Gonatodes lichenosus, Rojas-Runjaic, Fernando J. M., Infante-Rivero, Edwin E., Cabello, Pedro & Velozo, Pablo, 2010

Rojas-Runjaic, Fernando J. M., Infante-Rivero, Edwin E., Cabello, Pedro & Velozo, Pablo, 2010, A new non-sexually dichromatic species of the genus Gonatodes (Sauria: Sphaerodactylidae) from Sierra de Perijá, Venezuela, Zootaxa 2671, pp. 1-16 : 2-13

Gonatodes lichenosus , sp. nov.

Perijá Lichen-Gecko, Tuqueque Liquenoso de Perijá ( Figs. 1–5 )

Holotype. An adult male, MHNLS 19116 (field number SP191), from Manastara, Yukpa indigenous community, Río Negro basin, Parque Nacional Sierra de Perijá, Municipio Machiques de Perijá, Sierra de Perijá, Estado Zulia, Venezuela (10°02’52.0”N, 72°48’42.8”W; elevation 1132 m asl), collected on 18 March 2009, by Fernando J. M. Rojas-Runjaic, Pedro Cabello, and Pablo Velozo.

Paratypes. Three adult males ( MHNLS 19101, 19109 and 19110), and two adult females ( MHNLS 19107, 19111), same data as the holotype, collected between 16 to 18 March 2009.

Referred specimens (not paratypes): An adult female ( MHNLS 19108), and a juvenile ( MHNLS 19117), with the same data as the holotype, collected between 16 and 18 March 2009; a neonate ( MHNLS 19160), with the same data as the holotype, collected (as an egg) on 20 March 2009, and hatched in captivity on 24 April 2009.

Diagnosis. The new species can be readily distinguished from all congeners by the combination of the following characters: (1) body size moderate, with males from 39.05 to 41.4 mm, and females from 40.65 to 44.45 mm; (2) supraciliary spine absent; (3) dorsolateral light spots that coincide with clusters of enlarged, conical to spinelike scales; (4) 100 to 106 scales around midbody; (5) 42 to 45 ventral scales counted in a longitudinal row; (6) males with escutcheon area on belly and undersurface of thighs; (7) two lateral rows of scales on distal parts of fingers and toes; (8) ventral surface of tail with a pattern of scales consisting of two to four basal series of single midventral scales in contact posterolaterally on each side with one scale followed by a divided midventral scale in contact with two scales per side (1’2”), and continuing distally with repetitive series of single midventral scale in contact posterolaterally with one scale per side and single midventral in contact with two scales per side (1’1”); (9) males and females with cryptic coloration pattern dorsally, and yellow to ocher ventrally, without sexual dichromatism.

Gonatodes lichenosus , together with G. alexandermendesi Cole & Kok from Guyana and southeastern Venezuela (Cole & Kok 2006, Schargel et al. 2010), G. hasemani Griffin from south of the Amazonas River ( Avila-Pires 1995), and G. superciliaris Barrio-Amorós & Brewer-Carías from Sima Mayor of Sarisariñama tepui, southern Venezuela ( Barrio-Amorós & Brewer-Carías 2008), are the only species of Gonatodes in which clusters of enlarged conical to spinelike scales along the body are present (data from Avila-Pires 1995, Barrio-Amorós & Brewer-Carías 2008, Cole & Kok 2006, Rivero-Blanco 1979). However, Gonatodes lichenosus differs from these species (characters in parenthesis) in not having an elongate supraciliary spine (supraciliary spine present), having a subcaudal pattern 1’2” basally, that changes to 1’1” distally (medial subcaudal scales not distinctly differentiated from adjacent scales in G. hasemani ; and, 1’1” pattern in G. alexandermendesi and G. superciliaris ), and not having sexual dichromatism (sexual dichromatism present, with males showing bright and conspicuous colors, and females showing cryptic color patterns).

Only one other species of Gonatodes , from La Azulita (Estado Mérida, Venezuela) and until now undescribed ( Rivero-Blanco 1979) exhibits poorly defined sexual dichromatism; nevertheless there are some some evident color differences between sexes in this species, like the “golden appearance on the body” and the “flat gray gular region” in males. Gonatodes lichenosus differs from this undescribed species (characters in parenthesis) in not having any sexually dichromatic character (sexual dichromatism poorly defined but present as above mentioned), by the subcaudal pattern (subcaudal pattern 1’1’1”), and in having only two lateral rows of scales on distal the parts of fingers and toes (three lateral rows of scales on fingers and toes).

Three other species of Gonatodes are known from Sierra de Perijá: G. albogularis , G. v i t t a t u s and G. petersi ; the former two species inhabit the foothills up to 400 m, whereas the later is widely distributed on the eastern slope of Perijá from 200 to 1200 m ( Rojas-Runjaic & Infante 2009) and is likely sympatric with the new species. These three species, unlike G. l i c h e n o s u s, have a subcaudal pattern of 1’1’2” ( G. albogularis ) or 1’1’1” ( G. vittatus and G. p e t e r s i), and show very marked sexual dichromatism, with males exhibiting a very conspicuous light vertebral stripe ( G. vittatus and G. petersi ) or a yellow to orange head with a blue blotch on the cheeks ( G. albogularis ).

Description of holotype. An adult male ( Fig. 1 ), with SVL of 40.0 mm. Head 1.1 times longer than wide (HL: 10.1 mm; HW: 9.0 mm). Snout 3.6 mm long, subacuminate in dorsal view, rounded in profile, gently sloping toward top of head ( Figs. 2 a–b). Neck slightly narrower than head and body. Body wider than high, nearly cylindrical; axilla-groin distance 17.4 mm. Limbs and digits well developed; fourth toe length 4.9 mm, 0.66 times shank length (7.4 mm). Tail complete (with distal quarter regenerated), round in cross section, tapering toward tip, 1.2 times SVL (TL: 48.9 mm).

Tongue relatively wide, slightly narrowing anteriorly, tip rounded with a short median cleft, covered by scalelike papillae, which become smaller posteriorly. Teeth small, conical, subequal in length.

Rostral large, subpentagonal, visible from above, with a median cleft extending forward from posterior margin to near midpoint of the scale. Postrostrals three, lateral ones (supranasals) distinctly larger than medial, situated above the nasals, and medially in contact by projections of their medial anterior margins; medial postrostral similar in size to adjacent posterior scales on snout, separate from posterior margin of rostral by lateral postrostrals. Nostril bordered by rostral, lateral postrostral and three postnasals; not in contact with first supralabial. Postnasals much larger than adjacent loreals. Scales on snout and loreal region nearly round to nearly conical, juxtaposed. Loreal scales about 8 (both sides) in a straight line between postnasals and anterior margin of orbit. Scales decrease slightly in size from postrostrals to posterior part of head. Scales on supraorbital region similar (in size and shape) to, and continuous with those on top of head. Supraciliary flap without an elongate supraciliary spine, but two (both sides) conical supraciliary scales, somewhat larger and projecting posterolaterally on anterior half of row. Pupil round. Supralabials 4/5 (left/right), first largest, second through third or fourth roughly subequal, fourth scale below center of eye in right side, and the third on left side. Scales on temporal region similar to those on posterior upper part of head. Ear opening (0.6 mm) much smaller than eye (1.9 mm), vertically oval.

Mental large, with round anterior margin following lower lip, posterior margin roughly round. Postmentals two, distinctly larger than adjacent posterior scales ( Fig. 2 c). Scales on chin small and polygonal located directly behind postmentals, granular and tiny posteriorly; a few series of larger, polygonal, juxtaposed scales adjacent to infralabials. Infralabials five (both sides), decreasing in size posteriorly, first two very large and projecting onto chin, third below center of eye.

Scales on nape and on sides of neck granular, continuous with those on head and body. Scales on throat smooth, imbricate, with round posterior margin, with short transitional area of granular scales on chin and gular area.

Dorsals granular, on vertebral area similar in size to scales on snout and top of head; slightly larger dorsolaterally and on flanks. Several clusters of enlarged conical to spiniform scales on flanks of the neck and trunk, coinciding with small light spots ( Fig. 3 ); 4/3 clusters on neck composed of 1 to 6 scales, and 6/7 on flanks of the trunk composed of 6 to 17 scales. Transition between scales on flanks and ventrals somewhat abrupt but not clearly demarcated.

Ventral region with scales distinctly larger than dorsals, slightly smaller on chest than on belly, smooth, nearly hexagonal, with round posterior margin, imbricate, in oblique rows, also forming rather regular longitudinal rows on belly; with 42 scales along the midventral line between anterior margin of forelimbs and vent. Scales around midbody about 104, of which 16 are ventrals. Preanal scales at margin of vent much smaller than ventrals on belly. Escutcheon area present on posterior abdomen and on undersurface of thighs ( Fig. 4 a), composed of a cluster of 62 escutcheon scales on posterior portion of belly and preanal plate between thighs; clusters of 30/31 (right/left) escutcheon scales arranged in four transverse rows on ventral surface of thighs.

Scales on dorsum of tail becoming flat, smooth, rounded and imbricate (rather than conical), posterior to level of vent. Scales on underside of tail smooth, flat, imbricate, increasing in size toward midventral line; first five small subcaudals posterior to vent on midventral row increasing in size posteriorly but not clearly differentiated from adjacent laterals, followed by a midventral row of tranversely enlarged scales. First enlarged subcaudals arranged in two series of one single median scale in contact posterolaterally with one smaller scale, followed by a divided median scale in contact posterolaterally with two smaller scales (1’2”), and continuing posteriorly with a sequence of single median scales in contact posterolaterally with one or two smaller scales in an alternating fashion (1’1”) ( Fig. 4 b).

Scales on limbs smooth, flat, roundish, imbricate on anterior and ventral surfaces; granular and juxtaposed on dorsal and posterior surfaces. Lamellae under first (I) through fifth (V) finger (infraproximals in parentheses): I: 10/10(3/3), II: 12/12(4/4), III: 14/14(4/4), IV: 14/14(4/4), and V: 13/13(4/4), respectively. Lamellae under first through fifth toe (infraproximals in parentheses): I: 10/10(3/3), II: 12/12(4/4), III: 16/ 16(5/5), IV: 18/18(7/7), and V: 16/17(5/5), respectively. Infraproximal scales on fingers and toes enlarged and swollen ( Figs. 4 c–d). Fingers and toes with two lateral rows of scales distally. Claws exposed, non-retractile, between two basal scales (dorsal and ventral).

Color in life. ( Fig. 1 ) The dorsal surface of the head (snout, eyelids, interorbital and temporal areas, top of the head and nape) greenish gray, irregularly speckled with blackish brown. The loreal region has a blackish brown loreal stripe extending from the nostril to the anterior margin of eye. Two blackish chestnut postocular stripes, extend posteriorly from the orbital margin and expand posteriorly; the upper one is sinuous and extend to the neck, with the end pointing medially and near the end of the opposite stripe; the lower stripe extends towards the neck and blends with the background color of the shoulder. Rostral, supralabial, mental and infralabial scales have blackish brown vertical stripes alternating with narrow yellowish lines. A dirty beige vertebral stripe extends from the neck (continuing with the greenish gray dorsal area of the head) to near tail tip. This vertebral stripe is wide, irregularly and finely margined by blackish brown, with nine transversal dilatations between neck and pelvis, and three others on the tail. The flanks are blackish chestnut with several pale yellow flecks laterally aligned or in contact with the transversal dilatations of the vertebral stripe; these pale yellow flecks correspond with clusters of enlarged, conical to spiniform scales. The limbs are dirty gray, with wide blackish brown crossbands.

The ventral surfaces are ocher yellow, finely speckled with pale brown on chin, throat and lateral borders of chest and belly; with a faint pale brown longitudinal stripe at each side of the throat. The undersurface of limbs are dirty yellow, the palms and soles are dirty gray; the escutcheon scales on the belly and thighs are pale yellow, most with the distal border finely delineated with pale brown. The tail is blackish chestnut laterally and dirty yellow to pale yellow ventrally. The dorsal scales of tail have a pink iridescence.

The iris is brownish orange, with a thin golden ring around the pupil. The tongue is white with pale gray dots anterolaterally. The claws are white.

Color in preservative (after one year). The dorsum of the head, vertebral stripe and the background pattern of limbs are pale gray; the blackish brown and blackish chestnut colors of the loreal, postoculars, labial, and limbs stripes, flanks and tail have become pale brown; the pale yellow flecks that correspond with the clusters of enlarged scales have turned white; the palms and soles are pale gray; the chin, throat, chest, belly, and undersurface of the limbs are dirty white finely speckled with pale brown; in the escutcheon scales (belly and thighs) the white color is more intense and the finely delineate brown distal border is still distinct.

Variation in paratypes. The three adult males range in SVL from 39.05 to 41.4 mm (40.31 ± 1.0), and the two adult females range from 40.65 to 44.45 mm (42.55 ± 2.7). Supralabial counts vary from 4 to 6, and infralabial counts from 5 to 6. Loreal scales counted in straight line between postnasals and anterior border of orbit range from 7 to 9. Male MHNLS 19110 and females MHNLS 19107 and 19111, have three postrostrals in contact with rostral, whereas males MHNLS 19101 and 19109 have only two (supranasals) in contact with rostral, as in the holotype. Postmental scales range from two (MHNLS 19107, 19109) to four (MHNLS 19101). Flanks of neck and trunk with 10 to 24 (on each side), clusters of 1 to 17 enlarged, conical to spinelike scales, present in males and females but more conspicuous on males. Scales around the midbody range from 100 to 106, of which 14 to16 are ventrals. Ventral scales 43 to 45 along trunk. Escutcheon area on belly composed of 68 and 70 scales on males MHNLS 19109 and 19110 respectively, only 29 and less conspicuous in male MHNLS 19101, absent in females. Escutcheon scales on undersurface of thighs 18 to 30, only present in males. Subcaudal scale pattern composed of 1 (MHNLS 19110) to 4 (MHNLS 19107, MHNLS 19111) 1’2” series occupying shorter basal portion of tail, followed by numerous 1’1” series extending to rest of tail. In MHNLS 19101 and MHNLS 19111, the 1’1” series not present as tail is regenerated. Regenerated portion of tail with subcaudal pattern that differs significantly from original tail; midventral scales form single row of wide, but very short plates (longest side transverse to longitudinal axis of tail), each extending laterally to ventrolateral surface of tail, and in contact laterally with small scales that look just like those on original tail. Variation in number of lamellae under first through fifth fingers: I: 9–10(2–3), II: 11–13(3–4), III: 13–15(4), IV: 14–16(4–5), and V: 13–14(4–5). Variation in number of lamellae under first through fifth toe: I: 10(2–3), II: 12–13(4), III: 15–17(4–5), IV: 18–19(7), and V: 16–18(5). Morphometric variation of type series is presented on Table 1.

The coloration of the paratypes (based on photos in life) is like the holotype with only minor variations in dorsal color pattern and the ventral color of the tail ( Figs. 5 a–b). The dorsal surface of the head is more greenish and profusely speckled with blackish brown in the male MHNLS 19109. The specimens MHNLS 19107 ( Fig. 1 b), 19110 and 19111, have small white spots on the light background area, between the upper and lower postocular stripes (these spots correspond with clusters of enlarged conical to spinelike scales). The vertebral stripe is wider on the female MHNLS 19111 and male MHNLS 19110; much more irregularly bordered in the last one. In the regenerated portion of the tail (MHNLS 19109, 19111) the vertebral stripe is lost, and instead there is a dorsal pattern of irregular dark spots on a pale beige background. The blackish brown border of the vertebral stripe is wider and more conspicuous in MHNLS 19111 and 19109. The female MHNLS 19107 ( Figs. 1 b, 5a) has a lighter background color, the cephalic spot, loreal, labial and postocular stripes, border of the dorsal stripe, and the lateral spots of the flanks are light brown to brownish orange. In all paratypes the background color of the flanks of the trunk and neck is lighter (showing individual variation) and speckled with dark brown.

TABLE 1. Morphometric variation in the type series of Gonatodes lichenosus sp. nov. *: holotype.‾ X ± SD: mean ± standard deviation.

Specimen number Sex SVL TL HL HW EYN AXG Ventrally, from chin to vent the color pattern is almost uniform, varying from yellow (MHNLS 19107, 19110–19111) to ocher yellow (MHNLS 19109), between individuals, but not related with the sex. The specimens MHNLS 19107, 19110, and 19111, show several faint pale brown diagonal stripes on throat, whereas the specimen MHNLS 19109 has only small dark brown spots instead of stripes. The ventral color of the tail is quite variable: yellow finely speckled of pale brown in MHNLS 19109, skin color in MHNLS 19110, grayish beige in MHNLS 19111, and orange in MHNLS 19107 ( Fig. 5 b).

Distribution, habitat and natural history. Known only from the type locality in the valley of Manastara, around the homonymous Yukpa indigenous community, in the Río Negro basin, eastern versant of the Sierra de Perijá, northwestern Venezuela, at 1130 m ( Fig. 6 ). The vegetation of this altitudinal belt is described by Huber & Alarcón (1988) as ombrofilous submontane/montane evergreen forest; it extends between 800 and 2500 m asl, forming dense communities with medium to high canopy. The region has a biseasonal climatic regime, with a dry period in December–April, and a rainy period in May–November, with maximum rain peaks on May and October, and minimum on January and July ( Masciangioli & Febres 2000).

The Río Negro basin and particularly the valley of Manastara, although included in a protected area (Parque Nacional Sierra de Perijá), show a marked loss of the original forest, which have been replaced by grass savannas, coffee plantations ( Coffea arabica L., Rubiaceae ), malanga [ Xanthosoma sagittifolium (L.) Schot, Araceae ], and pastures for cattle. Currently the hills surrounding the valley of Manastara are almost entirely savannized, and relicts of primary forest persist only in the stepper slopes and along small streams of the valley ( Figs. 7a –b). The gallery forest along the Río Negro river is basically secondary and associated with shade coffee plantations. Goats have been recently introduced in the area and roam freely in the valley of Manastara and in other nearby communities, creating an additional impact on the vegetation of the basin.

The first specimen of Gonatodes lichenosus found during the survey (MHNLS 19101) was seen active at nigth (± 20 h), on the wooden post of a fence, near the indigenous community. Nocturnal activity is uncommon in these diurnal geckoes (except in G. antillensis , the only nocturnal species); however Rivero- Blanco (1979) commented upon specimens of a synanthropic population of G. albogularis seen foraging at nigth near artificial light. Our specimen of G. lichenosus was not near artificial light, which suggests it may have been resting and was disturbed by our presence.

The specimen MHNLS 19107 was found on the bark of a large tree basking head up, 1.5 m aboveground at 11 h, in a secondary gallery forest associated to a shade coffee plantation. This was the only specimen observed in a forested habitat; no other specimens were seen on trees or rocks of the secondary forest or at any nearby patch of primary forest. Nevertheless this species was frequently observed on trees, wooden fences, and other human structures in the community of Manastara, which reveal that this gecko is adaptable to changes in its habitat and can take advantage of the synanthropic environments. At least seven other species [ G. albogularis , G. h u m e r a l i s (Guichenot), G. petersi , G. purpurogularis Esqueda (as G. ligiae ), G. siegliei Donoso-Barros , G. taniae Roze , and G. vittatus ] have also been previously referred in synanthropic enviroments ( Oda 2004, Rivero-Blanco 1968, 1979, Rojas-Runjaic & Rivas 2006, Rojas-Runjaic & Infante 2009, Barrio-Amorós & Molina 2010), sometimes even showing populational densities greater than those found in natural environments ( Rivero-Blanco 1979).

The six other specimens collected (MHNLS 19108–19111, 19116–19117) were found between 11 and 13 h, basking and foraging on tree bark, or hidden in crevices and cavities of a large tree located in an open area between the houses of the community ( Figs. 7 b–c). Some specimens were located up to 4 m aboveground.

The same tree harbored a big colony of carpenter ants ( Camponotus sp., Formicinae ), and a stingless bees colony ( Melipona sp., Meliponini ), but no antagonistic interactions were observed between the geckoes and the stingless bees or the ants. It is possible that Gonatodes lichenosus has established a commensal relationship with these colonial insects, taking advantage of the protection that they offer to their colonies against potential predators.

On March 20, 2009, an egg (7.4 mm of diameter) of Gonatodes lichenosus was found in a crevice of a rotten tree in a gallery forest at the type locality. The egg was located at about 1.2 m aboveground, nearby was a large colony of carpenter ants Camponotus sp., and a skin of Amphisbaena sp. The egg was collected and maintained in a Petri dish with lightly damp cotton. On April 24, 2009 (after 35 days), a neonate measuring SVL of 17.7 mm, and TL of 17.4 mm, hatched.

None of the three other species of Gonatodes reported from Perijá ( G. albogularis , G. vittatus and G. petersi ) were found in the valley of Manastara; however G. petersi has been recorded from localities at similar altitudes and near the type locality of G. lichenosus , thus it is likely that these two species are sympatric in some parts of their distributions.

Etymology. The specific epithet lichenosus is a Latin adjective (masculine) derived from lichen - (Latin name for composite organisms made up from symbiotic association of a fungus with a photosynthetic partner algae or cyanobacteria) + - osus (an adjectival suffix meaning “full of”). The name was given in allusion to the aspect of the dorsal color pattern (particularly on the head) of this species that resembles the complex color designs of lichens covering the bark of trees and rock surfaces in environments with high humidity.

Figures

FIGURE 1. Gonatodes lichenosus sp. nov.: a. Male holotype (MHNLS 19116); b. Female paratype (MHNLS 19107).

FIGURE 2. Details of dorsal (a), lateral (b), and ventral (c) views of the head of Gonatodes lichenosus sp. nov. (male holotype, MHNLS 19116). Scale bar represents 2 mm.

FIGURE 3. Dorsal view of Gonatodes lichenosus sp. nov. (male holotype MHNLS 19116), showing clusters of enlarged, conical to spinelike scales on the flanks of neck and trunk. White arrows indicate the clusters of scales magnified in upper right and lower left frames.

FIGURE 4. Gonatodes lichenosus sp. nov. (male holotype, MHNLS 19116): a. Ventral view showing escutcheon areas on posterior part of belly and undersurface of thighs; b. Detail of subcaudal scale pattern; c. Ventral view of left hand (scale bar represent 1 mm); d. Ventral view of left foot (scale bar represents 2 mm).

FIGURE 5. Variation on dorsal (a) and ventral (b) color pattern of the type series of Gonatodes lichenosus sp. nov.; a: from left to right, female paratypes MHNLS 19107 and 19111, and male paratypes MHNLS 19109 and 19110; b: from left to right, female paratypes MHNLS 19107 and 19111, and male paratypes MHNLS 19110 and 19109. Note the absence of sexual dichromatism in both views.

FIGURE 6. Map of NW Venezuela showing major physiographic elements: Maracaibo Lake, and Sierra de Perijá to the west. Type locality of Gonatodes lichenosus sp. nov. is shown by a white circle.

FIGURE 7. a: General view of the Manastara valley in the Sierra de Perijá, estado Zulia, Venezuela, area where Gonatodes lichenosus sp. nov. inhabits; b – c: views of the Manastara community and the microhabitat where five specimens of the type series were collected.