Marbled Newt (Triturus marmoratus)

Marbled Newt (Triturus marmoratus)

They are svelte, a large squared head. Their skin is quite smooth. Their limbs are short and robust. Their fingers are short. In the aquatic phase, males have a tall body and tail crests, these two crests are connected at a dip. Females lack a body crest in both phases but have a quite small tail crest. In the terrestrial phase, the crests decline and become unnoticeable. Their skin becomes dry, rough and impervious.

They are marbled green and black; they have an orange colored line along the middle of their back this being more vivid for females. Their head is usually dark speckled with very light irregular spots and lines. The bottom of their flanks is spotted white. Their underbody is light gray speckled with black. In the aquatic phase, males have very tall body and tail crests, this is usually dark in color with light thin vertical bars. The lower part of the tail crest is usually uniform dark brown or black. Their belly is light gray speckled with white. In the terrestrial phase, the specimens become more vivid in color, their underside is light and their flanks may be bluish. Their external gills become reddish.

When young, they are very lightly colored (usually yellow). Their tail is clear with a series of small dark spots; these spots are not found on the body. Their external gills may also be very light.

Location:

Found in northern Portugal, northern Spain and central & western France.

Sexual differences

Females are generally robust and do not develop a body crest in their in the aquatic phase, and their tail crest is shorter then the males. The males’ tail is light in color. The males orange dorsal line is less evident then for the females.

Diet
They feed mainly on invertebrates such as spiders, water insects. They also eat insect larva. The larvas eat water insects, mainly water fleas up to a size of about 11 mm long.

Defensive habits
If they are disturbed they may place their tail perpendicularly and slowly move it from side to side, they also raise their lower body repeatedly.

Reproduction
The breeding season starts just after hibernation when the specimens first enter the water (mid-February to mid-May).

The male will swim in front of a female, arcing his back like a cat, he makes his tail vibrate in the direction of the female. In most cases, the female then allows him to mount her, then he lifts his tail exposing his cloacae. He then moves away and the female follows him. If the female then touches his tail with her head, the male produces a spermatophore which he lays on the bottom of the water. The female moves on top of this, the male comes around perpendicularly to the female and adjusts her position for her to be able to intake the sperm. A female may lay between 200 to 400 eggs per year, these eggs are laid one by one, individually. The eggs are about 1.8 to 2 mm in diameter, laid in individual balls of about 3 to 4 mm in diameter; they are light yellow, sometimes white or light green. They are uniform in color. The egg is encased in a transparent ball.

Sexual maturity, life span
Their average life span is about 9 years, they reach their sexual maturity in about three to four years.

Habits
Marbled newts are active during the night in their terrestrial phase; however they may be seen by day in the breeding season and in rainy conditions. Males are very territorial and defend parts of the ponds bottom where there is no vegetation.

Predators
In their aquatic phase, they are hunted by snakes. The larvas are eaten by insects and their larva.