Iberian painted frog
(Discoglossus galganoi)
This is one of two cryptic species of painted frog endemic to the Iberian Peninsula.  They’re so similar in appearance that it’s impossible to tell them apart by eye, and some research argues that they are in fact subspecies.  D. galganoi has a preference for semi-permeable siliceous and sandstone substrates, and is found in Portugal and western Spain, north of the Guadalquivir River, while D. jeanneae is found south and east of the River where substrates are impermeable clay, limestone or gypsum.  Females each lay up to 5,000 eggs per season, and choose a string of fathers to optimise genetic diversity within their brood.  Painted frogs are so-called because of their variety of colour patterns, complicating the identification of species within this group.  They have been evolving independently of any other lineage for over 200 million years, making them older than many species of dinosaur.

Urgent Conservation Actions
Endemic to Iberia.
Evolutionary Distinctiveness
Order: Anura
Family: Alytidae
The Alytidae are an ancient family found in Europe, the Middle East and Northwestern Africa, and are comprised of the midwife toads (Alytes) and painted frogs (Discoglossus).  Overall, this family is now named after the midwife toads.  The family name was formerly Discoglossidae or ‘disc-tongued frogs’ because, unlike the slender tongues of many amphibians, midwife toads and painted frogs possess a round and flattened tongue.  They diverged from the fire bellied toad lineage and all other amphibians about 210 millions years ago at the end of the Triassic period, around the same time that the first primitive mammals started to appear.  The midwife toad family therefore evolved at the feet of some of the earliest dinosaurs, and survived the dinosaur’s demise nearly 150 million years later.

Within the family Alytidae, the painted frogs diverged from the midwife toads about 155 million years ago, about 5 million years before the first birds started to appear in the fossil record.  Painted frogs are more different from their closest relatives in terms of evolutionary time than kangaroos are to elephants, as they started to evolve independently about 10 million years before the common ancestor of these two mammal groups.

The number of species in this group has been the subject of debate since the discovery of Discoglossus in the 1830s.  For over a hundred years it was contested whether the two described forms, D. pictus and D. sardus, even deserved subspecies status.  Developments in molecular biology allowing the study of genetic make-up have revealed a high level of divergence within the group, and have identified a number of new species.  It is currently being debated whether there are six or seven species within the Discoglossus genus. 

Prior to 1985, all Discoglossus populations on the Iberian Peninsula were thought to belong to D. pictus, which is also found on some Mediterranean islands and in Northern Africa.  Biochemical and genetic analyses have since revealed two endemic species, D. galganoi and D. jeanneae, thought to have over five million years of evolutionary isolation between them.  Other recent research has found conflicting results, however, and names them as the subspecies D. galganoi galganoi and D. galganoi jeanneae.  The distribution of D. pictus has since been revised to cover only the extreme northeast of Spain, where it is presumed to be an introduced species. 

This example illustrates the importance of taxonomic research (the science of classification) in conservation biology, as population estimates and range measurements which lump multiple species under one name can mean that a species is not protected when it may in fact consist of more than one species with low numbers and/ or very restricted ranges.  Certain researchers believe that in cases with any uncertainty in identification, species should be listed as ‘Data Deficient’, at least on a local level, rather than risk a generous classification.
Unlike their closest relatives the midwife toads, which are relatively stocky and toad-like, painted frogs have classic frog features such as a slim waist, long legs and webbed toes on their hind feet.  Their pupils are round, triangular or ‘upside-down teardrop’ shaped, and their skin is generally smooth and shiny with small but visible warts.  The name comes from the variety of colour variations and patterns seen in the group; some are plain in colour whilst others have stripes, spots, bands and blotches of varying tones.

There are three colour forms seen in D. galganoi: plain colour with no markings, large dark spots with light edges, and dark brown longitudinal bands with one bright band along each side and another down the middle.  The underside is whitish in colour, and warts (when present) are arranged in longitudinal patterns down the back.  It is very similar in appearance to the cryptic D. jeanneae.
This species of painted frog is generally found in or very close to water and lives to around 9 years old.  Sexual maturity is not reached until individuals are 3 to 5 years old.  D. galganoi becomes inactive when water temperatures get too low or when air humidity drops below 45%.  Activity is resumed when temperatures rise above 9°C, but the optimum water temperature for this species is a balmy 21 - 30°C.

Breeding season for the Iberian painted frog is October to late summer each year.  During this time, a female can produce up to six clutches of 300 to 1,500 eggs, totalling a massive 5,000 for the season.  Within each clutch of eggs she mates with a series of males, producing 20 - 50 eggs for each one.  This is a way of hedging bets - it spreads her chances of finding optimal paternal genes for her progeny. 

D. galganoi and D. jeanneae are cryptic species; their appearance is so similar that they can only be distinguished using biochemical markers or genetic analysis.  Recent investigations have led researchers to believe that while their distributions can overlap, the two species can be identified based on the environmental characteristics of the area in which they are found.  D. galganoi favours wide river basins with semi-permeable siliceous and sandstone substrates, and is usually found within the western half of the Iberian Peninsula (to which both species are endemic).  D. jeanneae, on the other hand, prefers mountainous areas liable to severe flooding, impermeable clay or limestone/ gypsum substrates, and has a more easterly distribution within the Peninsula. 
This species is often found in traditional farmland and other slightly modified landscapes.  It breeds in shallow ponds which can be temporary, and inhabits water bodies from mountain streams to brackish-waters along the seashore, and marshes to drinking troughs.  When on land it is found near water, in woodland edges, thickets, gullies, meadows and open areas. 
Discoglossus galganoi is endemic to the Iberian Peninsula, hence its common name, and has been found up to 1,940 metres above sea level - over 6,000 ft!  D. galganoi is restricted to granite and shale substrates in western Spain and Portugal, unless the cryptic D. jeanneae is included as the subspecies D. galganoi jeanneae, which is found on limestone and gypsum substrates in eastern Spain between the Strait of Gibraltar and the Pyrenees.

The Guadalquivir River had been considered a natural barrier between the two species/ subspecies and potentially the cause of their divergence, with D. galganoi found north of the River and D. jeanneae primarily to the south and east.  The use of ecological modelling in more recent research has suggested that the species are in fact parapatric, or separated by ecological niche rather than physical barrier.  Contact zones where the two occur in close proximity are located within substrate transition zones – this environmental gradient could have been the driving factor if it was indeed a case of parapatric speciation.
Population Estimate
The Iberian painted frog is said to be abundant throughout most of its range in Spain, although numbers are lower in the northeastern populations.  In Portugal, the distribution is patchy and populations are fragmented, but it can be locally abundant where it does occur.
Population Trend
This species is listed under the ‘Least Concern’ category in the 2006 IUCN Red List of Threatened Species.  This is because it has a wide distribution and is more tolerant to habitat modification than its more sensitive relatives, and it is presumed to have a large population.
Although this species is not thought to be seriously threatened overall, there are a number of threats facing populations at a more local level.  Hydroelectric projects are causing habitat loss in parts of Portugal, as is desertification in the more arid parts of its range such as in Southern Portugal.  Intensification of agricultural methods and introduced predatory fish and crustacean species (e.g. the Louisiana Crayfish Procamabrus clarkii) threaten populations through much of its range.
Conservation Underway
D. galganoi has been found in three National Parks in Spain – Doñana, Cabañeros and Islas Atlánticas de Galicia.  It is protected by national legislation in Spain and is listed in the national Red Data Book.  This species is also protected by EU legislation (under Appendix II of the Bern Convention and Annex IV of the Natural Habitats Directive).
Conservation Proposed
The IUCN call for research to ‘further clarify’ the distribution of this species and that of the Near Threatened Discoglossus jeanneae.  Crypsis can lead to identification problems, and the delineation of a species’ extent of occurrence has implications in its conservation status.
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Capula, M., Nascetti, G., Lanza, B., Bullini, L. and Crespo, E. G. 1985. Morphological and genetic differentiation between the Iberian and the other West Mediterranean Discoglossus species (Amphibia Salientia Discoglossidae). Monitore Zoologico Italiano (N.S.) 19: 69-90.

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Lanza, B., Cei, J. M. and Crespo, E. 1975. Immunological evidence for the specific status of Discoglossus pictus Otth, 1837 and D. sardus Tschudi, 1837, with notes on the families Discoglossidae Günther, 1858 and Bombinidae Fitzinger, 1826 (Amphibia Salientia). Monitore Zoologico Italiano (N.S.) 9: 153-162.

Lanza, B., Nascetti, G., Capula, M. and Bullini, L. 1984. Genetic relationships among West Mediterranean Discoglossus with the description of a new species (Amphibia Salientia Discoglossidae). Monitore Zoologico Italiano (N.S.) 18: 133-152.

Martinez-Solano, I. 2004. Phylogeography of Iberian Discoglossus (Anura: Discoglossidae). Journal of Zoological Systematics and Evolutionary Research 42(4): 298-305.

Real, R., Barbosa, A. M., Martínez-Solano, Í. and García-París, M. 2005. Distinguishing the distributions of two cryptic frogs (Anura: Discoglossidae) using molecular data and environmental modelling. Canadian Journal of Zoology 83: 536-545.

San Mauro, D. 2004. Phylogenetic relationships of discoglossid frogs (Amphibia: Anura: Discoglossidae) based on complete mitochondrial genomes and nuclear genes. Gene 343(2): 357-366.

Veith, M. and Martens, H. 1997. Discoglossus galganoi. In: Gasc et al. (eds.) Atlas of Amphibians and Reptiles in Europe. Societas Europa Herpetologica, Muséum National D’Histoire Naturelle, Paris.

Zangari, F., Cimmaruta, R. and Nascetti, G. 2006. Genetic relationships of western Mediterranean painted frogs based on allozymes and mitochondrial markers: evolutionary and taxonomic inferences (Amphibia, Anura, Discoglossidae). Biological Journal of the Linnean Society 87: 515-536.

Distribution dataset:  IUCN 2008. 2008 IUCN Red List of Threatened Species. http://www.iucnredlist.org

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