Newts and salamanders
Newts and salamanders are members of the Salamandridae family, which represents a diverse group of amphibians found across a wide geographical range, including North America, Europe, Asia, and parts of Africa. They are characterized by their long, slender bodies, smooth or rough skin, and distinctive coloration, which often features dark backs and bright underbellies. These cold-blooded animals typically measure between 2 to 6 inches in length, although some species, like the Chinese giant salamander, can grow significantly larger.
As carnivores, newts and salamanders primarily feed on worms, insects, and other small animals, employing various sensory adaptations for hunting. Their breeding habits vary, with some species returning to their birth ponds to lay eggs, while others give live birth. During their life cycle, these amphibians undergo metamorphosis, transitioning from aquatic larvae with gills to adult forms that can live both in water and on land. Most species have lifespans ranging from 10 years to over 50 years, contributing to their ecological roles in various habitats. Understanding their biology and life cycles enhances appreciation for these fascinating creatures and their environments.
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Newts and salamanders
Salamandridae is a large family of newts and salamanders covering the largest range in the world. They are found in western and eastern North America, Europe, Mediterranean Africa, West Asia, China, Southeast Asia, and Japan.
Kingdom: Animalia
Phylum: Chordata
Class: Amphibia
Order: Urodela
Family: Salamandridae
Genus: Various (see below)
Species: Various (see below)
Newts and salamanders in the Salamandridae family can be brown, black, or green on their backs, and yellow, orange, or red below. Some have dark, spotted markings. Newts and salamanders have long, slender bodies with long, slender tails. In the water, their skin is smooth and jelly-like, but on land, their skin can be very rough. Their skin produces poisons that protect them from predators. Salamanders and newts usually have four fingers on their front limbs and five toes on their hind limbs.
Newts and salamanders live in the water and on land. Like other amphibians, newts and salamanders are cold-blooded. This means their body temperatures are the same as the temperature of their surroundings. The average adult salamanders and newts measure 2 to 6 inches (5 to 15 centimeters) long and weigh 1/5 to 8 ounces (6 to 230 grams). The largest species is the critically endangered Chinese giant salamander (Andrias davidianus), which averages 3 3/4 feet (1 1/4 meters) long and weighs 55 to 66 pounds (25 to 30 kilograms). They may reach 6 feet (1 3/4 meters) long. The smallest species, the arboreal minute salamander (Thorius arboreus) is also critically endangered. It measures 2/3 to 3/4 of an inch (15 to 20 millimeters) long.
Salamanders and newts are carnivores, or meat-eating animals. Their diets usually include a variety of worms, slugs, insects, and crustaceans. Some salamanders use their senses of smell and touch to find their prey. Others have good eyesight to help them hunt for food.
When young salamanders and newts are old enough to breed, they often return to the ponds where they were born. They are similar but have very different breeding habits. Terrestrial, or land-dwelling, newts and salamanders that only go into the water to lay eggs have fewer young than aquatic salamanders, which lay up to 450 eggs. The terrestrial California or orange-bellied newt (Taricha torosa) lays 7 to 30 eggs in a clump on waterplants. Some species give live birth. The live-bearing fire salamander (Salamandra salamandra) gives birth to 10 to 30 live young.
After hatching, newts move into the water and change, or metamorphose, into water-dwelling animals. Their skin, breathing, and tails change. These changes help the newts to survive in their watery summer homes. In the water, newts mate, breed, and gain fatty weight to survive the winter on land. Some newts are aquatic, meaning they live in the water year-round, while others leave the water after their developmental years.
Most young salamanders and newts hatch out of their shells into their larval stages. During this stage, these young amphibians breathe through feathery gills. They lose their gills after a few months and then move on land to live as adult salamanders and newts. Lungless salamanders in the Plethodontidae family are never larvae. They hatch as a small version of an adult.
Most newts and salamanders have lifespans of 10 years, but some live to 55.
Bibliography
Heying, Heather. "Salamandridae." Animal Diversity Web, animaldiversity.org/accounts/Salamandridae. Accessed 1 May 2024.
"Salamander and Newt." San Diego Zoo Wildlife Alliance, animals.sandiegozoo.org/animals/salamander-and-newt. Accessed 1 May 2024.
"Salamandridae - Newts, True Salamanders." PBS, www.nhptv.org/wild/salamandridae.asp. Accessed 1 May 2024.