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)
Texella brevidenta	No accepted common name	Invertebrates	Yes	Not Listed	Not Listed	G1G2	S1	Yes	Habitat description is not available at this time.
Texella brevistyla	No accepted common name	Invertebrates	Yes	Not Listed	Not Listed	G1G2	S1	Yes	Habitat description is not available at this time.
Texella cokendolpheri	Cokendolpher cave harvestman	Invertebrates	Yes	E 12/26/2000	Not Listed	G1	S1	Yes	Small, eyeless harvestman; karst features in north and northwest Bexar County
Texella diplospina	No accepted common name	Invertebrates	Yes	Not Listed	Not Listed	G1G2	S1	Yes	Habitat description is not available at this time.
Texella fendi	No accepted common name	Invertebrates	Yes	Not Listed	Not Listed	G1G2	S1S2	Yes	Habitat description is not available at this time.
Texella grubbsi	No accepted common name	Invertebrates	Yes	Not Listed	Not Listed	G1G2	S1	Yes	Habitat description is not available at this time.
Texella hardeni	No accepted common name	Invertebrates	Yes	Not Listed	Not Listed	G1G2	S2	Yes	Habitat description is not available at this time.
Texella mulaiki	No accepted common name	Invertebrates	Yes	Not Listed	Not Listed	G2G3	S1	Yes	Habitat description is not available at this time.
Texella reddelli	Reddell harvestman	Invertebrates	Yes	E 09/16/1988	Not Listed	G2G3	S2	Yes	Small, blind, cave-adapted harvestman endemic to a few caves in Travis and Williamson counties
Texella renkesae	No accepted common name	Invertebrates	Yes	Not Listed	Not Listed	G1G2	S1	Yes	Habitat description is not available at this time.
Texella reyesi	Bone Cave harvestman	Invertebrates	Yes	E 09/16/1988	Not Listed	G2G3	S2	Yes	Small, blind, cave-adapted harvestman endemic to several caves in Travis and Williamson counties; weakly differentiated from Texella reddelli
Texiweckelia texensis	No accepted common name	Invertebrates	Yes	Not Listed	Not Listed	G2G3	S2	Yes	Habitat description is not available at this time.
Texiweckeliopsis insolita	No accepted common name	Invertebrates	Yes	Not Listed	Not Listed	G3	S2	Yes	Habitat description is not available at this time.
Tortopus circumfluus	No accepted common name	Invertebrates	Yes	Not Listed	Not Listed	G1G3	S2?	Yes	Mayflies distinguished by aquatic larval stage; adult stage generally found in shoreline vegetation
Toxolasma parvum	lilliput	Invertebrates	Yes	Not Listed	Not Listed	G5	S3	No	Reported from small streams, where it may penetrate into the headwaters, to large rivers, oxbows, sloughs, lakes, ponds, canals, borrow pits, and reservoirs. Primarily occurs in still to slow currents in mud and sand substrates (Coker et al. 1921; Read 1954; Neck and Metcalf 1988; Williams et al. 2008; Watters et al. 2009).
Trichodesma pulchella	No accepted common name	Invertebrates	Yes	Not Listed	Not Listed	GNR	S1	Not Evaluated	Habitat description is not available at this time.
Tricorythodes curvatus	No accepted common name	Invertebrates	Yes	Not Listed	Not Listed	G1G3	S2?	No	AR, OK, TX; mayflies distinguished by aquatic larval stage; adult stage generally found in bankside vegetation
Trigonogya reticulaticollis	No accepted common name	Invertebrates	Yes	Not Listed	Not Listed	GNR	S1	Yes	Habitat description is not available at this time.
Trigonoscutoides texanus	No accepted common name	Invertebrates	Yes	Not Listed	Not Listed	GNR	S2	Yes	This species is associated with early seral sand dune habitats found in the Permian Basin
Tritogonia nobilis	Gulf mapleleaf	Invertebrates	Yes	Not Listed	Not Listed	G4	SU	No	Reported from streams to rivers, lakes, and reservoirs. In riverine habitats it is often found in nearshore, backwaters, or riffles in still to moderate currents in mud, sand, gravel, or cobble substrates (Howells et al. 1996; Williams et al. 2008).
Tritogonia verrucosa	pistolgrip	Invertebrates	Yes	Not Listed	Not Listed	G4G5	S3S4	No	Reported from streams to rivers, lakes, and reservoirs, but considered less tolerant of impoundment (Haag and Cicerello 2016). Can occur in a variety of habitat types but most often found in main channel habitats such as riffles and runs with moderate current and sand, gravel, or cobble substrates (Howells et al. 1996; Williams et al. 2008).
Truncilla cognata	Mexican fawnsfoot	Invertebrates	Yes	PE 07/25/2023	T 01/17/2010	G1	S1	No	Occurs in large rivers but may also be found in medium-sized streams. Is commonly found in habitats with some flowing water, often in protected near shore areas such as banks and backwaters but also at the head of riffles; the latter more often supporting both sub-adults and adults. Typically occurs in substrates of mixed sand and gravel as well as soft unconsolidated sediments. Considered intolerant of reservoirs (Randklev et al. 2017b; Randklev et al. forthcoming). [Mussels of Texas 2019]
Truncilla donaciformis	fawnsfoot	Invertebrates	Yes	Not Listed	Not Listed	G5	S2	No	Reported from streams, rivers, lakes, and reservoirs. In riverine habitats occurs in mainchannel habitats such as riffles or runs with moderate to swift current and in areas with no current such as banks and backwaters. Found in firm mud, sand, gravel, and cobble substrates. Juveniles are often found attached to rocks and other hard surfaces by byssal threads, which are retained into adulthood (Haag 2012). May spend much of their lives well-buried in substrate (Parmalee and Bogan 1998; Williams et al. 2008).
Truncilla macrodon	Texas fawnsfoot	Invertebrates	Yes	T 07/05/2024	T 01/17/2010	G1	S2	Yes	Occurs in large rivers but may also be found in medium-sized streams. Is found in protected near shore areas such as banks and backwaters but also riffles and point bar habitats with low to moderate water velocities. Typically occurs in substrates of mud, sandy mud, gravel and cobble. Considered intolerant of reservoirs (Randklev et al. 2010; Howells 2010o; Randklev et al. 2014b,c; Randklev et al. 2017a,b). [Mussels of Texas 2019]
Truncilla truncata	deertoe	Invertebrates	Yes	Not Listed	Not Listed	G5	S3	No	Reported from streams, rivers, lakes, and reservoirs. In riverine habitats primarily occurs in mainchannel habitats such as riffles or runs with moderate to swift current but may occasionally occur in areas with no current. Typically found in sand, gravel, cobble substrates, but sometimes may occur in firm mud or in crevices among large rocks and boulders (Parmalee and Bogan 1998; Williams et al. 2008).