Philodryas amaru, Zaher, Hussam, Arredondo, Juan C., Valencia, Jorge H., Arbeláez, Ernesto, Rodrigues, Miguel T. & Altamirano-Benavides, Marco, 2014

Zaher, Hussam, Arredondo, Juan C., Valencia, Jorge H., Arbeláez, Ernesto, Rodrigues, Miguel T. & Altamirano-Benavides, Marco, 2014, A new Andean species of Philodryas (Dipsadidae, Xenodontinae) from Ecuador, Zootaxa 3785 (3), pp. 469-480 : 470-475

Philodryas amaru sp. nov.

Figs. 1–2

Holotype. Adult male ( FHGO 4749), collected by Ernesto Arbeláez on 6 June 2006, in the private land owned by Manuel Merchan, Termas de Aguas Calientes-Soldados (2° 55' 55'' S, 79°12' 37'' W, ca. 3196 m), Parroquia San Joaquín, Cantón Cuenca, Province of Azuay, Ecuador ( Fig. 1 ).

Paratypes. Two adult females ( FHGO 6399 and FHGO 6400) collected along with the holotype.

Diagnosis. A Philodryas that differs from all other species of the genus by the following combination of characters: Snout not acuminate anteriorly; maxilla with 14 to 15 prediastemal maxillary teeth and two ungrooved postdiastemal teeth; dorsal pattern with three stripes, one vertebral and two paravertebrals of similar width; ventral scales 184 in male (N=1) and 200 in females (N=2); subcaudal scales 119 in male and 102–112 in females; supralabial scales 7 or 8; nasal scale completely divided; loreal scale present; infralabial scales 9 or 10; dorsal scale rows 19/19/15; cloacal scale divided; dorsal scales with two apical pits; hemipenial body with a basal constriction and an asulcate surface ornamented by two parallel rows of enlarged body calyces extending from the tip of the lobes to the base of the hemipenial body.

Comparisons. Philodryas amaru differs from all cis-Andean congeners by the presence of two ungrooved postdiastemal teeth on the maxilla (vs. grooved postdiastemal teeth present in all cis-Andean species), and from the trans-Andean P. simonsii , P. chamissonis , and P. tachymenoides by the presence of three uniformly dark brown dorsal stripes with two scale rows width (vs. brownish dorsal stripes smaller, with less than one dorsal scale row of width in P. s i m o n s i i; only one vertebral stripe in P. chamissonis ; no dorsal stripes in P. tachymenoides ) and by the presence of two rows of large, shallow body calyces extending along the asulcate surface of the hemipenis from the tip of the lobes to the proximal one third of the hemipenial body (vs. two rows of large and deep body calyces in P. chamissonis ; more than two rows of smaller and shallow body calyces restricted to the asulcate surface of the lobes and distal portion of the hemipenial body in P. simonsii ). Furthermore, we refer to Table 1 for additional differences in meristic characters between trans-Andean species of Philodryas .

Description of the holotype. A large male with 622 mm TTL, 206 mm TL (33.1% of TTL), 17.7 mm head length (2.8% of TTL), 9.4 mm head width at broadest point, and 5.4 mm snout length. Head slightly distinct from neck in dorsal view ( Fig. 1 C); body robust. In lateral view, dorsal margin of the head rounded, with a marked inclination near to the snout ( Fig. 1 D). Snout rounded in dorsal and lateral views ( Fig. 1 ). Rostral scale subtriangular in frontal view, slightly wider than high (width 3.3 mm, height 2.1 mm), visible in dorsal view, contacting internasals, anterior nasals, and first supralabials. Internasals paired, polygonal, visible in lateral view, in broad medial contact, contacting nasals laterally and prefrontals posteriorly. Prefrontals paired, polygonal, as wide as long, in broad medial contact, with a dextral suture. Prefrontals contact posterior nasals, loreals and preoculars laterally, and preoculars, supraoculars and frontal posteriorly. Supraoculars polygonal, longer than wide, in contact with preoculars and postoculars laterally, with frontal medially, and with parietals posteriorly. Frontal pyramidal, longer than wide (4.8 mm length, 2.9 mm width), in contact with parietals posteriorly. Parietals polygonal, longer than wide, in broad medial contact with each other, contacting postoculars antero-laterally and temporals laterally. Nasal completely divided, with the suture vertical and the nostril mainly positioned in the dorsal region of the anterior nasal. Nasals rectangular, higher than long. Anterior nasals in contact with the first supralabial ventrally. Posterior nasals in contact with first and second supralabials, and loreal posteriorly. Loreal rectangular, slightly longer (1.6 mm) than high (1.3 mm), in contact with second and third supralabials ventrally, and preocular posteriorly. Preoculars nearly polygonal, higher than long, broadly bordering the orbit. Preocular contacting the third and fourth supralabials ventrally. Eye 2.8 mm of diameter, with rounded pupil. Two polygonal postoculars, with the upper one larger than the lower one. The upper postocular contacts the anterior temporal and the parietal posteriorly, while the lower postocular contacts the fourth and fifth supralabials ventrally and the anterior temporal posteriorly. Temporals 1 + 2, arranged in vertical rows. Seven supralabials, increasing in size posteriorly, with third and fourth scales bordering the ventral margin of orbit. Mental triangular, wider than long, and in broad contact with first infralabials laterally. Nine and 10 infralabials on the left and on the right sides, respectively. First pair of infralabials in medial contact. Two pairs of chinshields, with the anterior pair larger than posterior one. First four infralabials in contact with the first pair of chinshields on the left side and the first five on the right side. Mental groove composed by the first pair of infralabials and the two pairs of chinshields. Gular scales lanceolate, arranged in five diagonal rows. Maxilla with 15 prediastemal teeth and two ungrooved postdiastemal teeth. Dorsal scales smooth, arranged in 19/19/15 rows, with two apical pits in their distal tip. Scale row reduction from 19 to 15 rows along the right side of the dorsum occurs through the loss of the 8th row and the fusion of the 4th and 5th rows at the level of ventral 98. On the left side, scale row reduction from 19 to 17 occurs at the level of ventral 101 through the lost of the 8th row, and from 17 to 15 at the level of ventral 102 through the fusion of the 4th and 5th rows. Ventral scales smooth, with the posterior edge straight. Preventrals four and ventrals 184. Cloacal scale divided, and paired subcaudals 119 plus a terminal spine.

Coloration of the holotype in preservative. The dorsal surface of the head is light brownish grey while most of the labial scales and the ventral region of the head are light cream. The dorsum is light bluish grey with three longitudinal uniform black stripes, one vertebral and two paravertebrals. The vertebral stripe runs along the dorsoposterior part of the head and vertebral region, from the anterior tip of the parietal suture to the tip of the tail, occupying two rows of dorsal scales in the first third of the body and three rows posteriorly. The vertebral stripe tapers posteriorly from the level of the cloaca to the tip of the tail. The two paravertebral stripes extend on the lateral surface of the head as irregularly faded lines, on the loreal, uppermost margins of supralabials 2nd, 3rd, 6th, and 7th, postoculars, anterolateral margin of parietals, and temporals. Posterior to the temporal region, the paravertebral stripes turn into uniform black lines that run along the 4th and 5th paravertebral rows along the anterior one-third of the body, enlarging posteriorly to include the 3rd paravertebral row until the level of the cloaca. After the cloacal region, the paravertebral stripes taper posteriorly and fade away before reaching the tip of the tail. The belly is light bluish grey on its anterior one-third, and gradually turns into a darker bluish grey posteriorly, which covers the posterior two-third of the belly and the tail.

Coloration of the holotype in life. In the live specimen, the three vertebral and paravertebral stripes are dark brown while the dorsum is light brown, except for the first and second rows that are yellowish-green. The ventral surface on belly and tail is light yellow-brown to olive green. The head is light brown, while the supralabials and the ventral surface of the head are cream. The first, second, and third supralabials are bordered with dark brown ( Fig. 2 ).

Hemipenis of the holotype. The hemipenis is fully everted and maximally expanded ( Fig. 3 ), with 21.7 mm of total length, 8.4 mm at the widest point, and lobes with 3.9 mm length (18% of the length of the everted hemipenis). When inverted in the tail, it extends to the level of the 15th subcaudal (inverted hemipenis with 26.1 mm of total length) with the lobes bifurcating at the level of the 13th subcaudal (inverted lobes with 4.4 mm). The organ is flattened in lateral view, with a visible constriction at the base of the hemipenial body. It is semicalyculate, semicapitate, and slightly bilobed, with very short but clearly visible lobes. While the lobes are short, the capitulum covers half of the organ, being only feebly delimited by shallow edges and mostly restricted to the sulcate surface. The capitulum is formed by papilate calyces, which tend to be larger towards the tip of the lobes. The sulcus spermaticus divides on the proximal region of the organ (upper one-third from the base), and both branches extend centripetally along the sulcate surface diverging only slightly from each other to end at the tip of the lobes. The proximal half of the hemipenial body (including the constriction at the base) is covered with rows of small to medium-sized spines in its sulcate surface. Both lateral surfaces of the hemipenis are covered by two to three rows of lateral enlarged spines that converge to the asulcate surface to meet each other proximally on the asulcate surface above the basal constriction. Below the basal constriction, the asulcate surface is covered with small-sized spines. The asulcate surface of the lobes and distal half of the hemipenial body are covered with two rows of large and shallow body calyces that are ornamented by a row of spinulate papillae at their edge and extend from the midline of the hemipenis to the border of the rows of lateral enlarged spines. The spinulate papillae ornamenting the body calyces are large at the level of the lobes and gradually reduce in size towards the proximal half of the hemipenial body. The proximal half of the asulcate surface of the hemipenial body is ornamented with small-sized spines and lateral enlarged spines.

Variation. Differently from the male holotype, the two paratypes (FHGO 6399, 6400) are adult females with eight supralabial scales (with the 4th and 5th entering the orbit). Additionally, FHGO 6399 has 845 mm of TTL, 240 mm of TL (28.4% of TTL), 22.4 mm of head length (2.6% of TTL), three preventrals, 200 ventrals, 112 paired subcaudals, nine infralabials, first pair of chinshields bordered by the first four infralabials and second pair by 4th and 5th, 2 + 2 and 1 + 2 temporals in left and right sides, respectively. FHGO 6400 has 913 mm of TTL, 250 mm of TL (27.3% of TTL), 23.8 mm of head length (2.6% of TTL), three preventrals, 200 ventrals, 102 paired subcaudals, 10 infralabials, first pair of chinshields bordered by the first five infralabials and second pair by 5th and 6th, 1 + 3 temporals. In preservative, the coloration of the two paratypes is quite similar to the condition described for the holotype.

Etymology. The specific epithet amaru is derived from the Ecuadorian Kichwa dialect, meaning snake. Along the Andean region of Ecuador, Amaru is often known to represent a snake deity related to the economy and vitally of the water that allows the existence of Andean people. Also, “ Amaru ” or “snake” is considered to represent the first mother of the pre Inca Cañari culture that lived where presently is the city of Cuenca.

Distribution and natural history. The type locality is in the east versant of the inter-Andean valley of the Tomebamba River, in the southern portion of the Andes of Ecuador ( Fig. 4 ). The elevation in this region ranges from 2600 m to 4450 m, and is characterized by complex ecosystems that combine Andean temperate forests, high Andean forests of Polylepis (Rosaceae) , and high-altitude grasslands called Páramo ( Arbeláez & Vega 2008). Vegetational physiognomy at the type locality is dominated by secondary shrub forests called “Andean Chaparro” (Weimannia sp. Ocotea sp.), medium-size trees, and grasslands (Calamagostris intermedia) at higher altitudes ( Fig. 5 ).

We observed 33 individuals alive in the field from 2005 to 2008. All specimens were found active during the day (10:30h to 15:00h) in open grassland areas or between shrubs and water vegetation on the ground, under logs associated to water bodies from natural thermal ponds, streams, and in the border of rivers. Eggs of the P. amaru have been found in soil tunnels, galleries and under decaying logs. Three nest groups with 9, 10, and 13 light cream small elliptical eggs, respectively, were found about 150 cm underground. Two specimens that were manipulated regurgitated an Andean lizard ( Stenocercus festae ) and a marsupial frog of the genus Gastrotheca , respectively.

Figures

FIGURE 1. Holotype of Philodryas amaru (FHGO 4749) in dorsal (A) and ventral (B) views. Head of the holotype in right lateral (C), left lateral (D), dorsal (E), and ventral (F) views. Scale length = 10 mm.

FIGURE 2. Dorsal view of the holotype of Philodryas amaru in life (FHGO 4749) from Soldados, San Joaquin, Province of Azuay, Ecuador. Photograph by E. Arbeláez and A. Vega.

FIGURE 3. Hemipenis of the holotype of Philodryas amaru (FHGO 4749) in sulcate (A), asulcate (B), and top (C) views. Scale length = 5 mm.

FIGURE 4. Type locality of Philodryas amaru (circle with the white dot) and distribution records of Philodryas simonsii (squares). The white square corresponds to the type locality of Philodryas simonsii.

FIGURE 5. General view of the habitat in the type locality of Philodryas amaru, situated in Soldados, San Joaquin, Province of Azuay, Ecuador. Photograph from E. Arbeláez and A. Vega.

Tables

TABLE 1. Variation from selected meristic characters of the four trans-Andean species of Philodryas.

	P. amaru	P. chamissonis	P. simonsii	P. tachymenoides
Number of Ventrals	184 ♂ 200 ♀	167–194 ♂ 181–199 ♀	182–205 ♂ 189–215 ♀	185–189 ♂ 200–218 ♀
Subcaudals	119 ♂ 102–112 ♀	96–118 ♂ 93–109 ♀	103–125 ♂ 101–123 ♀	104–105 ♂ 96–108 ♀
Apical Pits	two	One	One	One
Supralabials	7 or 8	8	8	8 or 9
Infralabials	10–11	11	9–11	10–11
Maxillary Teeth	14–15	13–14	10–13	10–12