Discoglossus pictus

Discoglossus pictus Otth, 1837

Original Published Description:

Otth, A. (1837).  Beschreibung einer neuen europäischen Froschgattung, Discoglossus. Neue Denkschriften der Allgemeinen Schweizerischen Gesellschaft für die Gesammten Naturwissenschaften. 1, 1-8.

Common Names

Painted Frog (English)

Languages: English

Overview

Summary

Discoglossus pictus is found in the western Mediterranean Basin, on sandy coastal areas or in Mediterranean woodlands. Its morphology features characteristic dorsolateral folds and an inconspicuous tympanum. The species breeds in lentic freshwater marshes or brackish coastal marshes. Although the present species population is considered secure, there is a steady reduction in habitat from urbanization and from extraction of water resources for human use.

Author(s): Hogan, C.Michael
Rights holder(s): Hogan, C.Michael

Distribution

D. pictus is found in portions of North Africa as well as some European western Mediterranean areas. Countries of native occurrence include Algeria, Tunisia, France, Italy and Malta (Bosch et al. 2009). In Italy one of the main ecoregions of occurrence is the South Appenine mixed montane forests. The Mediterranean woodlands and forests is one of the chief ecoregions of occurrence in North Africa (World Wildlife Fund & Hogan, 2007).

Prior to the recognition of D. scovazzi as a separate species, the distribution of D. pictus included the Galita Islands (Salvador, 1996). It is not clear whether the population on the Galita Islands is D. pictus or D. scovazzi.

Author(s): Hogan, C.Michael
Rights holder(s): Hogan, C.Michael

Taxonomic Notes

Moroccan populations of D. pictus earlier considered to belong to this species are now separated as Discoglossus scovazzi (García-París and Jockusch, 1999).

Author(s): Hogan, C.Michael
Rights holder(s): Hogan, C.Michael

Description

Diagnostic Description

The characteristic appearance of D. pictus is frog-like, with a pointed snout and pupil that is round. There is an absence of any aubarticular tubercles. The tymphanum is inconspicuous. There is a dorsolateral fold on either side of the dorsum; however, those folds typically only extend from each shoulder to the corresponding eye. The dorsum exterior exhibits irregular dark blotches or longitudinal stripes (Salvador, 1996).

Author(s): Hogan, C.Michael
Rights holder(s): Hogan, C.Michael

Size

D. pictus adult males have a characteristic length of 70 millimeters, measured as snout to vent; correspondingly, adult females typically achieve a snout to vent length of 68 millimeters (Salvador, 1996).

Author(s): Hogan, C.Michael
Rights holder(s): Hogan, C.Michael

Morphology

The head of D. pictus is strongly depressed and narrow, evincing a rounded or pointed snout. The species tongue is disc-shaped. Fingers are abbreviated, with the first being shortest, the third longest, and the second and fourth of roughly equal intermediate length. The hindlimb architecture manifests considerable length, with some webbing in evidence betwixt the toes. A small inner metatarsal tubercle is visible. There are three palmar tubercles and subarticular tubercles are absent. The dorsum presents small glands, with overall skin-tone being smooth.

Color of the dorsum exterior is brown, olivaceous or gray, with a dark temporal band running from the tympanum to snout. There are dark spots of irregular size and shape in evidence on the dorsum; moreover, these spots may sometimes assume a form of longitudinal striping. The iris is bronze or golden. Venter is white or a yellowish color, less frequently olivaceous red.  Males exhibit black corneous excrescences on the limbs, throat and belly (Salvador, 1996).

Author(s): Hogan, C.Michael
Rights holder(s): Hogan, C.Michael

Ecology

Habitat and Ecology

D. pictus is present in a wide variety of western Mediterranean habitats, including open, sandy coastal areas, pastures, vineyards, woods and forests, often in dense vegetation proximate to surface water bodies. This anuran breeds in most types of lentic (still water) habitats; moreover, while classified by the IUCN as a freshwater species, it is sometimes present in not only in freshwater marshes, but also in brackish water. In Sicily, populations have been associated with irrigation channels, water cisterns, pipes and canals in cultivated areas (Bosch et al. 2009). While known to occur near sea level altitudes, the species has been observed at elevations up to 1000 meters in Algeria (Salvador, 1996).

In terms of habitat descriptions per ecoregion occurrence, D. pictus is known from the South Appenine mixed montane forests as well as the Mediterranean woodlands and forests (World Wildlife Fund & Hogan, 2007).

Aestivation is thought to occur by spending hot summer months beneath stones or in rock crevices (Salvador, 1996).

Author(s): Hogan, C.Michael
Rights holder(s): Hogan, C.Michael

Population Biology

In addition to its native range, there are introduced populations of D. pictus in Spain and France, which populations appear to be abundant and expanding their range. This anuran is somewhat common in Sicily. Further information is needed on the populations of the species over the rest of its distribution, though it is thought to be common in some portions of its range (Bosch et al. 2009).

Author(s): Hogan, C.Michael
Rights holder(s): Hogan, C.Michael

Life History

Reproduction

In breeding season, the males are the first individuals to congregate near surface water bodies. Mating occurs nocturnally.  Based upon Algerian observations, ova-deposition commences in February and may endure through May, depending on elevation and water occurrences (Salvador, 1996).

Author(s): Hogan, C.Michael
Rights holder(s): Hogan, C.Michael

Tadpole morphology

Tadpoles may attain a length of up to 41 millimeters (Salvador, 1996).

Author(s): Hogan, C.Michael
Rights holder(s): Hogan, C.Michael

Conservation

IUCN Red List Category and Justification of Conservation Status

D. pictus is listed as Least Concern by the IUCN in view of its relatively broad distribution, tolerance of a gamut of habitats, presumed large population, and because it is unlikely to be declining fast enough to qualify for listing in a more threatened category (Bosch et al. 2009).

Author(s): Hogan, C.Michael
Rights holder(s): Hogan, C.Michael

Threats

Sicilian populations of D. pictus appear to be locally threatened (but not necessarally endangered) by a decline of traditional rural land-use, including increasing urbanization. Maltese populations are reported to be threatened by groundwater extraction (Bosch et al. 2009).

Author(s): Hogan, C.Michael
Rights holder(s): Hogan, C.Michael

Taxonomy

  • Pseudis picta — Bonaparte, 1840 (synonym)
  • Rana picta — Schlegel, 1841 (synonym)
  • Pseudes pictus — Leunis, 1844 (synonym)
  • Discoglossus pictus var. ocellata Camerano, 1884 "1883" (synonym)
  • Discoglossus algirus Lataste, 1879 (synonym)
  • Discoglossus pictus — Boulenger, 1882 (synonym)
  • Colodactylus caerulescens — Boulenger, 1882 (synonym)
  • Discoglossus auritus Herón-Royer, 1888 (synonym)
  • Discoglossus pictus var. picta — Günther, 1859 "1858" (synonym)

References

Bosch, J., Andreone F., Tejedo M., Donaire-Barroso D., Lizana M., Martínez-Solano I., et al. (2009).  Discoglossus pictus. In: IUCN 2012. IUCN Red List of Threatened Species. Version 2012.2. .
García-París, M., & Jockusch E. L. (1999).  A mitochondrial DNA perspective on the evolution of Iberian Discoglossus (Amphibia: Anura). Journal of Zoology, London. 248,
Otth, A. (1837).  Beschreibung einer neuen europäischen Froschgattung, Discoglossus. Neue Denkschriften der Allgemeinen Schweizerischen Gesellschaft für die Gesammten Naturwissenschaften. 1, 1-8.
Pabijan, M., Crottini A., Reckwell D., Irisarri I., Hauswaldt J. S., & Vences M. (2012).  A multigene species tree for Western Mediterranean painted frogs (Discoglossus). Mol Phylogenet Evol. . 64(3), 690-6.
Salvador, A. (1996).  Amphibians of Northwest Africa. Smithsonian Herpetological Information Service. 109, 1-43.
 
World Wildlife Fund, & Hogan C. M. (2007).  Mediterranean woodlands and forests. Encyclopedia of Earth. National Council for Science and the Environment. Washington DC.
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