Pseudis paradoxa
Large Harlequin Frog ( Pseudis paradoxa )
The Great Harlequin Frog ( Pseudis paradoxa ), also called Paradoxical Frog, is a Froschlurch from the family of tree frogs ( Hylidae ). He is an unusual representative of the harlequin frogs ( Pseudis ), which can be up to 25 inches long as a tadpole, as adult animal, but shrinks to a length of only 4.5 to 7.5 centimeters.
From the skin secretion of Pseudis paradoxa more substances having antimicrobial activity have been isolated that are of interest for medical applications.
Description
The Great Harlequin frog is similar in appearance to the pond frog. He is green with dark green to olive-green stripes. In the females the throat region is whitish pale with scattered speckles. The head is short and construction for all pointed, the eyes are bulging. The oval pupils are placed horizontally. The skin is very slippery. Equipped with webbed toes hind legs are strong and significantly longer than the front legs. At the front legs splayed the thumb falls on the long finger be used in the mud for catching prey and for digging. To strengthen the legs has Pseudis paradoxa an additional bone between the two outer toes.
This Build the Great Harlequin frog is very well adapted to life in the water. He spends his life almost exclusively in the water, and usually hidden just below the water surface by floating plants, but can easily droughts by digging through the soil. The Great Harlequin frog feeds mainly on insects and small amphibians.
The Great Harlequin frog is one of the nocturnal frogs, only during the mating season, the animals are active during the day. During the mating season the males, which are usually slightly smaller than the females, this brought with her characteristic croaking lure. The females lay the frothy from spawning on aquatic plants, the fertilization of the egg takes place outside the body.
The embryos grow to greenish tadpoles with an extremely unusual length zoom. While the adult animals are only 4.5 to 7.5 cm long, reaching the larvae after four months just before their metamorphosis a length of up to 27 cm, which is three to five times as large as after metamorphosis. Although the Great Harlequin frog to the smaller frogs counts, its larvae are the largest known tadpoles. It is believed that the growth of the larvae is activated by the hormone prolactin.
Because of its unusual development of the frog got its name " Paradoxical Frog". The first reports of these frogs wrote irritated by a reverse development of frogs towards tadpoles. The naturalist Maria Sibylla Merian described in their expedition in Suriname in 1700 for the first time Pseudis paradoxa as a frog who is " transformed into a fish. " The scientific description was in 1758 by Linnaeus.
From the Grand harlequin frog five subspecies are known:
- Pseudis paradoxa paradoxa
- Pseudis paradoxa caribensis
- Pseudis paradoxa platensis
- Pseudis paradoxa occidentalis
- Pseudis paradoxa nicefori
Dissemination
The Great Harlequin frog is widespread on the island of Trinidad, and on the South American continent east of the Andes from Colombia to northern Argentina in the. The frog preferred standing waters and is found in tropical and sub-tropical climates at altitudes of up to 1000 m.
The tadpoles are in some regions of South America as a delicacy; but since the Great Harlequin frog is very shy, its stock is not considered endangered. In terrariums Pseudis paradoxa is rarely kept for breeding these frogs, little is known.
Special
From the skin secretion of the Great Harlequin frog four peptides could be isolated, their antimicrobial effect has been demonstrated in laboratory experiments. This Pseudine protect the frog from infection.
With that in laboratory synthesized peptide Pseudin -2 early reported after 2008 scientists from the University of Ulster in Northern Ireland and the University of the United Arab Emirates in Al- Ain, that this substance can stimulate the production of insulin in the human body. This could be used Pseudin - 2 for the treatment of diabetes mellitus type 2. Regarding the mechanism of action is one Pseudin -2 to the new class of Inkretinmimetika, the most well known, the drug exenatide, also animal origin.