Tomato frog
| Tomato frog | ||||||||||||
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Tomato frog |
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| Dyscophus antongilii | ||||||||||||
| Grandidier , 1877 |
The tomato frog ( Dyscophus antongilii ) is a frog from the family of narrow-mouthed frogs (Microhylidae) living on the island of Madagascar . It is one of three species in the genus Dyscophus .
features
The tomato frog has a stocky body, almost rounded in plan view, with a broad head and a very short snout. The eyes with their almost round pupils are set wide apart. The eardrums are visible and remain smaller than the diameter of the eyes. The jawbones are dentate. A clear sexual dimorphism can be observed, since the males are only 65 millimeters long at most, but the females up to 105 millimeters long. Such specimens then reach weights of up to 230 grams. On the webbed hind feet, the species has shovel-shaped grave calluses (compare for example: common garlic toad ) with which it can dig into the ground. The short legs do not enable the animals to make great leaps; for this they climb occasionally.
Due to the intense orange, red to red-brown color of the smooth-skinned upper side, the frog may be reminiscent of a tomato lying on the ground. The ventral side is yellowish-white; there may sometimes be black spots on the throat.
The tomato frog can not always be clearly distinguished from its relative, the spotted tomato frog ( Dyscophus guineti ), which is also found in Madagascar.
Occurrence and way of life
The distribution area extends on the east coast of Madagascar from the Bay of Antongil to the region south of Tamatave . The altitude distribution is between sea level and 200 meters above sea level .
The tomato frog lives terrestrially and is nocturnal; only when it gets dark does he leave his self-dug hiding place in the foliage of the tropical rainforest . The diet consists of insects and their larvae , mollusks , small mammals , other amphibians and earthworms . During the dry season, there is a rest phase.
In the event of disturbances and danger, the animal inflates and can squirt a skin gland secretion several centimeters. In humans, this discharge can lead to skin swelling on contact.
Reproduction, individual development
At the beginning of the rainy season in March, tomato frogs seek out swamps, shallow pools or moats. The male now utters courtship calls, which sound like dull chicken cackling, mainly at night with the help of his inner vocal sac. A series of six to 60 calls are generated, which can last up to 114 seconds and have fewer tones at the end than at the beginning. When mating, the male actually clasps the female with an axillary amplexus . However, it can occasionally slip backwards because it does not develop any calluses . Couples with an inguinal amplexus can also be found. The released and externally inseminated spawn spreads like a film on the surface of the water and contains around 1000 to 1500 black and white, three millimeter eggs per clutch.
The initially six millimeters large and transparent tadpoles hatch after 36 hours at a water temperature of 23.5 ° C. Like all larvae of the aquatic narrow- mouthed frog species, they have neither teeth nor horned beaks and filter food particles from the water. After six to nine weeks, they and their oar tails have reached a length of 45 to 55 millimeters and then complete the metamorphosis as 15 millimeter small frogs that go ashore. At this stage they are colored yellow (the flanks darker); Tomato frogs only get their red color from a size of around two centimeters.
Duration
The tomato frog is endangered in its population due to habitat destruction and at the same time a very small area of distribution. Additionally catches provide for the pet trade is a serious threat, although the species by CITES under protection of species stands.
In Europe, the tomato frog is only kept in a few zoos , for example the Zurich Zoo , the Bern Zoo, the Leipzig Zoo or the Cologne Zoo . Reproduction usually only succeeds there after the appropriate hormone administration or the imitation of environmental conditions that are as natural as possible.
Web links
- Species portrait of the tomato frog near Amphibiaweb (Engl.)
- Dyscophus antongilii inthe IUCN 2013 Red List of Threatened Species . Posted by: Christopher Raxworthy, Miguel Vences, Franco Andreone, Ronald Nussbaum, 2004. Retrieved September 16, 2013.