Euspondylus chasqui, Chavez, German, Siu-Ting, Karen, Duran, Vilma & Venegas, Pablo J, 2011

Chavez, German, Siu-Ting, Karen, Duran, Vilma & Venegas, Pablo J, 2011, Two new species of Andean gymnophthalmid lizards of the genus Euspondylus (Reptilia, Squamata) from central and southern Peru, ZooKeys 109, pp. 1-17 : 2-8

Euspondylus chasqui sp. n. Figs 1-2

Holotype.

(Fig. 1a) Adult male (CORBIDI 06963), Perú, Ayacucho Department, La Mar Province, Chiquintirca (13°01'59.7"S, 73°40'46.0"W), 2780 m elevation, collected by Germán Chávez on 24 August 2010.

Paratypes.

(Fig. 1b-d) CORBIDI 06955, 06966, 06968-69 (all adult females), 06961-62, 06965, 06967 (all adult males), 06964 (juvenile), same data as holotype; CORBIDI 08413, 08415-16, 08418-19, 08423 (all adult males), 08414, 08417, 08420-22, 08424-25, 08431-32 (all adult females), Perú, Ayacucho Department, La Mar Province, surroundings of Chiquintirca (13°01'17.4"S, 73°40'30.1"W), 2598 m elevation, collected by Vilma Duran and Karla García on 18 December 2010.

Diagnosis.

1) Head rounded in dorsal and lateral view, frontonasal length usually equal or slightly larger than frontal length; (2) nasoloreal suture present; (3) supraoculars four, anteriormost supraocular fused with anteriormost superciliary, all supraoculars separated from ciliaries; (4) superciliary series complete, five; (5) supralabial-subocular fusion absent; (6) postoculars three; (7) postparietals three; (8) supratympanic temporals three; (9) genials in two pairs, transverse sutures perpendicular with respect to midline of body; (10) dorsal scales rectangular, juxtaposed, keeled; (11) transverse dorsal count (enlarged rows at midbody) at midbody 20-28 in both sexes; (12) longitudinal dorsal count 35-43 in both sexes; (13) longitudinal ventral count 19-22 in both sexes; (14) lateral scale rows at midbody two or three; (15) femoral pores in males 8-11, in females 7-10; two scales between femoral pores; (16) subdigital scales on 4th finger 10-16, on 4th toe 17-26; (17) limbs overlapping, pentadactyl; digits clawed; forelimb reaching anteriorly to fourth supralabial; (18) anterior preanal plate scales paired; (19) hemipenis acapitate; flounces lacking calcified spines and forming two chevrons on distal half of hemipenis whereas basal half is covered with three transverse flounces; some asulcate flounces separated by a small expansion pleat; sulcate flounces about as wide as asulcate flounces; sulcus spermaticus single, flanked by a broad naked expansion pleat widened distally; (20) dorsum olive green, brown, or reddish brown with a middorsal pale stripe bordered by a discontinous dark line on neck and body more prominent in females than males; lateral ocelli present; ventral surfaces yellowish or reddish white; (21) transparent lower palpebral disc an undivided oval; (22) prefrontals present.

Euspondylus chasqui can be distinguished from other Peruvian species currently assigned to Euspondylus by the following character states (condition for Euspondylus chasqui in parentheses). Euspondylus maculatus and Euspondylus guentheri : a lower palpebral disc with vertical sections (palpebral disc an undivided oval), dorsal scales smooth or wrinkled (keeled), and longitudinal dorsal count 32-37 (35-43). Euspondylus caideni : by three or four superciliaries (five superciliaries), pale middorsal stripe absent (present), lateral ocelli absent (present), dorsal scales reduced in size above longitudinal band of laterals granules (not reduced), longitudinal dorsal count 41-48 (35-43). Euspondylus josyi : by having three supraoculars, exceptionally four, (four supraoculars), pale vertebral stripe absent (present), lateral ocelli absent (present), limb overlapping 10-13 dorsal scales (10-12), longitudinal dorsal count 29-35 (35-43) and SVL to 62.0 mm (74.0 mm). Euspondylus rahmi : anteriormost supraocular not fused with anterior most superciliary (fused), longitudinal dorsal count 49-54 (35-43), dorsal scales reduced in size above longitudinal band of laterals granules (not reduced) and maximum SVL 71.0 mm (74.0 mm). Euspondylus simonsii : a pale line between the tympanum and shoulder present (absent), dorsal scales smooth or only faintly keeled on posterior dorsum (all dorsal scales keeled), longitudinal dorsal count 33 -39 (35-43) and transversal count at midbody less than 35 (40-48). Euspondylus spinalis : head acuminate from the dorsal and lateral view (rounded), prefrontals present or absent (prefrontals present), adpressed limbs overlapping by fewer than 10 dorsal scales rows (adpressed limbs overlapping by 10-12 dorsal scale rows), dorsal scales reduced in size above longitudinal band of laterals granules (not reduced), longitudinal dorsal count 39-46 (35-43), femoral pores on one side in females 1-6 (8-10) and small SVL, according to a population from Oso Playa, Pasco Department, ranging between 44.0-55.0 mm (SVL ranging between 50.7-74.0 mm). Euspondylus nellycarrillae : dorsal scales subhexagonals (rectangular), and longitudinal dorsal count 41-49 (35-43), femoral pores of one side 12-15 in males, 12-14 in females (7-10 in females, 8-11 in males), and maximum SVL = 60.0 mm (74.0 mm).

Euspondylus chasqui can be distinguished from all species currently assigned to Petracola , Proctoporus and Riama by the presence of prefrontal scales (absent in all species in these three genera). Euspondylus chasqui can be further distinguished by the following character states (condition for Euspondylus chasqui in parentheses). All Bolivian and Peruvian species of Proctoporus except Proctoporus pachyurus and Proctoporus bolivianus : longitudinal dorsal count fewer than 36 scale rows (35-43 scale rows). Proctoporus pachyurus : longitudinal dorsal count 49-59 scale rows (35-43 scale rows). Proctoporus bolivianus : 4-8 femoral pores in males (7-11 femoral pores). All Petracola and Riama species: lower palpebral disc with vertical sections (palpebral disc an undivided oval). Northern Ecuador species of Riama excluding Riama columbiana : no band of granular scales along the sides of body between dorsal and ventral scales (granular scales present). Riama columbiana : limbs not overlapping when adpressed against body in adults (limbs overlapping), superciliary series incomplete (complete), and some supraoculars in contact with ciliaries (all supraoculars separated from ciliaries).

Euspondylus chasqui can be distinguished from Opipeuter xestus (condition for Euspondylus chasqui in parentheses): smooth dorsal scales (keeled); a single large elongate subocular (several small subocular scales); and in hemipenis morphology, large spines at the base of the sulcus spermaticus (no such spines present in Euspondylus chasqui ).

Description of the holotype.

Adult male (CORBIDI 06963) (Fig. 1a, 2a,b); SVL = 73.0 mm, tail (complete) length = 124.0 mm; axilla to groin distance 31.4 mm; head length 20.2 mm; head width 13.8 mm; shank length 10.7 mm.

Head scales smooth, glossy; rostral scale wider (3.2 mm) than long (1.6 mm), higher than adjacent supralabials, in contact with frontonasal, nasoloreal, and first supralabials posteriorly; frontonasal slightly longer (3.5 mm) than wide (3.4 mm), widest posteriorly, in contact with nasoloreal and frenocular laterally, prefrontals posteriorly; nasoloreal suture present; prefrontals present, in contact with each other medially, in contact with fused anteriormost superciliary-anteriormost supraocular, frontal posteriorly; frontal longer (3.7 mm) than wide (3.0 mm), anterior suture angular with point directed anteriorly, lateral sutures straight, posterior suture angular with point slightly directed posteriorly, in contact with second and third supraoculars laterally, frontoparietals posteriorly; frontoparietals pentagonal, in contact with third and fourth supraocular, parietals and interparietal posteriorly; supraoculars four, none in contact with ciliaries; superciliary series complete, anteriormost superciliary fused with anteriormost supraocular; interparietal heptagonal, longer (4.8 mm) than wide (2.7 mm), in contact with parietals laterally, postparietals posteriorly; parietals polygonal, in contact with fourth supraocular anterolaterally, temporal scales laterally, dorsalmost postocular, postparietals posteriorly; postparietals three, lateral postparietals polygonal, medial postparietal squarish; palpebral disc an undivided oval, unpigmented; frenocular squarish, in contact with nasoloreal anteriorly; postoculars three; temporals polygonal; supratympanic temporals three; supralabials seven; infralabials five; mental wider (2.9 mm) than long (1.5 mm), in contact with first infralabials, postmental posteriorly; postmental single, pentagonal, posterior suture angular, point directed posteriorly, in contact with first and second infralabials; genials in two pairs, anterior pair subquadrangular, in contact with second and third infralabials; posterior genials subpentangular, in contact with fourth and fifth infralabials laterally; scale rows between genials and collar fold (along midventral line) 12; medialmost scales of three penultimate gular scale rows slightly enlarged; posteriormost gular row enfolded posteriorly, concealing two granular scale rows; lateral neck scales rounded, smooth.

Dorsal scales rectangular, longer than wider, juxtaposed, keeled, 40 in a longitudinal count; some middorsal scales irregularly arranged; transverse dorsal count (enlarged rows at midbody) at fifth transverse ventral scale row 16, at 10th transverse ventral scale row 29, at 15th transverse ventral scale row 26; lateral scale rows at fifth transverse ventral scale row 14/ 16, at 10th transverse ventral scale row 4/4, at 15th transverse ventral scale row 3/3; lateral scales on body near insertion of forelimb small to granular; ventrals rectangular and juxtaposed; complete longitudinal ventral count 21; longitudinal ventral scale rows at midbody 12; 49 scales around midbody; anterior preanal plate scales two; posterior preanal plate scales four, all the scales at the same size; scales on tail rectangular and juxtaposed, keeled; at midventral subcaudals squarish.

Limbs pentadactyl; digits clawed; forelimb reaching anteriorly to fourth supralabial; dorsal brachial scales polygonal, of varying sizes, subimbricate, smooth; midbrachial anterodorsal scale at least twice as large as adjacent scales, smooth; anteroventral, ventral, and posteroventral scales roundish, imbricate, smooth; antebrachial scales polygonal, of various sizes; medial antebrachial scales small, rounded, smooth; dorsal manus scales polygonal, subimbricate; palmar scales small, oval, domelike; dorsal scales on fingers smooth, quadrangular, covering dorsal half of digit, overhanging supradigital scales, two on I, 5/4 on II, seven on III, nine on IV, five on V; subdigital scales 5/4 on I, 10/9 on II, thirteen on III, 14/15 on IV, 7/8 on V; anterodorsal thigh scales polygonal, at least five times as large as adjacent scales, becoming smaller ventrally, smooth; posterodorsal thigh scales small, rounded, arranged irregularly; anterior and anteromedial shank scales polygonal, subimbricate, smooth, anteriormost scales many times larger than lateral, posterolateral, and posteromedial shank scales; lateral, posterolateral, and posteromedial shank scales polygonal or roundish, juxtaposed, smooth; dorsal pes scales polygonal, subimbricate, smooth; scales on dorsal surface of digits single, quadrangular, smooth, overhanging supradigital scales, two on I, five on II, eight on III, 10/10 on IV, 6/7 on V; subdigital scales single or double, 6/7 on I, 9/10 on II, 16 /15 on III, 22/21 on IV, 10/11 on V; femoral pores nine or 10; two scales between medialmost femoral pores.

The completely everted hemipenis is an acapitate organ without a medial welt; apex with two large protrusions separated by the distal end of the sulcus spermaticus; sulcus spermaticus single, flounces lacking calcified spines and forming two chevrons on distal half of hemipenis; sulcate flounces about as wide as asulcate flounces; asulcate flounces becoming shorter distally, three in the basal half and eleven in each protrusion, distal chevrons separated by a small expansion pleat; sulcus spermaticus single, flanked by a broad naked expansion pleat widened distally.

Coloration in preservative.

Dorsal surface of head brown, dorsal surface of body and tail bluish brown with a middorsal dark bordered pale stripe on neck and body; lateral ocelli absent; ventral surfaces dirty white suffused with pale blue.

Coloration in life (Fig. 1a, d).

Dorsal surface of head olive green; lateral surface of head, around the labial region yellowish orange with dark spots in each labial scale; ventral surface of head, pregular and gular region yellowish orange with dark grey spots on the genials and pregular scales. Dorsal surface of body same color as head, but with black spots in each scale around middorsal region, that form two indistinct and discontinous lines that extend from occiput to posterior hind limbs forming a dark bordered middorsal pale stripe; lateral surface of body same coloration as dorsum with one indistinct ocellus on both sides above insertion of forelimbs, some lateral scales bearing black or small orange spots; ventral surface of body reddish cream (resembling clay). Limbs similar to body, ventral surface of arms olive cream, ventral surface of legs cream. Coloration of dorsal and ventral surfaces of tail like that of body.

Variation(Fig. 1b-d).

In the type series, the distinctness of the pale middorsal stripe is more noticeable in females than males, whereas the lateral stripes are obscure in some. Lateral ocelli are present forming a series from three to five ocelli on each side in females, and usually one on each side in males, only one male of the type series (CORBIDI 06967) has three ocelli on each side. Sexual dimorphism is evident in the size of the femoral pores, males have bigger femoral pores than females, but not in their number (8-11 in males versus 7-10 in females), however the main differences between females and males is the SVL (maximum SVL in females = 61.0 mm, maximum SVL in males = 74.0 mm). See Table 1 for variation in selected morphometric and squamation characters in the specimens examined.

Etymology.

The specific epithet is based on the Quechua word “chasqui”, which refers to the messengers of the Incan empire, men who, on foot, carried the messages throughout the imperial territory in the Cordillera de los Andes where these lizards are found.

Distribution and natural history.

Euspondylus chasqui is known from two localities within a studied area of approximately 12 km² in the Río Apurímac valley (Fig 4). It inhabits secondary forests and human settlements. The individuals observed were mostly found at midday under the rocks or foraging between stones, always near medium-sized rocks that they use for hiding. The soil under these rocks is generally more damp compared to the rest of the soil around. A clutch with two eggs was found under the litter, as well as several gravid females (CORBIDI 06955, 06966, 06968-69, 08417, 08420-21, 08424, 08431-32) from the dry and wet season (August and December, 2010) containing two eggs inside the abdominal cavity. This suggests that the maximum clutch size is two and that the reproductive cycle and birth of neonates can be at least twice a year. The egg length range is 3.4-14.1 mm (x- = 8.3 mm, n= 20) and width range is 2.8-5.9 mm (x- = 4.5 mm, n=20), SVL range of gravid females is 48.5-72.7 mm. We did not see nests sharing the same area. Euspondylus chasqui does not occur sympatrically with any other species of Euspondylus or Proctoporus ; however, a marsupial frog, Gastrotheca rebeccae , was found at the same location. Euspondylus chasqui was the most abundant species in the type locality, where 35 individuals were found in four hours by four surveyers.