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)
Fallicambarus houstonensis	Houston burrowing crayfish	Invertebrates	Yes	Not Listed	Not Listed	G2	S3	Not Evaluated	All species in the genus <i>Fallicambarus </i>are primary burrowers (Guiasu, 2007). It is clearly a primary burrower with 100% of adult and subadult specimens known from excavated burrows. Large numbers of juveniles were collected from Temporary pools (October through February) (Johnson, 2008).
Fallicambarus kountzeae	Big Thicket burrowing crayfish	Invertebrates	Yes	Not Listed	Not Listed	G2	S3	Not Evaluated	All species in the genus Fallicambarus are primary burrowers (Guiasu, 2007). It is a primary burrower with 100% of known adults and subadults collected from burrows. Small juveniles are common in open water during the cool season (Johnson, 2008).
Farrodes mexicanus	No accepted common name	Invertebrates	Yes	Not Listed	Not Listed	G1G2	SNR	Not Evaluated	In Big Bend National Park, larvae were found in small, permanently flowing, spring-fed creeks clinging to the underside of small stones and rocks in regions of the stream with little flow (Baumgardner and Bowles, 2005).
Faxonella blairi	No accepted common name	Invertebrates	Yes	Not Listed	Not Listed	G4G5	SNR	Not Evaluated	Temporary pools and roadside ditches in woodland habitats. In wet seasons they emerge from chimneyless burrows of 0.7 to 1.2 feet deep to live in shallow sloughs, swamps, ditches and overflow pools (Johnson and Johnson, 2008).
Fusconaia askewi	Texas pigtoe	Invertebrates	Yes	Not Listed	T 01/17/2010	G2?	S2S3	No	Occurs in small streams to large rivers, usually in water with at least some current; not known from reservoirs. Found in a variety of habitats but most common in riffles. Inhabits various substrates though most often sand, gravel, and cobble (Howells 2010a; Randklev et al. 2013b; Randklev et al. 2014a; Troia et al 2015).[Mussel of Texas 2019]
Fusconaia chunii	Trinity pigtoe	Invertebrates	Yes	Not Listed	T 03/30/2020	GNR	S1	Yes	Found in a variety of habitats but most common in riffles. Inhabits various substrates though most often sand, gravel, and cobble (species was recently split from Texas Pigtoe and occurs in similar habitats; Howells 2010a; Randklev et al. 2013b; Randklev et al. 2014a; Troia et al 2015). [Mussels of Texas 2020]
Fusconaia iheringi	Balcones spike	Invertebrates	Yes	E 07/05/2024	E 07/05/2024	G1	SNR	Yes	Habitat not yet described.
Fusconaia mitchelli	false spike	Invertebrates	Yes	E 07/05/2024	E 07/05/2024	G1	S1	No	Occurs in small streams to medium-size rivers in habitats such as riffles and runs with flowing water. Is often found in stable substrates of sand, gravel, and cobble (Howells 2010; Randklev et al. 2012; Sowards et al. 2013; Tsakiris and Randklev 2016). [Mussels of Texas 2019]
Gammarus hyalelloides	diminutive amphipod	Invertebrates	Yes	E 08/08/2013	E 03/23/2015	G1	S1	Yes	Known only from Phantom Lake Spring; omnivorous; amphipods are active mostly at night and spend daylight hours hiding under vegetation and other cover; vulnerable to reduction of springflow resulting from declining levels of groundwater
Gammarus pecos	Pecos amphipod	Invertebrates	Yes	E 08/08/2013	E 03/23/2015	G1	S1	Yes	Omnivorous; amphipods are active mostly at night and spend daylight hours hiding under vegetation and other cover; vulnerable to reduction of springflow resulting from declining levels of groundwater
Gomphus gonzalezi	Tamaulipan clubtail dragonfly	Invertebrates	Yes	Not Listed	Not Listed	G2	S2	Not Evaluated	Rivers, muddy to clear and rocky, should be watched for in substantial creeks as well. This species is considered rare and has a very restricted range in the Rio Grande Valley and southward in eastern Mexico. Abundance information is lacking (Ware et al 2016; Abbott 2005).
Haideoporus texanus	Edwards Aquifer diving beetle	Invertebrates	Yes	Not Listed	Not Listed	G1G2	S1	Yes	Habitat poorly known; known from an artesian well in Hays County
Heliastus subroseus	No accepted common name	Invertebrates	Yes	Not Listed	Not Listed	G2G3	S2?	Yes	Sand dunes with sparse vegeatation in back of the beach along the Texas coast.
Hemileuca chinatiensis	Chinati sheepmoth	Invertebrates	Yes	Not Listed	Not Listed	G3	S1S3	Not Evaluated	Habitat description is not available at this time.
Hesperia ottoe	Ottoe skipper	Invertebrates	Yes	Not Listed	Not Listed	G3	SNR	Not Evaluated	Habitat description is not available at this time.
Heterelmis comalensis	Comal Springs riffle beetle	Invertebrates	Yes	E 01/20/1998	E 04/27/2012	G1	S1	Not Evaluated	Comal and San Marcos Springs
Heterobrenthus texanus	No accepted common name	Invertebrates	Yes	Not Listed	Not Listed	GNR	S1	Not Evaluated	Habitat description is not available at this time.
Holospira hamiltoni	Hamilton holospira	Invertebrates	Yes	Not Listed	Not Listed	G1	S1	Not Evaluated	Habitat description is not available at this time.
Holospira mesolia	No accepted common name	Invertebrates	Yes	Not Listed	Not Listed	G1	S2	Not Evaluated	Habitat description is not available at this time.
Holospira riograndensis	Rio Grand holospira	Invertebrates	Yes	Not Listed	Not Listed	G1	S1	Not Evaluated	Habitat description is not available at this time.
Holospira yucatanensis	Bartsch holospira	Invertebrates	Yes	Not Listed	Not Listed	G1	S1	Not Evaluated	Habitat description is not available at this time.
Humboldtiana cheatumi	Davis Mountains threeband	Invertebrates	Yes	Not Listed	Not Listed	G2	S2	Not Evaluated	Terrestrial snail; deciduous leaf litter in cool, moist upper reaches of canyons in the Davis Mountains
Humboldtiana ferrissiana	Mitre Peak threeband	Invertebrates	Yes	Not Listed	Not Listed	G2	S1	Not Evaluated	Terrestrial snail; higher elevations of the Davis Mts., in leaf litter, under rocks
Humboldtiana fullingtoni	Capote threeband	Invertebrates	Yes	Not Listed	Not Listed	G1	SU	Not Evaluated	Habitat description is not available at this time.
Humboldtiana hoegiana praesidii	San Carlos Threeband	Invertebrates	Yes	Not Listed	Not Listed	G3T3	S3	Not Evaluated	Habitat description is not available at this time.