Nature Notebook – Salamander Shedding

We recently found one of our tiger salamanders writhing and contorting. It seemed to be experiencing a slow motion seizure. A few moments later, it crawled out of its skin. We had just witnessed a salamander molt.

Salamanders, like all amphibians, molt (shed their skin) several times throughout their lifetime, more so as juveniles when they are rapidly growing. Each species has an internal clock that determines the frequency of its molts. Temperature and light changes in its environment may influence this rhythm. However, hormones control the process.

The pituitary gland secretes a hormone that causes the thyroid gland to release another hormone. The result is an increase in the secretion of the mucus that is present in the skin to keep it moist. The additional mucus acts as a lubricant as the top layer of skin (the old stuff) separates from the layer below.

The loose skin usually gradually falls off in small pieces. In some species, a more dramatic whole body molt (such as our salamander’s) occurs. Evidence of any shedding is rarely found because the salamanders consume the “old” skin, which is full of essential proteins.