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)
Phreatodrobia imitata	mimic cavesnail	Invertebrates	Yes	Not Listed	Not Listed	G1	S1	Yes	Subaquatic; only known from two wells penetrating the Edwards Aquifer
Phreatodrobia micra	No accepted common name	Invertebrates	Yes	Not Listed	Not Listed	G2G3	S2	Yes	Habitat description is not available at this time.
Phreatodrobia plana	No accepted common name	Invertebrates	Yes	Not Listed	Not Listed	G2	S2	Yes	Habitat description is not available at this time.
Phreatodrobia punctata	No accepted common name	Invertebrates	Yes	Not Listed	Not Listed	G2	S1	Yes	Habitat description is not available at this time.
Phreatodrobia rotunda	No accepted common name	Invertebrates	Yes	Not Listed	Not Listed	G1G2	S2	Yes	Habitat description is not available at this time.
Phylocentropus harrisi	No accepted common name	Invertebrates	Yes	Not Listed	Not Listed	G1G2	S1	No	Lotic systems, but specifics unknown
Piruna haferniki	Chisos skipperling	Invertebrates	Yes	Not Listed	Not Listed	G2G3	S1?	No	Open oak/pine woodland, thorn scrub below oak zone, nectarivore/herbivore, adults in genus nectar and drink from damp soil; larva of subfamily feed on grasses or sedges, some very specialized, caterpillars of other Piruna eat leaves of broad-leaved grasses, including grama grass Bouteloua; diurnal, hibernates/aestivates; adults fly from March to possibly October
Plauditus texanus	No accepted common name	Invertebrates	Yes	Not Listed	Not Listed	G2G3	S1?	No	Larvae are associated with small to medium limestone cobble and macrophytes in shallow riffles of clear, cool, alkaline streams (P. McCafferty, personal communication, December 2003).
Pleurobema riddellii	Louisiana pigtoe	Invertebrates	Yes	PT 03/20/2023	T 01/17/2010	G1G2	S1	No	Occurs in small streams to large rivers in slow to moderate currents in substrates of clay, mud, sand, and gravel. Not known from impoundments (Howells 2010f; Randklev et al. 2013b; Troia et al. 2015). [Mussels of Texas 2019]
Pogonomyrmex comanche	Comanche harvester ant	Invertebrates	Yes	Not Listed	Not Listed	G2G3	S2	Yes	Habitat description is not available at this time.
Polyphylla monahansensis	Monahans lined june beetle	Invertebrates	Yes	Not Listed	Not Listed	GNR	S2	No	Habitat description is not available at this time.
Polyphylla pottsorum	No accepted common name	Invertebrates	Yes	Not Listed	Not Listed	GNR	S1	Not Evaluated	Habitat description is not available at this time.
Popenaias popeii	Texas hornshell	Invertebrates	Yes	E 03/12/2018	E 03/30/2020	G1	S1	No	Occurs in small streams to large rivers in slow to moderate current, often residing in rock crevices, travertine shelves, and under large boulders, where small-grained material, such as clay, silt, or sand gathers. Can also occur in riffles that are clean swept of soft silt; not known from reservoirs (Carman 2007; Inoue et al. 2014; Randklev et al. 2017b; Randklev et al. forthcoming). [Mussels of Texas 2019]
Potamilus amphichaenus	Texas heelsplitter	Invertebrates	Yes	PE 03/20/2023	T 01/17/2010	G1G3	S1	No	Occurs in small streams to large rivers in standing to slow-flowing water; most common in banks, backwaters and quiet pools; adapts to some reservoirs. Often found in soft substrates such as mud, silt or sand (Howells et al. 1996; Randklev et al. 2017a). [Mussels of Texas 2019]
Potamilus metnecktayi	Salina mucket	Invertebrates	Yes	Not Listed	T 01/17/2010	G1	S1	No	Occurs in medium to large rivers, where it may be found in substrates composed of various combinations of mud, sand, gravel, and cobble, as well as under rocks. It occurs in areas with slow to moderate current, most often in stable littoral habitats dominated by boulder or bedrock habitat; not known from reservoirs (Randklev et al. 2017b; Randklev et al. forthcoming). [Mussels of Texas 2019]
Potamilus streckersoni	Brazos heelsplitter	Invertebrates	Yes	Not Listed	T 03/27/2020	GNR	SNR	Yes	Reported from streams, but not far into the headwaters, to large rivers, and some reservoirs. In riverine systems occurs most often in nearshore habitats such as banks and backwater pools but occasionally in mainchannel habitats such as riffles. Typically found in standing to slow-flowing water in soft substrates consisting of silt, mud or sand but occasionally in moderate flows with gravel and cobble substrates (Randklev et al. 2014b,c; Tsakiris and Randklev 2016b; Smith et al. 2019) [Mussels of Texas 2020]
Praticolella candida	No accepted common name	Invertebrates	Yes	Not Listed	Not Listed	G2	S3	Yes	Habitat description is not available at this time.
Praticolella trimatris	No accepted common name	Invertebrates	Yes	Not Listed	Not Listed	G2	S3	Yes	Habitat description is not available at this time.
Procambarus brazoriensis	Brazoria crayfish	Invertebrates	Yes	Not Listed	Not Listed	G1	S1	Yes	The species is found in roadside ditches. In droughts, animals may burrow into substrate. The type locality is described as a ditch beside a road. The ditch was 100 m long and one metre wide which commonly contains water up to 0.3 m deep although does dry completely when there is no rain (Albaugh, 1975).
Procambarus nechesae	Neches crayfish	Invertebrates	Yes	Not Listed	Not Listed	G2	S1S2	Yes	Simple burrows in temporary or semi permanent pools in roadside ditches
Procambarus nigrocinctus	blackbelted crayfish	Invertebrates	Yes	Not Listed	Not Listed	G1G2	S1	Yes	It occurs in moderately flowing small creeks. Found among rocks and accumulated debris.
Procambarus nueces	Nueces crayfish	Invertebrates	Yes	Not Listed	Not Listed	G1	S1	Yes	Known only from one small sluggish stream tributary to the Nueces River; slightly sinuous channel with natural debris impeding flow; substrate of sand and gravel, also silt covered in deeper pooled areas; riparian edges of grasses, sedges, and herbaceous plants in mostly unshaded area
Procambarus regalis	regal burrowing crayfish	Invertebrates	Yes	Not Listed	Not Listed	G2G3	SNR	Not Evaluated	It is a burrower usually found near or within stre stands of prairie lands, but in some places, burrows completely cover fields. Burrow areas may be far from places where rain would regularly produce pools of temporary water and tunnel depth may exceed 6 feet. Excavation around the hole is more often seen as a plume or low hill than a chimney (Johnson and Johnson, 2008).
Procambarus steigmani	Parkhill Prairie crayfish	Invertebrates	Yes	Not Listed	Not Listed	G1G2	S1S2	Yes	Burrower in long-grass prairie; all animals were collected with traps, thus there is no knowledge of depths of burrows; herbivore; crepuscular, nocturnal
Procambarus texanus	Bastrop crayfish	Invertebrates	Yes	Not Listed	Not Listed	G1	S1	Yes	Ponds