Aquatic. Large. Color gray to reddish with dark blotches. Dark stripe through eye. Four limbs with four toes each. External gills large and reddish. 
Species: N. beyeri (Western Waterdog), N. louisianensis (Red River Mudpuppy), and N. maculosus (Common Mudpuppy)
Arkansas Herpetological Atlas 2019
This species complex is represented by 181 records from 19 sources: 148 museum (
), 0 literature (
), 0 research (
), and 6 observation (
), with 27 additional Trauth et al. (2004) locality points remaining unsourced (
). It has been museum vouchered for 39 of 75 counties (), with 11 additional counties having other forms of reported occurrence (). Years of collection range from 1855 to 2017.
This species complex inhabits perennial rivers, streams, and lakes throughout the state. Records from the University of Arkansas at Monticello, Drew County (ASUMZ 3412-3413 from 1978), are likely transplanted individuals associated with fish stocking. A questionable record attributed to Jonesboro, Craighead County (NCSM 60307 from 1974), is likely in reference to the institution source rather than collection site. A record from the Ouachita Mountains in Polk County (HSU 1559 from 2010) requires further clarification. A number of localities plotted by Trauth et al. (2004) remain unsourced. While the Necturus phylogeography is poorly resolved, what is currently ascribed as N. beyeri (■) may occupy the Red River watershed in southwest Arkansas and possibly the Mississippi River (Dixon, 2013; Powell et al., 2016), with a number of existing museum specimens potentially in warrant of reexamination (UAFMC 0068-0735-1066 from 1953, ASUMZ 29009 from 2005, MPM 13959 from 1970, and NLU 39120 from 1973).
