Mabuya altamazonica, Miralles & Barrio-Amorós & Rivas & Chaparro-Auza, 2006

Miralles, Aurélien, Barrio-Amorós, César L., Rivas, Gilson & Chaparro-Auza, Juan Carlos, 2006, Speciation in the “ Várzéa ” flooded forest: a new Mabuya (Squamata, Scincidae) from Western Amazonia, Zootaxa 1188 (1), pp. 1-22 : 6-11

Mabuya altamazonica , new species

Holotype: MNHN 2006.0291 , an adult female, May 2005, collector undetermined. Typelocality : Kilometer 34 on road Tarapoto­Yurimaguas (600 m asl), Concesión de Manejo de Fauna Silvestre ASPRAVEP ( Asociación de Productores de Ranas Venenosas Progreso ), Rio Cainarachi, Departamento San Martin, Peru.

Paratypes: Thirty one specimens. Peru: DEPARTAMENTO DE AMAZONAS : AMNH 57020 , confluence between Rio Santiago and Rio Marañón (180 m asl) . DEPARTAMENTO DEL CUZCO: FMNH 81376 , 81377 , Prov. Paucartambo, Hda Villacarmen (around 550 m asl) ; FMNH 168240 , 168255 , Quincemil, on the Rio Marcapata (780 m asl) . DEPARTAMENTO DE LORETO: AMNH 57035 , Yarina, Rio Huallaga valley (180 m asl) ; AMNH 60583 , 60584 , Quache (?), Rio Pastaza valley, frontier Peru­Ecuador (around 130 m asl) ; AMNH 73472 (= 3 embryos) , FMNH 45523 , Iquitos (around 100 m asl) ; MNHN 1978.2141 , Colonia, Bora tribe’s village on the Rio Zumun , tributary of Rio Yahuashacu, coll. in 1978 by M . T. Rodrigues; MNHN 1999.4827 , 1999.4828 , 1999.4829 , Estiron, coll. in 1978 by J. P. Gasc. DEPARTAMENTO DE MADRE DE DIOS : FMNH 40429 , Candamo (around 450 m asl) ; FMNH 168227 , Manu, between Rio Madre de Dios and Rio Manu (400 m asl) ; FMNH 168344 , 168349 , 168418 , 168452 , Avispas, near Rio Inambari , 145 km W Puerto Maldonado (480 m asl) ; MCZ 183676 , Tambopata (around 230 m asl) , coll. in 1996 by J. E. Cadle. DEPARTAMENTO DE PASCO : LACM 76853 to 76855 , no exact locality. DEPARTAMENTO DE SAN MARTIN : AMNH 126375 , Tarapoto farms. DEPARTAMENTO DE UCAYALI : AMNH 57036 , at mouth of Rio Tambo (confluence between Rio Tambo and Rio Bajo Urubamba = Upper Rio Ucayali (260 m asl); AMNH 57037 , Orellana , Rio Ucayali valley (150 m asl).

Additional material examined: Three specimens ( FMNH 134461–63 ) were collected in the valley between Palca and Tarma, departamento de Junin, at 1500 m asl. We refrain to include those specimens in the type series given (1) the altitude of this locality which seems to be exceptional for this lowland species, and (2) its uncommon colour pattern with two very dark solid dorsolateral bands .

Moreover, we had also the opportunity to study two specimens ( UMMZ 68102 , 68103 ) from the departamento de Santa Cruz, Eastern Bolivia. Those specimens are morphologically very similar to the holotype. Such a locality would extend remarkably the

distribution of this species to the south. However, this data being very approximate, we believe that it needs confirmation.

All latter specimens (from Bolivia and from the Peruvian Andes) are morphologically very close to the type­series and for the time being there are no objective arguments for not considering them as M. altamazonica . However, given the lack of reliability about their identification and their uncommon localities, we prefer to discard them herein from the discussion.

Diagnosis

A relatively big sized Mabuya having paired prefrontals and frontoparietals, four supraoculars, most frequently five subequal supraciliaries, seven supralabiales with the fifth being the largest and placed under the eyes, parietals in broad contact behind the interparietal and a single pair of nuchals. Two upper and two lower lateral dark stripes; back spotless or covered by many dash­shaped chocolate spots; palms and soles dark.

Mabuya altamazonica differs from the nine species of Mabuya occurring potentially in western Amazonian and peri­Andean regions [ M. bistriata ( Spix 1825) , M. carvalhoi Rebouças­Spieker & Vanzolini 1990 , M. cochabambae Dunn 1936 , M. dorsivittata Cope 1862b , M. frenata ( Cope 1862a) , M. guaporicola Dunn 1936 , M. meridensis Miralles et al. 2005b , M. nigropalmata Andersson 1918 , M. nigropunctata ( Spix 1825) ] by the combined presence of: paired frontoparietals (versus frontoparietals fused together in M. carvalhoi , M. frenata and M. nigropalmata ), paired prefrontals (versus prefrontals fused together in M. carvalhoi ), a single pair of nuchals (versus two to four pairs in M. carvalhoi and M. nigropalmata ), four supraoculars (versus three in M. cochabambae and M. dorsivittata ), most often five subequal supraciliaries (versus four, with the second largest in M. bistriata , M. dorsivittata , M. guaporicola and M. meridensis ), absence of a vertebral thin stripe (contrary to M. cochabambae , M. dorsivittata , M. guaporicola and M. meridensis ), seven supralabials with the fifth being the largest and placed under the eyes (versus eight supralabials with the sixth being the largest and placed under the eyes in M. frenata and most specimens of M. nigropunctata ), parietals in broad contact behind the interparietal (versus parietals separated by the interparietal or barely in point contact in M. nigropunctata ), palms and soles darker than belly (versus light palms and soles in M. bistriata , M. carvalhoi , M. cochabambae , M. dorsivittata , M. frenata and M. guaporicola ), and fore­ and hind limbs touching (or almost touching) each other when adpressed against body (versus fore­ and hind limbs distinctly separated from each other when adpressed against body in M. cochabambae , M. dorsivittata , and M. guaporicola ).

Description of the holotype

Specimen MNHN 2006.0291 (figs 1, 2, 3a–b) in a perfect state of conservation and coloration, with an abdominal slit.

Snout­vent length 92.1 mm; tail length 91.4 mm (a little piece of tip of the tail was amputed); head length 16.3 mm. Fore­ and hindlimbs hardly touching each other when adpressed against body.

Rostral wider than high, contacting first supralabials, nasals and supranasals. Paired supranasals in median contact, contacting anteriormost loreal. Frontonasal diamondshaped, wider than long, laterally contacting anterior loreal. Paired prefrontals roughly quadrilateral, medially separated by frontonasal, wider than long, contacting frontonasal, both anterior and posterior loreals, first supraciliaries, first and second supraoculars, and frontal. Frontal lanceolate, approximately twice as long as wide, wider anteriorly, in contact with frontonasal, prefrontals, second supraoculars and frontoparietals. Four supraoculars; the first the smallest, the second the longest and widest. Posteriormost supraocular in contact with the frontal is the second ( Greer & Broadley 2000). Five subequal supraciliaries on the right side; on the left side four supraciliaries, the third being the longest and probably resulting from the fusion of two supraciliaries. Paired frontoparietals, longer than wide, in broad contact at midline, in contact with frontal, all supraoculars except the first, parietal and interparietal. Interparietal rhomboid, longer than wide, wider anteriorly. Parietal eye hardly distinct. Parietals larger than interparietal, wider than long, in contact with each other behind interparietal and overlapping the upper temporal scale ( Greer & Nussbaum 2000). Single pair of transversely enlarged nuchals, each as wide as three rows of dorsals.

Nasal subrectangular. Nostril located posteriorly. Postnasal small, in contact with supranasal, anterior loreal and first supralabial. Two subrectangular loreals behind nasal, subequal in size, the second slightly higher. First loreal in contact with first, second and third supralabials, second loreal in contact with third supralabial. One presubocular in contact with fourth and fifth supralabials. One preocular, in front of presubocular and behind second loreal, in contact with third and fourth supralabials. Lower eyelid undivided with a transparent disk, one row of small scales across its dorsal edge ( Greer & Broadley 2000). Seven supralabials; the fifth is the widest and forms the lower border of the eyelid. Seven infralabials. Temporals imbricate, smooth, cycloid, not distinctly delimited from scales on the nape or sides of the neck. Two pretemporals. One primary temporal, two secondary temporals in contact and three tertiary temporals ( Greer & Broadley 2000). Earopening relatively small, round, with undulating anterior margin and smooth posterior margin. Auricular lobules absent.

Mental wider than long, posterior margin straight. Postmental wider than long, adjacent to first and half of second infralabials. Two pairs of chin shields, first in contact with postmental, posterior half of second and anterior half of third infralabials. Gulars similar in size and outline to ventrals.

Palms and soles covered with small tubercles, subequal in size. Both regions delimited by a row of larger and flatter scales. Subdigital lamellae smooth, single, 11 and 12 under fourth finger, 14 and 15 under left fourth toe. Finger and toes clawed. Relative length of the toes in the following order: I <II <III = V <IV.

All scales, except head shields and scales on sole and digits, cycloid, smooth and imbricate. Thirty scale rows around midbody, 52 transverse rows of dorsal scales, 31 transverse rows of ventral scales. Four preanals larger than adjacent ventral scales. Median subcaudal series of scales twice as wide as long on the posterior half of the tail.

Coloration in preservative: background colour of flanks and upper side of the head, neck, back, limbs and tail olive­bronze. Venter, lower side of head, throat, lower side of limbs and tail immaculate bluish­grey.

Back nearly spotless, just with three widespread little black dots. Lateral and upper sides of limbs spotted with many small, fused dark dots. Palms and soles dark brownblack. Preanals pale cream.

Four dark brown stripes run along body. Two upper lateral stripes; margins darker and strongly contrasted; about three scales wide at midbody; from nostrils, loreals, upper half part of supralabials, around eyes and temporals, along upper half part of ear­openings, on neck, above arms, on sides until insertion of hindlimbs and continuing on the sides of tail. Two lower lateral stripes not well defined; from corner of mouth, below ear­opening, above forelimb until insertion of hindlimb; dorsal margins darker and relatively well contrasted, whereas limits between ventral margins and venter not distinct.

Four whitish stripes run along body; two very thin and hardly distinguishable dorsolateral stripes separating dark dorsolateral stripes from the background colour of the back; and two more contrasting lateral stripes separating the dark upper lateral from lower lateral dark stripes. The coloration in life is slightly lighter than in preservative.

Variation

The following summary of meristic and measurement variation gives the range for each character, followed by the mean, ± the standard deviation, and sample size in parentheses. For some bilateral characters, the sample size has been noted as the number of sides rather than specimens, and this is then indicated after the sample size. Dorsal scale rows: 48–55 (52.44 ± 1.98, 26); midbody scale rows: 26–31 (29.19 ± 1.35, 26); ventral scale rows: 28–36 (32.12 ± 1.91, 24); lamellae under fourth finger: 11–15 (12.19 ± 1.04, 48 sides); lamellae under fourth toe: 13–19 (15.67 ± 1.49, 46 sides); head length: 14.1–17.7 (15.56 ± 0.86, 22); snout–vent length: 72.3–97.2 (84.23 ± 7.26, 21); tail length: 115.0–156.0 (128.94 ± 11.67, 10).

Internasals: 96.2% in broad contact and 3.8% separated (n = 26). Prefrontals: 7.7% in broad contact, 30.8% in point contact and 61.5% separated (n = 26). Parietals 96.0% in contact behind the interparietal (n = 25). Fifteen specimens have five subequal supraciliaries on both sides (58%); four specimens have four supraciliaries with second enlarged, on both sides (15%); three specimens have five subequal supraciliaries on one side and four subequal supraciliaries on the other (12%), three specimens have four subequal supraciliaries on both sides (12%), and one specimen has six supraoculars on one side and five on the other. All studied specimen have seven supralabials on both sides (n = 26), except the specimen (AMNH 57036) which has eight supralabial on the right side and seven on the left side.

The dorsal coloration of Mabuya altamazonica is highly polymorphic (fig 3a–d): some specimens have an homogeneous spotless back (ex. holotype MNHN 2006.0291), whereas some others have a lot of aligned chocolate brown dash­shaped spots on the back, approximately forming two discontinuous and not well defined dorsolateral stripes, running on the back from the prefrontal to the middle of the tail (ex. FMNH 168255). However, most of the specimens are intermediate between those two patterns of coloration. Those different patterns of coloration seem to be randomly distributed in the area of distribution of M. altamazonica , and there is no evidence of any biogeographical cline (fig 4).

Etymology

The specific name refers to the distribution of this taxa, endemic to the extreme occidental part of the Amazon forest, and literally means “from the upper Amazonia”.

Distribution and ecology

Mabuya altamazonica is confined to virtually all the Peruvian Amazonia , extreme western part of the Amazon Basin. The presence in Ecuador is highly probable, as one locality ( AMNH 69053 , 69054 ) lies in the border with Peru (fig 4). Mabuya altamazonica is a lowland species, all studied specimens having been found at an altitudinal range from 150 to 780 m above sea level .

The holotype was captured in pre­montane forest at 600 m asl. The concession ASPRAVEP have a medium precipitation of 2500 mm /year at the lower valley ( R. Schulte, pers. com.) .

As all others species belonging to the genus Mabuya , M. altamazonica is viviparous, embryos having been found in the uterus of the female AMNH 60583.