Neuse River waterdog
- Taxon: Freshwater salamander
- Range: Neuse and Tar River basins, North Carolina
- Status: At-risk species
The Neuse River waterdog (Necturus lewisi) is a permanently aquatic salamander. It can grow up to 11 inches long. It has a reddish brown body with an irregular pattern of large blue or black spots. The waterdog has a laterally compressed tail the same coloration as the body; however, the belly is typically a dull brown or gray color with spots similar to those seen elsewhere on the body. Adult Neuse River Waterdogs have elongated heads with squared-off noses, cylindrical trunks, and tails that are laterally compressed and ridged. Three dark-red, bushy gills project from either side of the head and a dark line runs through the eye. The skin is smooth, slimy and a light rusty brown color, with the belly being a paler brown or grayish. There are dark brown or blackish spots throughout the surface that are smaller on the underside. The limbs are rather small, and the front and hind feet have four toes each (unlike most salamanders, which have five toes on each back foot).
Its appearance is significantly different in earlier life stages, as hatchlings and larvae. Hatchlings are light brown in color with dark lines from each nostril through the eye to the gills, with a white patch behind the eye and above the line. Their heads are round when compared to the square, elongated heads of the adults. Hatchlings have spots with concentrations highest on the tail, making the tail darker than the head and trunk. Their forelimbs have three complete toes, and a bud that will later develop into the inner fourth toe. The hindlimbs are not yet developed.
Post-hatchling larvae have a broad, light tan, dorsal stripe from the snout to the tail, and along the dorsal region are small, poorly defined, dark spots. The underside of the larvae is white or has a faint network of lines.
The sexes (genders) are similar in appearance, and adults can be distinguished only by the shape and structure of the cloacal area. Waterdogs breed annually, mating in the fall/winter, seasons and females spawn in the spring. Clutch sizes vary from an average of 25 to 90 eggs. Both parents guard the nest. Longevity of Neuse River Waterdog is unknown. However, its close relative, Necturus maculosus may live for over 30 years.
The Neuse River waterdog specific habitat characteristics include low to moderate gradient streams and low current velocity. It is a fully aquatic salamander, never leaving the water. It lacks lungs, getting oxygen from the water via external gills and needs clean, flowing water with high dissolved oxygen concentrations. The species dwells in streams wider than 15 meters but has been found in smaller creeks.
The species thrives in cold water, and is much more active in colder seasons and when water is near-freezing. Researchers have documented activity decreasing after the water temperature rises above 18ºC. waterdogs spend about 85% of the time under large granite rocks or in burrows. In early spring they move into leaf beds over mud banks on the low-energy sides of riffles and where leaves were intact or only slightly decomposed and many small critters are in the leaf litter.
Neuse River waterdogs are sight and scent feeders, with prey consisting of aquatic arthropods (primarily ostracods and copepods), hellgrammites, mayflies, caddisflies, crayfish, beetles, caterpillars, snails, spiders, earthworms, centipedes, millipedes, slugs) and some small fish like darters and pirate perch. All prey are ingested whole, and larger items are sometimes regurgitated and then re-swallowed.
The Neuse River waterdog is endemic to the Tar-Pamlico and Neuse River basins in North Carolina. Its historical distribution includes the Piedmont and Coastal Plain regions of North Carolina within all major tributary systems of the Tar and Neuse, including the Trent River Basin.
Today, the species is known to occupy the Neuse and the Tar River basins of North Carolina. The species is not known to migrate.
Counties where the Neuse River waterdog is known or believed to occur:
The Neuse River waterdog is extremely susceptible to the effects of siltation, or the deposit of sediments in freshwater. The major threats to this species arise from water development projects such as the construction of impoundments and stream channelization. Pollution from industrial and urban development can also cause loss of habitat by lowering dissolved oxygen levels and increasing suspended solids and sediments in streams.
Other nonpoint sources of pollution carried into the streams by water, or runoff also affects the Neuse River waterdog. Natural and human-made substances like animal waste, fertilizers, pesticides, herbicides, and chemicals associated with coal mining can all cause changes in water chemistry that severely impact aquatic species. Increased levels of nitrogen and phosphorus, excessive algal growth, instream oxygen deficiencies, increased acidity, and conductivity can all have adverse effects on the health of river dwelling species.
How you can help
Individuals can do a number of things to help protect freshwater species, including:
- Conserving water to allow more water to remain in streams.
- Using pesticides responsibly, especially around streams and lakes, to prevent runoff into mussel habitats.
- Controlling soil erosion by planting trees and plants to avoid runoff of sediments into freshwater areas.
Partnerships, research and projects
The Service and state wildlife agencies are working with numerous partners to conserve the Neuse River waterdog and restore its habitat while meeting the socioeconomic, political and cultural needs of current and future generations. Land trusts are targeting key parcels for acquisition. Federal, state, and university biologists are surveying and monitoring species occurrences, and recently there has been increased interest in efforts to consider captive propagation and species population restoration via augmentation, expansion, and reintroduction efforts.
The North Carolina Department of Environmental Quality has special nutrient management plans for the Tar-Pamlico River Basin and the Neuse River Basin to help reduce nutrients that cause excessive growth of microscopic or macroscopic vegetation and lead to extremely low levels of dissolved oxygen in the water.
Federal Register notices
The following Federal Register documents were automatically gathered by searching the Federal Register Official API with this species’ scientific name ordered by relevance. You can conduct your own search on the Federal Register website.
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