Eastern Newt Notophthalmus viridescens

Description: Adult Morphology: Eastern newts have an unusual and variable life history and a correspondingly variable morphology. Aquatic adults are typically olive-green or brown dorsally with a yellow venter. The side of the body is often marked with 3-7 red spots; these are encircled in black pigment in N. v. viridescens, but not in N. v. louisianensis. Eastern newts have two longitudinal cranial crests on the head, and aquatic males have tall dorsal and ventral fins on the tail. During the breeding season, males also develop thick keratinous regions on the feet and hindlimbs. If their pond dries, adults can leave the water and live terrestrially. These individuals usually show a reduced tail fin and more granular skin. Directly after metamorphosis, many newts enter a unique life-history phase called the "eft", which is characterized by its small size and bright red or orange, granular skin (see Natural History for more information).

Size: Adult newts grow to 2-2.5 inches SVL, and most efts are approximately 1-2 inches in total length.

Larvae: Larvae look superficially similar to Ambystoma but have a more pointed snout. A dark bar through the eye can be a good distinguishing feature. As they mature, larvae display coloring and patterning similar to that of adults.

Eggs: Eggs are laid singly and attached to aquatic vegetation or detritus. They are rarely seen.

Similar Species: Newts are easily distinguished from other species of salamanders in Indiana. An eft could be confused with a red salamander (Pseudotriton ruber) or cave salamander (Eurycea lucifuga), but both of these species have much smoother and wetter skin.

Distribution: Eastern newts are one of the most widely-distributed salamanders in the country and can be found across most of the eastern United States.

Eastern newts have been documented statewide in Indiana but appear to be relatively spotty. Indiana represents a contact zone between the central newt (N. v. louisianensis) and the red-spotted newt (N. v. viridescens), with the former occurring in the western part of the state and the latter in the eastern. Many of the newts in Indiana may be intergrades.

Activity: Aquatic adults can be found in permanent ponds year-round, and efts are often common after summer and fall rains.

Breeding Season: Minton (2001) reports witnessing breeding activity between mid-January and mid-March near Bloomington, and our observations are consistent with his.

Taxonomy: Four subspecies of eastern newts are recognized nationwide, two of which occur in Indiana: the central newt (N. v. louisianensis) and the red-spotted newt (N. v. viridescens). The eastern newt is one of three species of the genus Notophthalmus (Family: Salamandridae), and is the only representative of either group in the state of Indiana..

Ecology: Habitat: Aquatic adult eastern newts are found in a variety of mostly permanent ponds, but they can also be found in ephemeral wetlands. When these bodies of water dry, the adults can often be found huddled underneath logs within the former pond margins. Efts are fully terrestrial and can wander many miles from breeding ponds. They can occasionally be found underneath logs on forested hillsides and often emerge en masse after summer rains. Unlike most salamanders, it is not entirely unusual to see an eft crawling on leaf litter during daylight hours. Efts may wander the forested landscape for up to ten years before returning to the breeding pond to reproduce.

Diet: Adult newts eat a variety of aquatic invertebrates and become seasonally important predators of other amphibians' eggs. Efts eat a variety of terrestrial invertebrates..

Reproduction and Life History: Males court females and lead them to a spermatophore deposited on the pond bottom. Often, this involves grabbing the female around the neck with his hindlimbs--an embrace that can last many hours. In fact, eager males in the breeding season will occasionally confuse a herpetologist's finger with an unresponsive female and clasp on tightly! Eggs are fertilized internally and them laid singly in aquatic vegetation and detritus..

Conservation: Because newts have multi-stage life histories, often relying on both terrestrial and aquatic habitats, the preservation of forested land surrounding breeding ponds is important. Where they occur, newts are often abundant in Indiana.

Literature

Brodman, R. 2003. Amphibians and Reptiles from Twenty-three Counties of Indiana. Proceedings of the Indiana Academy of Science 112.1:43-54.

Kinney, V. C., N. J. Engbrecht, J. L. Heemeyer, and M. J. Lannoo. 2010. New County Records for Amphibians and Reptiles in Southwestern Indiana. Herpetological Review 41.3:387

Klueh-Mundy, S and J. Mirtl. 2014. Notophthalmus viridescens. Eastern Newt. Geographic distribution (Sullivan County). Herpetological Review 45:457.

Minton, S. A. Jr. 2001. Amphibians and Reptiles of Indiana. Indiana Academy of Science, Indianapolis, IN

Petranka, J. W. 1998. Salamanders of the United States and Canada. Smithsonian Institute Press, Washington D.C.

Distribution Map
Distribution map of Eastern Newt (Notophthalmus viridescens)
Photographs