Polychrus auduboni (Hallowell)

Murphy, John C., Lehtinen, Richard M., Charles, Stevland P., Wasserman, Danielle, Anton, Tom & Brennan, Patrick J., 2017, Cryptic multicolored lizards in the Polychrus marmoratus Group (Squamata: Sauria: Polychrotidae) and the status of Leiolepis auduboni Hallowell, Amphibian & Reptile Conservation (e 132) 11 (1), pp. 1-16 : 6-10

Polychrus auduboni (Hallowell) new combination

Figure 6 (holotype), 1a, b

Leiolepis auduboni Hallowell 1845 : ANSP 8138 , Type locality: “ Colombia within 200 miles of Caracas.” Collected by Samuel Ashmead. Restricted here to La Cumbre, Maracay, Aragua, Venezuela (~ 10.233333 -67.333336).

Polychrus marmoratus marmoratus – Burt and Burt 1933: 41. [in part]

Polychrus marmoratus – Roze 1958:2.

Referred specimens: Skeletal and cleared and stained specimens examined: Trinidad. AMNH 148543 female; FMNH 49840, FMNH 49845, FMNH 49848, UF 18395, males, UF 18922. Venezuela. FMNH 17791 (Sucre, Venezuela) male. Alcohol specimens examined: Polychrus auduboni (n = 66). Tobago. UWIZM.2012.27.47, Arnos Valle Bridge Courtland River (~ 11.206 -60.760), UWIZM.2012.42.12, Bloody Bay River Bridge (11.301070 -60.626965); St. John; Charlotteville ; Charles Turpin Estate (11.3165 -60.5499) FMNH 217257 , USNM 227928–30 , UWIZM 2011.30 .2 UWIMZ CAREC. R.129, UWIMZ 2012.27.42 Charlotteville, Tobago (11.3165 -60.5499). Trinidad. Arima Valley (10.684883 -61.281702) UWIZM 2012.27 .61, Bush-bush (10.360255 -61.090106), Curepe (10.636930 -61.405493), UWIZM 2010.12.49; Brickfield (10.455021 -61.467952) FMNH 49839 , 49841 , 49843 , 49844 , 49846 ; San Rafael (10.57174 -61.2642325) FMNH 49847 , 49849 ; Port-Of-Spain (10.666667 -61.50579) MCZ R-79119–79123; San Fernando (10.2833 -61.4667) R-100484–87, R-119881; Tunapuna-Piarco (10.585543 -61.329526) CM S4846 , S6520 , S6534 , S6539 , S6543 , S6561 ; Trinidad (no specific locality) MCZ R-12065, R-145299, R-145300–07, R-68888, R-69417, UMMZ 123692 , UWIZM 2010.12.47a–c, BMNH 92.9 .10.2, 97.7.23.17. Venezuela. Aragua (10.233333 -67.333336), CM S7412 , S7425 ; UMMZ 124309 ; Distrito Capital (10.46786 -66.90625); CM 22797 , 64748 , MCZ R-109009, Falcon (11.016667 -68.566666), R-48729- 30, R-49053; La Culebra, base of Duida (3.7299633 -65.80171967) R-58330; Monagas (10.2 -63.533) R-9981; Sucre (10.147126 -63.808614), MCZ R-50202, CM S7874 , S7915 , S7918 , S7949 ; within 200 mi from Caracas ANSP 8138 ; Uroma, Yaracuay (10.48.3337 -68.31668) FMNH 29189–91 .

Diagnosis: Loreal usually fragmented into two scales; supranasal not in contact with loreal; two or three internasals; loreal contacts upper labials 2–3–4; vertebral rows 93–112; scales around mid-body 62–80; lamellae on fourth toe 30–43; usually three scales (2–4) between the first canthals, and five scales (4–6) between the second canthals; nasal does not usually contact first upper labial, but does contact the second and third; total femoral pores 17–28; multicarinate scales in paravertebral rows few or none; paravertebrals much larger than laterals; the number of supraocular rows usually five, rarely four or six; scales on anterior of snout finely striated with scattered tiny tubercles; scales on anterior surface of humerus keeled.

Re-description of holotype: Hallowellss (1845) description for this species is of little or no use in distinguishing it from Polychrus marmoratus or other taxa in this genus. Based upon photographs and the original description: Adult female with a snout-vent-length (SVL) of 101 mm. The head is 0.29 of the SVL; 0.65 times longer than wide, as wide as high. Snout blunt. Neck narrower than the head, almost as wide as the anterior portion of the body. Body compressed. Tail almost round in cross section, tapering toward the tip, 2.83 times SVL. Rostral pentagonal, almost two times as wide as high, visible from above, bordered posteriorly by two large postrostral scales. Scales on snout heterogeneous in size, irregularly polygonal, juxtaposed, rugose. Three scales across snout between anterior canthals, five scales across snout between posterior canthals, two canthals between nasal and supraciliaries, anterior one largest. Supranasals separated by three scales across the snout. Supraorbital semicircles more or less distinct, with 6/7 scales, separated medially by one row of scales, slightly smaller in size than those of supraorbital semicircles. Thirty-eight scales in supraocular region distinctly smaller than those on snout, polygonal to rounded, juxtaposed, flat and smooth, irregularly arranged except a row of smaller scales adjacent to supraciliaries. Supraciliaries 8/9, juxtaposed, smooth, in a continuous series with canthals. Scales in the parietal region are irregular polygonal, juxtaposed, flat, smooth, intermediate in size between those on snout and on supraocular region. Scales in interparietal region polygonal, juxtaposed, rugose, some somewhat swollen. Parietal eye absent. Loreal region with two scales. Nostril directed laterally, in upper anterior of a single nasal, nasal pentagonal and in contact with first and second supralabial. Orbit length 0.29 times head length. Eyelids partially fused, covered by granules of almost same size throughout the eyelids. A continuous series of two preoculars and two suboculars, in direct contact with supralabials and four postoculars. Upper labials seven on both sides, followed to rictus by a few relatively small scales. Temporal region with seven vertical rows of polygonal or rounded, juxtaposed, flat, and smooth scales, followed by two or three rows of granular scales near the ear, delimited dorsally by a single row of five or six enlarged supratemporal scales. Ear opening vertically oval with smooth margin, tympanum superficial. Mental bell-shaped, almost 2.5 times wide as long. Lower labials taller than upper labials, six on each side, followed by several small scales to rictus. Lateral scales on chin slightly larger than median scales. Gular crest reduced but present, composed of about 10 enlarged, conical scales between mental and dewlap (anterior most obscured by thread holding tag). Dewlap has scales the same size and structure as chin scales, which are separated from each other by an extensible skin covered with granules, reaches level of forelimbs. Scales on anterior nape relatively small, granular, and almost rounded, juxtaposed, convex, in about 17 rows, posteriorly grading into dorsals. Scales on the sides of the neck about the same size as those on the nape but more elongated, merging ventrally with the gulars. Paravertebrals polygonal to rounded, juxtaposed, to some extent convex but mostly flat and keeled, 110 paravertebral scales in a mid-dorsal line between the occiput and the posterior margin of the hind limbs. Lateral scales are of a similar size and same shape as those of dorsum, convex, smooth, in poorly defined, oblique rows. Ventrals larger than dorsals, flat, keeled, lanceolate, and imbricate, in poorly defined, oblique and transverse rows. Scales around mid-body about 80. Preanal plate has scales which are slightly smaller than ventrals, in nine rows. Preanal pores absent. Femoral pores indicated on 14/13 notched scales (female). Tail has rhomboidal, flat, sharply keeled scales, distinctly larger than the dorsals, arranged in longitudinal and oblique rows; keels aligned longitudinally; on ventral surface of the tail, scales are slightly larger and more rectangular. Tail not regenerated ending somewhat bluntly. Scales on forelimbs slightly larger than dorsals, polygonal to rounded, flat, keeled, mostly imbricate but more juxtaposed on upper arm, slightly smaller on ventral aspect of forearms, towards posterior aspect ventrals become smaller. Scales on hind limbs are as large as dorsals, polygonal to rounded, keeled, smooth, and imbricate on thigh and ventrally, juxtaposed on dorsal surface of tibia, slightly larger and slightly keeled on ventral part of tibia, and slightly lanceolate. Toward posterior aspect of thighs, both dorsally and ventrally, scales become distinctly smaller. Subdigital lamellae of fingers and toes single, short, with multiple keels, 25 under fourth finger, 34 under fourth toe.

Variation: We examined 66 specimens of this species. Females were significantly larger than males in size (p = <0.05, 53 df). Body length: females SVL X = 116.3 (n = 31), males SVL X = 105.1 (n = 24). Tail length: females X = 291.9 (n = 26), males X = 277.1 (n = 19), statistical tests inconclusive as to significant difference. Forelegs 0.30–0.48 of the SVL, X = 0.37, SD = 0.51; hind legs 0.37–0.65 of the SVL X = 0.52, SD = 0.60. Rostral broader than tall, contacts two postrostrals. Scales on snout slightly imbricate. Nasal with large nare, single supranasal above on the snout, separated by 1–3 internasals. Supranasal rarely makes contact with loreal. First pair of canthals (most anterior) separated by three (rarely two) scales, second pair of canthals separated by 4–6 scales (usually 5). Semicircle scales 10–16, the total bilateral average 12.4, they were usually separated by a single scale (or scale row) anteriorly, and a double row posteriorly. Ciliaries 10–13, usually with two keels, supraocular scales polygonal to round in five or six rows between ciliaries and semicircle scales, first row or first two rows of supraoculars with keels (first row sometimes appears to be a second row of ciliaries), supraoculars highly variable in number (26–44). A prenasal scale usually separated the postrostral from the nasal. The nasal was mostly in contact with second upper labial, sometimes in narrow contact with the first or the third upper labial. Loreal usually in two parts, an anterior quadrangular scale and a posterior triangular scale; loreal usually contacts upper labials 2–3–4, sometimes 2–3 or 3–4; first canthal usually makes contact with loreal; loreal usually not in contact with supranasal. Upper labials 6–9 per side, usually seven and the bilateral average for total upper labials was 14.86; fifth upper labial usually under middle of eye, sometimes the seam of 4–5, and rarely the seam of 5–6. Lower labials 6–9, usually seven, and the total bilateral average for lower labials was 14.8 scales. Orbital scales: preorbitals two or three, rarely one; suborbitals usually two; and postorbitals usually three or four, rarely two. Temporal scales usually in 7–8 vertical rows between post orbitals and tympanum, separated from parietal scales by a row of 4–5 enlarged supratemporals. Gulars (counted between tympani) 39–60 (X = 46.4), rows of gulars separated by numerous micro-scales that vary in size. Dorsal scales in 62–80 rows around mid-body (X = 71.5); 93–112 scales along the vertebral line from the occiput to the posterior edge of the hind legs; on the vertebral line 10–14 rows of slightly enlarged, pentagonal to hexagonal, keeled scales, which gradually become elongate and ovate laterally, often losing the keels laterally (note these may appear as a mid-dorsal stripe) transitioning into sharply keeled, pointed, imbricate ventrals; scales similar to the ventrals in size and shape extend onto the anal plate. Scales on tail pentagonal, heavily keeled, and imbricate. Scales on limbs keeled, imbricate, and slightly more ovate proximally than distally.

Coloration: In alcohol the specimen is a uniform brown, see Fig. 5 . In life, highly variable, may change quickly from bright green with white lateral blotches bordered in black to almost a uniform brown. See Figure 1a, b .

Distribution: Polychrus auduboni occurs in the Cordillera de Costa of Venezuela, Trinidad and Tobago. It is also likely present on the Isla de Margarita, in the forested areas of the llanos, and Orinoco Delta. However, it may be replaced by another species in Bolivar, Venezuela.

Natural History: Beebe (1944) discussed the natural history of this lizard. Unfortunately, he combines information from both Caripito Venezuela and Kartabo, Guyana and it is not possible to unravel the comments he makes about P. marmoratus from Guyana, and from this species from Venezuela. However, Test et al. (1966) observed P. auduboni in the Botanical Garden at Caracas and above Turiamo Pass, Aragua, Venezuela. The latter individual was kept alive and is described as moving slowly and deliberately, unless grasshoppers were placed in its cage, at which time it jumps or runs towards the insects. The authors also describe tail waving as a human approached the cage, and interpret this as defensive behavior. During the day, the lizard was green in color but changed to gray-green at night while it slept on a branch. Its prey may also include humming birds. We have observed this lizard on Trinidad and Tobago, active during the day in secondary forests, climbing through branches and drinking water from the surface of leaves. Several times we have observed pairs together in the same or adjacent trees. Known predators include the hawk Leucopternis albicolis , house cats, and the parrot snake Leptophis coeruleodorsus ( Murphy 1997; Renoir Auguste, pers. comm.).

Comparisons: Distinguished from Polychrus marmoratus by few or no multicarinate paravertebral scales on the dorsum (many in P. marmoratus ); paravertebrals consistently larger than laterals; loreal is one or two scales (3–4 in P. marmoratus ); 17–28 femoral pores (8–19 in P. marmoratus ).

Figures

Fig. 6. ANSP 8138. The holotype for Leiolepis auduboni Hallowell. Photo credit: Ned Gilmore.

Fig. 5. On the supraoccipital process, from the posterior perspective, the presence of a median seam that runs the length of the process, down to the rim of the foramen magnum (DW).

Fig. 1. A–B: Polychrus auduboni from the Arima Valley, Trinidad (JCM). C–D: Polychrus marmoratus, probably from Suriname, (Toan Leenders). E: Polychrus sp. from 4.5 km S of Cumanacoa, Venezuela at 300–400 m asl (Walter E. Schargel). F: Polychrus sp. from Vitória do Xingu, Pará, Brazil (Pedro Peloso). G: Polychrus sp. Camamu, Bahia, Brazil. H: Polychrus sp. from Guarapari, Espirito Santo, Brazil (bottom) (Pedro Peloso).