Observations by akuruvilla

Scientific and Common Name

Notophthalmus viridescens
Commonly known as the eastern newt, the eastern red-spotted newt, or red efts

Habitat and Geographic Range

Eastern newts spend their larval stage in an aquatic environment, they then live on land as juveniles and once they reach sexual maturity they return to the water to breed, some developing larger tails to help them swim, while other return to land and only go back to the water to breed (Regosin et al., 2005). Thus, given their stages of development, they tend to live in wetlands and marshes (Strain, Turk, and Anderson, 2014). The geographic range of the eastern newt extends along the eastern side of North America from Quebec and Nova Scotia all the way down to Florida (Yotsu-Yamashita et al., 2012).

Size/Weight and Lifespan

The size and weight of eastern newts varies between sexes, however, on average they weigh approximately 4g and are approximately 43.5mm in length from snout to vent (Attum, Eason, and Cobbs, 2002).
Eastern newts spend 2-5 months in water as larva (Brossman et al., 2014), 2-7 years as juveniles on land, then they spend 1-9 years as adults on either land or water depending on their morphological characteristics (Roe and Grayson, 2008). Thus their lifespan ranges from 3 to 16 years.

Diet

The diet of the eastern newt primarily consists of invertebrates, including aquatic insects, ringed worms, zooplankton, springtails, water mites, microcrustaceans, molluscs, and arious terrestrial invertebrates (Strain, Turk, and Anderson, 2014).

Reproduction and Communication

The eastern newt displays multiple forms of courtship, the initial being securing the female around the neck using its hind legs and holding her in the mating position for up to three hours then doing a lateral display similar to a dance for a few minutes. Once he has performed both acts of courtship he deposits spermatophores in front of the female and it is up to her whether she picks them up in her cloaca or not. Additionally, males are limited in sperm production during the mating season, thus they choose to court females that are most likely to bare offspring and the fecundity of females has a positive correlation with their size, meaning that males usually court the larger females (Verrell, 1985).

Predation

Eastern newts are most vulnerable to predators while they are still in their aquatic larval stage; predators including, fish, aquatic insects and adults of the species (Brossman et al., 2014). Furthermore, the predators of adult eastern newts include frogs, turtles, snakes and other salamanders. However, eastern newts have a very potent neurotoxin, known as tetrodotoxin, in their skin and organs that can have major adverse effects on these predators, which serve as protection for the eastern newt (Brossman et al., 2014). Additionally, it was recently discovered that a Chinese praying mantis may also be a predator of the eastern newt, and it is not affected by the toxin (Mebs, Yotsu-Yamashita, and Arakawa, 2016).

Conservation Status

Since Eastern newts have different habitats based on their stage of life, they are very susceptible to the negative impacts of habitat fragmentation (Roe and Grayson, 2008). They are not currently on any endangered species lists.

Did You Know?

Eastern Newts are a keystone predator in many ecosystems where other invasive amphibians have been introduced, such as the Cuban treefrog, Osteopilus septentrionalis. A single adult eastern newt can effectively mitigate the effects of this “competitively superior invasive species” (Smith, 2006).