Agama tassiliensis, Geniez, Philippe, Padial, José M. & Crochet, Pierre-André, 2011

Geniez, Philippe, Padial, José M. & Crochet, Pierre-André, 2011, Systematics of north African Agama (Reptilia: Agamidae): a new species from the central Saharan mountains, Zootaxa 3098, pp. 26-46 : 32-38

Agama tassiliensis sp. nov.

Holotype. MNHN 2010.0632, adult male collected on April 21 th 2009 in the Tassili n’Ajjer (south-eastern Algeria), 5 km south-south-west from Iherir [WGS84 25.3500°N / 8.3911°E / 1428m a.s.l.] by P.-A. Crochet, P. Geniez and O. Peyre. See Figure 2 .

Chresonyms. Agama impalearis: Joger 1979 ; 1981; Schleich et al. 1996; Kriska 2001. Agama agama: Angel and Lhote 1938 ; Angel et al. 1954; Le Berre 1989; Sindaco and Jeremčenko 2008.

Etymology. The name comes from the Berber word “tassili”, referring to sandstone plateaux of the Sahara. It also refers to the Tassili n’Ajjer, a Saharan massif where the holotype was collected.

Specimens examined. 68 specimens from the entire known distribution range of the species (cf. Distribution and Appendix I).

Diagnosis. A medium to large size Agama (reaching 13.4 cm of SVL and around 37 cm of total length) belonging to the Agama impalearis complex (medium proportions, dorsal scales regularly keeled, at least 3 spines on the anterior border of the ear opening, a nuchal crest in both sexes but no caudal crest, see also genetic data) and characterized by the following features (see also Tables 3, 4, 5, 6 and Fig. 2 , 3 , 4 ): head angular, 63 to 73 rows of dorsal scales at midbody, 4th toe slightly larger than 3rd (sometimes of same size), a relatively large number of supralabials (around 12, min. 10 max. 16), a large number of subdigital lamellae (15–20 under the 4th finger, average 17.37, and 18–24 under the 4th toe, average 20.47), a well-developed crest composed by (8) 10 to 15 spines and a frequently orange eye contour. Males in breeding condition can be brightly coloured: head and throat orange or red, body dark blue, legs and tail blue, crest and vertebral stripe generally reddish to red. Also, the new species is diagnosed by possessing 6 pure simple private nucleotide character states in the fragment of mitochondrial 16S gene sequence when compared with the other members of the impalearis clade (all positions refer to the Pseudotrapelus complete mitochondrial sequence NC_013603, when they are dependent on ambiguous alignment this is indicated): A at positions 2127 (ambiguous alignment) and 2194; two Cs inserted immediately after position 1926; G at position 2218; and T, inserted after position 1926, 4bp after the two Cs.

Table 3. Mean (standard deviation), minimum-maximum (n=sample size) for selected characters in the Agama impalearis species group and. agama .

Table 4. Frequency (in %) of vertebral stripe colour characters in each taxon (adult males only). I = indistinct, concolorous, GG = grey to greyish, WY = white to yellow, OR = orange to red. n = sample size.

I GG YW OR n A. tassiliensis n. sp. 3 0 18 79 33 A. impalearis 3 10 87 0 60 A. spinosa 8 15 77 0 13 A. boueti “ castroviejoi ” morphotype 11 22 67 0 9 A. boueti 17 72 11 0 18 A. agama 22 0 16 62 32 Table 5. Frequency (in %) of throat colouration characters in each taxon. W = white (no marbling); G = pale grey to brown

grey marbling; D = dark grey, dark purple or black marbling; B = uniformly blue throat or blue marblings; O = uniformly

orange to red throat or with orange to red marblings.

Adult males Adult females

W G D B O n W G D B O n A. tassiliensis n. sp. 0 17 26 0 56 23 0 25 75 0 0 16 A. impalearis 0 19 48 28 5 42 0 42 52 7 0 31 A. spinosa 10 10 0 0 80 10 25 50 0 0 25 4 A. boueti “ castroviejoi ” morphotype 0 57 43 0 0 7 0 50 50 0 0 4 A. boueti 40 47 13 0 0 15 57 37 3 3 0 35 A. agama 13 13 4 0 70 23 7 14 79 0 0 14

Table 6. Frequency (in %) of relative lenght of 3rd and 4th toes.

3rd> 4th 3rd = 4th 3rd <4th n A. tassiliensis n. sp. 0 17 83 6 A. impalearis 16 52 32 31 A. spinosa 0 21 79 14 A. boueti “ castroviejoi ” morphotype 0 75 25 8 A. boueti 70 19 11 27 A. agama 0 0 100 13

Comparison with similar species. Very similar to Agama impalearis ( Fig. 5 A) but the latter has a shorter, blunter head, 3rd and 4th toes often of equal length (see Table 6), a lower number of subdigital lamellae (12–16 under the 4th finger, 13.76 on average, 14–18 under the 4th toe, 15.84 on average, Table 3) and the vertebral stripe of males is whitish to yellowish, the throat frequently dark blue (never red) and the head yellow, brown, reddishbrown or blue.

Even more similar to the genetically closely related A. spinosa ( Fig. 5 B), but adult males of the latter exhibit a pure white crest and vertebral stripe, a much higher crest and the throat is more bloody red. In addition, most specimens (of all age and sex) of A. spinosa have a dark area just behind the gular fold (visible on preserved specimens) that is absent in A. tassiliensis .

Some specimens of A. boueti ( Fig. 5 C), especially the ‘ castroviejoi’ morphotype ( Fig. 5 D) occurring in the western parts of the Sahara, can be very similar as well, but this species has a less slender head, a lower number of spines in the crest (5–9, 7 in average), less than 64 rows of dorsal scales (more than 62 in A. tassiliensis ), and the head, throat or vertebral spine are never orange or red, but grey, greyish, whitish or yellowish. In addition, A. boueti (including the ‘ castroviejoi’ morphotype) has a narrow (always 2 scales wide) and straight vertebral stripe, while A. tassiliensis has a more irregular, often poorly marked, and usually broader vertebral stripe.

Despite a similar general appearance, A. agama ( Figs 6 , 7 ) obviously differs from A. tassiliensis by a lower number of supra and infralabials, which are longer, a greater number of subdigital lamellae (16–22 beneath the 4th finger, average 19.68, 19–25 beneath the 4th toe, average 22.38), which are smooth while they are keeled (strongly so in A. boueti ) in the members of the A. impalearis group, a different colouration for females and young specimens with turquoise blotches on the nape and frequently a diffuse orange zone on the flanks, and a different colouration for nuptial males (wholly orange head and throat, black or blackish body, multicoloured tail with black, whitish, orange and black from base to tip, and lack of a coloured vertebral stripe).

Distribution. Only known from the central and southern Saharan mountains: the Acacus Mountains in southwestern Libya, the Ahaggar Mountains (= Hoggar) and Tassili n’Ajjer in south and south-eastern Algeria, the Aïr Mountains in northern Niger and the Adrar des Iforas in north-eastern Mali ( Fig. 8 ).

Ecology and conservation. The new species has only been seen on rocky substratum, especially prominent rocks, slopes, boulders, but also flatter areas such as rocky plateaux or river beds. It can occur on houses when they are adjacent to natural rocky habitats but nowhere truly colonizes human habitats, in contrast to Agama agama south of the Sahara. Like closely related species, it is a fully diurnal species that can bask in the sun even during the hottest hours of the day. It is usually common throughout its range, which lies in areas where human impact is still very limited. We are not aware of any direct threat, and the species does not seem to be specifically hunted, collected or destroyed by the local human populations in areas that we have visited. Its conservation status would thus probably qualify as “Least Concern” based on the current situation.

Description of the holotype. Adult male in semi-nuptial colouration with the following features: SVL 166 mm, tail partly broken, pileus length 25.3 mm, pileus width 15.2 mm, foreleg length 51.1 mm, hind leg 81.3 mm, length of 1st to 5th fingers respectively 5.3, 8.7, 10.6, 10.2 and 8.2 mm, length of 1st to 5th toes respectively 6.8, 9.5, 13.7, 15.0 and 12.1 mm, 22 rows of pileus scales from the nose to the beginning of the crest and 18 between the eyes, 12 supralabials and 11 infralabials on each side, 67 rows of scales around midbody, 20 subdigital lamellae under the 4th finger and 23 under the 4th toe, a nuchal crest made of 13 vertical spines, 11 preanal pores, 8 spiny tufts on each side of the ear area and the neck, scales of the dorsum, forelegs, hindlegs and tail strongly and regularly keeled. Colouration (in the field, cf. Fig. 3 ): head reddish-brown with some yellowish small blotches, eye surround orange, dorsum dark purplish-grey, a broad dark orange vertebral stripe from the nape to the base of the tail extending from the orange crest, forelegs, hindlegs and tail greyish blue, fingers and toes yellowish, throat yellowish densely marbled purplish (orange on the gular fan), gular fold slightly darker, underparts whitish with a pale blue suffusion on the breast. GenBank accession number of the 16S gene fragment: JN665063 .

Figures

FIGURE 2. Agama tassiliensis n. sp., holotype, MNHN 2010.0632, adult male from Algeria, Tassili n’Ajjer, 5.5 km SSSW of Iherir [25.3500 ° N / 8.3911 ° E], photo P. Geniez. A: dorsal view of the live specimen. B: ventral view of the live specimen.

FIGURE 3. Variation in Agama tassiliensis n. sp. from Tassili n’Ajjer and Acacus Mountains. A: PGe. 921, adult male in breeding colouration, Algeria, Tassili n'Ajjer, surroundings of Tamarit near Djanet, photo G. Vigo. Note the broad (3 – 4 scales wide), bright red vertebral stripe (can be orange to red in other specimens), a coulour never encountered in the other members of the A. impalearis group. In A. agama the crest area can be orange but this colour does not extend onto the back. B: PGe. 991, gravid adult female, Algeria, Tassili n'Ajjer at 24.5847 ° N / 9.3235 ° E, photo G. Vigo. Note that the colours are typical of gravid females of the A. impalearis group, and very different from those of the A. agama group (cf. Fig. 6). C: PGe. 999, juvenile, Libya, ca 100 km N. of Ghat, Wadi Maghidet, photo G. Vigo. D: Habitat of Agama tassiliensis n. sp., Algeria, Tassili N’Ajjer, 5.5 km downstream of Issendelene, photo P. Geniez.

FIGURE 4. Variation in Agama tassiliensis n. sp. from Aïr Mountains, Niger. A: PGe. 869, adult male from Idoukal'n Taghès, photo S. Sant. B: Brito code 362, adult male of from 20 km S. of Timia, photo J. C. Brito.

FIGURE 5. Adult males of the other members of the Agama impalearis group. A: A. impalearis, PGe. 840, adult male, Algeria, Moudjebarah frescos near Aïn Naga village, photo J. Viglione. Note the broad (3 – 4 scales wide), whitish vertebral stripe (orange to red in A. tassiliensis n. sp.) and the less pointed snout than in A. tassiliensis. B: A. spinosa, T 3092, adult male. Egypt, Wadi el Gemal, photo P. - A. Crochet. Note the throat and the eye surround which are bloody red (not bright red, vermillon or orange as A. tassiliensis n. sp.), and the higher, pure white crest compared with A. tassiliensis. C: A. boueti, PGe. 1002, adult male, Niger, Termit mountain, photo M. Ascani. Note the reduced number of crest spines (6 in this specimen), the relatively faded coulouration and the uniformly pale throat. D: A. boueti of the “ castroviejoi ” morphotype, PGe. 847, adult male, Mauritania, track from Nouatil pass to Zerga, photo P. Geniez. Note the reduced number of crest spines (7 in this specimen) and the whitish vertebral stripe which is relatively narrow, not exceeding two scales in width.

FIGURE 6. Comparisons of head characters in Agama tassiliensis n. sp. and A. agama. A: A. tassiliensis n. sp., PGe. 998, non nuptial adult male from Algeria, Tassili n’Ajjer, 40 km NNW of Djanet, photo G. Vigo. Note the numerous, square-shaped labial scales (13 supralabials in this specimen), the numerous (12 in this specimen) and orange crest spines and the presence of spines around the ear opening. B: A. agama, MNHN 1990.4668, preserved adult male from Niger, Maradi, photo P. - A. Crochet. This species has fewer, more elongated labials (7 supralabials in this specimen), numerous crest spines (19 in this specimen) but a lower crest than A. tassiliensis. Note also the less developed spine tuffts around the ear opening.

FIGURE 7. Agama agama. A: PGe. 947, adult male in breeding colouration, Chad, N’Djamena, photo M. Braham-Chaouche. Note the orange colour of the head which does not extend onto the vertebral area, the uniformly black body and the yellow, orange and black tail, a colouration never found in members of the Agama impalearis group. B: PGe. 1003, adult female, Mali, Djenné, photo A. Auricoste.

FIGURE 8. Distribution of Agama tassiliensis n. sp. based on the specimens or photographs that we have examined for this study. The arrow shows the type locality.