Description:Necturus beyeri is a neotenic species of aquatic salamander with adults reaching a standard length of up to 184.0 mm in males and 177.0mm in females. Average male snout-vent length is 134.2 mm and average female snout-vent length is 120.8 mm. Males reach sizes that average 13 mm longer in standard length than females. Maximum tail length in males is 68 mm and in females is 66 mm. The body is near cylindrical. This species is identified as a member of the family Proteidae by retention of external gills in adults, and the presence of four robust limbs with four toes on the hind limbs. Typically, seventeen costal grooves are present (range of 16 to 18). Reproductive males can be distinguished from adult females by the presence of a swollen cloaca, a cloacal lining of finger-like projections, and a spur-like tip on each side of the posterior end of the cloacal opening. Tails of both sexes are laterally compressed.

Habitat: This species lives in streams with sandy bottoms. It remains on the substrate or burrows into it, sometimes hiding in debris. Gulf Coast Waterdogs occur in slow-moving streams where they may occupy undercut banks, overhanging stumps, sunken logs, rocks, or accumulated piles of submerged leaf litter

Range: Recent molecular analysis has partitioned N. beyeri into four lineages that range in the Gulf Coast Plain of the United States from Alabama to Texas. The Mobile lineage is restricted to the Mobile and Biloxi drainages in Alabama and Mississippi, respectively. The Pearl lineage is restricted to the Wolf and Pearl drainages in Mississippi and Louisiana, respectively. The Pontchartrain lineage is found in the Bayou Bonfouca to the Blind River, Louisiana. Lastly, the Western lineage can be found from the Calcasieu drainage in Louisiana, to the West Fork of the San Jacinto River in Texas. The type locality for the species is the Upper Calcasieu River at Oakdale, Allen Parish, Louisiana.

Found in these States: AL | LA | MS | TX

Diet: Larvae and adults eat isopods, midges, may?ies, and caddisflies.

Reproduction: Adult Gulf Coast Waterdogs are most likely to be detected in winter months (November to January), when mating occurs. Fertilization occurs via transfer of a spermatophore deposited by a male to a female who picks it up with her cloacal lips. Fertilized eggs are retained within a female's uterus until the clutch is deposited in April or May. Nest sites are found under rocks, logs or other sunken objects where 26 to 37 eggs are laid, and the female attends the clutch. Hatching occurs about two months after oviposition. After hatching, larvae can be sampled from leaf packs, eventually reaching adult size in 4 to 6 years.

Status: Listed as Least Concern in view of its wide distribution and presumed large population.

Taxonomy: This may be a species complex that could be split into different taxa as research indicates; the Apalachicola (N. moleri) and Escambia (N. mounti) waterdogs were split from this species in 2020; previously, they were all grouped together as the Gulf Coast waterdog.