Turtle imitates fish

Reptile lives underwater for six months without appearing

Musk turtle © University of Vienna
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The musk turtle can live under water for about six months without appearing. How she creates this and how the animal breathes in time has now been revealed by Viennese scientists in the journal "The Anatomical Record". Thereafter, there are papillae in the mouth and pharynx of the turtle - lobe-shaped, blood vessel-covered surface structures - which absorb the oxygen contained in the water and release carbon dioxide.

Like the proverbial fish in the water, the musk turtle moves because it does not appear for up to six months. The starting point of the new study was an analysis of eating behavior: "We came across the flap-like surface structures of the mouth and throat, which are particularly pronounced in the musk turtle, " says Egon Heiss from the Department of Theoretical Biology at the University of Vienna.

So far, the function of the papilla was a mystery, because other, not under water breathing turtle species have surface enlarging protuberances.

No breathing over the skin

Since these large, branched musk-turtle papillae are not related to food intake, the scientists researched their breathing. So far, it was assumed that the gas exchange - absorb oxygen, release carbon dioxide - successes over the skin. Sea snakes, many amphibians and soft-shelled toads breathe this way. However, the skin of the musk turtle is thick, horny and there are few vessels underneath. She can not breathe with it.

Papillae under the microscope

Unlike the papillae: They are traversed by numerous blood vessels. The researchers examined very thinly cut tissue, which they obtained from the museum and from which they created digital images under the light microscope. In addition, a scanning electron microscope was used, which provided remarkably high magnifications of the surface structures. display

Heiss explains the results of the investigations: "The images show how present these papillae are. They are relatively large, branched and found in large numbers. And they are perfectly flushed, as the turtles regularly supply their throat with fresh water. So it is clear that these animals have developed something similar to gills. "

An unusual turtle

The Musk turtle is unusual in many ways: with a size of 7.5 to 10 centimeters, it is one of the smallest species of turtles - giant tortoises in the Gal√°pagos Islands, however, reach a tank length of over one meter. Their appearance resembles - although sea turtle - the tortoise.

In addition, according to the researchers, they are able to produce a strong-smelling secretion, with which they deter their enemies. The home of the musk turtle are the waters of North America, where it mainly consumes snails.

Schildk ten oldest animal vertebrates

The Department of Theoretical Biology at the University of Vienna is not only researching musk turtles, but also the Spanish ribbed newt, the young Asian giant tortoise and the Mexican cockerel. Heiss is especially fond of turtles: There have been around 220 million years. They are the oldest terrestrial vertebrates and still exist. That's just fascinating

(idw - University of Vienna, 02.06.2010 - DLO)