Species of Greatest Conservation Need

**Species of Greatest Conservation Need** (Updated: 06/16/2025)
Scientifc Name	Common Name	Taxonomic Group	SGCN Status	Federal Status	State Status	Global Rank	State Rank	Endemic	General Habitat Type(s)
Microphis brachyurus	opossum pipefish	Fish - Bays and Estuaries	Yes	Not Listed	Not Listed	G4G5	S3	No	Adults are only found in low salinity waters of estuaries or freshwater tributaries within 30 miles of the coast (Gilmore 1992), where they also give birth. Young move or are carried into more saline waters off the coast after birth. Newly released larvae must have conditions near 18 ppt salinity for at least two weeks after birth to survive, indicating a physiology adapted for downstream transport to estuarine and marine environments (Frias-Torres 2002). Juvenile migration toward the ocean depends on water flow regimes, salinity, and vegetation for cover and capturing prey (Frias-Torres 2002). Seawalls, docks, and riprap construction destroy habitat and poor water quality and alteration of flow regimes may prevent migration (NMFS 2009).
Paralichthys lethostigma	southern flounder	Fish - Bays and Estuaries	Yes	Not Listed	Not Listed	G5	S2S3	No	This is an estuarine-dependent species that inhabits riverine, estuarine and coastal waters, and prefers muddy, sandy, or silty substrates (Reagan and Wingo 1985). Individuals can tolerate wide temperature (~5-35�C) and salinity ranges (0-60 ppt). Southern Flounder spawn in offshore waters of the Gulf of Mexico from October to February (Reagan and Wingo 1985). The oceanic larval stage is pelagic and lasts 30�60 days. Metamorphosing individuals enter estuaries and migrate towards low-salinity headwaters, where settlement occurs (Burke et al. 1991, Walsh et al. 1999). The young fish enter the bays during late winter and early spring, occupying seagrass; some may move further into coastal rivers and bayous. Juveniles remain in estuaries until the onset of sexual maturation (approximately two years), at which time they migrate out of estuaries to join adults on the inner continental shelf. Adult southern flounder leave the bays during the fall for spawning in the Gulf of Mexico. They spawn for the first time when two years old at depths of 50 to 100 feet. Although most of the adults leave the bays and enter the Gulf for spawning during the winter, some remain behind and spend winter in the bays. Those in the Gulf will reenter the bays in the spring. The spring influx is gradual and does not occur with large concentrations that characterize the fall emigration.
Agonostomus monticola	mountain mullet	Fish - Freshwater	Yes	Not Listed	Not Listed	G5	S2	No	Catadromous. Adults can be found great distances upstream. Potential to occur in all river systems in Texas from Rio Grande to Sabine River. Rheophilic, fast, strong swimmer often associated with swift currents and possibly near large boulders; found in abundance or at rest in deeper pools of stream below falls and rapids.
Ammocrypta clara	western sand darter	Fish - Freshwater	Yes	Not Listed	Not Listed	G3	S3	No	Neches, Sabine, and Red River basins. Associated with substrates of course sand and fine gravels in moderate current in medium to large streams. Habit of burrowing in sand may prevent direct observations.
Anguilla rostrata	american eel	Fish - Freshwater	Yes	Not Listed	Not Listed	G4	S4	No	Originally found in all river systems from the Red River to the Rio Grande. Aquatic habtiats include large rivers, streams, tributaries, coastal watersheds, estuaries, bays, and oceans. Spawns in Sargasso Sea, larva move to coastal waters, metamorphose, and begin upstream movements. Females tend to move further upstream than males (who are often found in brackish estuaries). American Eel are habitat generalists and may be found in a broad range of habitat conditions including slow- and fast-flowing waters over many substrate types. Extirpation in upstream drainages attributed to reservoirs that impede upstream migration.
Atractosteus spatula	alligator gar	Fish - Freshwater	Yes	Not Listed	Not Listed	G3G4	S4	No	From the Red River to the Rio Grande (Hubbs et al. 2008); occurs in the Trinity River upstream of Lake Livingston. Found in rivers, streams, lakes, swamps, bayous, bays and estuaries typically in pools and backwater habitats. Floodplains inundated with flood waters provide spawning and nursery habitats.
Campostoma ornatum	Mexican stoneroller	Fish - Freshwater	Yes	Not Listed	T 07/18/1977	G3G4	S1	No	Occurs primarily in Mexico and ranges into Texas in Rio Grande tributaries in Brewster and Presidio counties (Big Bend region; Hubbs 1940; Hubbs 1954; Hubbs et al. 1991). Occurs in riffles, chutes, and pools of rivers and creeks, in warm, clear (sometimes slightly turbid) water over sand, pebble, gravel, rock, and bedrock substrates, at depths of 10 cm to 1 meter; prefers headwaters.
Campostoma spadiceum	highland stoneroller	Fish - Freshwater	Yes	Not Listed	Not Listed	G4G5	SNR	No	Rare, restricted range in U.S; in Texas only found in Aiken Creek, a tributary of the Sulphur River. Bright red or red-orange coloration in median and paired fins. Found in small, stony-bottomed upland headwaters to small rivers with relatively clear water and substantial base flow and current velocities (Cashner et al. 2010).
Cycleptus elongatus	blue sucker	Fish - Freshwater	Yes	Not Listed	T 07/18/1977	G3G4	S3	No	Blue Sucker usually inhabit rapids, riffles, runs and pools with moderate to fast current, with bottoms of exposed bedrock sometimes in combination with hard clay, sand, gravel, and boulders; generally intolerant of highly turbid conditions. Adults winter in deep pools and move upstream in spring to spawn on riffles. Current distribution in Texas includes the Red River downstream of Lake Texoma, Sabine and Neches rivers, and Colorado River downstream of Austin, Texas. May occur in other river systems (Warren et al. 2000).
Cyprinella lepida	plateau shiner	Fish - Freshwater	Yes	Not Listed	T 03/30/2020	G1G2	S2?	Yes	Edwards Plateau portion of Nueces basin, mainstem and tributaries of Nueces, Frio, and Sabinal rivers; may also be endemic to upper reaches of the Guadalupe River; clear, cool, spring-fed headwater creeks; usually over gravel and limestone substrates.
Cyprinella proserpina	proserpine shiner	Fish - Freshwater	Yes	Not Listed	T 07/18/1977	G3	S2	No	Limited range includes Devils and lower Pecos rivers, Las Moras, Pinto, and San Felipe creeks, and Independence Creek in the Rio Grande watershed in western Texas. Associated with spring-fed tributaries and spring-runs. May be found in flowing pools, swift runs and riffles.
Cyprinodon bovinus	Leon Springs pupfish	Fish - Freshwater	Yes	E 09/15/1980	E 05/15/1975	G1	S1	Yes	Leon Creek, a tributary of the Pecos River (Pecos County); Diamond Y Spring. Natural spring-fed marshes, pools, and slow-flowing waters; usually near edges with minimal growth of vegetation.
Cyprinodon elegans	Comanche Springs pupfish	Fish - Freshwater	Yes	E 03/11/1967	E 05/19/1974	G1	S1	Yes	Restricted to small series of springs and their outflows, and man-made irrigation canals in the area of Balmorhea, Texas, including Phantom Springs (Jeff Davis County), San Solomon Springs, Giffin Springs and Toyah Creek (Reeves County). Native range: Comanche, Phantom Cave, San Solomon springs (Pecos and Reeves counties). Prefers fast-flowing water. Originally in Comanche Springs, San Solomon, and Phanton Cave, presently restricted to San Solomon and Phantom Cave and associated springs, and downstream irrigation canals; found in constantly discharging springs and in swift-flowing water of canals and earthen ditches
Cyprinodon eximius	Conchos pupfish	Fish - Freshwater	Yes	Not Listed	T 07/18/1977	G3G4	S1	No	Devils River and Alamito Creek. The Devils River and Alamito Creek populations are morphologically and biochemically distinct from the Rio Conchos (Mexico) populations. Shallow water (<25 cm) on bedrock shelves and in coves, sloughs, and backwaters over soft bottoms, all where current is negligible and bottom generally devoid of aquatic macrophytes.
Cyprinodon pecosensis	Pecos pupfish	Fish - Freshwater	Yes	PT 11/22/2024	T 03/01/1987	G2	S1	No	Originally Pecos River basin, presently restricted to upper basin only; shallow margins of clear, vegetated spring waters high in calcium carbonate, as well as in sinkhole habitats
Cyprinodon rubrofluviatilis	Red River pupfish	Fish - Freshwater	Yes	Not Listed	T 03/30/2020	G5	S2	No	Native to the upper Red River and Brazos River basins where it is typically found in saline waters of main channels and in saline springs. Introduced populations also exist in the Canadian River and Colorado River basins. River edges, channels, backwaters, over sand bottoms. Males establish spawning territories typically in shallowest waters up to 50 cm over sandy shoals and in small coves with little or no current.
Dionda argentosa	manantial roundnose minnow	Fish - Freshwater	Yes	Not Listed	Not Listed	G3	S2	Yes	Lower Pecos River, Devils River, San Felipe and Sycamore creeks. Val Verde County. Headwaters and runs of spring-influenced waters.
Dionda diaboli	Devils River minnow	Fish - Freshwater	Yes	T 11/19/1999	T 07/18/1977	G1	S1	No	Devils River, San Felipe and Sycamore creeks in Val Verde County; Las Moras (extirpated) and Pinto creeks in Kinney County. Restricted to clear, spring-fed waters having little temperature variation. Found over gravel-cobble substrate, usually associated with aquatic macrophytes.
Dionda episcopa	roundnose minnow	Fish - Freshwater	Yes	Not Listed	T 03/30/2020	G4	S1	No	Pecos River and Limpia Creek. Restricted to clear, spring-fed waters having little temperature variation.
Dionda flavipinnis	Guadalupe roundnose minnow	Fish - Freshwater	Yes	Not Listed	Not Listed	GNR	SNR	Yes	Endemic to Guadalupe and southern Colorado drainages; primarily restricted to clear spring-fed waters that have slight temperature variations.
Dionda nigrotaeniata	Medina roundnose minnow	Fish - Freshwater	Yes	Not Listed	T 03/30/2020	GNR	S1	Yes	Upper Medina River system; Primarily restricted to clear spring-fed waters that have slight temperature variations
Dionda serena	Frio roundnose minnow	Fish - Freshwater	Yes	Not Listed	T 03/30/2020	GNR	S2	Yes	Upper Nueces River system; Primarily restricted to clear spring-fed waters that have slight temperature variations
Dionda texensis	Nueces roundnose minnow	Fish - Freshwater	Yes	Not Listed	Not Listed	GNR	SNR	Yes	Endemic to the headwaters of the Nueces River; habitat unknown but likely similar to Devils River Minnow (Often found in association with spring outflows over gravel-cobble substrate and adjacent to aquatic macrophytes; may inhabit a microhabitat associated with the interface between spring runs and the river).
Erimyzon claviformis	western creek chubsucker	Fish - Freshwater	Yes	Not Listed	T 03/01/1987	G5	S2S3	No	Eastern Texas streams from the Red River to the San Jacinto drainage. Habitat includes silt-, sand-, and gravel-bottomed pools of clear headwaters, creeks, and small rivers; often near vegetation; occasionally in lakes. Spawning occurs in river mouths or pools, riffles, lake outlets, or upstream creeks. Prefers headwaters, but seldom occurs in springs.
Etheostoma fonticola	fountain darter	Fish - Freshwater	Yes	E 10/13/1970	E 05/19/1974	G1	S1	Yes	Known only from the spring-fed San Marcos and Comal rivers in dense beds of aquatic plants growing close to bottom; may be found in slow- and fast-flowing habitats.