Epirus water frog

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Epirus water frog
Epirus water frog: Adult female during the reproductive period

Epirus water frog: Adult female during the reproductive period

Systematics
without rank: Amphibians (Lissamphibia)
Order : Frog (anura)
Subordination : Neobatrachia
Family : Real frogs (Ranidae)
Genre : Water frogs ( pelophylax )
Type : Epirus water frog
Scientific name
Pelophylax epeiroticus
( Schneider , Sofianidou & Kyriakopoulou-Sklavounou, 1984)

The Epirus water frog or Epirus frog ( Pelophylax epeiroticus or Rana epeirotica ) belongs to the family of real frogs (Ranidae) within the order of the frog auger . In addition, it is reckoned according to appearance, way of life and relationships to the water frogs , which are now placed in their own genus Pelophylax . The species is native to western Greece and southern Albania . The type locality is the east bank of Lake Ioannina, 5 kilometers south of Amphithea, Epirus region.

features

The Epirus water frog has a body length of about 60 to 100 mm, with the males reaching sizes between 60 and 85 and the females between 65 and 100 mm. In the males and females of the type locality, the mean body length is 74.4 millimeters and 83 millimeters, respectively. The back color is olive to light green with irregular dark green spots; however, there are also brown specimens with dark brown spots. Usually a light green vertical stripe is formed on the middle of the back. The skin is smooth with flat dorsal ridges. The top of the hind legs is also olive to light green with dark, arched spots. The ventral side is whitish. The yellow color of the flanks and loins is characteristic. The webbed feet reach to the tips of the toes and are only slightly indented.

Brown phenotype of the Epirus water frog

The males have paired, black to dark gray vocal sacs and dark rutting calluses . The heel bumps are triangular and small. A mean length of 3.53 millimeters was calculated for the males of the type locality, and 3.95 millimeters for the females; it is positively correlated with body length.

Externally, the Epirus water frog of which is sympatrically occurring Balkan water frog ( pelophylax kurtmuelleri ) not easy to distinguish, especially as hybrids of both types occur. A sure distinguishing feature of the Epirus water frog is its mating call, which is strikingly different from that of the Balkan water frog and also clearly audible from that of the hybrids.

distribution and habitat

Distribution of the Epirus water frog

The distribution area of ​​the Epirus water frog is limited to the west of Greece west of the Pindos Mountains, the northwest of the Peloponnese, the island of Corfu and the coastal plain near Saranda in the extreme south of Albania . The height distribution ranges from sea level to 480 m (Ioannina Lake). The Epirus water frog lives in still waters, such as lakes, ponds, marshland, swamps, canals with mostly rich, low vegetation and on the banks of rivers with low flow speeds, generally in areas with a wide and open horizon. The river systems in Epirus and the two rivers Pinios and Alfios in the Peloponnese have large populations.

Pelophylax epeiroticus lives sympatric, partly also syntopically with Pelophylax kurtmuelleri and with one or more types of hybrids. Pelophylax epeiroticus is always the dominant species, followed by Pelophylax kurtmuelleri and hybrids.

Reproductive behavior

The spawning period extends from the end of April to the beginning of May, depending on the latitude and altitude of a population and the local weather, it can be postponed by a few days. When there is high reproductive activity, the call begins in the morning around 9 a.m. and lasts until around midnight or longer, with a longer interruption at dusk, during which the frogs prey on insects. Calling Epirus water frogs have been observed in water temperatures between 13 and 24.5 ° C.

Mating call

Sound images (oscillograms) of two pairing calls at 24.5 ° C (above) and 14.0 ° C water temperature (below).

The calls consist of very short impulses with intervals in between, which is why the calls sound creaky (see illustration). According to the calculated equations, the calls last 616 milliseconds at a water temperature of 15 ° C and consist of 32 pulses. As the temperature rises, the duration of the calls decreases while the number of impulses per call increases. At a water temperature of 24.5 ° Celsius, the highest when pairing calls were recorded, the average call duration is 493 milliseconds, the number of pulses an average of 45.4 pulses per call. The frequency spectrum has a strong component between 1400 and 2400 Hertz. The males usually utter the calls in series.

Hybrids

Since the Epirus and Balkan water frog are socialized, hybridization occurs. The hybrids are distinguished from the parent species by morphological features, but most clearly by the mating call, which is typically exactly intermediate between the mating calls of Pelophylax epeiroticus and Pelophylax kurtmuelleri . Mating calls from hybrids with differing characteristics allow the assumption that backcrosses with the two parent species also occur.

Systematics

The Epirus water frog belongs to the complex of forms of the water frogs ( Pelophylax ), which has not yet been systematically processed and is difficult to determine due to the diverse hybrid formations . Other closely related and recognized water frog species on the southern Balkan peninsula including the Mediterranean islands are the Balkan water frog ( Pelophylax kurtmuelleri ), the scutarian water frog ( P. shqipericus ) and the Crete water frog ( P. cretensis ). The Karpathian water frog ( P. cerigensis ) is called a form with an unexplained status. Bedriaga's water frog ( Pelophylax cf. bedriagae ) also occurs in the Middle East , which, according to now dubious opinions, should also occur in Turkey, Cyprus and several Greek islands.

Danger

The Epirus water frog is classified as endangered ("Vulnerable") in the IUCN's Red List of Threatened Species because it has a relatively small distribution area of ​​less than 20,000 km² and this is highly fragmented. In addition, an increasing deterioration of its habitats is noted. The main threat to this species comes from the pollution and drainage of suitable habitats through agriculture, tourism and the settlement of its habitat. In Albania, the frog is also hunted and eaten commercially.

Evidence cited

  1. ↑ a b c d e f Hans Schneider, Theodora S. Sofianidou, Pasqualina Kyriakopoulou-Sklavounou: Bioacoustic and morphometric studies in water frogs (genus Rana) of Lake Ioannina in Greece, and description of a new species (Anura, Amphibia). In: Journal for Zoological Systematics and Evolutionary Research. Volume 22, 1984, pp. 349-366.
  2. ^ Dieter Glandt: Pocket dictionary of the amphibians and reptiles of Europe. Quelle & Meyer, Wiebelsheim 2010, ISBN 978-3-494-01470-8 .
  3. ^ Hans Schneider, Theodora, S. Sofianidou, Byron Asimakopoulos: Distribution of the water frog Rana epeirotica (Amphibia, Anura) in Greece. In: JJ van Gelder, H. Strijbosch, PJM Bergers (Eds.): Proceedings of the Fourth Ordinary General Meeting of the Societas Europaea Herpetologica. Nijmegen 1987, pp. 365-367.
  4. ^ Theodora S. Sofianidou, Hans Schneider: Distribution range of the Epirus Frog Rana epeirotica (Amphibia: Anura) and the composition of the water frog populations in western Greece. In: Zoologischer Anzeiger. Volume 223, 1989, pp. 13-25.
  5. ↑ Hans Schneider, Idriz Haxhiu: The distribution of the Epeirus frog (Rana epeirotica) in Albania. In: Amphibia-Reptilia. Volume 13, 1992, pp. 293-295.
  6. ↑ Hans Schneider, Theodora S. Sofianidou: Hybrid types of water frogs living sympatrically with Rana epeirotica and Rana ridibunda in Greece. In: JJ van Gelder, H. Strijbosch, PJM Bergers (Eds.): Proceedings of the Fourth Ordinary General Meeting of the Societas Europaea Herpetologica. Nijmegen 1987, pp. 347-352.
  7. ↑ Jörg Plötner: The West Palearctic Water Frogs - From Martyrs of Science to Biological Sensation. In: Supplement to the magazine f. Field Herpetology. Volume 9, Bielefeld 2005, ISBN 3-933066-26-3 .
  8. ↑ Pelophylax epeiroticus in the endangered Red List species the IUCN 2009. Posted by: Uzzell, T. et al. , 2008.

literature

  • Axel Kwet: Reptiles and Amphibians of Europe. Franckh'sche Verlagsbuchhandlung, Stuttgart 2005, pp. 108-109, ISBN 3-440-10237-8 .
  • Hans Schneider, Theodora S. Sofianidou, Pasqualina Kyriakopoulou-Sklavounou: Bioacoustic and morphometric studies in water frogs (genus Rana) of Lake Ioannina in Greece, and description of a new species (Anura, Amphibia). In: Journal for Zoological Systematics and Evolutionary Research. Volume 22, 1984, pp. 349-366.
  • Hans Schneider, Theodora, S. Sofianidou, Byron Asimakopoulos: Distribution of the water frog Rana epeirotica (Amphibia, Anura) in Greece. In: JJ van Gelder, H. Strijbosch, PJM Bergers (Eds.): Proceedings of the Fourth Ordinary General Meeting of the Societas Europaea Herpetologica. Nijmegen 1987, pp. 365-367.
  • Hans Schneider, Idriz Haxhiu: The distribution of the Epeirus frog (Rana epeirotica) in Albania. In: Amphibia-Reptilia. Volume 13, 1992, pp. 293-295.
  • Hans Schneider, Theodora S. Sofianidou: Hybrid types of water frogs living sympatrically with Rana epeirotica and Rana ridibunda in Greece. In: JJ van Gelder, H. Strijbosch, PJM Bergers (Eds.): Proceedings of the Fourth Ordinary General Meeting of the Societas Europaea Herpetologica. Nijmegen 1987, pp. 347-352.
  • Theodora S. Sofianidou, Hans Schneider: Distribution range of the Epirus Frog Rana epeirotica (Amphibia: Anura) and the composition of the water frog populations in western Greece. In: Zoologischer Anzeiger. Volume 223, 1989, pp. 13-25.
  • Hans Schneider: Bioacoustics of the Froschlurche - native and related species. With audio CD. Supplement to the Zeitschrift für Feldherpetologie 6. Laurenti Verlag, Bielefeld 2005. ISBN 3-933066-23-9 . Audio samples 75–79.
  • Theodora S. Sofianidou: Electrophoretic study of hybrids of water frogs (Rana epeirotica, R. balcanica) in the Ionian zone of Greece. In: Israel Journal of Zoology. Volume 42, 1996, pp. 149-157.
  • Anna Tsiora, Pasqualina Kyriakopoulou-Sklavounou: Male reproductive cycle of the water frog Rana epeirotica in northwestern Greece. In: Amphibia-Reptilia. Volume 22, 2001, pp. 291-302.
  • Anna Tsiora, Pasqualina Kyriakopoulou-Sklavounou: A skeletochronological study of age and growth in relation to adult size in the water frog Rana epeirotica. In: Zoology. Volume 105, 2002, pp. 55-60.

Web links

Commons : Epirus Edible Frog ( Pelophylax epeiroticus )  - Collection of images, videos and audio files