Pleurodeles, Michahelles, 1830

BEUKEMA, WOUTER, DE POUS, PHILIP, DONAIRE-BARROSO, DAVID, BOGAERTS, SERGÉ, GARCIA-PORTA, JOAN, ESCORIZA, DANIEL, ARRIBAS, OSCAR J., MOUDEN, EL HASSAN EL & CARRANZA, SALVADOR, 2013, 3661, Zootaxa 3661 (1), pp. 1-60 : 29-31

Genus Pleurodeles

Sharp-Ribbed Newt, Pleurodeles waltl Michahelles 1830

Figs. 8I–K .

Background information. Initial reports of Pleurodeles sp. in Morocco were attributed to Pleurodeles poireti ( Gervais 1835) , which added considerable confusion to the already ambiguous systematic situation of the genus

Pleurodeles in North Africa ( Pasteur 1958; Carranza & Arnold 2004). Furthermore, Alluaud (1923) suggested that P. poireti and P. waltl occurred in sympatry around Rabat, which was finally refuted by Pasteur and Bons (1959) and Pasteur (1968), who unambiguously attributed Moroccan populations to P. waltl . Recent research has shown that populations of Sharp-Ribbed Newts in Morocco are closely related to those from south, south-eastern and eastern Spain, suggesting that they diverged during the Holocene. This relation has been attributed to a very recent either natural ( Batista et al. 2003) or anthropogenic (Carranza & Arnold 2004) colonization of the African continent from the Iberian Peninsula. However, Stoetzel et al. (2010a) and Bailon et al. (2011) reported on fossilized Pleistocene Pleurodeles remains from several northwestern Moroccan sites, possibly attributable to an earlier than expected presence of P. waltl or the prior existence of a currently extinct lineage. The latter hypothesis is especially interesting due to a suggested Upper Miocene colonization of the African continent by Pleurodeles sp. via the Gibraltar land bridge, which subsequently diverged into the current Pleurodeles nebulosus ( Guichenot 1850) and P. poireti in the eastern Maghreb, but disappeared from Morocco (Carranza & Arnold 2004; Veith et al. 2004).

Moroccan P. waltl have been described as morphologically different from their Iberian counterparts due to their smaller total length, lower dorsal tail crest, rapid development of the crest during the reproductive period and the rare display of the distress call ( Pasteur 1958). This has been interpreted as the possible occurrence of an undescribed taxon in Morocco (e.g. Pasteur & Bons 1959; Schleich et al. 1996). The measurements presented by Pasteur (1958) were based on an undisclosed number of samples from uncertain origin, in which only a distinction was made between ‘Morocco’ and ‘Iberia’. According to these data, Moroccan individuals are characterized by an average SVL of 58.8 mm (max TL 218 mm), while Iberian individuals show an average SVL of 100.5 mm (max TL 280 mm, in contrast to the erroneous report of 300 mm by Schleich et al. 1996). The current measurements based on 65 individuals (50 females, 16 males) originating from Forêt de Mamora, near Rabat show an average SVL and TL of respectively 79.0 and 173.2 (max 270.0) mm for females, and 62.3 and 131.4 mm (max 145.3) for males ( Table 3). The recovered sexual dimorphism might be partially related to the relative small amount of males measured. These data reveal larger average sizes for Moroccan P. waltl when compared to those presented by Pasteur (1958), of which at least the females are of comparable length to those from the Iberian Peninsula. However, it has to be noted that there is considerable geographical variation regarding size of P. waltl on the Iberian Peninsula, ranging from a maximum TL of 312 and 286 mm for respectively males and females in Huelva ( González de la Vega 1988) to a maximum TL of 259 and 251 mm (average 176.84 and 175.63 mm) for respectively males and females in Catalunya ( Fontanet & Horta 1989). In conclusion, the presence of considerable interpopulation variation in terms of at least size differences in combination with the very recent African colonization by P. waltl ( Batista et al. 2003; Carranza & Arnold 2004) make it seem unlikely that a distinct subspecies inhabits Morocco.

Natural history. The main distribution of P. waltl comprises the Atlantic lowlands ranging from Tanger southwards to Essaouira, where the species generally occupies temporary ponds and flooded fields ( Pasteur & Bons 1959). Several populations are found in the western Rif- and Middle Atlas Mountains, where they can be found in (temporary) ponds and slow flowing streams (D. Donaire-Barroso & W. Beukema, pers. obs.) or lakes (e.g. Dayets, Stemmler 1965). Reproductive activity is dependent of altitude, starting with the onset of the winter (lowland) or spring (mountains) rains, during which males develop extended dorsal and ventral tail fins. Along the Atlantic Coast and at lower altitudes inland, larvae can be found from January onwards ( Dorda 1984; Lapeña et al. 2011; pers. obs. P. de Pous). Juveniles are mostly found on land, also during the winter, only becoming aquatic once they reach sexual maturity ( Pasteur & Bons 1959). Pleurodeles waltl is a highly aquatic newt which may stay aquatic outside of the reproductive period. However, as most of these water bodies dry out during summer, aestivation takes place on land under stones, logs or in fissures in clay soils ( Pasteur & Bons 1959). The natural history of populations in the western Rif Mountains and Middle Atlas Mountains is not well known.

Distribution. Within Morocco, P. waltl mainly occurs in the north-western part of the country, following the Atlantic coast to the south as far as Essaouira ( Bons & Geniez 1996) where its presence was recently confirmed by Harris et al. (2008). While the species is especially common in lowland areas (e.g. Pasteur & Bons 1959; El Hamoumi 1988; El Hamoumi & Himmi 2010), P. waltl also occurs in mountainous terrain of the western Rif ( Fahd & Mediani 2007). A single record from the eastern Rif Mountains (Talamagaït, indicated in Fig. 9B by a question mark, Mellado & Mateo 1992) is in need of confirmation. Additionally, P. waltl occurs sporadically in the Middle Atlas in the vicinity of Dayets ( Stemmler 1965; Bons & Geniez 1996). The distribution map ( Fig. 9B ) is composed of records from Bons and Geniez (1996), Carretero et al. (2004) and Harris et al. (2010). New distribution records fill in prior large gaps in the north-western range of P. waltl , showing the species to be commonly present in the lowlands and mountainous areas of the Tingitana Peninsula. A second significant population cluster is located around Rabat, in the cork oak forests of Mamora, Temara and Ben-Slimane. Additionally, the species appears to be widespread on the Doukkala plain, between the occurrences near El Jadida and Safi ( Bons & Geniez 1996; Carretero et al. 2004).

National Red List Status. Near Threatened.

Figures

FIGURE 8. Members of the Salamandridae family native to Morocco. A: Salamandra algira spelaea Beni Snassen (DE). B-D: Salamandra algira tingitana; B: Jbel Musa (PdP); C: Tagramt (SB); D: Cudia Adru (DD). E-H: Salamandra algira splendens ssp. nov.; E: Bou Iblane (DD); F: Chefchaouen (DD) (holotype specimen); G: Bab Berret (DE); H: Ketama (DD). I-K: Pleurodeles waltl; I: Forêt de Mamora (WB); J: Casablanca (Gabriel Martínez del Mármol); K: Moulay Abdeslam (SB).

FIGURE 9. Niche models and distribution records of Salamandra algira (A); Pleurodeles waltl (B); Alytes maurus (C); and Discoglossus spp. (D) in Morocco. Warmer colours indicate higher climate suitability. Dark spots indicate records derived from literature, white spots show new records.