The western waterdog (''Necturus beyeri'') is a

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

of aquatic

salamander Salamanders are a group of amphibians typically characterized by their lizard-like appearance, with slender bodies, blunt snouts, short limbs projecting at right angles to the body, and the presence of a tail in both larvae and adults. All t ...

in the family

Proteidae The family Proteidae is a group of aquatic salamanders found today in the Balkan Peninsula and North America. The range of the genus ''Necturus'' (commonly known as waterdogs or mudpuppies) runs from southern central Canada, through the midwe ...

. It is

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found else ...

to the southeastern

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territori ...

, where it occurs in

Alabama (We dare defend our rights) , anthem = "Alabama" , image_map = Alabama in United States.svg , seat = Montgomery , LargestCity = Huntsville , LargestCounty = Baldwin County , LargestMetro = Greater Birmingham , area_total_km2 = 135,765 ...

Louisiana Louisiana , group=pronunciation (French: ''La Louisiane'') is a state in the Deep South and South Central regions of the United States. It is the 20th-smallest by area and the 25th most populous of the 50 U.S. states. Louisiana is borde ...

Mississippi Mississippi () is a state in the Southeastern region of the United States, bordered to the north by Tennessee; to the east by Alabama; to the south by the Gulf of Mexico; to the southwest by Louisiana; and to the northwest by Arkansas. Miss ...

, and

Texas Texas (, ; Spanish: ''Texas'', ''Tejas'') is a state in the South Central region of the United States. At 268,596 square miles (695,662 km2), and with more than 29.1 million residents in 2020, it is the second-largest U.S. state by ...

Taxonomy

This may be a

species complex In biology, a species complex is a group of closely related organisms that are so similar in appearance and other features that the boundaries between them are often unclear. The taxa in the complex may be able to hybridize readily with each oth ...

that could be split into different taxa as research indicates;NatureServe. 2015
''Necturus beyeri''.
NatureServe Explorer Version 7.1. Retrieved 25 June 2016. 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. It is closely related to '' Necturus alabamensis''.IUCN SSC Amphibian Specialist Group. 2014
''Necturus beyeri''.
The IUCN Red List of Threatened Species 2014. Retrieved 25 June 2016. Studies indicate that as currently defined, it comprises four lineages: the "Mobile" lineage (ranging from the Mobile River to the Biloxi River), the "Pearl" lineage (ranging from the Wolf River to the

Pearl River The Pearl River, also known by its Chinese name Zhujiang or Zhu Jiang in Mandarin pinyin or Chu Kiang and formerly often known as the , is an extensive river system in southern China. The name "Pearl River" is also often used as a catch-a ...

), the "Pontchartrain" lineage (ranging from the Bayou Bonfouca in

to the Blind River), and the "Western" lineage (ranging from the

Calcasieu River The Calcasieu River ( ; french: Rivière Calcasieu) is a river on the Gulf Coast in southwestern Louisiana. Approximately long,U.S. Geological Survey. National Hydrography Dataset high-resolution flowline dataThe National Map, accessed June 20, ...

to the west fork of the San Jacinto River).

Description

Adults are in length. It is brown with light brown and black speckles. It exhibits

neoteny Neoteny (), also called juvenilization,Montagu, A. (1989). Growing Young. Bergin & Garvey: CT. is the delaying or slowing of the physiological, or somatic, development of an organism, typically an animal. Neoteny is found in modern humans compa ...

, retaining its gills and larva-like tail into adulthood. It can be distinguished from ''N. moleri'' and ''N. mounti'' (formerly thought to be conspecific) by its comparatively larger size, heavier spotting, and the unstriped larvae with numerous white spots.

Ecology

This species lives in streams with sandy bottoms. It remains on the substrate or burrows into it, sometimes hiding in debris. Individuals of both sexes move more during the colder months of the year and seem to use one site as a home area from which they occasionally exhibit long-distance movements.Brenes, Roberto, and Neil B. Ford. "Seasonality and Movements of the Gulf Coast Waterdog (Necturus Beyeri) in Eastern Texas". The Southwestern Naturalist, vol. 51, no. 2, 2006, pp. 152–156. JSTOR The female attaches its eggs to aquatic debris.''Necturus beyeri''.
AmphibiaWeb. 2016.

References

Proteidae Endemic fauna of the United States Amphibians of the United States Amphibians described in 1937 {{salamander-stub