Friday, August 14, 2009

Spotted Salamander

Isn't this the cutest face? It appears we're keeping an alien in our home, but it's actually a spotted salamander (Ambystoma maculatum) larva. This unique pose was the result of "Sam" eating a worm that perhaps was a bit larger than he expected.

This neat little creature began its life in a gelatinous mass like the one pictured here. The green color is caused by a symbiotic algae (Oophila amblystomatis). The algae provides oxygen to the developing embryos. In return, the embryos supply the algae with the nitrogen and phosphorus it needs.

In late winter or early spring (usually in March or April in Massachusetts), adult spotted salamanders head out to lay eggs in the pool from which they hatched. The migration is stimulated by warming temperatures and the first spring rain. Sadly, a number of migrating salamanders don't make it to their destination. Many are killed crossing roads despite the salamander tunnels some communities have built under busy routes along the migration path. Some towns shut down roads along salamander migration routes in an effort to increase the number of salamanders that make it back to lay eggs.

Egg masses can be found attached to submerged sticks. It takes from 1-2 months for the eggs to hatch. The frilly-gilled larvae only have front legs and a pair of "balancers" which they eventually lose. They are fully aquatic and eat tiny creatures like fairy shrimp and small insects.

In the photo below, the hind legs have recently emerged.

As they grow larger and stronger, the larvae take on more substantial prey such as tadpoles and earthworms. Here "Sam," is approaching and attacking a worm.

Spotted salamander maturation is influenced by the climate of their habitat. In warmer regions, salamanders will be sexually mature in 2 or 3 years, while it may be 5 or 6 years before they are ready to breed in colder locations.

We observed our salamander larva from April to July, watching it metamorphose from a larva into an air-breathing amphibian. As the days passed, the larva's light grey body became speckled with dark spots. By July, it was coming to the surface of the water to gulp air.

It took the larva about three and a half months to begin losing its gills. It seemed as though they shrunk overnight. Some mornings we were shocked at how much smaller the salamander's gills were than the previous day.

By early August, its skin was completely dark and yellow spots began to appear. Now we were sure that "Sam" was a spotted salamander. We were so lucky to have witnessed this amazing transformation.

Finally, it was time to release our friend back to the pond. He'll spend the remainder of the summer and the upcoming fall and winter under the cover of leaf litter within a quarter to a half mile of the pond where he hatched. Hopefully he'll return in a few years to start his own family.


  1. What a wonderful post! You led us all the way through his whole life cycle, up to the moment that he went on his big journey into the wild =) What a cute guy. We wish him the best!

  2. HI! It was a truly fantastic experience, especially the way it lost its gills little by little every day. When I took the photos, he was very curious and would come right up to the side of the tank to see what I was up to. This was one of the highlights of our summer.

  3. Awww!!! sooo cute! with your help we've identified our recent find! (a spotted salamander baby!) Thanks for the help! :)