Pristimantis miktos, Ortega-Andrade, H. Mauricio & Venegas, Pablo J., 2014

Ortega-Andrade, H. Mauricio & Venegas, Pablo J., 2014, A new synonym for Pristimantis luscombei (Duellman and Mendelson 1995) and the description of a new species of Pristimantis from the upper Amazon basin (Amphibia: Craugastoridae), Zootaxa 3895 (1), pp. 31-57 : 35-45

Pristimantis miktos sp. nov.

( Figs. 2 , 5 )

Eleutherodactylus luscombei —In part. Univ. Kansas Sci. Bull., 55: 354. Eleutherodactylus (Eleutherodactylus) luscombei — Lynch and Duellman, 1997, Univ. Kansas Mus. Nat. Hist. Spec. Publ., 23: 227.

Pristimantis luscombei — Heinicke, Duellman, and Hedges, 2007, Proc. Natl. Acad. Sci. USA, Suppl., 104: Table 2.

Pristimantis luscombei — Hedges, Duellman, and Heinicke, 2008, Zootaxa, 1737: 128.

Pristimantis luscombei — Duellman and Lehr, 2009, Nature und Tier Verlag: 190.

Pristimantis luscombei — Ortega-Andrade and Valencia, 2010, Herpetology Notes, 3: 251–256.

Holotype: QCAZ 53531, an adult female collected on 25 June 2012 at Juyuintza, S2.110, W76.190, 200 m altitude, by H. Mauricio Ortega-Andrade, Pastaza Province, Ecuador.

Paratypes: ECUADOR: Orellana: Obe oriental, S1.1, W75.87, 212 m, collected by H. M. Ortega-Andrade on 22 August 2005, specimens DHMECN 3365–66; Parque Nacional Yasuní, S0.99, W76.25, 270 m, collected by J. Valencia, specimens FHGO 5252–54. Pastaza: Bufeo, S2.19, W76.79, 311 m, collected by H. M. Ortega-Andrade on 5 June 2007, specimen DHMECN 4448; Juyuintza, S2.11, W76.19, 192 m, collected by H. M. Ortega-Andrade and F. Timias on 25 June 2012, specimens QCAZ 53528–30; Lorocachi, S1.63, W75.97, 195 m, collected by O. Torres-Carvajal, M.C. Terán, X. Cisneros on 20 February 1996, specimen QCAZ 10131. PERU: Loreto: Andoas, S2.35111, W75.81622, 182 m, collected by V. Duran on 1 March 2008, specimens CORBIDI 4653, 4934, 4941, 4946, 4952, 4962, 5043; Curaray Paiche, Lote 66, S2.01836, W74.96976, 179 m, collected by G. Gagliardi, specimen GGU 663; Curaray Paiche, Lote 67, S1.49719, W75.39673, 190 m, collected by G. Gagliardi, specimen GGU 476, 508, 511, 536; Iquitos, S3.75, W73.25, 94 m, collected by L. N. Cotlow, specimen MZUNAP 989; Jibarito, S2.73691, W76.03007, 211 m, collected by G. Chávez on 12 September 2008, specimen CORBIDI 6562; Jibarito, S2.73565, W76.03178, 211 m, collected by G. Chávez on 14 July 2009, specimen CORBIDI 6588; Nanay, Lote 123, S3.20457, W74.71207, 154 m, collected by G. Gagliardi, specimens GGU 807-808; San Jacinto, S2.33083, W75.86369, 169 m, collected by A. Delgado on 1 September 2008, specimen CORBIDI 1183; 1202; Shiviyacu, S2.48187, W76.08565, 218 m, collected by A. Delgado on 7 July 2009, specimens CORBIDI 6429-30.

Diagnosis. The new species is placed in the genus Pristimantis following our phylogenetic analyses (see above). Pristimantis luscombei is characterized by: (1) skin of dorsum shagreen with or without scattered low tubercles in females; males with dorsum shagreen with scattered tubercles or pustules, and a X-shaped scapular fold (sensu Duellman & Lehr 2009); dorsolateral folds absent; skin of belly areolate; discoidal fold barely evident; (2) tympanic annulus and membrane visible on skin, round, its length about two-thirds length of eye; (3) snout short, sub-acuminate in dorsal view, rounded in profile; lips not flared, canthus rostralis weakly concave in dorsal view, rounded in cross-section; (4) upper eyelid about 80% of inter-orbital distance, bearing one small non-conical tubercle; (5) dentigerous processes of vomer narrow, oblique, bearing 2‒3 small teeth; (6) males lack vocal slits, vocal sac; white nuptial excrescences are present on thumb; (7) fingers large and slender, first shorter than second; discs on outer fingers expanded, bluntly rounded, about 1.5x the width of digit proximal to pad; supernumerary tubercles large, rounded; (8) fingers lacking lateral fringes; (9) forearm in females bearing a single low, non-conical ulnar tubercle; males bearing two or three small non-conical tubercles; (10) heel bearing a single sub-conical tubercle; outer border of tarsus shagreen in females, bearing three or four small sub-conical tubercles in males; inner border of tarsus smooth; (11) two metatarsal tubercles; inner elliptical, about 5x the outer tubercle; supernumerary plantar tubercles absent or barely visible; (12) toes lacking lateral fringes; webbing absent; discs equal in size or slightly smaller than those on fingers; Toe V longer than Toe III; (13) in life, dorsum reddish–brown with some greenish orange stains in scapular region, with or without pale yellowish spots; snout with yellowish white reticulated blotches, upper lips with dark brown diagonal stripes; cream interorbital stripe or stains in some males. Groin yellowish-tan; anterior and posterior surfaces of thighs uniform brown. The belly is cream with minute brown flecks or brown mottling. Iris deep orange, finely reticulated with black. In preservation, all brown areas turn into dark brown to metallic green, with cream tubercles and dermal ridges. Dorsal surfaces of thighs with dark brown transversal stripes; anterior and posterior surfaces of thighs uniform brown. Snout cream, reticulated. Belly cream with minute brown flecks; (14) SVL in adult males 19.0±1.1 (17.7–21.3 mm); females with 27.9± 1.3 mm (26.7–29.2 mm).

Differences with other species of Pristimantis in the upper Amazon Basin that have brownish dorsum and a differentiated tympanum are listed in Table 1. The new species is most similar to P. altamnis ( Elmer & Cannatella 2008) , P. d e l i us ( Duellman & Mendelson 1995), P. l i br a r i us ( Flores & Vigle 1994), P. luscombei ( Duellman & Mendelson 1995) , P. kichwarum ( Elmer & Cannatella 2008) , P. matidiktyo ( Ortega-Andrade & Valencia 2012) and P. ockendeni ( Boulenger 1912) , being differentiated from all these species by having a deep orange iris, finely reticulated with black, easily distinguished in living specimens. In preserved specimens, the new species can be differentiated from P. luscombei , P. altamnis and P. kichwarum by lacking a thin W-shaped dermal ridge on scapular region. Also, from P. ki chw ar um by having a dark black canthal stripe, and by smaller size of P. miktos (females 23.6± 1.2 mm and males 17.9± 1.1 mm in P. k i ch w a r u m vs. females 28.6± 0.9 mm and males 19± 1.1 mm in P. m i k t os). Pristimantis altamnis is similar in size to P. m i k t os, but lacks ulnar tubercles and bears a weak tarsal fold. The skin texture is smooth in P. librarius and P. ockendeni , in contrast with the shagreen with scattered tubercles or pustules in the new species. Furthermore, both species have dorsal color pattern that includes inverted brown chevrons, in contrast with the reddish brown with or without pale yellowish spots or blotches in P. miktos . Also, P. ockendeni lacks tubercles on eyelids (present in the new species). Pristimantis miktos resembles P. delius and P. matidiktyo in having a shagreen dorsum, but it can be distinguished from those two species by lacking a tarsal fold and a by having a black canthal stripe. Furthermore, females of P. deli us commonly have a stripped dorsal pattern. Pristimantis miktos has tubercles or pustules on dorsum, which are absent in P. matidiktyo .

Furthermore, the latter species presents a characteristic bicolored iris that is yellowish silver and is heavily reticulated with black and has a median dark reddish stripe. Other Pristimantis in the Upper Amazon Basin differ from the new species by lacking a differentiated tympanum (P. m a r t i a e, P. carvalhoi , P. quaquaversus , P. imitatrix , P. croceoinguinis , P. acuminatus , P. tantanti and P. academicus ), by having contrasting colors in groin and hidden surfaces of limbs ( P. diadematus , P. lythrodes , P. orcus , P. altamazonicus , P. divnae and P. eurydactylus ), by having a greenish dorsum in life ( P. pseudoacuminatus , and P. paululus ), by having enlarged conical tubercles on eyelids ( P. orphonolaimus ) or by having a yellow interorbital bar and dorsolateral stripes ( P. aureolineatus ).

Description of holotype ( Fig. 5 ). Body slender; head wider than body; slightly longer than wide, about 40% of SVL; snout short, sub-acuminate in dorsal view, rounded in profile; distance from nostril to corner of eye slightly shorter than diameter of eye; canthus rostralis weakly concave in dorsal view, rounded in cross-section; lips not flared; internarial area not depressed, nostrils slightly protuberant, directed anterolaterally, situated about threequarters the distance from the eyes to the tip of the snout; interorbital area flat, IOD 37% of head width; eye large, protuberant, its diameter is about 2.5x depth of lip below eye and about 32% of head length; upper eyelid about 80% of inter-orbital distance; bearing a single, small non-conical tubercle; no interocular fold; cranial crests, absent. Tympanic annulus and membrane visible on skin; prostrictal tubercles, low, barely visible in preservative; choana small, triangular, not concealed by the palatal shelf of maxillary arc; dentigerous processes of vomer narrow, oblique, bearing 2‒3 small teeth, positioned posterior to level of choanae; tongue elliptical, posterior border notched, not adherent to the floor of the mouth in about 30% of its length.

Skin on dorsum shagreen with low granulated tubercles on flanks; no occipital ridges or dorsolateral folds; ventral surfaces of belly, chest, throat and thighs areolate; discoidal folds barely visible; no thoracic fold. Forearm slender; fingers large and slender, all with oval (broader than long) pads, Fingers III-IV with large pads, all fingers with large discs; pad on Finger III about 1.5x wider than narrowest portion of penultimate phalanx; disc on Finger I distinctive smaller than those on other fingers; relative length of Fingers I <II<IV<III; subarticular tubercles large, subconic; supernumerary tubercles low, elliptical; palmar tubercle bifid, 1.5x size of oval thenar tubercle; anterbrachial tubercle, small; a single ulnar tubercles are present on the posterior part of forearm; outer edge of forearm shagreen, tubercles present, small.

Hind limbs slender; tibia length in about 47% of SVL; knee lacking tubercles; heel with a single, sub-conical tubercle; foot length in about 64% of SVL; outer and inner border of tarsus shagreen; inner metatarsal tubercle oval, 5x size of round outer; supernumerary tubercles barely visible, rounded, small; subarticular tubercles subconical, rounded; toes lacking lateral fringes; webbing absent between toes; pads of Toes III −V large, in all other pads and discs of toes like those of fingers; relative lengths I<II<III<V<IV; Toe III extending to proximal edge of penultimate subarticular tubercle on Toe IV; Toe V extending to distal edge of ultimate subarticular tubercle on Toe IV. Vent opening puckered, shagreen, not extended, lacking tubercles on its border, located at upper level of thighs.

Measurements (in mm) of holotype. Specimen QCAZ 53531 is an adult female with following measurements: SVL=26.7; HL=10.72; HW=9.79; ED=3.72; IOD=3.63; EN=3.1; TD=1.16; TL=12.62; FoL=17.1. Proportions: HL/SVL=0.4; HW/HL=0.91; TL/SVL=0.47; FoL/SVL=0.64; EN/HL=0.29; ED/HL=0.35; IOD/ HW=0.37.

Variation. Measurements are listed on Table 2. Sexual dimorphism is evident in this species, males being smaller (19± 1.1 mm; 17.7–21.3 mm) than females (28.6± 0.9 mm; 27.9–29.2 mm). Furthermore males often have a more tuberculated dorsum, tarsus and heel, having a thick X-shaped dermal fold on scapular region (e.g. DHMECN 3365, QCAZ 53528, Fig. 6 ), and a pale yellow color in groin, compared with the shagreen dorsum and Measurements Pristimantis luscombei Pristimantis miktos sp. nοv.

Females (N =7) Males(N =4) Females(N =4) Males (N =8) creamy tan groin in juveniles and females. Some specimens may present yellow dots on dorsum (e.g. QCAZ 53528, 53529), but the proportional occurrence of this variation is in about 6% of the total specimens reviewed. In five paratypes, (CORBIDI 1202, 4941, 6562, 6588) the ventral coloration is paler (creamy white) with few scattered brown flecks or mottling; specimens CORBIDI 4946 and 6429 have the top of the snout and sides of the head pale brown and barely reticulated, differentiated from the well-defined cream reticulation on the snout of the other specimens.

Coloration in life ( Figs. 5 , 6 ). The dorsal sides of the body are dark brown to tan with dark blotches and/or yellow spots, and with faint, dark transverse bars on the hind limbs. During the day the coloration turns darker. The dorsum in juveniles tends to be reddish brown. The snout has reticulated white blotches, and there are no canthal or postorbital stripes, but lips are barred with dark brown stripes below the eyes. A cream interorbital stripe is present in some males. The groin is pale yellow with the anterior and posterior surfaces of thighs uniform brown. The belly is cream, densely stippled with brown flecks. The iris is deep orange, finely reticulated and bordered around with black.

Coloration in preservative. Dorsum dark brown to metallic green (e.g. DHMECN 4448), with cream tubercles and dermal ridges in males. Dorsal surfaces of thighs with dark brown transversal stripes; anterior and posterior surfaces of thighs uniform brown. Snout and interorbital stripe reticulated, pale cream. Belly cream with brown flecks. Darker coloration in preserved specimens could depend of the time in which each specimen was prepared as voucher.

Etymology. The specific name is derived from the Greek word “ miktos ” (“mixed together, blended”) and refers to the fact that this species was mixed with the type specimens of another one.

Natural history and distribution. Pristimantis miktos is known from five scattered localities along the Amazonian evergreen lowlands of Ecuador, in Orellana and Pastaza Provinces, and seven localities from Loreto Department in northern Peru, at elevations between 195 and 300 m a.s.l. The distribution area covers 44,196.7 km 2 in the upper Amazon basin ( Fig. 4 ). This rare species is a forest inhabitant that can be found perching at night on leaves (0.3– 1.5 m) such as those of heliconia or other low plants of terra firme forest. The mating call and reproductive behavior are unknown.

Figures

FIGURE 2. Specimen of Pristimantis miktos sp. nov. a) misidentified into the type series of P. luscombei (B − C). From left to right: (A) KU 222002, adult female; b) KU 222004, adult male; c) KU 222006, adult male. Note the dorsal and ventral pattern, the presence of a W-shaped fold on occiput (shown by the arrow in b) and the pointed tip of snout in Pristimantis luscombei, compared with P. miktos sp. nov.

FIGURE 4. Distribution map and occurrence areas (polygons) for Pristimantis luscombei and P. miktos sp. nov. in the upper Amazon Basin. Dark brown shaded colors represent areas above 1000 m above sea level.

FIGURE 5. Views of the holotype, in life and preservative, of Pristimantis miktos sp. nov., QCAZ 53531, from Juyuintza, Pastaza province, Ecuador. Note de distinctive deep orange iris and the reticulated cream pattern on snout in life. Photographs by H. M. Ortega-Andrade.

FIGURE 6. Dorsal and lateral views of living specimens of Pristimantis luscombei (a – b), an adult male (c-d) and adult female (e-f) of P. miktos sp. nov. Arrows show the location of a W-shaped dermal ridge in a male of P. luscombei, and an X-shaped dermal fold in a male of P. miktos (QCAZ 53530). Also note the more tuberculated dorsum and tarsus in the adult male of P. miktos (c-d), compared to the shagreen dorsum of the female holotype (e-f, QCAZ 53531). Both species can also be distinguished by their iris coloration, bronze and finely reticulated with black and with a median reddish stripe in P. luscombei, and deep orange with fine black reticulation in P. miktos.