Stenocercus catherineae, Venegas & García-Ayachi & Chávez-Arribasplata & Chávez & Wong & García-Bravo, 2020

Venegas, Pablo J., Garcia-Ayachi, Luis A., Chavez-Arribasplata, Juan C., Chavez, German, Wong, Ivan & Garcia-Bravo, Antonio, 2020, Four new species of Stenocercus Dumeril & Bibron, 1837 (Squamata, Iguania) from the Department of Amazonas in northeastern Peru, Evolutionary Systematics 4 (2), pp. 79-108 : 79

Stenocercus catherineae sp. nov. Figs 1 , 2 , 3

Type material.

Holotype:

PERU • ♂, adult; Amazonas Department, Bongará Province, Florida District, Huembo; 5°51.47'S, 77°58.75'W; 2090 m a.s.l.; 09 Dec. 2019; P.J. Venegas and L.A. García-Ayachi leg.; CORBIDI 21365.

Paratypes:

PERU • 1 ♂, 1 ♀, adults, collected with the holotype; CORBIDI 21366-67 • 1 ♂, juvenile; Amazonas Department, Bongará Province, Cuispes District, Cuispes; 5°55.49'S, 77°56.94'W; 1850 m a.s.l.; 8 Mar. 2017; G. Chávez leg.; CORBIDI 18662 • 1 ♀, 1 ♂, adults; Amazonas Department, Bongará Province, Valera District, Cocachimba; 6°2.76'S, 77°53.55'W; 1460 m a.s.l.; 22 May 2007; by P.J. Venegas leg.; CORBIDI 501-02.

Diagnosis.

Stenocercus catherineae sp. nov. differs from other species of Stenocercus except for S. aculeatus , S. angulifer Werner, 1901, S. huancabambae Cadle, 1991, S. philmayi sp. nov., S. prionotus Cadle, 2001, and S. scapularis Boulenger, 1901 by having: (1) projecting-angulate temporals, (2) laterally oriented nostrils; (3) dorsal and lateral scales of body similar in size, and (3) scales on posterior surface of thighs keeled and imbricate.

Stenocercus aculeatus , S. angulifer , S. prionotus , and S. scapularis can be easily distinguished from S. catherineae sp. nov. by having strongly keeled ventrals, whereas in the new species ventrals are feebly to moderately keeled. Stenocercus aculeatus , S. angulifer and S. scapularis also have a dorsolateral crest (absent in S. catherineae sp. nov.); and S. prionotus lacks a postfemoral mite pocket (present in S. catherineae sp. nov.). Stenocercus catherineae sp. nov. differs from S. philmayi sp. nov. by having smaller dorsal scales with 43 to 53 vertebrals and 46 to 59 scales around midbody versus 32 to 38 vertebrals and 34 to 45 scales around midbody in S. philmayi sp. nov. The gular region in adult males of S. catherineae sp. nov. is black, whereas in S. philmayi sp. nov. it is cream.

The new species is most similar to S. huancabambae (Fig. 4A, B ) with which it shares ventral scales strongly keeled, like the rest of the aforementioned species, and a strongly compressed tail. Furthermore, both species are geographically close at the northern extreme of the central Andes in the Department of Amazonas ( Cadle 1991; Torres-Carvajal 2007b). Nevertheless, the new species can be distinguished from S. huancabambae (characters in parentheses) by having the parietal eye not visible through the interparietal cornea (visible); postfemoral mite pocket as a distinct, deep slit-like opening (shallow slit-like opening, Fig. 3 ); dark patch covering most of the gular region of adult males present (absent); black patch on ventral surface of neck absent (present as a circular or elongate blotch, Fig. 4B ); and a strongly compressed tail in adult males (very strongly compressed tail as a tape-like along its proximal two thirds).

At the locality of Cuispes, and probably also in Huembo, S. catherineae sp. nov. and S. flagracanthus sp. nov. exist in sympatry; however, both species are strikingly different. S. flagracanthus sp. nov. has a relatively short tail armed with projecting spines, whereas S. catherineae sp. nov. has a long tail, compressed laterally, and a projecting vertebral crest.

Definition.

(1) Maximum SVL in males 83 mm (n = 3); (2) SVL in females 75 mm (n = 2); (3) vertebrals 43-53; (4) paravertebrals 62-73; (5) scales around midbody 46-59; (6) supraoculars 4; (7) internasals 4-6; (8) postrostrals 2-4; (9) loreals 5-6; (10) gulars 22-26; (11) subdigitals on Finger IV 18-21; (12) subdigitals on Toe IV 25-30; (13) posthumeral mite pocket present as a deep depression with a wide opening [Type 3 of Torres-Carvajal (2007b)]; (14) postfemoral mite pocket present as a distinct pocket with a posteroventrally oriented slit-like opening [Type 2 of Torres-Carvajal (2007b)]; (15) parietal eye not visible through interparietal cornea in any specimens (n = 6); (16) scales on occipitoparietal region large, multicarinate, not imbricate; (17) projecting angulate temporals present; (18) row of enlarged supraoculars present, occupying most of supraocular region; (19) scales on frontonasal region and supraoculars slightly imbricate, multicarinate; (20) preauricular fringe present, short; (21) neck folds absent; (22) lateral and dorsal nuchals similar in size; (23) posterior gulars rhomboidal, projected posteriorly, keeled and imbricate, not notched; (24) lateral and dorsal body scales similar in size; (25) vertebrals larger than adjacent paravertebrals, forming a distinct vertebral crest; (26) dorsolateral crest absent; (27) ventrals keeled, imbricate, mucronate; (28) scales on posterior surfaces of thighs keeled, imbricate, mucronate; (29) inguinal granular pocket absent; (30) inguinal groove absent; (31) preanals not projecting; (32) tail strongly compressed laterally in adult males; (33) tail length 65-70% of total length; (34) caudal whorls per autotomic segment three; (35) caudals not spinose; (36) dark brown stripe extending anterodorsally from subocular region to supraciliaries always present; (37) dark patch extensively covering gular region of females present; (38) dark patch covering gular region in adult males present; (39) black patch on ventral surface of neck in adult males absent; (40) dark midventral longitudinal mark such as faint line, conspicuous stripe, or extensive patch in adult males absent; (41) dark patches on ventral surface of thighs in adult males absent; (42) two xiphisternal and three postxiphisternal pairs of inscriptional ribs fused medially, forming three chevrons (Pattern 6A of Torres-Carvajal 2004).

Description of the holotype.

Adult male (Fig. 1 ); SVL 82 mm; TL 156 mm; maximum head width 15.7 mm; head length 18.7 mm; head height 12.8 mm; occipitals, parietals, interparietals, and postparietals large, multicarinate, slightly imbricate; parietal eye not visible; supraoculars in four rows, multicarinate, slightly imbricate, subequal in size; one canthal; canthal not in contact with the nasal; scales on frontonasal region slightly imbricate and multicarinate; internasals four; postrostrals three, two most lateral wider than long on each side, medial postrostrals as long as wide; supralabials four; infralabials five; loreals four; lorilabials in one row; preocular one, in contact with canthal; lateral temporals keeled, imbricate; gulars in 22 rows between tympanic openings; all gulars keeled, imbricate, apical pit absent; second infralabial not in contact with second and third sublabials; mental in contact with first pair of infralabials; lateral and dorsal scales of body and neck keeled, imbricate, mucronate; lateral and dorsal body scales similar in size; scales around midbody 46; vertebrals larger than dorsals, 43 scales on vertebral row, serrate vertebral crest present; paravertebrals 65; ventrals broad, rhomboidal, keeled, imbricate; preauricular fringe short, composed of three enlarged scales, all similar in size; antegular, gular, postauricular, oblique, supraauricular, longitudinal and antehumeral neck folds absent; limb scales keeled, imbricate; ventral scales of hindlimbs keeled and ventral scales of upper arms keeled, mucronate; lamellae on Finger IV 18; lamellae on Toe IV 27; tail strongly compressed laterally; caudals keeled, imbricate, mucronate; basal subcaudals keeled, imbricate; tail length 1.9 times SVL; posthumeral mite pocket present as a deep depression with a wide opening; postfemoral mite pocket present as a distinct deep pocket with a posteroventrally oriented slit-like opening; postfemoral region composed of imbricate, smooth scales that become keeled towards the tail.

Coloration in life

(Fig. 2A, B ). Dorsum pale brown with the first two chevrons over the vertebral line black and the rest slightly darker than the background; cream line extending vertically from the arm insertion to the scapular region surrounded by a black blotch; dorsal surface of limbs darker than the dorsum with faint dirty cream transverse bars; flanks reddish brown, including the tail, becoming red toward the venter and dotted with white; subocular and loreal regions creamy white; dorsal surface of head black with the superciliaries and rostral cream; labials, sublabials and mental black, extending as an irregular longitudinal stripe to the neck; gular region black with cream irregular blotches to the sides; a black irregular stripe extends from the gular region ventrolaterally to the arm insertion; ventral surface of neck, chest and forelimbs are dirty cream with a black spot ventrolaterally in the arm; belly and ventral surface of tail pink; pelvic region and ventral surface of hindlimbs dirty cream. The iris is reddish brown.

Coloration in preservative

(Fig. 1D, E ). It is similar to the coloration in life with the dorsal surface of trunk, limbs and tail darker than in life. Moreover, the reddish coloration of the flanks almost disappears.

Intraspecific variation.

Measurement and scutellation characters of Stenocercus catherineae sp. nov. are presented in Table 1 . The second infralabial is in contact with the third sublabial in all specimens, and the first pair of postmentals are not in contact medially in two specimens ( CORBIDI 501 and 21367). The three male paratypes are identical to the holotype, including a juvenile ( CORBIDI 18662), varying only by having few scattered white dots on the head and, the black patch on the gular region extends to the ventral surface of the neck as a bold band ( CORBIDI 21366) (Fig. 2C, D ). Ventral scales in the juvenile male are strongly keeled and mucronate.

Sexual dimorphism is evident in adult individuals. In two adult female paratypes (Fig. 2E, H ) dorsal coloration is dusty brown with cinnamon vertebral chevrons along the back and tail, and cinnamon blotches along the flanks; hindlimbs with scattered dark brown transverse stripes; head in both specimens are darker than the rest of body, being dark gray ( CORBIDI 501) or dark brown ( CORBIDI 21367); sides of head grayish white ( CORBIDI 21367) or dark gray ( CORBIDI 501) with the loreal and subocular region white, and labials brown. Ventral coloration is pale brown with the gular region dark brown ( CORBIDI 21367) or dusty cream with the gular region dark gray ( CORBIDI 501) but both specimens have a faint pink hue on belly and base of tail (Fig. 2F, H ).

Distribution and natural history observations.

Stenocercus catherineae sp. nov. is only known from three proximate localities at Huembo and Cuispes in the northern extreme of the Cordillera Central at the Río Utcubamba basin in the Department of Amazonas, at elevations between 1466 to 2085 m a.s.l. (Fig. 5 ). According to the terrestrial ecoregions of the world by Olson et al. (2001), this species occurs in the Peruvian Yungas ecoregion. The habitat at the type locality of S. catherineae sp. nov. is a steep area located on the sides of the Río Chido with presence of corn, coffee and fruit plantations, and some patches of secondary forest and shrub vegetation. Several individuals were observed basking on fallen tree trunks or at the base of bushes close to trails between 1000 and 1200 hours. When the lizards were disturbed, they ran to hide inside fern patches. No other lizards or reptiles were observed in sympatry.

At Cuispes only one individual was collected in the croplands close to the village. Other squamate reptiles collected with S. catherineae sp. nov. at Cuispes were Atractus sp. Wagler, 1828, Dipsas palmeri Boulenger, 1912, and S. flagracanthus sp. nov. At Cocachimba, the two specimens collected were found basking at 1000 hours on the base of rocky fences with bushes along a trail. An uncollected adult female was observed basking at 900 hours on a fallen wall of an abandoned house. The general landscape at Cocachimba is composed of croplands of corn, fruit and sugar cane bordered by rocky fences and some streams with narrow fringes of riverine forest or shrub vegetation. Other species of squamate reptiles collected with S. catherineae sp. nov. at Cocachimba were: Atractus sp., Chironius exoletus Linnaeus, 1758, Mastigodryas boddaerti Sentzen, 1796, and Petracola angustisoma Echevarría & Venegas, 2015.

The female paratype ( CORBIDI 21367) collected during the rainy season (December 2019) had 2 well developed follicles, one in the left and the other in the right ovary. The sizes of these follicles are 10.83 × 9.67 mm and 10.99 × 9.53 mm; their volumes were 530.2 mm³ and 522.6 mm³, respectively.

Etymology.

The specific name is a noun in the genitive case and is a patronym for Catherine Dupont, a Peruvian veterinary specialist in One Health, who is actively working searching and monitoring viruses and other zoonotic pathogens. The specific name of this lizard is in recognition of her passion for the natural world and its creatures, and her selfless support of the herpetological division of CORBIDI.

Figures

Figure 1. Stenocercus catherineae sp. nov. preserved holotype, adult male, SVL 82 mm (CORBIDI 21365): dorsal (A), lateral (B), and ventral (C) views of the head; dorsal (D) and ventral (E) views of the entire specimen. Photographs by Luis A. Garcia-Ayachi. Scale bars: 10 mm.

Figure 2. Dorsolateral and ventral views of Stenocercus catherineae sp. nov. in life: (A, B) holotype, adult male, SVL 82 mm (CORBIDI 21365); (C, D) adult male, SVL 79 mm (CORBIDI 21366); (E, F) adult female, SVL 75 mm (CORBIDI 21367); (G, H) adult female, SVL 75 mm (CORBIDI 501). Photographs by Pablo J. Venegas.

Figure 3. Lateral view of the postfemoral mite pocket in three species of Stenocercus: (A) S. catherineae sp. nov. (CORBIDI 21365), (B) S. philmayi sp. nov. (CORBIDI 21092), and (C) S. huancabambae (CORBIDI 19747). Photographs by Luis A. Garcia-Ayachi. Scale bars: 5 mm.

Figure 4. Dorsolateral and ventral views of adult males of three species of Stenocercus: (A, B) S. huancabambae, (C, D) S. aculeatus, (E, F) S. prionotus from northern-central Peru, and (G, H) S. prionotus from southern Peru. Photographs by: (A - D) Pablo J. Venegas, (E) Andy Barboza, (F) Diego Vasquez, and (G, H) German Chavez.

Figure 5. Distribution map of S. catherineae sp. nov. (red triangles), S. dracopennatus sp. nov. (yellow star), and S. philmayi sp. nov. (blue squares), and the similar species: S. aculeatus (fuchsia diamonds), S. angulifer (blue diamonds), S. huancabambae (orange diamonds), S. prionotus (turquoise diamonds), and S. scapularis (red diamonds). Symbols with a dot in the middle correspond to type localities. White circles with a dot are important cities for reference.