Salamanders, often mistaken for lizards, are actually fascinating amphibians living primarily near or in water. With over 600 species worldwide, these unique creatures showcase a variety of sizes and possess special respiratory abilities, enabling them to absorb oxygen both in and out of water. Notably, their moist, smooth bodies are scale-free and have remarkable regenerative capabilities. Interestingly, while all newts belong to the salamander family, not every salamander is a newt.
As we delve into the world of salamanders, we’ll uncover the ten largest species, evaluating them based on length (measured from nose to tail) and considering weight when their sizes are similar. These giant salamanders, sometimes as big as a large dog, demonstrate an impressive array of behaviors and adaptations in diverse ecosystems and habitats, playing crucial roles in maintaining the balance of their freshwater environments.
#10: Common Mudpuppy
The Common Mudpuppy (Necturus maculosus), often referred to as a waterdog, is an aquatic salamander found in North America. These creatures are distinguished by their rust-brown hue and preference for residing in muddy water environments. With their small, flat limbs, they are adept at traversing the bottom of rivers and lakes. They typically measure around 13 inches in length but can reach up to 17.1 inches.
Inhabiting areas from southern Canada to Georgia, and spanning from the Midwest to the east coast, mudpuppies spend their days concealed beneath rocks and logs. Once night falls, they emerge, ready to hunt. Their diverse diet includes insects, small fish, amphibians, worms, spiders, and mollusks. These creatures face few predators, and fishermen typically release them if accidentally caught. The Common Mudpuppy’s extensive distribution has led to their classification as a species of Least Concern by the IUCN.
#9: Olm
The Olm, also known as Proteus anguinus, is a unique salamander species native to Europe, living solely in underwater caves. Sometimes referred to as the “human fish” due to its pinkish skin, their size usually ranges from 8 to 12 inches, with some rare instances reaching 16 inches.
These fascinating creatures have an impressively long lifespan, living up to 100 years. They inhabit cave waters in Central and Southeastern Europe, specifically in countries like Slovenia, Croatia, and Bosnia and Herzegovina.
Though the Olm is blind, it has developed heightened senses to compensate for its lack of vision. This salamander can perceive sound waves in the water and ground and can identify organic compounds in the water. Their diet primarily consists of small crustaceans, snails, and insects, which are ingested whole.
Unfortunately, due to their extreme sensitivity to environmental changes and pollution, the International Union for Conservation of Nature (IUCN) classifies the Olm as a vulnerable species. Their delicate, yet fascinating existence highlights the importance of preserving clean environments for the survival of unique species like the Olm.
#8: Axolotl
The Axolotl, also known as the Mexican walking fish, has its origins in the ancient Nahuatl language. This fascinating creature is a cousin of the land-dwelling tiger salamander but stands apart because it remains in water throughout its life, never undergoing metamorphosis. Typically, adult axolotls measure around 9 to 12 inches in length, but they can occasionally grow up to 18 inches. They come in an array of different colors, from pale pink and black-eyed to a gorgeous golden variety with matching eyes, and even a brownish shade with hints of olive.
Native exclusively to Mexico, axolotls once inhabited the freshwater Lake Chalco, which no longer exists, and the now severely diminished Lake Xochimilco. They feed on a diet of mollusks, worms, insects, and small fish, sucking their meals right into their mouths. A key feature of axolotls is their incredible regenerative abilities, allowing them to regrow whole limbs. Sadly, habitat destruction, pollution, and rivalry with invasive species have led to a dramatic decline in their population, leaving fewer than 1,000 adults in the wild. This has resulted in these captivating creatures being listed as Critically Endangered by the IUCN.
#7: Reticulated Siren
The Reticulated Siren (Siren reticulata), also referred to as the leopard eel, is a relatively recently documented salamander species. It was officially described and recognized by scientists in 2018. Known for their distinctive eel-like appearance, these unique creatures can grow up to 24 inches in length, with some individuals slightly exceeding 12 inches.
As one of the largest newly documented animals in the United States within the past century, the Reticulated Siren is primarily found in the wetlands and marshes of southern Alabama and the Florida panhandle. Its greenish-grey body further contributes to its eel-like nickname.
Despite their recent discovery, not much is known about the ecology or history of the Reticulated Siren. Even their feeding habits remain a mystery, although it is believed that they consume a similar diet to other aquatic salamanders. So far, the International Union for Conservation of Nature (IUCN) has not evaluated or assigned a conservation status to this elusive species.
#6: Lesser Siren
The Lesser Siren (Siren intermedia) is a fascinating aquatic salamander, often called a two-legged siren, dwarf siren, or mud eel due to its unique appearance with only two legs. Its size varies from 7 inches to an impressive 27 inches, and it typically shows a dark green or bluish-black color.
Native to the eastern United States and northern Mexico, the Lesser Siren makes its home at the bottom of streams, hiding under mud during the day. At night, they emerge to hunt for worms, insects, snails, crustaceans, and even tadpoles of other amphibians. If their watery habitat dries up, these adaptable creatures burrow down into the mud, secreting fluids from their skin to retain moisture.
Although some populations face threats from pollution and habitat destruction, the International Union for Conservation of Nature (IUCN) classifies the Lesser Siren as a species of Least Concern, ensuring that their unique presence continues to grace our aquatic ecosystems.
#5: Greater Siren
The Greater Siren (Siren lacertina) holds the title of being the largest salamander within its genus and the lengthiest one found in North America. These extraordinary creatures can reach lengths of 7 to 38 inches and weigh up to 2.2 pounds. Their coloration typically consists of olive green or grey shades, complemented by yellow dots running down their sides.
Residing in coastal plains stretching from Washington D.C. to Florida, Greater Sirens favor wetland habitats and marshes with slow-moving water. To avoid dehydration, they burrow into the mud for protection. These salamanders have a diverse diet, munching on insects, spiders, mollusks, crustaceans, crayfish, and even small fish. Occasionally, they opt for algae as a meal.
Though their population range has decreased, the International Union for Conservation of Nature (IUCN) still considers them a species of Least Concern, meaning they are not currently at a high risk of extinction.
#4: Hellbender
The Hellbender (Cryptobranchus alleganiensis) might not be the longest salamander in North America, but it holds the title for being the heaviest. These creatures generally measure between 12-30 inches and weigh around 3.3-5.5 pounds. The origin of their name is uncertain, but it could be related to their unique appearance or the peculiar movement of their skin while breathing.
Hellbenders can be found across the eastern United States, mainly inhabiting rocky rivers and swiftly flowing streams. This habitat preference is likely connected to their breathing technique, as they absorb oxygen through capillaries in their skin folds rather than using gills like other salamanders.
Their diet mainly consists of:
- Crayfish
- Small fish
- Occasionally other hellbender’s eggs
As their population has been declining sharply, the International Union for Conservation of Nature (IUCN) now classifies them as a Near Threatened species. This fascinating creature is a unique part of the aquatic ecosystem in the eastern United States, and it’s essential to continue monitoring and protecting them for future generations.
#3. Japanese Giant Salamander
The Japanese giant salamander (Andrias japonicus) holds the title for the largest salamander species outside of China. These amphibians can stretch up to 5 feet in length and weigh nearly 58 pounds. Sporting brown and black skin, they effortlessly camouflage at the bottom of streams. Their Japanese name, Ōsanshōuo, aptly means “giant pepper fish.”
These giant salamanders reside in the clear, fast-flowing rivers across southwestern Japan. Similar to hellbenders, they rely on rapid water flow over their bodies to absorb sufficient oxygen. Predominantly feeding on insects, frogs, and fish, their metabolism runs slow enough to allow them to survive weeks without food.
Although they appear in Japanese legends, these salamanders face challenges like pollution, overcollection, and habitat loss. As a result, the IUCN classifies them as a Near Threatened species.
#2: South China Giant Salamander
The South China giant salamander (Andrias sligoi) holds the title as one of the largest salamander species on Earth. With the largest recorded specimen reaching nearly 5.9 feet in length, it is a close relative of the Chinese giant salamander. First documented in 1924 by a British zoologist, this creature has unique characteristics that set it apart from its relatives, meriting its own classification.
Once widespread throughout southern China, the South China giant salamander thrived mainly in the Pearl River basin and near the Nanling Mountains. Unfortunately, their numbers have dwindled drastically due to overcollection for food and medicinal purposes. Nowadays, most of these salamanders reside alongside other giant salamander species in farms, and it is uncertain if any still exist in the wild. As a result of its transition to primarily a farmed species, the IUCN has classified the South China giant salamander as Critically Endangered.
Presently, detailed information about the South China giant salamander’s genome, behavior, and physical characteristics remains scarce. Efforts to study and conserve this fascinating species continue to be an essential focus for future research.
#1: Chinese Giant Salamander
The Chinese giant salamander (Andrias davidianus) holds the title as the largest and one of the heaviest amphibians on Earth. These fascinating creatures can grow up to 5.9 feet in length and weigh as much as 130 pounds. They have a diverse palette of colors, including dark brown, red, black, and even albino tones, all while bearing a speckled pattern.
Locals commonly call them “infant fish” due to their unique vocalizations that resemble a baby’s cry. These ancient amphibians have existed for nearly 170 million years and once lived all over China, but their habitats are now highly fragmented.
Chinese giant salamanders reside in rocky crevices close to clear water lakes or fast-flowing streams. Although they are mostly found in China, some have been released into rivers in Japan. They have an eclectic diet, feeding on insects, worms, amphibians, crabs, shrimp, fish, and even water shrews. They rely on sensing vibrations to hunt their prey.
Unfortunately, their numbers have been dwindling since the 1950s, with over 80% of their wild population now gone. Because of this, they have been classified as a Critically Endangered species by the IUCN. Efforts to protect this extraordinary amphibian are now of great importance.