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)
Rhadine speca gentilis	No accepted common name	Invertebrates	Yes	Not Listed	Not Listed	G2T1	S1	Not Evaluated	Habitat description is not available at this time.
Rhadine speca speca	No accepted common name	Invertebrates	Yes	Not Listed	Not Listed	G2T1	S1	Not Evaluated	Habitat description is not available at this time.
Rhadine subterranea	No accepted common name	Invertebrates	Yes	Not Listed	Not Listed	G2	S2	Yes	Habitat description is not available at this time.
Rhadine tenebrosa	No accepted common name	Invertebrates	Yes	Not Listed	Not Listed	G1G2	S1S2	Yes	Habitat description is not available at this time.
Sagittunio subrostratus	pondmussel	Invertebrates	Yes	Not Listed	Not Listed	G5	S4	No	Reported from streams to rivers, where it can invade headwater systems but is rarely in large river systems. Can also inhabit natural and artificial ponds, lakes, reservoirs, and canals. In riverine habitat typically occurs in backwaters, pools, sloughs, and oxbows in little to no current in substrates of mud or sand (Parmalee and Bogan 1998; Williams et al. 2008; Watters et al. 2009; Haag and Cicerello 2016; Watters 2018).
Salimuzzamania howdeni	No accepted common name	Invertebrates	Yes	Not Listed	Not Listed	GNR	S1	Yes	Habitat description is not available at this time.
Satyrium polingi	Poling's hairstreak	Invertebrates	Yes	Not Listed	Not Listed	G3	S1	No	Oak woodland with Quercus grisea as substantial component, probably also uses Q. emoryi; larvae feed on new growth of Q. grisea, adults utilize nectar from a variety of flowers including milkweed and catslaw acacia; adults fly mid May - Jun, again mid Aug - early Sept
Schistocerca camerata	No accepted common name	Invertebrates	Yes	Not Listed	Not Listed	GNR	S1	Not Evaluated	Habitat description is not available at this time.
Seborgia hershleri	No accepted common name	Invertebrates	Yes	Not Listed	Not Listed	G1G2	S2	Yes	Habitat description is not available at this time.
Somatochlora margarita	Texas emerald dragonfly	Invertebrates	Yes	Not Listed	Not Listed	G2G3	S2	No	East Texas pineywoods; springfed creeks and bogs; small sandy forested streams with moderate current
Sonorella huecoensis	Huecos Mountains talus snail	Invertebrates	Yes	Not Listed	Not Listed	G1G2	S1	Yes	Habitat description is not available at this time.
Sonorella metcalfi	Franklin Mountain talus snail	Invertebrates	Yes	Not Listed	Not Listed	G2	S2	No	Terrestrial; bare rock, talus, scree; inhabits igneous talus most commonly of rhyolitic origin
Sparbarus coushatta	No accepted common name	Invertebrates	Yes	Not Listed	Not Listed	G1G2	SNR	Not Evaluated	Habitat description is not available at this time.
Spectralia prosternalis	No accepted common name	Invertebrates	Yes	Not Listed	Not Listed	GNR	S2	Yes	Habitat description is not available at this time.
Speocirolana hardeni	No accepted common name	Invertebrates	Yes	Not Listed	Not Listed	G2G3	S2	No	Habitat description is not available at this time.
Speodesmus falcatus	sickled cave millipede	Invertebrates	Yes	Not Listed	Not Listed	GNR	S1	Yes	Habitat description is not available at this time.
Speodesmus ivyi	Ivy's cave millipede	Invertebrates	Yes	Not Listed	Not Listed	GNR	S2	Yes	Habitat description is not available at this time.
Speodesmus reddelli	Reddell's cave millipede	Invertebrates	Yes	Not Listed	Not Listed	GNR	S2	Yes	Habitat description is not available at this time.
Sphalloplana mohri	No accepted common name	Invertebrates	Yes	Not Listed	Not Listed	G3G4	S3	Yes	Habitat description is not available at this time.
Sphingicampa blanchardi	No accepted common name	Invertebrates	Yes	Not Listed	Not Listed	G1	S1	Probable	Woodland - hardwood; Tamaulipan thornscrub with caterpillars host plant, Texas Ebony (Pitheocellobium flexicaule) an important element
Stallingsia maculosus	Manfreda giant-skipper	Invertebrates	Yes	Not Listed	Not Listed	G1	S1	No	Most skippers are small and stout-bodied; name derives from fast, erratic flight; at rest most skippers hold front and hind wings at different angles; skipper larvae are smooth, with the head and neck constricted; skipper larvae usually feed inside a leaf shelter and pupate in a cocoon made of leaves fastened together with silk
Streptocephalus mattoxi	crenatethumb fairy shrimp	Invertebrates	Yes	Not Listed	Not Listed	G1	S1	Yes	Occurs in turbid, warm water temporary playas.
Strophitus undulatus	creeper	Invertebrates	Yes	Not Listed	Not Listed	G5	S1	No	Reported from headwater streams to large rivers, though may be rare in these systems, occasionally in lakes and canals. In riverine habitats can be found in riffles or areas with less current such as banks, backwaters or pools. Can occur in a variety of substrates including mud, sand, gravel, and may also be found wedged in cracks in bedrock slabs or among macrophyte beds (Parmalee and Bogan 1998; Williams et al. 2008; Watters et al. 2009; Haag and Cicerello 2016).
Stygobromus alabamensis	No accepted common name	Invertebrates	Yes	Not Listed	Not Listed	G5	S1	No	Habitat description is not available at this time.
Stygobromus balconis	Balcones Cave amphipod	Invertebrates	Yes	Not Listed	Not Listed	G2G3	S2	Yes	Subaquatic, subterranean obligate amphipod