Böttger's dwarf clawed frog
| Böttger's dwarf clawed frog | ||||||||||||
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Böttger's dwarf-clawed frog at the amplexus |
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| Hymenochirus boettgeri | ||||||||||||
| ( Tornier , 1896) |
Böttger's dwarf clawed frog (also written Boettgers; Hymenochirus boettgeri ) is one of four species from the genus of the dwarf clawed frog and belongs to the family of tongue-less frogs within the order Froschlurche . Little clawed frogs could be described as a smaller version of the clawed frogs. But unlike these, they have webbed fingers between the front fingers.
Etymology and history of research
The German trivial name and the scientific addition “ boettgeri ” honor Oskar Boettger , the former curator of the herpetological department of the Senckenberg Natural History Museum in Frankfurt am Main .
It was first described in 1896 by Gustav Tornier, who first assigned the species to the genus Xenopus and then again in 1897 with the same text and an identical illustration. Tornier had only a single type copy available for his processing , which was captured by Franz Stuhlmann in 1891 as part of an Africa expedition led by Emin Pascha in the Ituri region (upper reaches of the Aruwimi ; today the Democratic Republic of the Congo ) and taken to Europe in alcohol had been sent. Tornier specifies the “Ituri ferry at Wandesoma” as the type location. What exactly is meant by this is unclear. Stuhlmann describes in his expedition report an "Itúri ferry" with the local name "Mbáu", which is said to be located near a "settlement of the Wandesáma, called Vundenakáma". According to Stuhlmann, the place should be in the east of what is now the province of Ituri , in an area in which the Ituri river takes a southerly course before it turns west towards the Congo .
In the same year 1896 of the first description, George Albert Boulenger reports doubts about the assignment to the genus Xenopus and places the frog in its own genus Hymenochirus . Shortly afterwards, when Boulenger had his own evidence, which had been collected by George Latimer Bates in the area of the Benito River (Mbini) in what is now Equatorial Guinea , he confirmed his assessment in a second publication and at the same time strongly criticized Tornier's first description, which he wrote described as "very inadequate". In particular, he criticized the fact that Tornier had apparently failed to check his type specimen for the presence or absence of teeth, which would have enabled him to exclude an assignment to the genus Xenopus (teeth in the upper jaw), since Hymenochirus boettgeri is completely toothless.
Occurrence
Boettger's pygmy clawed frog is a widespread and frequent frog in the central African rainforest in the wider Congo Basin . The distribution area extends from southeast Nigeria , southern Cameroon to the south over Equatorial Guinea, Gabon and the Republic of the Congo and to the east over the south of the Central African Republic and across the Democratic Republic of the Congo until the forest areas merge into the savannas of East Africa. The species is listed by the IUCN as "not endangered" ("least concern"). It prefers herbaceous, shady still waters of the lowland rainforests and small pools along calm flowing waters. They lead a year-round aquatic way of life and only leave their waters when they dry out or the food supply runs dry.
features
Boettger's dwarf clawed frogs reach a size of 3 to 4 cm. The top is colored light to medium brown or gray. The underside is light to whitish. In addition, there are individually arranged spots and points on the rough skin. In females and males, a dark stripe runs from the mouth to behind the eyes. The skin is covered with numerous "spines" or "tubercles", which are particularly large and clearly developed on the flanks and on the hind legs. The head is flat and slightly elongated, which means that the mouth has a rather pointed shape. If you look at the head from the side, it looks like a fish. The jaws are toothless. In adult females, there is an elongated notch on the back. The forelimbs are quite narrow, with a tiny "hand" with four fingers at the end. The fingers are about half or at most up to ⅔ covered by webbed feet. The significantly larger hind legs are also webbed and have five toes. As with their relatives, the clawed frogs, the three inner toes are equipped with horn claws.
Hymenochirus boettgeri differs from Hymenochirus feae in that the fingers and toes are not completely enclosed by the webbed feet , from Hymenochirus curtipes in the longer legs and the more pronounced "skin tubercles" on the flanks and legs and from Hymenochirus boulengeri also in the longer hind legs.
Way of life
During the day, the sociable animals usually hide on the ground, in shallow hiding places made of roots or stone. In the afternoon you can see them on the surface of the water. They also like to hide in damp piles of leaves on the bank. So their aquatic way of life is not as strict as once assumed. If their ancestral water dries up or the food runs dry, they even leave it. Pygmy-clawed frogs are crepuscular and nocturnal. In the early evening they go in search of food. Mainly insect larvae and small crustaceans are hunted, but carrion is also eaten. They can perceive and determine their prey via sensory cells on the body. Then they fix their victim with their eyes and snap shut. Since pygmy clawed frogs have neither a tongue nor teeth, they use the technique of sucking to catch their prey.
Individual evidence
- ^ B. Beolens, M. Watkins & M. Grayson: The Eponym Dictionary of Amphibians. 250 pp., Pelagic Publishing, Exeter, 2013. ISBN 978-1-907807-42-8 (reading sample)
- ↑ G. Tornier: Reptiles and Amphibians (Creeping Animals). In: K. Möbius (Hrsg.): German East Africa: scientific research results about the country and people of our East African protected area and the neighboring countries - Volume III: The animal world of East Africa and the neighboring areas. 164 p., Geographische Verlagsbuchhandlung Dietrich Reimer, Berlin, 1896.
- ^ A b c G. Tornier: Die Kriechthiere German-East-Africa - Contributions to the systematics and the theory of descending. 164 p., Geographische Verlagsbuchhandlung Dietrich Reimer, Berlin, 1897. (digitized version)
- ↑ F. Stuhlmann: With Emin Pascha in the heart of Africa. 901 p., Geographische Verlagsbuchhandlung Dietrich Reimer, Berlin, 1894. (digitized version)
- ^ GA Boulenger: A new Genus of Aglossal Batrachians. In: The Annals and Magazine of Natural History, including Zoology, Botany, and Geology. Vol.XVIII (6th series), no.CVII, p. 420, 1896. (digitized version)
- ↑ a b c d G. A. Boulenger: On Hymenochirus, a new Type of Aglossal Batrachians. In: The Annals and Magazine of Natural History, including Zoology, Botany, and Geology. Vol. IV (7th series), No. XX, pp. 122–125, 1899. (digitized version )
- ^ A b IUCN SSC Amphibian Specialist Group. 2014. Hymenochirus boettgeri . The IUCN Red List of Threatened Species 2014: e.T58154A18396612. Retrieved April 23, 2018.
- ^ GA Boulenger: Report on the batrachians collected by the late L. Fea in West Africa In: Annali del Museo civico di storia naturale di Genua. Series 3, Vol. II, pp. 157–172, 1905 (digital version )
- ^ GK Noble: Contributions to the herpetology of the Belgian Congo based on the collection of the American Museum Congo Expedition, 1909-1915. Part III. Amphibia. In: Bulletin of the American Museum of Natural History. Vol. XLIX, pp. 147–347, 1924. (digital copy )
- ↑ G.-F. de Witte: Batraciens récoltés au Congo Belge par le Dr. H. Schouteden et par MG-F. de Witte. In: Annales du Musée du Congo Belge, Zoology (C). Série I, Tome III, Fascicule 4, pp. 153-188, Pl. V-XI, 1934.
- ↑ Profile: Pygmy-clawed frog. Retrieved April 2, 2018 .