These embryos hatch in three to five weeks, depending on water temperature. Salamander larvae have feathery external gills and four legs, which distinguish them from frog larvae, which have internal gills and no legs. Larvae metamorphose by late summer, when they are about 2 to 2.5 inches long, and leave the pools to find underground homes in surrounding uplands. The marbled salamander is extremely rare in New Hampshire, having been found in only a few places in the southern part of the state. This species also lives underground most of the year, but adults breed in the fall, selecting dry beds of autumnal pools to breed and lay eggs.
Males leave the sites soon after breeding, while females stay behind to guard and incubate the eggs.
When rains fill the breeding pools, females leave. The eggs hatch into aquatic larvae, which will remain in the pool until they metamorphose in late fall or early spring. Other salamanders that may be found in vernal pools include the eastern spotted newt and four-toed salamander . Newts typically live in permanent water, such as ponds and lakes. Some individuals may select a vernal pool in which to transform into their aquatic adult phase.