Although the main focus of the Texas hornshell CCA/CCAA is protecting the federally endangered Texas hornshell mussel, the program also covers four other species. These species are referred to as the Other Covered Species through-out the program. The Other Covered Species include the Rio Grande River Cooter (Pseudemys gorzugi), Gray Redhorse (Moxostoma congestum), Blue Sucker (Cycleptus elongatus), and Pecos Springsnail (Pyrgulopsis pecosensis).
The Rio Grande River Cooter (Pseudemys gorzugi), also known as the Western River Cooter in New Mexico, is a large turtle with yellow-green stripes on the head and neck, and red, yellow, and black markings on the legs. Females average 195.3 mm and males average 152.3 mm in carapace length (Degenhardt et al. 2005). This species is rather sedentary, with maximum movements of only 300 meters (Degenhardt et al. 2005). The Rio Grande River Cooter occurs in large, deep pools of rivers, and is found in the Black, Delaware, and Pecos rivers in New Mexico and Texas (Degenhardt et al. 2005).
The Rio Grande River Cooter (Figure 2) is currently listed as “threatened” by the NMDGF, and the Center of Biological Diversity petitioned the FWS in 2012 to consider this species for protection under the ESA (NMDGF 2014). It is also a Bureau of Land Management (BLM) sensitive species as listed in BLM Manual 6840 (BLM 2008). Threats to the species include recreation (such as hunting and fishing), predation, wildfires, and runoff pollution (NMDGF 2014).
The Gray Redhorse (Moxostoma congestum) (Figure 3) is a host fish for Texas Hornshell glochidia (Levine et al. 2012). Historically, the Gray Redhorse ranged from central and west Texas and northwestern Mexico to the Pecos River and Rio Grande in southern New Mexico and Texas (NMDGF 2014). In New Mexico, the Gray Redhorse historically occupied the Rio Grande downstream of Socorro and the Pecos and Black rivers from Roswell south to the Texas border (NMDGF 2014).
Due to Golden Algae (Pyrmnesium parvum) blooms, in New Mexico, the Gray Redhorse currently only exists in the lower Black River from Blue Springs to the Pecos River confluence (NMDGF 2014). In conjunction with the BLM, the Gray Redhorse has been reintroduced into the Delaware River by NMDGF. NMDGF and BLM field surveys conducted in 2016 on the Delaware River revealed initial successful reproduction by the species (BLM 2013; Tim Frey BLM pers. com.). Further augmentation of the Gray Redhorse may continue when deemed essential to the species persistence. The Gray Redhorse was listed as “threatened” by the NMDGF in 1976 and then as “endangered” in 2008. It is also a BLM sensitive species as listed in BLM Manual 6840 (BLM 2008). Threats to the species include range fragmentation, contamination of surface waters, modified flow regimes, and Golden Algae blooms (NMDGF 2014). Depletion of surface waters is a major cause of decline of the Gray Redhorse (Bean et al. 2009; Hoagstrom 2001).
The Blue Sucker (Cycleptus elongatus) is a host fish for Texas Hornshell glochidia (Levine et al. 2012). Historically, the Blue Sucker occupied the Pecos River north of Carlsbad downstream to the New Mexico/Texas border and the lower Black River (NMDGF 2014). The Blue Sucker has declined throughout much of its native range. It has further declined since 2002 in the Pecos River, in part due to the effects from Golden Algae blooms, from Brantley Reservoir downstream (NMDGF 2014).
It is likely extirpated from the Pecos River and the status of the population in the Black River is unknown (NMDGF 2014). The Blue Sucker (Figure 4) was listed as “endangered” by the NMDGF in 1976 (NMDGF 2014). It is also a BLM sensitive species as listed in BLM Manual 6840 (BLM 2008). Threats to the species include range fragmentation by dams, water contamination, Golden Algae blooms, and water quality changes in the Black River drainage (NMDGF 2014).
Springsnails are tiny mollusks with conical shaped shells that range in color from gray to light brown. The Pecos Springsnail (Pyrgulopsis pecosensis) (Figure 5), which has been listed as a state “threatened” species by the NMDGF since 1983, historically occupied only Blue Springs and Castle Springs associated with the Black River in Eddy County, New Mexico. The species has since been extirpated from Castle Springs (NMDGF 2014).
Threats to the Pecos Springsnail include water diversion, drought, underground pumping of water, pollution from oil and gas exploration and production, and poor range management (NMDGF 1996).
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