The Red Spotted Newt

Notophthalmus viridescens

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The term newt can be applied to any of a number of species of semi-aquatic salamanders in the family Salamandridae.

Most species within the family Salamandridae are found in Europe. In fact only two (2) genera of newts are found in the United States.

The Red-Spotted or Eastern Newt is one of the most abundant salamanders in New England. Unlike other salamanders, newts have a rough skin and indistinct costal grooves. The 2 1/4 to 4 3/4 inches long adults are usually aquatic. Dorsally adults are usually olive green although color may range from a yellowish brown to a greenish brown peppered with red spots. Ventrally they are yellow with black spots.

NEWT, ADULT STAGE

Adult red-spotted newts can be found in a variety of habitats. They are the only species of New England salamander that can co-exist with populations of fish. This is because newts secrete noxious substances from their skin. Newts may be found in marshes, back waters of streams, vernal pools, and even permanent ponds and lakes. Aquatic adults may be active all year long and are frequently seen swimming about under the ice.

Red-Spotted Newts have a complex life history. The adults usually spend the winter on land, underground. In the early spring they emerge and return to the water. They live in permanent bodies of water and reproduce in the spring through early summer. The female deposits her 300-400 eggs one at a time, attaching them to submerged vegetation. Depending on water temperature, the eggs may take several weeks to hatch. The aquatic larvae remain in the pond until late summer.

NEWT, LARVAL STAGE

They resorb their gills and change into the bright orange terrestrial stage called efts. Newts remain in this terrestrial eft stage for up to 7 years, after which they undergo a second metamorphosis where they lose their red orange color and become more drab olive-colored adults.

TERRESTRIAL RED EFT STAGE

There are populations of red-spotted newts that don't conform to this scenario. Skip Lazell, in his book "This Broken Archipelago," mentions two alternative life history strategies. In some coastal populations the terrestrial red eft stage is omitted. The larvae continue to grow in size. They eventually become sexually mature while still retaining their larval appearance. They look similar to a typical adult newt yet retain their external gills.

In other populations, newts enter the red eft stage and never undergo a second metamorphosis. These yellowish terrestrial adults retain the eft morphology. They live around the edge of ponds and marshes, forage terrestrially and return to water only to breed.

Whether a bright orange terrestrial eft or a fully aquatic adult, newts are one of our most common and easily observed salamanders.

Reference:

Lazell, James. D. 1976. This Broken Archipelago: Cape Cod and

the Islands, Amphibians, and Reptiles. Quadrangle/New York

Times Book Co., New York.