Gonatodes rayito, Schargel, Walter E., Rivas, Gilson A., García-Pérez, Juan E., Rivero-Blanco, Carlos, Chippindale, Paul T. & Fujita, Matthew K., 2017

Schargel, Walter E., Rivas, Gilson A., García-Pérez, Juan E., Rivero-Blanco, Carlos, Chippindale, Paul T. & Fujita, Matthew K., 2017, A new species of Gonatodes (Squamata: Sphaerodactylidae) from the western versant of the Cordillera de Mérida, Venezuela, Zootaxa 4291 (3), pp. 549-562 : 553-559

Gonatodes rayito sp. nov.

( Figs. 3–5 )

Gonatodes petersi Donoso-Barros : Esqueda (2004) [two specimens, ULABG 4726, 4741 , from near Santa Apolonia , Mérida, Venezuela]

Gonatodes vittatus (Lichtenstein) : Rivas et al. (2006) [in part, specimens from Mérida] Gonatodes v. vittatus (Lichtenstein) : Rivero-Blanco (1967) [specimens of G. v. vittatus reported in sympatry with G. albogularis in “Sur del Lago” are likely G. rayito based on locality. The two live specimens of G. v. vittatus pictured from “La Azulita” are also G. rayito ]

Holotype. MCNG 2231 (field number WES 3146), an adult male from road towards Las Mercedes/ El Frío, less than 1 km away from Panamericana road (8° 53' 40.9'' N; 71° 20' 44.2'' W; 90 m), Mérida State, Venezuela, collected on October 7, 2006 by Juan E. García-Pérez, Walter Schargel, and Hector Aguilar.

Paratypes. 17 specimens, all from Venezuela (states in upper case) . MÉRIDA: MCNG 2232 (♂), same data as the holotype . MBLUZ 828-1 (♂), 828-2 (♀): Hacienda La Onia, El Vigia (8°35'48" N, 71°41'27" W; 150 m). EBRG 4889 (♀), MBLUZ 1398 (juvenile): near Cueva del Pirata, La Azulita (8°42’47” N, 71°26’26” W; 1030 m). MCNG 2233 (♀), UTA 63886 (♀): road from La Azulita to Santa Elena (8°44'21.2" N, 71°26'53.1" W; 850 m) . EBRG 4890 (♂), MCNG 2236 (♂): San Felipe, road between Estanques and Santa Cruz de Mora (08°26'21.18" N, 71°34'53.64" W; 670 m) . TÁCHIRA: MCNG 2237 (♀) , UTA 63888 (♂): Río La Blanca , road Colon-La Fria, (08°04'45.60" N, 72°14'14.34" W; 560 m) . MCNG 2235 (♂), UTA 63889 (juvenile): Socorro, road La Grita-La Fría (08°10'53.34" N, 72°13'58.56" W; 230 m). TRUJILLO: MBLUZ 283-1 (♂), 283-2 (♀) , UTA 63887 (♂), MCNG 2234 (♂): from town of Betijoque (no geographic coordinates obtained in the field; elevational range of town 450–550 m).

Definition. The new species can be distinguished from all congeners by a combination of the following characters: (1) small size (largest specimen examined has a SVL of 40.3 mm), (2) 98–118 scales around midbody, (3) elongated supraciliary spine absent, (4) two lateral scale rows on the digits, (5) subcaudal pattern Type B, (6) scales posterior to the postmentals gradually transitioning from larger polygonal and juxtaposed into smaller granular and somewhat imbricate ( Fig. 3 ), (7) brown iris, and (8) adult males with a yellowish to reddish brown hood and a distinct white middorsal stripe.

Diagnosis. Gonatodes rayito differs from all congeners, except G. atricucullaris , G. eladioi , G. petersi and G. vittatus , by having a distinct pale middorsal stripe. This stripe is white and conspicuous in males, but is creamish and less prominent in females. It differs from G. atricucullaris , a species known only from Departamento de Cajamarca, Peru, in having a white, transverse, lateral bar anterior to the forelimb insertion, which is not present in the Peruvian species. Additionally, males of G. rayito have a white or yellow gular region as opposed to having a black gular region with white spots. In G. atricucullaris this black coloration also extends dorsally on the head. Gonatodes eladioi , a species known only from the state of Pará, Brazil, differs from the new species in having a white postocular stripe (absent in G. rayito ) and in having a different subcaudal pattern in its original (=unregenerated) tail. In G. eladioi there is a medial row of enlarged subcaudals in which there are larger scales in contact with three scales laterally, separated from each other by a single smaller scale which contacts two scales laterally (subcaudal pattern type C of Rivero-Blanco & Schargel 2012), whereas in G. rayito the larger subcaudals scales are separated by two smaller scales (subcaudal pattern type B of Rivero-Blanco & Schargel 2012).

The new species is most similar and closely related to G. petersi and G. vittatus , but differs from these two species in aspects of color pattern, size and scale counts ( Table 1). Gonatodes petersi and G. rayito differ in several aspects of coloration in males ( Fig. 4 ). The background dorsal coloration of G. petersi is brown versus gray in G.

rayito . The pale background coloration of the gular region in G. petersi extends up to the lips and, posterior to the eye onto the lower lateral halves of the head and the neck, whereas in G. rayito this pale coloration might extend barely to the lips but not onto the sides of the head or neck. Males of G. rayito have a yellowish to reddish brown hood that extends posteriorly to about the level of the ear opening that is not present in G. petersi . Also, adult males of G. rayito have a mostly black to very dark gray venter as opposed to a dingy white to pale gray venter in G. petersi . Females of G. rayito have a wider and more conspicuous pale middorsal stripe compared to G. petersi ( Fig. 5 ).

Gonatodes rayito (most adults larger than 35 mm in SVL) is larger than G. vittatus (adult maximum SVL about 35 mm; Rivero-Blanco 1979). Males of G. rayito have small, white, lateral ocelli and spots (absent in G. vittatus ), and lack any ferruginous coloration along the body flanking the middorsal stripe (a dull orange to reddish brown coloration flanks the middorsal stripe along the body in G. vittatus ; see Fig. 4 ). Females of G. rayito have a wider and more conspicuous pale middorsal stripe compared to G. vittatus . In females of G. rayito there are small dark brown spots laterally that are irregular in shape, poorly defined, and are not arranged in any obvious pattern, whereas in females of G. vittatus the dark markings are larger, well-defined, rounded in shape, and arranged into a somewhat regular pattern of transverse rows ( Fig. 5 ). In addition to differences in coloration, G. rayito has fewer infraproximal lamellae on the fourth toe, generally having 6 (14 out of 17 specimens examined), and rarely 5 (one specimen out of 17) or 7 (two specimens out of 17), as opposed to having generally 7–9 (32 specimens out of 34), and rarely 6 (two specimens out of 34). Also, G. rayito has more scales around midbody than G. vittatus (98–118 vs. 78–96, respectively). Finally, males of both of G. petersi and G. vittatus commonly have a gular region that has conspicuous, striated, black markings that are absent in some individuals, whereas markings like this have not been observed in G. rayito , yet some pale gray suffusion in the gular region might be present in some individuals of this species.

Description of holotype. An adult male ( Fig. 4 ), with snout-vent length of 35.7 mm. Tail length 41.3 mm, complete, with distal fourth regenerated. Head 1.4 times longer than wide (HL: 9.2 mm; HW: 6.4 mm). Snout short (2.3 mm), 0.25 times HL, somewhat acutely rounded in dorsal view, sloping toward top of head with an approximate 45° angle. Neck slightly narrower than head and body. Body roughly cylindrical, somewhat wider than high; axilla-groin distance 15.4 mm. Limbs well developed with moderately long digits, fourth toe length 4.8 mm, 0.75 times shank length (6.4 mm). Tail round in cross section, tapering toward tip.

Tongue relatively wide with bluntly rounded tip, covered by small scale-like papillae, which become smaller and less defined posteriorly; tip of tongue with a short median cleft. Teeth small, subequal, conical.

Rostral large, visible from above, with a median cleft extending forward from the top posterior margin to near tip of snout. Three postrostrals, laterals (supranasals) much larger than medial one, which is subequal to the adjacent group scales between anterior margin of the orbit and the postrostrals. Nostril bordered by rostral, 4/3 postnasals and lateral postrostral (supranasal). Uppermost postnasals larger than lower ones and than scales on the loreal region. Scales on top of snout and loreal region small, irregular, and juxtaposed. Loreal scales number about 9 in a line between postnasals and anterior margin of eye socket. Scales decrease slightly in size from the postrostrals toward posterior part of head. Scales on supraorbital region similar (in size and shape) to and continuous with those on top of head. Supraciliary flap poorly developed; supraciliary scales small and granular posteriorly, larger and conical anteriorly, slightly protruding laterally. Pupil round. Supralabials 5/5 to level of center of eye, gradually decreasing in size posteriorly, first one contained 0.5 times in snout length; last supralabial followed by about 8/9 much smaller, mostly granular scales along the lip to rictus of mouth. Scales on temporal region similar to those on posterior part of top of head. Ear opening (0.8 mm) roughly oval, much smaller than eye (2.3 mm).

Mental large, roughly rhomboidal. Postmentals 3, distal ones hexagonal, medial pentagonal, small, subequal, slightly larger than adjacent posterior row of scales. Scales on chin small, polygonal, and juxtaposed directly behind postmentals, gradually becoming smaller, granular, and somewhat imbricate posteriorly; a few larger, polygonal scales adjacent to infralabials though. Infralabials 5/5 to level of center of eye, gradually decreasing in size posteriorly, first pair very large and projecting onto ventral plane. Supralabials and infralabials with many minute tubercles.

Scales on nape and on sides of neck granular to somewhat conical. Scales on throat smooth, imbricate, with round posterior margin, with a short transitional area with the granular scales on the gular region.

Dorsals granular to subconical, oval-shaped at base, slightly larger than scales on top of head, somewhat projecting posteriorly but not significantly overlapping with adjacent posterior scales; dorsolaterally and on flanks scales are slightly larger and especially towards ventrolateral region. Transition between scales on flanks and ventrals somewhat abrupt but not clearly demarcated by a single row of scales. Ventral region with scales distinctly larger than dorsals, smooth, imbricate (each scale overlapping anterior portion of scale lying posteriorly), with round posterior margin, set in rather regular longitudinal rows, slightly and gradually increasing in size, with 37 scales along the midventral line between posterior margin of forelimbs an anterior margin of backlimbs, 46 counted all the way to the vent. Scales around midbody about 110, of which 18 are ventrals. Scales on preanal region similar to ventrals, except on small region that folds into vent, which has minute scales arranged in three rows. Escutcheon present as a wide patch of silver white (abdomen) or pale gray (thighs) scales, extending throughout most of the venter and ventral surfaces of thighs, becoming rather conspicuous on the posterior half of the body.

Dorsal and lateral scales on tail slightly larger than on body, flat, imbricate, with round posterior margin; a short transition area between the granular body scales and the caudal scales just described, extends posteriorly about 3 mm from base of tail. Underside of tail with smooth, flat, imbricate scales, increasing in size toward midventral line; first 8 small subcaudals posterior to vent on midventral row increasing in size posteriorly but not clearly differentiated from adjacent laterals, followed by a single longitudinal row of enlarged, roughly hexagonal, medial subcaudals; each medial subcaudals wider than long, with anterior and posterior margins parallel and in transverse position, and two lateral margins converging distally forming vertex with internal angle of about 90°. Medial subcaudals are divided in larger scales that contact three scales laterally, and smaller scales that contact two scales laterally; the larger scales occur every two smaller scales in a regular pattern throughout most of the tail.

Scales on limbs granular and juxtaposed on dorsal, posterior and posteroventral surfaces, otherwise scales are smooth, flat, imbricate with round exposed margin. Lamellae under first (I) through fifth (V) finger (infraproximals in parentheses): I: 9/9, II: 12/12(3/3), III: 14/14(3/3), IV: 15/15(4/4), and V: 13/13(3/3), respectively. Lamellae under first through fifth toe (infraproximals in parentheses): I: 10, II: 13/12(3/3), III: 15/16(3/4), IV: 17/17(6/6), and V:?/16(?/4), respectively. Fingers and toes mostly with two, and in a few instances with three lateral rows of scales distally. Claws exposed, non-retractile, between two or three basal scales.

In preservative (in 70% ethanol after 10% formalin fixation) the background dorsal coloration of the whole specimen is mostly grayish brown to pale, medium brown. A white middorsal stripe, 1–2 mm wide, extends from the tip of the snout to close to the tip of the tail. This white stripe has black edges that extend posteriorly from the tip of the snout, but fade gradually into the background coloration at midbody. The white stripe is more conspicuous anteriorly and becomes less defined and irregular on the posterior half of the body and on the tail. Sides of the head and neck grayish brown with black suffusion on the loreal region and irregularly on the supralabials; four small (about half the size of the ear opening) white spots are roughly arranged in a longitudinal row with the first spot located between the eye and the ear opening, and the posterior three located between the ear opening and forelimb insertion. A white transverse, club-shaped bar narrowly edged by black, with wider end dorsad, extends from the anterior edge of the forelimb insertion up to the lateral edge of the middorsal stripe. A few small, white spots and ocelli are present on the sides of the body, mostly on the anterior half. Limbs dorsally with the same background coloration as the body; digits with several inconspicuous dark markings forming rings. Tail dorsally with diffuse black markings, edged posteriorly by creamish white, vaguely forming incomplete rings. Ventral surfaces of head, pectoral region, thighs, shanks and tail very pale gray. Underside of digits suffused with dark gray, especially towards the anterior portion of the lamellae. Abdomen black, except the area covered by the escutcheon, which is silver white (see above).

Variation. The type specimens are nine males, six females, and two unsexed juveniles. The largest male specimen in the type series is MBLUZ 283-1 measuring 39.9 mm in SVL; the largest female is MBLUZ 283-2 measuring 40.3 mm in SVL. The smallest specimen is an unsexed juvenile (MBLUZ 1398) measuring 21.7 mm in SVL. There are 4–5 supralabials to the level of the center of the eye, followed posteriorly by 1–2 slightly smaller polygonal scales and multiple small granular scales to the rictus of the mouth. There are 3–4 infralabials to the level of the center of eye, followed posteriorly by 2–3 slightly smaller polygonal scales and a few small granular scales to the rictus of the mouth. Loreals 8–10. Postmentals 2–4. Scales around the midbody 98–118, of which 14– 19 are ventrals. There are 35–40 scales along the midventral line between posterior margin of forelimbs an anterior margin of backlimbs, 42–52 counted all the way to the vent. The variation in the number of lamellae under first through fifth fingers (infraproximals in parentheses): I: 8–10, II: 11–12(3), III: 13–15(3–4), IV: 13–16(3–5), and V: 12–14(3–4). The variation in the number of lamellae under the first through fifth toe: I: 7–10, II: 11–13(3–4), III: 13–16(3–4), IV: 16–19(5–7), and V: 15–18(4–5). The subcaudal pattern of regenerated tails is of roughly hexagonal plates that are about three times wider than short. These plates cover most of the subcaudal surface and contact 2 or 3 scales laterally.

Like most other species in the genus, G. rayito is strongly sexually dimorphic in coloration. Male paratypes are basically the same in coloration as the holotype except as noted below. One male (MCNG 2234) is unique in having a large (as big as the eye) white ocellus anterior to the transverse neck bar, yet this ocellus is present only on the left side. Small white spots on the side of the neck and head, such as those described in the holotype, might or might not be present, with four being the maximum number to have been noted. White spots and ocelli on the sides of the body seem to be always present but there is considerable variation in number, size and location. MBLUZ 283-1 has the highest number of lateral ocelli/spots with about 28 on the right side, and also has some of the largest ocelli, about three or four on each side are as large as the eye. The fewest lateral spots/ocelli occur in the holotype, which has about five on each side. Most lateral spots/ocelli seem to be concentrated on the anterior half of the body but they can also be found as far back as just anterior to the groin. The smallest male (MCNG 2232, SVL 29.6 mm) differs from the other males in having a pale gray venter (as opposed to dark gray to black), having the black edges of the middorsal stripe poorly developed and for the most part made of well-spaced, paired, black spots, and having better defined black transverse markings on the tail.

Females are pale gray to grayish brown with a creamish white middorsal stripe with diffused dark brown edges. As in the males, this middorsal stripes extends from the tip of the snout to almost the tip of the tail. A series of well-spaced, paired, dark grayish brown to black spots in contact with a pale gray spot posteriorly, edge the middorsal stripe. On the tail these paired spots come into contact medially forming short black transverse markings. Top and sides of the head, and sides of the body with small, dark gray irregular markings. Lateral white spots and ocelli are also present in females, yet they are less conspicuous than in males. The ventral surface of the head, body and tail are creamish white to very pale gray, with a few scattered, tiny dark gray spots. The unsexed juvenile has the color pattern of a female but in other species in the genus the distinctive male coloration develops ontogenetically.

Color in life. Coloration is almost the same in life as it is in preservative with the noteworthy exceptions described below. In life males have a yellow to reddish brown hood (lost in preservative) that extends from the tip of the snout to about the level of the ear opening, and its dissected middorsally by the black-edged white stripe. Males can have a white or mustard yellow gular region, which in preservative becomes dingy white to pale gray.

Etymology. The specific name is the Spanish word meaning “little lightning” or “little ray”, a name informally coined by the late naturalist Dr. Richard Schargel for individuals of this species as well as of G. petersi and G. vittatus . The name refers to the notion that, because males of this group of species have a conspicuous middorsal white stripe, when they flee they resemble a “little white lightning.” Richard kept many species of Gonatodes in captivity and also helped support the first author on his research on the genus.

Distribution and natural history. Gonatodes rayito is distributed along the slopes of the western versant of the Mérida mountain range, in the states of Mérida, Táchira and Trujillo, with an estimated elevational range from 50 to 1100 m. The original vegetation in this area is mostly “evergreen forest per se” following Huber & Oliveira- Miranda (2010), but a significant portion of it has been transformed to agricultural land. Specimens were collected and observed active throughout the day in moderately shaded areas, most often on trees and rocks, but also on walls of houses and other human infrastructure. Because G. rayito has a relatively wide distribution (straight line distance between the most distant localities is roughly 220 km) and seems to thrive in rural areas, there should be little conservation concern for it.

At its lower altitudinal range of distribution G. rayito is widely sympatric with G. albogularis ( Duméril & Bibron, 1836) and individuals of both species are often found on the same trees. On one occasion a male G. albogularis was observed directing territorial displays towards a female of G. rayito that had fled towards the male when we approached the tree where the two individuals were perched. At the upper altitudinal range (above 500 m), specifically in the localities of La Azulita in Mérida Sate, and Río La Blanca in Táchira Sate, G. rayito was found in sympatry with a large undescribed species of Gonatodes (see Rivero-Blanco 1979). However, the large species of Gonatodes was found on large trees and rock walls in forested areas nearby streams, whereas G. rayito was found on rocks and smaller trees in more open areas not necessarily associated to streams.

Figures

FIGURE 3. Illustrations of the head (holotype) in dorsal, lateral and ventral view, and of the manus and pes (EBRG 4890) in ventral view, of Gonatodes rayito sp. nov.

FIGURE 4. Male specimens of Gonatodes rayito sp. nov. (top, photo of the holotype by JEGP); G. vittatus (middle, photo by Marcial Quiroga-Carmona) from Valencia, Carabobo; and G. petersi (bottom, photo by JEGP) from Finca El Deseo, Zulia. All localities are in Venezuela

FIGURE 5. Female specimens of Gonatodes rayito sp. nov. (top, photo of MCNG 2237 by JEGP), G. vittatus (middle, photo by Marcial Quiroga-Carmona), from Valencia, Carabobo; and G. petersi (bottom, photo by JEGP), from Finca El Deseo, Zulia. All localities are in Venezuela.