Hylinae Rafinesque

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 : 44-46

Subfamily Hylinae Rafinesque

Mediterranean Tree Frog, Hyla meridionalis Boettger 1883

Figs. 15A–C .

Background information. The presence of Hyla in Morocco has been reported from as early as the Upper Pliocene based on fossil remains ( Bailon 2000). In a recent phylogeographical study, Recuero et al. (2007) recovered three subgroups divided into two major clades by means of mtDNA analyses, between which the High Atlas Mountains seem to act as a geographical barrier. Surprisingly, the southern clade is closely related to southern Iberian populations, while the northern clade shows affinity to circum-Pyrenean populations. As a result Recuero et al. (2007) presumed H. meridionalis to be of African ancestry, with European populations originating from relatively recent arrival (either by means of natural colonization or anthropogenic introduction). Stöck et al. (2008b) and Stöck et al. (2012), based on both mtDNA and nDNA analyses could not confirm the results of Recuero et al. (2007), although the former studies were limited by small sample sizes. Conclusively, while an African origin for H. meridionalis seems credible based on fossil and mtDNA data, further research is needed to clarify intraspecific variation of this species across its entire distribution range ( Stöck et al. 2008b; Stöck et al. 2012).

Tadpole. The tadpole of H. meridionalis was described by Héron-Royer (1884) based on material from “Midi de France ”, and by Boulenger (1897) by means of specimens of uncertain origin. A drawing of the tadpole is shown in Fig. 12H . Fully developed tadpoles are characterized by their olive-greenish dorsal colour and lateral positioned eyes. Body shape ovoid. Eyes positioned laterally on head. Interorbital space one 1 ½ times as wide as the internarial space. Spiracle sinistral, directed upwards. Tail twice the length of the body. Muscular part of the tail discontinuously interspersed, and bordered above and below by a black line. Dorsal tail fin high and rounded, extending onto the dorsum near the position of the eyes. Ventral tail fin equally developed, extending on the venter beyond the anus. Lips bordered with papillae, absent in the middle of the upper border, usually forming two rows on the lower lip. Two tooth rows on the upper (unlike one, as displayed by Pasteur & Bons 1959) and three on the lower labium. Lower supralabial row with large median gap. Colour olive or green with a golden gloss, lateral parts interspersed with golden spots. Venter white with golden or yellowish spots. Tail and tailfins inconspicuously grey or back spotted.

Bioacoustics. Schneider (1968) described the advertisement call of H. meridionalis originating from southern France. The call is characterized by a higher number of pulses (paired with longer call duration) compared to other European Hyla spp. , which however decrease as temperature decreases (averagely 41.95 pulses at 10ºC, 36.85 at 20ºC). Call interval is relatively long, ranging from nearly 2.5 seconds at 6 ºC to 823.20 ms at 19 ºC. The recordings of the advertisement call (n= 13) of two males presented herein ( Fig. 7D ) recorded at 14.8°C with a humidity of 85.80% were composed of 35 to 57 pulses (median = 41), with a dominant frequency ranging from 2194 to 2359 Hz. Note length varied between 40.9 to 68.4 ms (averagely 0.553 ± 0.087 seconds), while the pulse rate ranged from 74.91 to 86.54 seconds (averagely 80.61 ± 4.16).

Natural history. Hyla meridionalis can be found near permanent or temporary water bodies, often characterized by an abundance of aquatic vegetation ( El Hamoumi et al. 2007). Throughout the north-western lowlands and the Rif- and Atlas Mountains, H. meridionalis is one of the most common species. In contrast to its common name, the Mediterranean Tree Frog can also be abundant in areas without significant tree cover, such as the stony Doukkala plain or high-altitude areas in the Middle- and High Atlas ( Bons & Bons 1959). At the southern margins of the distribution such as the Anti-Atlas and the Ouarzazate depression, H. meridionalis occurs in arid terrain near temporary streams characterized by little vegetation. Doumergue (1901) describes reproduction to take place between the end of February and the end of April, while Bons (1970) observed reproduction in the Middle Atlas at the end of March. In the Mamora forest region near Rabat, reproduction starts in late January and continues until March ( El Hamoumi 1988; pers. obs. P. de Pous). Individuals mainly consume insects ( Doumergue 1901).

Distribution. The distribution map ( Fig. 16A ) is composed of records from Bons and Geniez (1996), Fahd et al. (2007), Harris et al. (2008) and Barnestein et al. (2010). New records reveal a continuous distribution from the north Atlantic Coast to the Rif Mountains, which is expanded along the Atlantic Coast and several areas of northern Morocco. The absence of this species in many parts of north-eastern Morocco and the Middle- and High Atlas is likely due to a lack of distributional research. Several new records have been found along the southern margin of the species distribution, where H. meridionalis occurs near (semi)permanent water bodies. The recently discovered localities near Sidi Ifni ( Donaire et al. 2004; Barnestein et al. 2010) represent the southernmost records of this species on the African continent.

National Red List Status. Least Concern.

Taxonomic comment. Following Recuero et al. (2007) and Stöck et al. (2008b) at least two Hyla taxa are present in the Maghreb. The boundary between these taxa has not yet been identified, but is presumed to be located in central Algeria.

Figures

FIGURE 7. The amplitude (upper) and frequency (lower) of the advertisement call of respectively A: Amietophrynus mauritanicus. B: Barbarophryne brongersmai. C: Bufotes boulengeri. D: Hyla meridionalis. E-F show the amplexus calls of respectively a Pelobates varaldii male and female.

FIGURE 12. Tadpoles of Moroccan anurans. A: Alytes maurus, Ketama. B: Discoglossus scovazzi, Safi. C: Discoglossus pictus, Tafuyalt (Algeria). D: Amietophrynus mauritanicus, Mohammedia. E: Barbarophryne brongersmai, Smimou. F: Bufo bufo, Tazekka. G: Bufotes boulengeri, Dayet Aoua. H: Hyla meridionalis, Mohammedia. I: Pelobates varaldii, Kenitra. J: Pelophylax saharicus, Sidi Ifni. All drawings made by DE.

FIGURE 15. Members of the Hylidae, Pelobatidae and Ranidae families native to Morocco. A-C: Hyla meridionalis; A: Casablanca (Gabriel Martínez del Mármol); B: Oukaimeden (Frank Deschandol); C: Sidi Ifni (SB). D-F: Pelobates varaldii; D: Forêt de Mamora (WB); E-F: Forêt de Mamora (PdP). G-I: Pelophylax saharicus; G: High Atlas (WB); H: Forêt de Mamora (WB); I: Rabat (PdP).

FIGURE 16. Niche models and distribution records of Hyla meridionalis (A), Pelobates varaldii (B) and Pelophylax saharicus (C) in Morocco. Warmer colours indicate higher climate suitability. Dark spots indicate records derived from literature, white spots show new records.