Ameiva aggerecusans, Koch, Claudia, Venegas, Pablo J., Rödder, Dennis, Flecks, Morris & Böhme, Wolfgang, 2013

Koch, Claudia, Venegas, Pablo J., Rödder, Dennis, Flecks, Morris & Böhme, Wolfgang, 2013, Two new endemic species of Ameiva (Squamata: Teiidae) from the dry forest of northwestern Peru and additional information on Ameiva concolor Ruthven, 1924, Zootaxa 3745 (2), pp. 263-295 : 274-280

Ameiva aggerecusans sp. nov.

Figs. 5–6

Diagnosis and comparison. This comparatively small Ameiva is diagnosed by the following combination of characters: (1) maximum known SVL of 99.3 mm; (2) lacking longitudinal ridge on frontal scale; (3) frontal plate divided in two subequal scales; (4) postnasals separated from prefrontals by frontonasals; (5) parietal scales 5–7; (6) median gular scales not enlarged; (7) enlarged median mesoptychial scales slightly larger than largest gulars; (8) gulars posterior to the interauricular crease smaller than anterior gulars; (9) nasal suture passes through the superior half or centrally through nostril; (10) rostral not contacting or in short contact with postnasal; (11) supranasals not contacting or in short contact with supralabials; (12) scales of circumorbital semicircle not extending to anterior margin of third supraocular; (13) 30–33 enlarged ventral scales between gular and vent; (14) 10–12 longitudinal rows of ventral plates, outermost often distinctly smaller; (15) 73–92 DOM; (16) 144–198 DL; (17) postbrachials not or hardly dilated; (18) 31–39 LFT; (19) 26–32 SCF; (20) 12–22 FP; (21) cream-colored vertebral stripe present in most females and juvenile specimens.

Ameiva aggerecusans sp. nov. can be differentiated from all other mainland congeners except for A. bifrontata , A. concolor and A. nodam sp. nov. by having a transversely divided frontal plate. From A. bifrontata and A. nodam sp. nov. this species can be distinguished by lacking distinctly dilated postbrachials. It resembles A. concolor but has a lower maximum SVL and a distinctly more defined cream-colored vertebral stripe on the dorsum.

Holotype. An adult male (ZFMK 85024, Figs. 5 , 6 A) from Balsas, Province of Chachapoyas, Region of Amazonas, Peru (06°49’11.6’’S, 78°00’12.2’’W, 1000 m above sea level), collected on 0 8 July 2005 by P. Venegas and C. Koch.

Description of holotype: An adult male with a SVL of 99.3 mm. Head 0.28 times SVL, 2.32 times longer than wide, 0.9 times as wide as high. Snout elongate, bluntly pointed; canthus rostralis distinct. Neck only slightly narrower than head, and body. Body cylindrical. Limbs well developed, forelimbs 0.36 times SVL, hindlimbs 0.71 times SVL, tibia 0.21 times SVL. Tail slightly pentagonal in cross section, tapering toward the tip; 2.11 times SVL. Rostral in posterior part acute-angled and bordered by supranasals, as wide as high; smooth, with a little suture on each side posterolaterally; visible from above. Supranasals almost triangular, in short medial contact, and in short contact with first supralabials, bordered posteriorly by hexagonal frontonasal. Postnasal almost trapezoid, not contacting rostral, in median contact with frontonasal and in broad contact with loreal and first and second supralabial. Oblique nasal suture passing through the superior half of the oval nostril. Prefrontals paired and roughly pentagonal, medial suture about twice as long as that between supranasals; laterally in contact with loreal, first supraocular and first supraciliary. Frontal plate divided in two subequal scales, the suture between both scales forming a straight line; anterior frontal pentagonal, laterally in contact with first and second supraoculars, larger than posterior frontal; posterior frontal almost squarish, laterally in contact with second and third supraoculars. Paired frontoparietals, slightly longer than wide and with long medial suture; laterally in contact with third supraocular, and small circumorbital scales bordering posterior part of third and fourth supraocular. Interparietal almost squarish, wider than adjacent parietals, sutures with parietals straight; interparietal bordered at each side by two irregular parietals divided by an oblique suture; outermost parietals slightly larger than inner parietals; parietal series composed of 5 scales including interparietal. Supraoculars four at each side. Circumorbital semicircle formed by 14 scales on each side, bordering inner edge of third supraocular and posterior edge of fourth supraocular, separating the latter from frontoparietals; fourth supraocular separated from parietals by two rows of circumorbital scales. Laterally, second and third supraocular separated from supraciliaries by a single row of small scales; 21 combining both sides. Supraciliaries seven (on left side), first highest, fourth longest, remaining ones shorter and subequal. Loreal very large, single, in contact with postnasal, frontonasal, prefrontal, first supraciliary, second preocular, first subocular, and third and fourth supralabials. Preoculars two; first granular, second distinctly larger, but explicitly smaller than suboculars. Suboculars three, first one almost squarish, second and third longer than wide, all in contact with supralabials, second subocular longest. A curved keel reaching from first through second subocular. Postoculars small, in two rows, first consisting of five and second of four scales. Enlarged supralabials eight, fifth below center of eye, third largest; followed to commissure of mouth by seven small scales. An indistinct row of seven slightly enlarged supratemporals. Temporal region with polygonal scales, slightly smaller centrally. External auditory meatus large, vertically oval, bordered by granular scales, anterior margin semicircular, posterior one straight. Tympanum recessed. All dorsal and lateral head scales juxtaposed and smooth. Mental anteriorly rounded, posteriorly straight, bordered by first infralabials and postmental. Postmental single and pentagonal, in contact with first and second infralabials, and followed by eight pairs of enlarged chinshields. First pair in broad medial contact and in contact with infralabials. Second pair of chinshields separated from infralabials by one row of small, almost granular scales, and third pair of chinshields separated by two of those granular scale rows. Remaining chinshields separated from infralabials by one or two larger scales, almost equal in size than posterior chinshields and separated medially by scales of anterior gular region. Medial chin scales moderately small, convex, smooth, juxtaposed, oval or polygonal, in slightly oblique rows, all subequal in size. Enlarged infralabials eight, fifth and sixth below center of eye; followed to commissure by 6 smaller scales. Gular region divided into two areas: anterior region with round or polygonal, juxtaposed, smooth and flat scales in slightly oblique rows, subequal in size, delimited posteriorly by line uniting lower margin of ear openings. Posterior gular region covered by smaller polygonal or round scales in transverse rows. Mesoptychial scales moderately enlarged, slightly larger than anterior gular scales, in about three rows, polygonal or hexagonal, flat, smooth, and juxtaposed. Scales on nape and sides of neck similar in size to dorsals. Dorsals and scales on flanks granular, small, round, smooth, slightly larger in vertebral region; 188 DL; 88 DOM. Ventrals large, smooth, rectangular, wider than long, in 10 longitudinal and 32 transverse rows; transition between ventrals and scales on flanks sharp. Preanal shield with three distinctly enlarged scales. Preanal plate surrounded anteriorly and laterally by smaller scales; posteriorly by much smaller scales. 19 FP in a continuous row along each thigh, first pair of pores medially separated by five scales. Each pore surrounded by four scales, anterior one distinctly larger than posterior ones. Scales on tail dorsally rectangular, smaller than subcaudals, longer than wide, slightly keeled in anterior part, stronger keeled in posterior part, slightly imbricate; arranged in transverse and nearly longitudinal rows, continuous with subcaudals around tail (except first few rows incomplete ventrally); 28 SCF. In medial verticile caudals longer and narrower than in anterior and posterior part of tail. Subcaudals rectangular, smaller than ventrals, wider than long close to base, longer than wide in posterior part of the tail, smooth, mostly juxtaposed. Forelimbs with row of very large, smooth, juxtaposed or slightly imbricate, almost rectangular (distinctly wider than long) antebrachial scales on anterodorsal aspect of forearms and similar but smaller brachial scales on upper arms that extend almost to insertion of forelimbs. Antebrachials and brachials separated by smaller scales at elbow. Dorsoposterior, posterior, and ventral aspect of arms with small almost granular scales, almost equal in size than dorsals, except for scales directly adjacent to brachials and antebrachials, which are slightly to moderately enlarged and irregular. Legs with large, smooth, imbricate scales on anterior and ventral aspects of thighs, and ventral aspect of shanks. Row of large, almost rectangular scales anteriorly on thigh, gradually becoming smaller and irregular toward pores. On ventral aspect of shanks, two rows of very large scales, anterior larger and more or less trapezoidal. Tibiotarsal spurs form a cluster of three rows, each existing of about 4–5 sharply mucronate scales which are positioned along the postaxial edge of the distal end of the shank. Elsewhere on hindlimbs scales granular and slightly smaller than dorsals. Subdigital lamellae of toes transversely enlarged and single, moderately to distinctly tuberculate towards base. Lamellae of outer toe continuing to heel. On palms lamellae of outer and inner fingers continuing to wrist and only separated by few granules, tubercular and increasing in size towards it. Supradigital scales dilated, single and smooth. 18 LFF; 35 LFT.

Measurements of holotype (in mm). SVL 99.3; HL 28.43 HH 13.5; HW 12.2; SL 16.3; ED 6.6; DSN 3.0; DNE 8.9; DEE 7.1; TL 209.5; AGL 45; BHM 15.8; BWM 19.6; FLL 36.7; HLL 70.5; TIL 21.1.

Coloration of holotype: In life ( Fig. 6 A), the dorsal surface of the head and body of the male holotype is reddish-brown and mottled with small frayed dark-brown spots of various sizes, less mottled and slightly lighter colored towards the cloacal region. The sides of the head are cream-colored with some dark dots in the temporal region. The granules on the eyelids are white to grayish-white. Head ventrally white to grayish-white. Body laterally and outermost row of ventral grayish mottled with frayed blackish spots of various sizes. Other ventrals yellowish-white to pale yellow in thoracal region. Forelimbs dorsally striking greenish-yellow ( Fig. 6 E), ventrally pale yellow. Hindlimbs and tail dorsally pale brown, ventrally off-white.

In preservative, the ground color is dorsally light to moderately brown and grayish on flanks, mottled with blackish spots. Sides of the head are gray-brownish. Ventrals pale gray to yellowish-white. Forelimbs dorsally greenish-gray. Hindlimbs and tail dorsally grayish intermixed with some brownish parts. Pattern and coloration of remaining body parts as in life.

Variation. Paratypes (20): Two adult males (ZFMK 85010, 85013), two subadult males (ZFMK 85009, 85011) and an adult female (ZFMK 85012) with the same data as the holotype; an adult male (ROM 16453), an adult female (ROM 16326) and a juvenile (ROM 16459) from Balsas, Province of Chachapoyas, Region of Amazonas, Peru, collected 27 June 1986 by L.D. Wilson; two adult males (CORBIDI 0 5765, ZFMK 90860), an adult female (CORBIDI 05764) and a juvenile (ZFMK 90859) from Balsas, Province of Chachapoyas, Region of Amazonas, Peru (06°49’11.6’’S, 78°00’12.2’’W, 1000 m above sea level), collected on 19 April 2009 by A. Garcia Bravo and C. Koch; three adult males (KU 134829, 134830, 134832), an adult female (KU 134831) and a juvenile (KU 134833) from Balsas, Province of Chachapoyas, Region of Amazonas, Peru, collected on 29 April 1970 by T.H. Fritts; an adult male (ZFMK 90858) from Chacanto, Province of Celendin, Region of Cajamarca (06°50'41.5”S, 078°01’50.8”W, 852 m a.s.l.), collected on 16 April 2009 by A. Garcia Bravo and C. Koch; an adult female (ZFMK 90861) and a juvenile (CORBIDI 05766) from Zapatalgo, Province of Utcubamba, Region of Amazonas (06°04'S, 78°29'W, 1011–1029 m a.s.l.), collected on 0 7 December 2008 by A. Garcia Bravo and C. Koch.

Description of paratypes: Maximum SVL in male paratypes 92.6 mm, maximum total length in male paratypes 327.6 mm (both ROM 16453); maximum SVL in female paratypes 71.2 mm, maximum total length in female paratypes 242.2 mm (both KU 134831). Shape of head, body, limbs as in holotype. HL 0.24–0.29 (0.28 ± 0.01, n = 20) times SVL in both sexes; HH 0.11–0.14 (0.13 ± 0.01, n = 12) times SVL; HW 0.11–0.13 (0.12 ± 0.01, n = 21) times SVL; SL 0.57–0.69 (0.63 ± 0.04, n = 12) times the HL; ED 0.23–0.36 (0.27 ± 0.04, n = 12) times the HL; DSN 0.10–0.18 (0.12 ± 0.02, n = 12) times the HL; DNE 0.27–0.35 (0.31 ± 0.02, n = 12) times the HL; DEE 0.20–0.26 (0.23 ± 0.02, n = 12) times the HL; TL 1.62–2.68 (2.30 ± 0.30, n = 18) times SVL; AGL 0.40–0.48 (0.44 ± 0.03, n = 12) times SVL; FLL 0.33–0.41 (0.37 ± 0.02, n = 12) times SVL, HLL 0.56–0.82 (0.73 ± 0.06, n = 12) times SVL, TIL 0.18–0.23 (0.2 ± 0.02, n = 12) times SVL; foot 0.36–0.43 (0.4 ± 0.02, n = 12) times SVL.

Arrangement, shape and surface of scales as in holotype except for the following variations: Rostral in posterior part right- to acute-angled, in most specimens in anterior part laterally stretched, projecting beyond the nasal suture and in small contact with postnasal, in few specimens not projecting beyond the nasal suture and not contacting postnasals. Supranasals in short contact with first supralabial or not contacting supralabials. Postnasal trapezoid or almost triangular, in short contact with rostral or not contacting rostral, in contact with first and second supralabials and in some specimens also third supralabial. Oblique nasal suture passing through the superior half or centrally through nostril. Medial suture of prefrontals slightly longer or up to twice as long as medial suture between supranasals. Posterior frontal almost squarish or slightly pentagonal. Interparietal squarish, almost rectangular or irregularly pentagonal, as high or higher than wide; outermost parietals slightly smaller or larger than inner parietals; parietal series composed of 5–7 scales, mostly five, including interparietal. Supraoculars 3–5 (mostly four) at each side, the latter normally much smaller than the others. Circumorbital semicircle formed by 8– 16 scales at left side, 16–31 scales combining both sides, bordering fourth up to middle or anterior portion of third supraoculars, occasionally extending to frontal suture and thus contacting second or even first supraocular and separating third supraocular from frontoparietals entirely (most specimens) or by parts; bordering posterior edge of last or last two supraoculars, and separating them from parietals by 2–4 rows of circumorbital scales. Laterally, second and third supraocular separated from supraciliaries by a single, occasionally double row of small scales; 22–28 combining both sides. Supraciliaries six or seven, anterior ones normally longer than those in posterior part. Loreal contacting third and fourth supralabials and occasionally in narrow contact with second and fifth supralabial and/or first supraocular, and first and/or second prefrontal. Preoculars 1–2. Postoculars in indistinct two rows, first consisting of 4–7 and second of 3–5 scales. Enlarged supralabials 5–7, fifth or sixth below center of eye; followed to commissure of mouth by 5–10 small scales. Row of slightly enlarged supratemporals distinguishable in most specimens, consisting of 4–9 scales decreasing in size posteriad. Temporal region with polygonal or rounded, slightly convex scales. External auditory meatus slightly oval or almost round. Postmental followed by 7–8 pairs of enlarged chinshields. First pair and in few specimens also second pair in contact with infralabials. Enlarged infralabials five or six (seven in one specimen), fifth or sixth below center of eye; followed to commissure by 6–10 smaller scales. Scales on nape and sides of neck similar in size or slightly smaller than dorsals. 144–198 (175 ± 14.60, n = 13) DL. 73–92 (85 ± 6.03, n = 13) DOM. Ventrals in 10–12 longitudinal and in 30–33 (32 ± 0.98, n = 21) transverse rows, outermost ventrals nearly as wide as those of the adjacent row or distinctly smaller. Preanal shield with 2–3 rows of enlarged scales. 12–22 (20 ± 2.16, n = 19) FP; not or only hardly visible in some female and juvenile specimens. Tail round or slightly pentagonal in cross section; 26–32 (29 ± 1.94, n = 13) SCF. Postbrachials not or hardly dilated. 1–2 rows of slightly to moderately enlarged irregular, hexagonal scales adjacent to brachials. On ventral aspect of shanks, two (occasionally three) rows of enlarged scales, anterior largest, dilated, and more or less trapezoidal, posterior one (or two) rhomboidal, decreasing in size from anterior toward posterior row. Tibiotarsal spurs form a cluster of 2–3 rows of about 3–6 sharply mucronate scales. Subdigital lamellae of toes mostly single, sometimes paired on inner toes. 16–20 (18 ± 1.00, n = 21) LFF; 31–39 (34 ± 1.87, n = 21) LFT.

Color variation: In life, juveniles ( Fig. 6 D) show a dark brown dorsal ground color on head, body and limbs; a light cream-colored or vanilla-colored vertebral stripe, 4–15 scales in width, extending from behind the head to the base of the tail or less, very striking in anterior part and fading towards posterior part in most specimens; rostral, supralabials and infralabials light yellowish-brown; lower eye granules, suboculars and lower temporals creamwhite; lateral body parts between armpit and groin cream-colored; tail dorsally reddish-brown or medium brown, lightening towards tip; venter cream-white or grayish-white, limbs and tail ventrally cream-white; tubercular lamellae of hands and feet accentuated with brown. Males dorsally reddish-brown or grayish-brown with or without a trace of a white to cream-colored vertebral stripe in anterior part, normally not reaching base of tail; sides brownish-gray or bluish-gray; dorsum of head and body and lateral body parts with or without mottling of tiny, indistinct black spots of various sizes; most specimens with a dark, fringed dorsolateral stripe, which begins faintly and discontinuously behind the eye and almost extends to the insertion of the hindlimbs, being broadest at midbody; dorsal coloration of the tail as in juveniles; head ventrally cream-white, immaculate; venter and ventral surface of limbs and tail immaculate, cream-white to pale yellow, especially frontlegs can show a yellow dorsal and ventral coloration in some males; tubercular lamellae of hands and feet as in juveniles. Females have a grayishbrown to bluish-gray or dark brown dorsal ground color, on body and limbs, head usually brown or grayish-brown; dorsum with ( Fig. 6 B) or without a light vertebral stripe, with or without a dark, fringed dorsolateral stripe; lateral body parts between armpit and groin maybe bright cream-colored, dirty gray or whitish; tail dorsally as in juveniles and males; venter, limbs and tail ventrally as in juveniles as well as ventral parts of hands and feet.

In preservative, the general dorsal color is mainly grayish-brown or dark brownish-black; if present, the vertebral stripe is white or grayish-white, the dark dorsolateral, fringed stripes are dark brown to blackish-brown; the tail is grayish in anterior part fading posteriad into beige; no yellow coloration of male frontlegs visible; venter, limbs and tail ventrally cream-colored and may be interspersed with pale gray or bluish-gray.

Etymology. The specific epithet is an agglutination of the Latin nomen “agger” which means dam and the verb “recusare” which means reject. As in Ameiva nodam sp. nov. this name was chosen to further emphasize our protest against the possible dam constructions along the Marañón river.

Distribution and natural history. This species is endemic to the dry forest of the canyon of the Marañón River in the Northern Peruvian Andes ( Fig. 3 ) from Zapatalgo, Province of Utcubamba, Region of Amazonas (1029 m) to Balsas, Province of Chachapoyas, Region of Amazonas, where it reaches its so far highest known distributional level (1037 m, Fig. 7 ). The lowest distributional level of this species is found in Chacanto, Province of Celendin, Region of Cajamarca (852 m).

Similar to the new A. nodam sp. nov., individuals of Ameiva aggerecusans sp. nov. were found moving quickly on the ground in low vegetation during daytime or sleeping under stones during nighttime. Air temperature during the active hours of the species was between 28.6°C and 42°C and substrate temperature of the ground was between 28.7°C and 46.8°C. This species was also found in the same habitat together with the tropidurid lizard Microlophus stolzmanni .

Figures

FIGURE 3. Maximum clade credibility tree (A) of the Ameiva ameiva-bifrontata - group inferred with BEAST using 866 bp of mitochondrial DNA (concatenated 12 S and 16 S rRNA). Values above branches are posterior probabilities, outgroup (Holcosus festivus) not shown. Map (B) showing the distribution of A. nodam sp. nov. (red triangles), A. aggerecusans sp. nov (orange squares) and A. concolor (green dots). The stars mark the type localities of A. nodam sp. nov (red), A. aggerecusans sp. nov (orange) and A. concolor (green). The following abbreviations for the locality names are used: LAB = La Balza; PER = Perico; BEL = Bellavista; JGA = Jaén / Gotas de Agua; BAC = Bagua Chica; PUC = Pucará; CUE = Cumba; PUW = Puerto Malleta; ZAP = Zapatalgo; CHA = Chacanto; BAL = Balsas; PPY = Paipoy; CAL = Calemar; VIJ = Vijus; CGL = Chagual; PIA = Pías.

FIGURE 5. Male holotype of Ameiva aggerecusans sp. nov. (ZFMK 85024): dorsal (A), lateral (B) and ventral (C) views of head, ventral aspect of left foot (D), ventral aspect of left hand (E), ventral view of cloacal region and right thigh with femoral pores (F).

FIGURE 6. Male holotype of Ameiva aggerecusans sp. nov. (ZFMK 85024) from Balsas, Amazonas, Peru (A); adult female (ZFMK 90861) from Zapatalgo, Amazonas, Peru with dorsal stripe (B); adult male (ZFMK 85010) from Balsas, Amazonas, Peru with a dark, fringed dorsolateral stripe (C); and juvenile (ZFMK 90859) from Balsas, Amazonas, Peru (D); close-up of front leg coloration of ZFMK 85024 (E).

FIGURE 7. Habitat of Ameiva aggerecusans near Balsas, Amazonas, Peru.