Phyllodactylus paralepis, Mccranie, James R. & Hedges, S. Blair, 2013

Mccranie, James R. & Hedges, S. Blair, 2013, A new species of Phyllodactylus (Reptilia, Squamata, Gekkonoidea, Phyllodactylidae) from Isla de Guanaja in the Honduran Bay Islands, Zootaxa 3694 (1), pp. 51-58 : 53-56

Phyllodactylus paralepis sp. nov.

( Fig. 2 , 3 )

Phyllodactylus palmeus Dixon, 1968:419 (part).

Phyllodactylus insularis Echternacht, 1968:151 .

Phyllodactylus palmeus Wilson & Hahn, 1973:104 (part). Phyllodactylus palmeus McCranie et al., 2005:78 (part).

Holotype. FMNH 283552 (genetic sample 1, Genbank accession KF245415 ), an adult male from Savannah Bight, 16.29078°, -85.50300°, Isla de Guanaja, Islas de la Bahía, Honduras, 15 m elevation, collected 20 September 2012 by James R. McCranie & Leonardo Valdés Orellana.

Paratypes (7). FMNH 283553, adult female from East End, 16.486°, -85.832°, Isla de Guanaja, near sea level, collected 19 September 2012 by James R. McCranie & Leonardo Valdés Orellana; USNM 580288 (genetic sample 2, Genbank accession KF245416 ), 580289, adult males, 580290, an adult female, East End, Isla de Guanaja, collected 16 November 2011 by James R. McCranie; FMNH 283554, an adult female from Hotel Posada del Sol ruins, Isla de Guanaja, 16.462117°, -85.853867°, near sea level, collected 21 September 2012 by James R. McCranie and Leonardo Valdés Orellana; USNM 565401, an adult female from East Bight, Isla de Guanaja, collected 9 May 2007 by Alexander Gutsche & James R. McCranie; KU 101377, an adult male, Isla de Guanaja, no other data, 30 m, collected on 10 July 1996 by A. C. Echternacht.

Referred specimens. See Appendix I.

Geographic distribution. Phyllodactylus paralepis is known to occur only at low elevations on Isla de Guanaja in the Islas de la Bahía, Honduras ( Fig. 4 ).

Diagnosis. Phyllodactylus paralepis has more closely spaced (0–1 granules separating) tubercles ( Fig. 3 ) on the dorsal surfaces than does P. palmeus (1–3 granules separating dorsal tubercles). In addition, P. paralepis has 41–53 tubercles in the paravertebral row from the rear of the head to the tail and 16–17 dorsal tubercle rows across the midbody (versus 35–43 tubercles from head to tail and 11–15 tubercle rows across midbody in P. palmeus ). Those two species also differ from each other in amount of sequence divergence (2.9 %; Fig. 1 ). Phyllodactylus paralepis also differs significantly in sequence divergence (9.8 %) from the remaining species of Phyllodactylus occurring in Honduras ( P. tuberculosus ). Morphologically, P. paralepis differs from P. tuberculosus , which occurs in southern Honduras, in having 41–53 tubercles in the paravertebral row from the rear of the head to the tail and 29–36 tubercles in the paravertebral row between the levels of the axilla and groin (versus 26–32 tubercles from head to tail and 20–24 tubercles between axilla and groin in P. tuberculosus ). Dixon (1960) described P. insularis from Half Moon Cay in Belize about 230 km W of Isla de Guanaja. According to Dixon (1960), P. insularis has a distinct white subocular spot and dark brown dorsal surfaces, and lacks enlarged tubercles on the dorsal surfaces of the thighs (versus white subocular spot absent, pale brown dorsal surfaces, and enlarged tubercles present on thighs in P. paralepis ).

Description of holotype. Rostral ca. two-thirds as high as wide, its dorsal edge with slight posterior inward curve, and with a median groove about half length of rostral; internasals paired, somewhat rectangular, in broad contact medially, bordered posteriorly by six granules and postnasal of each side; nostril surrounded by rostral, first supralabial, internasal, and two postnasals; shallow internasal and frontal depressions present; 16 scales present between nostril and eye (loreals); scales in medial loreal region ca. three times larger than interorbital scales; 22 scales across snout between third supralabials; 16 scales between anterior edges of orbits and 24 midorbital scales; eye large, its diameter contained in snout length slightly less than two times; pupil vertically elliptical, with reticulated edges; eyelid with one row of granules and one larger outer row of scales, ultimate 4–5 pointed; diameter of ear contained in eye diameter ca. five times; ear opening vertically subtriangular, not denticulate, scales on anterior and posterior edges rounded, subequal in size; rear of head with many large tubercles intermixed with granular scales; six supralabials and infralabials to point below center of eye; mental bell-shaped, slightly longer than wide, bordered posteriorly by two postmentals; postmentals much longer than wide, their median edges in broad contact with one another; postmentals bordered posteriorly by eight smaller scales; postmentals contacting only first infralabial on each side.

Dorsum with 16 transverse (across body) rows of enlarged, keeled tubercles at midbody, paravertebral row with 49 tubercles from rear of head to base of tail, 30 between levels of axilla to groin; paravertebral rows separated from each other by 0–1 rows of granules; four rows of tubercles reach to rear of head on right side, three on left side; six rows of tubercles across base of tail; 3–3 enlarged preanal scales present; venter with 60 longitudinal and 27 transverse scale rows.

Dorsal surface of upper arm with flattened scales, forearm with scattered tubercles dispersed among smaller flattened scales; dorsal surface of thigh with 4–5 larger tubercles among smaller scales; lower hind limb with 12– 14 tubercles dispersed among smaller scales; fourth finger lamellae 9–10, that of fourth toe 12–12; claw hidden when viewed from below; terminal pad large, paired pad scales longer than wide, truncated.

Measurements in mm: snout-vent length 60.1; axilla-groin length 27.9; forelimb length 15.5; hind limb length 24.1; tail length 69; head length 15.6; head depth 6.8; head width (midorbital) 9.2; eye diameter 3.9; ear longitudinal diameter 0.8; snout length 6.3; eye-ear length 5.4.

Color in life ( Fig. 2 ): dorsum pale greenish brown with Sepia (219) mottling and Mikado Brown (121C) tubercles; top and lateral surfaces of head similar to that of body, except Sepia pigment forming longitudinal lines on snout and supralabials; dorsal surface of tail brown with Sepia crossbands; dorsal surfaces of limbs pale brown with Sepia and Raw Umber (123) mottling and crossbands; chin, throat, and belly pale brown with Raw Umber mottling on anterior half of belly and Sepia mottling and blotches on posterior half of belly; ventral surfaces of limbs pale brown, except soles and palms pinkish brown; digital pads dirty white to white; iris golden brown.

Color in alcohol: dorsal ground color pale tan with narrow dark brown, incomplete medially, reticulated crossbands; dorsal surfaces of limbs pale tan with dark brown reticulated crossbands; top of head pale brown with reticulated dark brown lines; side of head with dark brown postnasal and postorbital lines; tail tannish brown with narrow reticulated dark brown crosslines; supralabials cream with small dark brown spots on those anterior to eye; ventral surfaces of head and body nearly immaculate cream; venter of limbs nearly immaculate cream, except that posterior ventrolateral edges mottled with dark brown; palms, soles, and digits tan; subcaudal surface cream with dark brown mottling on anterior third, becoming crossbanded with dark brown on tan ground color on distal half.

Variation. Snout-vent length of the type series ranges from 55.6–70.4 (60.8 ± 6.7) in males, 60.1–63.3 (61.8 ± 1.5) in females; postmentals number two in all, with postmentals contacting only first infralabial on each side in all; midorbital scales 20–25 (22.9 ± 1.6); scales across snout between third supralabials 20–29 (25.1 ± 3.1); longitudinal and transverse ventral scales 53–61 (57.6 ± 3.4) and 25–28 (26.9 ± 1.0), respectively; scales bordering postmentals 4–8 (6.3 ± 1.4); scales bordering posterior edge of internasals 5–8 (6.5 ± 0.9); scales between nostril and eye (loreals) 12–16 (14.3 ± 1.6); fourth toe lamellae 12–14 (12.6 ± 0.7); fourth finger lamellae 9–12 (10.6 ± 1.0); tubercles in paravertebral row from rear of head to base of tail and between axilla–groin 41–53 (47.3 ± 3.7) and 29–36 (31.4 ± 2.3), respectively; tuberculate rows across base of tail 6–8 (7.0 ± 1.1); supralabials and infralabials six in all but one with eight.

The paratypes have a somewhat more muted dorsal pattern in alcohol than does the holotype that consists of scattered dark brown spotting and mottling, otherwise they are similar in color to that described above for the holotype. A juvenile referred specimen (FMNH 283555; SVL 27.1 mm) is very similar in color in alcohol to that of the holotype, except that the dark dorsal crossbands on the anterior third of the body are solid, thus more distinct than in the holotype. The photographs of Phyllodactylus paralepis in Köhler (2000, 2003, 2008; all as P. palmeus ) show a dorsal pattern similar to that seen in the holotype ( Fig. 2 ).

Habitat. Phyllodactylus paralepis is a nocturnal gecko that before the invasion of Hemidactylus species was common on the walls of buildings in Savannah Bight. Those Hemidactylus species appear to have replaced P. paralepis in edificarian situations in recent years. However, P. paralepis remains common in non-edificarian situations on Guanaja. Other places of nocturnal activity include in walls of caves and on coconut and thorn palms. Its diurnal hiding places include termite nests, beneath tree bark, and especially within the bases of palm fronds and associated coverings. It can also be seen inside coconut palm debris lying on the ground and occasionally in Sea Grape ( Cocoloba uvifera ) leaf litter. Echternacht (1968: 151) reported finding one under “loose palm bark about 1.5 m above ground.” Phyllodactylus paralepis occurs sympatrically with two other native gekkotan species, Sphaerodactylus alphus McCranie & Hedges and S. guanajae McCranie & Hedges. See Conservation status for comments on co-occurrence with recently introduced gecko species.

Conservation status. Two species of Hemidactylus , H. frenatus Schlegel and H. mabouia (Moreau de Jonnès) have been introduced to Isla de Guanaja in recent years. Hemidactylus mabouia was abundant on the walls of a hotel in Savannah Bight during 2007 (Gutsche & McCranie 2009), but that species has now apparently been displaced by the more aggressive H. frenatus (JRM personal observations). Hemidactylus frenatus was first introduced on the Honduran Bay Islands on the island of Utila (Köhler 2001). Phyllodactylus palmeus was formally a common species on Isla de Utila, but has now been completely eradicated in edificarian situations on Utila by H. frenatus . To make matters worse, H. frenatus has successfully invaded non-edificarian situations on Utila, where during September 2012 it was a more commonly found species in forested areas along the east coast than was P. palmeus . As H. frenatus populations on Utila apparently have at least a seven year head start on that island compared to the populations of Hemidactylus on Guanaja, it can be expected that H. frenatus will likewise invade the similar non-edificarian situations on Guanaja and begin the process of displacing P. paralepis there as well.

The introduced Hemidactylus mabouia population on the island of Curaçao has been noted to have displaced the native Phyllodactylus martini van Lith de Jeude in houses on that island (van Buurt 2005). Apparently, island populations of Phyllodactylus are generally more vulnerable to displacement by invasive species of Hemidactylus .

Etymology. The specific epithet paralepis is formed from the Greek para (near) and lepis (scale) and refers to the closely spaced tuberculate dorsal scales in this Guanaja Island endemic.

Figures

FIGURE 1. Phylogenetic tree of six species of Phyllodactylus from a maximum-likelihood analysis of DNA sequences of 16 S rRNA. A scale bar is indicated. The numbers at nodes are bootstrap (left) and Bayesian (right) support values. The tree is rooted with the phyllodactylid species Gymnodactylus amarali.

FIGURE 2. Adult male holotype (FMNH 283552; SVL 60.1 mm) of Phyllodactylus paralepis sp. nov. in life. Photograph by J. R. McCranie.

FIGURE 3. Comparison of spacing of enlarged dorsal tubercles between A) Phyllodactylus paralepis sp. nov. (FMNH 283552) and B) P. palmeus (KU 203123). Photographs by J. R. McCranie.

FIGURE 4. Map of Honduras showing localities for specimens examined of Phyllodactylus paralepis sp. nov. (squares) and P. palmeus (circles).