Pelodytes punctatus ( Daudin, 1802 )

Díaz-Rodríguez, Jesús, Gehara, Marcelo, Márquez, Rafael, Vences, Miguel, Gonçalves, Helena, Sequeira, Fernando, Martínez-Solano, Iñigo & Tejedo, Miguel, 2017, Integration of molecular, bioacoustical and morphological data reveals two new cryptic species of Pelodytes (Anura, Pelodytidae) from the Iberian Peninsula, Zootaxa 4243 (1), pp. 1-41 : 21-23

Pelodytes punctatus ( Daudin, 1802)

Common Parsley frog ( Fig. 8 )

Identity. Described as Rana punctata Daudin, 1802 , from a locality in France ("aux environs de Beauvais", Department Oise, northern France) ( Frost 2015). One synonym, Rana plicata Daudin, 1802 , from near Montpellier, France ( Frost 2015). We could not locate the type specimens in the Paris museum (see also Frost 2015), but a more intensive search of that and other French collections might be warranted to ascertain the fate of the types of these two nomina. However, because the localities of both taxa are deeply in the range of the genetic lineage D, there is no doubt about the identity of this lineage with the name Rana punctata , and the status of Rana plicata as its junior synonym.

Morphology. A medium sized frog with an average SVL of 35.5 mm (maximum SVL 41.6 mm) in males and 38.8 mm (51.0 mm) in females ( Table 3 ). As all congeners its dorsal skin has tubercles and folds forming an irregular pattern of discontinuous dorsolateral folds, with considerable variation among individuals. Ventral side whitish, dorsally with irregular greenish dots and patches which typically are centered on the tubercles and folds, and sometimes extending around these. No webbing between fingers and weakly expressed between toes, except in males (where foot webbing are clearly expressed). Males with distinct nuptial pads on fingers and arms. Further morphometric values are summarized in Table 3 , and original measurements in Supplementary Table S2.

Distribution. Pelodytes punctatus is widely distributed in France, extending into northwestern Italy (Liguria and Piedmont) and northeastern Spain (Catalonia) ( Le Garff 1989; Salvidio & Bologna 2007). The northern limits are currently in the French department of Nord-Pas-de-Calais, where its presence is rare and limited ( Duguet & Melki 2003). Fossil evidence indicates its existence further to the north in the past (Blain et al. 2014). In Italy, it is distributed in coastal Liguria ( Salvidio et al. 2004), and in Piedmont ( Boulenger, 1897) where it has recently been rediscovered ( Andreone & Sindaco 1998; Sindaco et al. 2002). In the Iberian Peninsula, it is restricted to the northeast, including eastern Catalonia ( Martínez-Rica 1983; Barbadillo 2002b), where it reaches its maximum altitude in the Pyrenees (2,000 m; Borrás & Polls 1987; Guix et al. 2009). In France and Italy, P. punctatus inhabits plains ( Guyétant et al. 1999; Salvidio et al. 2004; Pottier 2008), is absent from most of the French Pyrenees ( Boulenger, 1897; Guyétant & Geniez 2013) and only exceeds elevations of 1,000 m in the Massif Central and in the Alpes Maritimes ( Salvidio & Bologna 2007). The fossil record suggests an ancient presence of P. punctatus at the east of its present distribution ( Blain & Bailón 2003; Delfino 2004). The current distribution is roughly within the region of subtropical climate with dry summers in the Koppen-Geiger classification ( Peel et al. 2007), and extends into the oceanic temperate region in western France and the northeast of the Iberian Peninsula.

Natural history. Numerous studies on Pelodytes biology have been performed in France, Italy and northeastern Spain and therefore the respective data can be reliably assigned to P. punctatus . This encompasses general accounts on the biology of the species (e.g., Elzen 1975, 1976), diet analysis of adults from Catalonia ( Bea et al. 1994), and diet preferences of tadpoles ( Richter-Boix et al. 2007). Reproduction is related to an increase in seasonal rainfall and occurs early in the year, usually before that of other anuran species, with two breeding periods: one at mid-fall and another in late winter and spring ( Sindaco & Andreone 1988; Toxopeus et al. 1993; Guyétant et al. 1999; Boix et al. 2004; Egea-Serrano et al. 2005; Richter-Boix et al. 2006; Petitot et al. 2014). Reproduction in autumn is often minor and irregular ( Cayuela et al. 2012), however, in southern populations the breeding season extends all year round (A. Montori pers. com.). This reproductive strategy may reduce interspecific competition ( Jakob et al. 2003; Richter-Boix et al. 2006) and does not result in an inhibition of gene flow between early and late reproduction groups ( Jourdan-Pineau et al. 2012). Breeding occurs in seasonal water bodies, mainly slow-flowing streams and ephemeral ponds located in cultivated areas, grasslands, shrubs and meadows (although the ponds often are more permanent than those used by P. atlanticus sp. nov. and P. ibericus ). The species is frequently found at the entrance of caves and karstic sites ( Elzen 1976; Olague & Lagares 2000; Sánchez-Herráiz 2004; Blain et al. 2008b; Vento & Pérez 2011). Pelodytes punctatus tolerates high levels of salinity and shows a preference for clayeye soils as P. hespericus sp. nov. (but unlike P. ibericus , see however Reques and Tejedo 2014). Eggs are black and small (diameter 1.5–2 mm), arranged in strings of 70–80 mm length and containing 40 – 700 eggs. Overall clutch size can be up to 1,600 eggs ( Boulenger, 1897; Lanza 1983; Toxopeus et al. 1993). Hatching success might be related to water oxygen content ( Guyétant et al. 1999). The incubation period is 8–9 days at 14–20°C ( Nöllert & Nöllert 1992). Larvae reach metamorphosis in roughly two months but this period can be delayed to up to four months ( Sindaco & Andreone 1988; Guyétant et al. 1999), and up to eight months in hibernating larvae ( Lataste, 1876). Phenotypic plasticity in morphology and larval development has been documented ( Johansson and Richter-Boix 2013). Males reach sexual maturity at one year of age and females at two years and longevity can reach 8 years (in males) and 10 years (in females), similarly to other species of the genus ( Esteban et al. 2004, Erişmiş et al. 2011). The sex ratio within a population is close to 1:1 ( Toxopeus et al. 1993). The IUCN threat status of P. punctatus is Least Concern ( Denoël et al. 2009); however, in the edge of its range (north of France , Italy and east of Spain ), the species is generally scarce and highly threatened, due to the loss of breeding sites, close to local extinction in some areas ( Parent 1989; Salvidio et al. 2004; Escoriza 2015).

Advertisement call and reproductive behavior. The advertisement call of P. punctatus has been described by several authors ( Hotz 1971; Elzen 1975; Paillete et al. 1992). Several call parameters (e.g., call duration) were found to depend on the temperature ( Boulenger, 1897; Paillete et al. 1992). As with all western Pelodytes , the call consists of two notes (A and B) and has been reported as typically containing only a single B note following A ( Paillette et al. 1992). Our analysis shows that also sequences of several B notes can be emitted following an A ( Fig. 7 ), and it remains to be assessed by a more detailed study whether populational variation exists in the frequency of B series. Males call from positions partially or even completely submerged in the water, and occasional episodes of mortality due to sudden drops in temperature have been observed ( Montori et al. 2011).

Males remain for a longer period of time than females at the breeding sites and show a marked philopatry ( Toxopeus et al. 1993). Female release calls have been mentioned by Elzen (1976). The amplexus is inguinal and usually lasts a few hours ( Guyétant 1986).

Tadpole. We assessed morphology in one tadpole in developmental stage 34 (field number ZCMV 14045 , BL 22.2 mm, TL 44.5 mm, from Palamós , Catalonia) . The examined tadpole has an elliptical body, a narrowly rounded snout in dorsal view, protruding eyes from the surface of the body and a very short tail with a typical braided line pattern; and spiraculum sinistral. The distance between eyes is moderately wide and nares are very large, round, positioned high dorsally, and situated nearer to snout than to eye and below the eye level. Moderately wide oral disk ( Fig. 9b ), emarginated, upper labium is wider than lower labium, LTRF is 5(2–5)/5(1–3). The upper jaw sheath is partially keratinized with pointed serrations, moderately wide without medial convexity. The lower sheath is wide V-shaped, partially keratinized and partially hidden by the upper one. Both jaw sheaths have a smooth surface. This tadpole is characterized by the presence of a network of dark lines, as it is also typical for larvae of the anuran genera Bombina and Discoglossus , covering the whole body, in addition to the presence of sparse dark spots. The venter is transparent with irregularly spiral shape intestinal coils.

Figures

FIGURE 7. Bioacoustic differences between lineages of Pelodytes occurring in the Iberian Peninsula. For raw data, see Supplementary Table S 3. The boxplot shows the average number of B notes per call series, i. e, every call consisting of one A note and one or more B notes. Average values were first computed per individual, and then summarized across species. Differences are significant between P. hespericus sp. nov. and all other species, and between P. atlanticus sp. nov. and P. ibericus (ANOVA with Tukey's post-hoc test; see Results).

FIGURE 8. Comparative photos of Pelodytes punctatus in life. The upper two photos show a male and a female from near Montpellier, France; the lower two pictures show a male and a female from near Vic, Girona, Spain. Specimens not collected. Images not to scale. Identity of P. punctatus individuals assessed by geographical location; specimens not DNA barcoded.

FIGURE 9. a – c, Mouthparts of preserved tadpoles of three species of Pelodytes. Note the absence of a central gap in the third anterior labial tooth row in P. ibericus. d, mouthpart, and e, lateral view of a living tadpole of P. ibericus from near Jerez de la Frontera.