wetlands and biodiversity

Smooth newt  






This is a male smooth newt in it’s beautiful fluorescent colour during spawning period. Daytime in spring the males are often found in groups in shallow waters where they hunt females down and impress them with their colourful outfit. When they have found a female mating happens several times in the shrubs. The sperm is transferred to the female’s rear end where they are fertilized before they are individually placed on leaves.

Newts are sometimes called water-lizards and the males sure look like smal dinosaurs with their impressive large back comb. Imagine if they would be 10 meters long instead of 10 cm.

The tail also has great function as it gives the speed with a slapping motion just like fish would do.

The front-feet on a fully grown newt have four fingers with small claws. The claws are especially usefull when the newt is moving on land for example when climbing on vertical walls that have a slightly uneven surface. The feet are also used to dig and drag themselves into cavities or to paddle precise during short distances. Their feet do not have only one purpose and their exterior therefore is a compromise. The skin is covered with tiny warts. Looking at their soles of the feet they seem moist and smooth.

A young female can utilize the surface tension of the water to sunbathe. She is floating, something that the great crested newt never would do since they rather sit on the bottom of the waterbody.


                         

   


Her colour is somewhere between green-brown and grey-green without any special signs. Unlike the great crested newt the lower part of the abdomen on females can increase it size a lot during ovulation. Maybe this is not that surprising as the eggs from the two species are almost the same size but the smooth newt only is a fourth of the great crested newts body volume and half of the length.

The tiny newly hatched larvae is only 1 cm long and eats algae and bacteria that is served on plants and rocks. When growing, water fleas and other small insects will serve as the main food source in the water.

On land they often have to dig for larvae in soft forest beds or in compost heaps. The small larvae requires a lot of nutrients to survive the winter when it digs itself down under the frostline and hiding under stumps and rocks. In the water it is possible to attract grownup individuals with little worms.












Observing the females during ovulation shows that they roll around on the bottom of the waterbody with leaves as they lay eggs on them. Unlike the great crested newt the smooth newt places its eggs on individual and detached plant pieces, maybe because they don’t have the same strength in their feet to fold the leaf. The result is a small light brown egg attached to the leaf with a transparent gel.
 wetlands tjänster projekt_swe
 
© Peter Feuerbach