European pond turtle

Description

The European pond turtle reaches a dorsal carapace length of less than 12 cm and more than 20 cm, respectively, depending on subspecies and sex, with northern and eastern subspecies generally growing larger than southern ones. Adults exhibit marked sexual dimorphism, with females growing larger than males, their weight usually ranging from 400 to 700 g. However, in exceptional cases a weight of up to 1500 g can be reached. The coloration of the animals is also very variable. Certain pattern elements can be typical for individual subspecies. The often dark, brown or black dorsal carapace may bear a pattern of fine yellow dots or lines, often radiating from a center on the individual shields. However, there are also forms with dark markings on a light background. The ventral carapace (plastron) may be uniform yellow, mottled cloudy, speckled, dark, or even completely black. However, it is usually distinguished by a black center. The limbs and neck are dark brown to black in color and often have yellow markings as well.

The carapace of the European pond turtle is oval and rather flat; females have a slightly more convex carapace than males. The ventral carapace and dorsal carapace are joined in the area known as the bridge by a flexible layer of cartilage and elastic, membranous tissue. The middle suture of the ventral carapace develops into a hinge in older animals, allowing the anterior plastron lobe some mobility.

The limbs and tail are covered with coarse scales, and the skin of the head and neck is smooth. Behind the head, which is wider than the neck, a fold of skin can be seen that forms a pocket-like covering when retracted. The anterior end of the head is acute-angled when viewed from above, and the jaws bear edentulous sharp horny edges. The eyes, located laterally in the front of the head, have a round pupil. Eye coloration can vary by sex: adult males have a reddish iris in some subspecies, especially the nominate Emys orbicularis orbicularis, but most often they have a brownish iris coloration. The iris of females, however, is yellow in most cases.

There are webbed toes between the five toes of the front legs and the four of the hind legs. All toes are also provided with a claw, whereby especially the front claws are clearly more curved in the males. The European pond turtle belongs to the long-tailed turtle species. This is especially pronounced in hatchlings, but even in adults the tail still reaches the length of half the carapace. In males, the root of the tail is thickened, and the cloaca is clearly located behind the edge of the dorsal carapace.

Habitat

The European pond turtle lives in still or slow-flowing waters, in the shore area of inland lakes, in ponds, ditches and the oxbows of rivers. In the south of the range, streams are also colonized. Along the Mediterranean coast it penetrates into the brackish zones of river mouths. Heavily weedy, nutrient-rich waters with muddy bottoms are preferred. It can even be found in muddy cattle troughs on occasion. Branches sticking out of the water, trees felled by beavers, root stumps and other dead wood are needed for sunbathing, also grass stumps, old nests of water birds and the like are visited for this purpose. Also important are shallow still water zones that are warmed by the sun.

In Austria, the last naturally reproducing population is found in the Danube floodplains east of Vienna, as well as some released specimens on the Wienerberg in the municipal area of Vienna.

The text is a translation of an excerpt from Wikipedia (https://de.wikipedia.org/wiki/Europäische_Sumpfschildkröte). On wikipedia the text is available under a „Creative Commons Attribution/Share Alike“ licence. Status: 26 May 2021