Alsodes cantillanensis Charrier, Correa, Castro & Méndez, 2015, sp. nov.
Creators: name: Charrier, Andrés
name: Correa, Claudio
name: Castro, Camila
name: Méndez, Marco A.
Publisher: name: Zenodo
Year: 2015
Subjects: Biodiversity
Taxonomy
Animalia
Chordata
Amphibia
Anura
Cycloramphidae
Alsodes
Alsodes cantillanensis

description: Alsodes cantillanensis sp. nov.
Holotype. A male (SSUC-Am-168; Fig. 1 A and Fig. 2) collected by Andrés Charrier and Alexander Baus in Quebrada Infiernillo, Fundo San Juan de Piche, Altos de Cantillana mountains (33°55’32.6”S, 71°02’34.6”W, 850 m a.s.l.; Fig. 3), on 3 August 2011.
Paratype. A female (SSUC-Am-169) collected by Andrés Charrier and Alexander Baus at the same place and date as the holotype.
Diagnosis. Alsodes cantillanensis can be distinguished from all other congeneric species for the following combination of characters: 1) thorny patches of the chest of males with spines uniformly distributed; 2) head with a triangle between the posterior border of the eyes and the snout tip, which contrasts with the background coloration; 3) superior part of the iris gold-yellowish brilliant, almost uniform; 4) postocular fold well-developed, extending beyond of the insertions of arms; 5) snout slightly truncated in dorsal and lateral profile; 6) dorsal skin smooth; 7) dorsal coloration ochre (holotype) or orange (paratype), with small and diffuse dark spots irregularly distributed; and 8) posterior legs slightly barred.
Description of the holotype. Male, SVL 45.9 mm. Head 1.24 times wider than long (Figs. 2 A and 2B). HL 34.4% the SVL. Snout slightly truncated in lateral view (Fig. 2 C). Nostrils with scarce relief and dorsolateral orientation, located midway between the tip of the snout and the anterior border of the eye. ID a quarter of the HW. EL 1.4 times the ID. Well-developed canthus rostralis, with a dark coloration on its underside, extending beyond the insertions of arms. Tympanic ring absent. Supratympanic fold well developed, without granulations. Chest with two clearly delimited bilateral nuptial round thorny patches. Spines of the chest patches minute, whitish and uniformly distributed (Fig. 2 B). White thorny excrescences on the interior of the first and second fingers (Fig. 2 D). Dorsum, arms, legs and ventral surface of body smooth. Granular flanks. Hands without webbing. Fingers with white rounded tips, in order of increasing length: II <I <IV <III (Figs. 2 D and 2E). Outer metacarpal tubercle rounded, and bigger than the others tubercles (Fig. 2 E). Inner metacarpal tubercle ovoid, smaller than the outer, but also well developed. One subarticular tubercle on digits I and II, and two on digits II and IV (Fig. 2 E). Posterior legs with slightly marked dark transversal bars. Feet without webbing. Toes long, with white rounded tips, without lateral fringes, in order of increasing length: I <II <V <III <IV (Fig. 2 F). Inner and outer metatarsal tubercles present, similar in size, the inner ovoid and the outer rounded. General dorsal coloration ochre, with a lighter triangle on the head between the posterior border of the eyes and the snout tip. A very thin yellowish vertebral line in the posterior half of the dorsum. Ventral coloration whitish. Measurements of the holotype (in mm) are, SVL: 45.9; HL: 15.8; HW: 19.6; IOD: 5.6; ID: 5.1; EL: 6.9; ThL: 24.6; TL: 24.1; FL: 41.4.
Comparison with congeneric species. Alsodes cantillanensis can be distinguished from A. nodosus, its sister species, for the following characters (Fig. 1) (characters of A. nodosus in parentheses): superior part of the iris gold-yellowish, almost uniform (black, with small yellow spots), a light triangle on the head (absent), dorsal skin smooth (granular), and a regular arrangement of spines in the chest patches (spines arranged in at least nine small clusters in each chest patch) (see description of A. nodosus in Cuevas 2013). Externally, A. cantillanensis resembles more A. vanzolinii Donoso-Barros: both taxa have dorsal smooth skin, a triangle of lighter color on the head (yellowish and much more marked in A. vanzolinii, where it contrasts with the lateral dark coloration of the head), and the upper part of the iris yellowish (although in A. vanzolinii the iris coloration is more discontinuous; see Fig. 1 of Rabanal & Alarcón 2010). However, A. vanzolinii has the dorsum dark brownish with yellowish spots and the posterior extremities strongly barred (Donoso-Barros 1974; Formas 1980; see Fig. 1 of Rabanal & Alarcón 2010). Furthermore, the phylogenetic analyses show that A. cantillanensis is closer to A. nodosus than to A. vanzolinii; these three species constitute one of the two main clades in which the genus is divided (Fig. 4). Alsodes cantillanensis also can be distinguished from the species of the other main clade by other characters. For example, the new taxon has no webbing toes, unlike A. gargola, A. montanus, A. pehuenche, and A. tumultuosus; it lacks of a black triangular zone on top of head extending backwards from space between the eyes, present in A. hugoi, A. igneus Cuevas & Formas, A. barrioi Veloso, Díaz, Iturra & Penna, and A. norae Cuevas; and it also differs of A. monticola, which has a green-grass dorsal color, of A. verrucosus Philippi which has the dorsal skin granular, and of A. vittatus, which has a well-defined vertebral line extending from the tip of the snout to the vent. Finally, A. cantillanensis lacks of folds of loose skin on the lateral areas of the body like A. australis, A. coppingeri, and A. kaweshkari. Furthermore, all these species have allopatric distributions with respect to A. cantillanensis (see Cuevas & Formas 2005).
Etymology. The specific name of the new taxon is the genitive Latin form of Cantillana, part of the name (Altos de Cantillana) of a mountain system with foothills covered by forests close to Santiago (65 km).
Variation. Outside of the obvious differences due to the sex of the specimens of the type series (patches of spines on the chest and arms thicker in the male), the most remarkable difference between them is the dorsum background coloration: the holotype is ochre, with a lighter triangle on the head, and the paratype is orange, with the triangle reddish-orange. The holotype and other individuals observed in the type locality and in Quebrada Lisboa (see below) had a thin yellow vertebral line in the posterior part of the dorsum. These individuals exhibited an overall ochre coloration, but with different tones. Measurements of the paratype (in mm) are, SVL: 44.2; HL: 14.9; HW: 18.7; IOD: 5.3; ID: 4.7; EL: 6.4; ThL: 24.6; TL: 25.3; FL: 39.6.
Distribution and natural history. The new species is only known from the type locality and one nearby site, Quebrada Lisboa (33°55’33.6”S, 71°01’05.3”W, 729 m a.s.l), both within the Natural Sanctuary San Juan de Piche, in the western slopes of the Altos de Cantillana mountains (Fig. 3). Altos de Cantillana mountains have a maximum height of 2281 m a.s.l. and are located in an area with Mediterranean climate that has less than 600 mm of rain per year and an average temperature of 10.7°C (Costa 2002). Alsodes cantillanensis inhabits mixed old grown forest of Nothofagus macrocarpa, Drymis winteri, Mirtacea sp., and vains of the genus Proustia. Specimens of the type series were found under rocks under the water during spring in the morning. Others (not collected) were found under a thick cover of litter fall near the stream (30 cm) and under logs close to the water. Additional specimens were observed at night walking along the stream of Quebrada Lisboa. In the creek at the type locality, the amphibians Alsodes nodosus (“sapo arriero”) and Pleurodema thaul (four-eyed frog) also were found.
Molecular data and phylogenetic relationships. The combined alignment of the four fragments had 3024 nucleotide sites in length (318 of cytb, 1999 of the fragment 12S-16S, 310 of rhod, and 397 of SINA). Only the fragment 12S-16S showed gaps (36 sites, including the outgroup). MP analysis including the sites with gaps was based on 359 parsimony-informative characters. Thirteen most parsimonious trees were found, with a length of 878 steps, which differ only in the relative position of A. gargola, A. igneus, A. neuquensis, A. norae, and A. pehuenche (data not shown; see consensus tree in Fig. S1). MP analysis treating gaps as missing also produced 13 trees (829 steps, 339 parsimony-informative characters) differing only in the relative position of the same taxa (data not shown). Regarding the BI, the post burn-in mean ln-likelihood values of the two independent analyses were - 8296.26 and -8297.08. Convergence and mixing of chains were achieved according to ASDSF (<0.002), ESS (> 200), and PSRF (0.9999–1.0001) values. Results of these analyses are shown as the 50% majority-rule consensus tree (Fig. 4), where bootstrap values of MP analysis including sites with gaps were added. Topologies of MP and BI analyses were highly congruent, showing two main clades for the genus with high statistical support (Fig. 4), which agrees with the hypothesis of Blotto et al. (2013). One clade is comprised by A. nodosus, A. cantillanensis, and A. vanzolinii, including the specimen identified a priori as A. cf. vanzolinii, and the other by the rest of Alsodes species. Within this main clade, two groups can be recognized also with high MP bootstrap support and Bayesian posterior probability: one comprised by all samples of A. nodosus (including one specimen from Pemehue, here labeled as A. aff. nodosus, a candidate species according to Blotto et al. 2013) and the two samples of the new species, and the other by the specimen of A. vanzolinii from Ramadillas (type locality) and the specimen of A. cf. vanzolinii from R.N. Los Queules. Within the second main clade, the group comprised by A. coppingeri, A. valdiviensis, and A. verrucosus diverges first, followed successively by A. hugoi plus A. tumultuosus, and A. barrioi (Fig. 4). The rest of species, A. gargola, A. igneus, A. neuquensis, A. norae, and A. pehuenche, form a politomy in the consensus tree. In summary, MP and BI analyses show that all samples of A. nodosus group with high support values and constitutes the sister group of the new species, ratifying the morphological distinction between both taxa (Fig. 1). However, the more compelling evidence to support the specific status of A. cantillanensis is that is sympatric and clearly diagnosable of A. nodosus at Quebrada Infiernillo.
description: Published as part of Charrier, Andrés, Correa, Claudio, Castro, Camila & Méndez, Marco A., 2015, A new species of Alsodes (Anura: Alsodidae) from Altos de Cantillana, central Chile, pp. 540-550 in Zootaxa 3915 (4) on pages 542-544, DOI: 10.11646/zootaxa.3915.4.5, http://zenodo.org/record/238372