Hellbenders, Sirens and Mudpuppies

Hellbenders, Sirens and Mudpuppies rank amongst some of the world’s largest amphibians – Hellbenders (Cryptobranchus alleganiensis) growing to an impressive 28 inches (70cm) or more, while the Greater Siren (Siren lacertina) grows to nearly 40 inches (1m).

Generally these animals are more commonly seen as pets in their native North America, where, despite their typically drab colours and camouflaged appearance, they have found a number of fans.

With these aquatic salamanders increasingly pressurised in many parts of their natural range, a number of dedicated keepers are hoping that captive breeding may ultimately safeguard the future of these most intriguing and secretive of amphibians.

Hellbenders

Hellbenders are impressive looking salamanders, with their flattened heads and bodies, loose flaps of skin and sturdy legs making them look like one of the giant amphibians that ruled the earth long before the dinosaurs. This American species is related to the much larger – and endangered – Chinese Giant Salamander (Andrias davidianus) and the family resemblance is strong, although at 6ft (1.8m) long, Andrias dwarfs its close relation.

Its size alone means that Hellbenders are not the easiest proposition for the aquarium, but add to this the fact that they are normally found in clear fast-flowing streams and rocky-bottomed rivers and eat sizeable quantities of crayfish and they clearly become something only for the experienced specialist. However, if its particular demands can be met, the “Devil Dog” or “Allegheny Alligator”, as the Hellbender is also called in some parts of its range, it can thrive, with a lifespan in captivity of a quarter of a century or more.

Sirens

Named after the legendary Sirens of Greek mythology who were said to lure their victims to their doom with their irresistible singing, these amphibians are elongated and totally aquatic, with only two tiny front limbs in an otherwise essentially eel-shaped body. The link to the mythical songstresses may not be quite so far-fetched as it might at first seem. When caught, all of the siren species often make what are described as “yelping” sounds – the Lesser Siren (Siren intermedia) in particular being unusually vocal for a tailed amphibian.

Most of these animals naturally live in warmer, weedy ponds and ditches – making their habitat much easier to reproduce in the aquarium than the Hellbender’s – and although the Greater Siren is a true giant, smaller species such as the dwarf Siren (Pseudobranchus striatus), at an average length of 8 inches (20cm), is much easier to accommodate.

Mudpuppies

There are five species of Mudpuppies or Water-dogs to be found in America – the Alabama Waterdog (Necturus alabamensis), Gulf Coast Waterdog (N. beyer), Neuse River Waterdog (N. lewisi) Dwarf Waterdog (N. punctatus) and the Common Mudpuppy (N. maculosus). Outside of America, their closest living relative is the Olm (Proteus anguinus) – a rare, blind, cave salamander from Northern Italy and Slovenia.

Mudpuppies are very similar to the Axolotl, being another kind of entirely aquatic salamander which retains most of its larval characteristics into adulthood – and make equally good aquarium pets. Most of the Water-dogs only grow to around 8 or 10 inches (20 – 25cm) and even the Mudpuppy itself is scarcely huge, growing to little more than 14 or 16 inches (35 – 40cm) in length, which makes finding a tank to suit a fairly easy task.

They seem to be remarkably adaptable animals, naturally found in varied habitats ranging from clear, fast-flowing shallow streams to weed choked ponds, deep lakes and muddy rivers. Particularly secretive and nocturnal amphibians, mudpuppies appear to take well to captivity, many living for 20 years or more.

Food and Feeding

All of these species are predators, mostly feeding at night and taking any appropriately sized aquatic prey that they can overpower, including crayfish, freshwater shrimps, fish, insect larvae and worms. The sirens, especially the Greater and Lesser Sirens also eat a certain amount of aquatic plant material from time to time.

For any amphibian fan, Hellbenders, Sirens and Mudpuppies have a tremendous appeal and although they are not the most readily available – or in some cases, easiest – of species, their unusual appearances and fascinating way of life making them well worth getting to know a little better.