

s. It consumes large amounts of sand and sediment, suggesting that it forages on the riverbed. It may also consume some plant material.Marks, D. E., et al. (2001)
Foods of the smalleye shiner and sharpnose shiner in the Upper Brazos River, Texas.
''The Texas Journal of Science'' 53(4), 327-34. Its life history is not well documented.

Conservation

Several threats have contributed to the decline of the species. Inflow from

s has altered the physical and biological characteristics of the river system, such as temperature, flow patterns, and turbidity, and have contributed to

habitat fragmentation Habitat fragmentation describes the emergence of discontinuities (fragmentation) in an organism's preferred environment (habitat), causing population fragmentation and ecosystem decay. Causes of habitat fragmentation include geological proces ...

and other changes to the ecosystem. The Possum Kingdom,

Granbury Granbury is a city in and the county seat of Hood County, Texas, United States. As of the United States Census, 2020, 2020 census, the city's population was 10,958, and it is the principal city of the Granbury micropolitan area, Granbury micro ...

, and Whitney Reservoirs have produced changes in the aquatic faunal communities of the Brazos River. The construction of more reservoirs is expected to prevent the fish from recolonizing habitat where it is now absent. The

invasive plant An invasive species is an introduced species that harms its new environment. Invasive species adversely affect habitats and bioregions, causing ecological, environmental, and/or economic damage. The term can also be used for native speci ...

salt cedar The genus ''Tamarix'' (tamarisk, salt cedar, taray) is composed of about 50–60 species of flowering plants in the family Tamaricaceae, native to drier areas of Eurasia and Africa. The generic name originated in Latin and may refer to the Ta ...

(''Tamarix'' spp.) has become abundant along the Brazos River, its spread aided by the construction of reservoirs. The plant likely increases sedimentation and alters water flow, making parts of the habitat unsuitable for the fish. The Brazos River is a relatively saline river because of the salts in the surrounding land and a salty

aquifer An aquifer is an underground layer of water-bearing material, consisting of permeability (Earth sciences), permeable or fractured rock, or of unconsolidated materials (gravel, sand, or silt). Aquifers vary greatly in their characteristics. The s ...

beneath, and the fish is adapted to the saline waters. There is increasing interest in

desalination Desalination is a process that removes mineral components from saline water. More generally, desalination is the removal of salts and minerals from a substance. One example is Soil salinity control, soil desalination. This is important for agric ...

of the river water for municipal use. Planned desalination projects include the construction of wells, pipelines,

evaporation pond Evaporation ponds are artificial ponds with very large surface areas that are designed to efficiently evaporate water by sunlight and expose water to the ambient temperatures. Evaporation ponds are inexpensive to design making them ideal for mul ...

s, and reservoirs for water treatment. These projects, as well as ongoing

wastewater Wastewater (or waste water) is water generated after the use of freshwater, raw water, drinking water or saline water in a variety of deliberate applications or processes. Another definition of wastewater is "Used water from any combination of do ...

and agricultural runoff, are expected to alter water and habitat quality.

Gravel Gravel () is a loose aggregation of rock fragments. Gravel occurs naturally on Earth as a result of sedimentation, sedimentary and erosion, erosive geological processes; it is also produced in large quantities commercially as crushed stone. Gr ...

and

sand mining Sand mining is the extraction of sand, mainly through an open pit (or sand pit) but sometimes mined from beaches and inland dunes or dredged from ocean and river beds. Sand is often used in manufacturing, for example as an abrasive or in conc ...

have produced significant effects on the lower Brazos, but their specific impacts on the fish are not clear.

Algal bloom An algal bloom or algae bloom is a rapid increase or accumulation in the population of algae in fresh water or marine water systems. It is often recognized by the discoloration in the water from the algae's pigments. The term ''algae'' encompass ...

s may also affect the species, but evidence is not yet available.

References

{{DEFAULTSORT:shiner, sharpnose sharpnose shiner Endemic fauna of Texas sharpnose shiner Taxonomy articles created by Polbot ESA endangered species

Description

Distribution

Biology

Conservation

See also

References