710.
Mudpuppy
(Necturus maculosus)
LC
Overview
This unthreatened salamander inhabits the Great Lakes and other major water bodies of North America.  It is one of a number of unusual salamanders that do not develop into adults in the normal way, retaining juvenile features and their aquatic lifestyle through sexual maturity.  It can breathe using its lungs, its feathery red external gills or through its skin, and in this way can survive in the most poorly oxygenated waters.  It spends its time on the bottom of the water, in crevices under rocks and logs, and eats anything from insects to other salamanders.

 
Urgent Conservation Actions
Distribution
Great Lakes and major rivers of the U.S. and Canada.
Evolutionary Distinctiveness
Order: Caudata
Family: Proteidae
The Proteidae are an ancient family of salamanders which diverged from their closest relatives 190 million years ago, in the early Jurassic Period.  The family consists of just six known species that are still alive today, so seeing as it’s been around since the time of the dinosaurs, these six species represent a massive chunk of evolutionary history.  The six members of the Proteidae family are the Olm Proteus anguineus, a ghostly white cave dwelling species from Eastern Europe, and the five members of the North American genus Necturus, to which the mudpuppy belongs.  They are all paedomorphic, which means they look like juvenile salamanders even when they’re fully grown.  Two subspecies of Necturus maculosus are recognised: Necturus maculosus maculosus and the Red River Mudpuppy Necturus maculosus louisianensis.
Description
Mudpuppies have elongated bodies with short, sturdy legs and four toes on each of the four feet.  The head is flattened, and has three large ‘bushes’ of red feathery gills on either side.  They have small eyes, and lip folds which help them to capture prey underwater.  The tail is short and flattened laterally, making it a powerful swimming tool.  Adult mudpuppies are usually 20 to 30cm long, but the largest ever recorded was almost 50cm.

The skin of a mudpuppy is smooth, and is brown to grey with a mottled pattern of spots all over (maculosus meaning ‘full of spots’).  The underside is lighter in colour, and a dark stripe runs down each side of the head through the eye.  The larvae are nearly black, and have a yellow band running down each side. 
Ecology
Salamanders begin life as aquatic larvae, with gills and other adaptations for the water, and usually grow into terrestrial adults which are adapted to life on land.  Once they have completed the initial stage of their lifecycle, metamorphosis transforms larvae into the adult form so that they can climb out of the water and survive on land.  ‘Paedomorphic’ or ‘neotenic’ species fail to undergo this transformation, and so retain their gills and finlike tail into adulthood, remaining aquatic all their lives.  Neotenic salamanders retain the healing abilities of larvae throughout their lives, and are able to regenerate damaged or lost limbs and even vital structures such as parts of the brain.  Some may even end up with extra appendages if a new leg has been grown whilst the damaged one has ended up fully repaired.

This species mostly mates in the Autumn, but females can store sperm for many months and usually lay eggs the following Spring.  Around 60-120 eggs are attached to the underneath of a rock or log in shallow water, and the female lays beneath them in an ‘excavated nesting cavern’ until they hatch two months later.  Most hatchlings stay within the protection of the nest cavity for another two months, before leaving to find their own similar retreat.  It takes five years for a mudpuppy to reach adulthood and sexual maturity. 

Their external gills allow mudpuppies to extract oxygen from slow moving water, but they can also ‘breathe’ through their skin, and at the surface using their lungs if oxygen levels are really low.  They eat insects, worms, molluscs, fish and even other salamanders, and are preyed upon by large fish, aquatic birds, snapping turtles, watersnakes, otters and mink.
Habitat
Necturus maculosus inhabits freshwater rivers, streams, ponds and lakes, and lives on the bottom where it hides under rocks and debris during the day.  Adults prefer well-aerated water, but withstand a variety of conditions such as clear to silted waters and an abundance or lack of underwater vegetation.  Larvae and juveniles may take up residence under layers of silt in holes that collect organic debris.
Distribution
All five members of the Necturus genus are North American.  This species is native to the U.S. and Canada, and is found throughout the Great Lakes and drainage basins of the St Lawrence, Allegheny, Ohio, lower Missouri, Arkansas and Mississippi Rivers.  It ranges from southern Manitoba to southern Quebec, south to Oklahoma, northern Louisiana, northern Mississippi, northern Alabama, and northern Georgia.  There are also disjunct populations in Massachusetts and Connecticut, although their origin in these states has been debated.  It has been reported at depths of up to 27 metres in Lake Michigan.
Population Estimate
The actual population size is unknown, but is thought to exceed 10,000.  It is abundant in many northern lakes and rivers.
Population Trend
The overall population trend is stable, although local population declines have been reported following heavy siltation and water pollution, and its current status is unknown in many localities.
Status
This species has been categorised as ‘Least Concern’ by the IUCN, as it has a wide distribution, large population, and is able to tolerate some degree of habitat modification.  On a smaller scale, however, mudpuppies are considered Endangered/ Extirpated (locally extinct) in Maryland, Threatened in Iowa, and are a Species of Special Concern in Indiana and North Carolina.
Threats
The IUCN reports that there are no major threats to this species.
Links
References
Amphibiaweb: Information on amphibian biology and conservation [web application]. 2009. Berkeley, California: AmphibiaWeb. Available: http://amphibiaweb.org/. (Accessed: Mar 20, 2009.)

Frost, D. R. 2009. Amphibian Species of the World: an Online Reference. Version 5.3 (12 February 2009). Electronic Database accessible at: http://research.amnh.org/herpetology/amphibia/. American Museum of Natural History, New York, USA.

Gibbs, J. P., Breisch, A. R., Ducey, P. K., Johnson, G., Behler, J. L. and Bothner, R. C. 2007. The Amphibians and Reptiles of New York State: Identification, Natural History, and Conservation. Oxford University Press, Oxford.

Hammerson, G. 2004. Necturus maculosus. In: IUCN 2008. 2008 IUCN Red List of Threatened Species. www.iucnredlist.org. Downloaded on 20 March 2009.

Larson, A. 2006. Proteidae. Mudpuppies, waterdogs. Version 23 August 2006 (under construction). http://tolweb.org/Proteidae/15449/2006.80.23 in The Tree of Life Web Project, http://tolweb.org/

Roelants, K., Gower, D. J., Wilkinson, M., Loader, S. P., Biju, S. D., Guillaume, K., Moriau, L. and Bossuyt, F. 2007. Global patterns of diversification in the history of modern amphibians. PNAS 104(3): 887-892.

Distribution dataset:  IUCN 2008. 2008 IUCN Red List of Threatened Species. http://www.iucnredlist.org

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