What Salamanders Are Fully Aquatic?

Salamanders are quiet, secretive creatures that tend to avoid attention. They live in damp forests, under rocks, or near streams, moving slowly and carefully through their surroundings. This leads to a clear question: what salamanders are fully aquatic, and how do they live differently from the rest?

Fully aquatic salamanders include axolotls, sirens, amphiumas, mudpuppies, olms, and several species of cave and stream-dwelling salamanders.

Axolotls Stay in Water Their Whole Lives

One of the most well-known aquatic salamanders is the axolotl. Native to lakes and canals in Mexico, axolotls are different from most salamanders because they never go through full metamorphosis.

Axolotls hatch from eggs and grow into adults, but they keep features normally found only in larvae, like feathery gills on the sides of their heads. This is called neoteny, which means keeping juvenile traits into adulthood.

Axolotls live their entire lives underwater, using their external gills and lungs to breathe. They do not need to come onto land and rarely leave the water unless something is wrong.

In the wild, axolotls are endangered due to pollution and habitat loss, but they are often kept in captivity for research or as pets. Their ability to regrow body parts also makes them important to scientists studying regeneration.

Sirens Are Legless and Live in Wetlands

Another group of fully aquatic salamanders are the sirens. These unusual animals live in swamps, ponds, and wetlands in the southeastern United States.

Sirens are long, eel-like salamanders with small front legs and no back legs at all. They breathe through gills and lungs but never leave the water. Sirens can survive in slow-moving or still waters that many other amphibians can not tolerate.

Some species, like the lesser siren and the greater siren, are found in shallow waters with lots of plants. They feed on insects, worms, and small aquatic animals.

When conditions become dry, sirens can bury themselves in the mud and go into a state of dormancy, sometimes for months. But they never emerge to live on land.

Amphiumas Look Like Eels but Are Salamanders

Amphiumas are another fully aquatic group found in the southeastern United States. They live in swamps, ditches, and slow-moving streams.

Amphiumas look like sirens at first glance, but they have small legs on both the front and back of their bodies.

There are three main species, named for how many toes they have: the one-toed, two-toed, and three-toed amphiuma.

Amphiumas can grow very large, with the largest species reaching over 3 feet in length. They breathe using lungs but do not leave the water. Instead, they rise to the surface to gulp air.

These salamanders are active at night and are rarely seen during the day. They feed on fish, frogs, insects, and even other salamanders.

Amphiumas are known for their strong bite and can defend themselves if handled. Like sirens, they never complete metamorphosis and remain fully aquatic.

Mudpuppies Are Common in Northern Lakes and Rivers

Mudpuppies, also known as waterdogs, are fully aquatic salamanders found in rivers, lakes, and streams across parts of North America.

They belong to a group called Necturus and are easy to recognize because they keep their feathery gills throughout their lives. Mudpuppies do not leave the water, even as adults.

These salamanders are active at night and hide under rocks or logs during the day. They eat worms, snails, crayfish, and other aquatic animals.

Because they are sensitive to pollution and water quality, mudpuppies are often used as indicators of clean, healthy freshwater ecosystems. In some places, they are mistakenly believed to be pests, but they are harmless and play an important role in the food chain.

Olms Are Blind Cave Dwellers

The olm is one of the most unusual aquatic salamanders in the world. It lives in underground caves and streams in parts of Europe, especially Slovenia and Croatia.

Olms have adapted to life in complete darkness. They are pale or white in color, completely blind, and can live for decades, sometimes over 100 years.

Like axolotls, olms remain in a larval form for their entire lives. They have gills, lungs, and no pigment in their skin. Their slow metabolism allows them to survive for long periods without food.

Olms are rarely seen due to their hidden, deep cave homes. They are specially adapted for their environment and would not survive on land or in open sunlight.

Cave Salamanders and Stream-Dwelling Species

In addition to well-known aquatic salamanders like axolotls and mudpuppies, there are many other species that live fully or mostly underwater, especially in caves and fast-moving mountain streams.

For example:

• The Texas blind salamander and Georgia blind salamander are small, aquatic species that live in underground springs and cave systems. They are similar to olms but live in North America.
• Several species in the genus Eurycea, such as the Zigzag salamander and Chattahoochee slimy salamander, have aquatic forms that never leave the water in certain regions or life stages.
• Some giant salamanders, like the Japanese giant salamander and the Chinese giant salamander, are fully aquatic as adults and live in rivers. They grow very large and breathe through their skin.

These species may be less familiar than axolotls or mudpuppies, but they show the wide variety of aquatic salamanders that exist in different parts of the world.

How Aquatic Salamanders Breathe

Breathing is one of the biggest differences between aquatic and land-dwelling salamanders.

Most aquatic species use external gills, which are feathery structures on the sides of the head that absorb oxygen from water. Some species, like sirens and axolotls, also have lungs and can rise to the surface to take in air.

Other aquatic salamanders, like the giant salamanders, do not have gills. Instead, they absorb oxygen directly through their skin. This is possible because their skin stays moist and has many blood vessels close to the surface.

Because of these breathing methods, aquatic salamanders must stay in water. If they dry out or are removed from their environment, they can not survive for long.

Special Adaptations for Life in Water

Aquatic salamanders have many body features that help them live in water full-time:

• Flattened tails help with swimming. Reduced limbs are common in species that don’t walk on land.
• External gills improve oxygen exchange. Light-colored or camouflaged skin helps them blend into underwater surroundings.
• Lateral lines, similar to those in fish, help them detect movement and vibrations.

These adaptations are not found in most land-dwelling salamanders, showing how their bodies are shaped by their watery environments.

Differences From Semi-Aquatic Species

Not all salamanders that live near water are fully aquatic. Many species, like the spotted salamander or tiger salamander, lay their eggs in ponds but then live most of their adult lives on land.

These semi-aquatic species depend on water during breeding season but breathe with lungs and live under logs, leaves, or burrows the rest of the year.

Fully aquatic salamanders are different. They stay in the water their entire lives, from egg to adult, and never live on land.

This difference is important when caring for salamanders in captivity or protecting them in the wild. Aquatic species need water quality, oxygen levels, and space to swim. Land-based species need moisture but also air and shelter on land.

Conclusion

Some salamanders live entirely underwater. These fully aquatic species include axolotls, sirens, amphiumas, mudpuppies, olms, and many cave or stream-dwelling types.

Their bodies are shaped by a life in water, with gills, reduced limbs, and specialized ways of breathing.

Unlike land-dwelling salamanders, they do not come out onto land at any point in their lives.