Pristimantis zorro, Rivera-Correa & Daza, 2020

Rivera-Correa, Mauricio & Daza, Juan M., 2020, Out of the blue: A new rain frog species of the genus Pristimantis (Anura Craugastoridae) from the northern Cordillera Central in Colombia, Zootaxa 4838 (1), pp. 83-101 : 85-90

Pristimantis zorro sp. nov.

( Figs. 2–4 )

Holotype. MHUA-A 8813 , adult male, Colombia, Departamento de Antioquia, Municipio de Guatapé, Vereda El Tronco (6.30199, -75.14165; 1860 m a.s.l.), collected on May 21, 2015 by Juan M. Daza.

Paratypes. MHUA-A 8814–8817 adult males; all collected along with the holotype . MHUA-A 11165–11167 , adult males; all collected at the type locality on April 9, 2017 by Carlos Marin . MHUA-A 12092 adult male; collected at the type locality on October 15, 2016 by Mauricio Rivera-Correa and Daniela Murillo . MHUA-A 12093 adult male; collected at the type locality on November 11, 2019 by Mauricio Rivera-Correa , Jaime Culebras , Alejandro Ramírez and Carlos Rivera . MHUA-A 12094 adult male; collected at the type locality on February 8, 2020 by Mauricio Rivera-Correa , Khristian Venegas , Eliza Patiño , Diego Botero and Hader Correa .

Diagnosis. We assigned the new species to the genus Pristimantis based on our phylogenetic results. The new species ( Figs. 2 A-H) is characterized by a combination of (1) skin texture of dorsum smooth, venter areolate; dorsolateral and discoidal fold absent; (2) tympanic membrane and tympanic annulus evident, supratympanic fold differentiated; horizontal diameter of tympanum 23–33% of eye diameter; (3) snout moderate in length, with small rostral papilla, subacuminate in dorsal view and truncate in profile; (4) tubercles on upper eyelids and cranial crests absent; (5) dentigerous process of the vomer present; (6) males with vocal slits and median subgular vocal sac; nuptial pads absent; (7) Finger I shorter than Finger II; discs broadly expanded and elliptical; (8) fingers with nar- row lateral fringes; (9) antebrachial and ulnar tubercles absent; (10) tubercles on heel very small and outer edge of tarsus absent; inner tarsal fold absent; (11) inner metatarsal tubercle oval, two-to-three times as long as round outer metatarsal tubercle; supernumerary plantar tubercles small and low, at the base of Toes III and IV; (12) toes with narrow lateral fringes; webbing absent; fifth toe longer than third; (13) in life, dorsum light green to green-yellow; well-defined canthal stripe; blotch covering the front of the face, including inter-nostrils area forming a facial mask; inter-orbital brown bar and supra-tympanic brown stripe present; blotches on the wrist of the hand, forming a bracelet ( Fig. 2 ); iris is copper with fine brown reticulation; yellow throat; venter cream; posterior surfaces of thighs and shanks yellow; (14) adults small, SVL in males 19.5–21.5 (20.5 ± 0.495, n = 11).

Description of the holotype. Adult male, head as wide as long; snout relatively short, acuminate in dorsal and truncate in lateral view, but with small conical papilla at tip (snout–eye distance 16% of SVL); canthus rostralis indistinct; loreal region slightly concave; nostrils directed anterolaterally, protuberant, inter-nostrils area slightly concave in dorsal view; interorbital area flat, as broad as upper eyelid; cranial crests absent; upper eyelid without tubercles; tympanic membrane and tympanic annulus distinct, round; supratympanic fold differentiated; tympanum diameter 26% of eye diameter; postrictal tubercles low, inconspicuous. Choanae small, nearly rounded, not concealed by palatal shelf of maxillary; dentigerous process of the vomer present, elliptical, low, with three teeth each; tongue longer that wide, posterior one-half free from floor of mouth. Texture of skin of dorsum, flanks and venter smooth, dorsolateral, thoracic and discoidal folds absent; cloacal sheath absent.

Forearm slender; radio–ulna length 20% of SVL; ulnar tubercles and ulnar fold absent; hand length longer than radio–ulna length (hand length 31% of SVL); fingers with narrow lateral fringes; relative lengths of fingers I <II <IV <III; palmar tubercle bifid, thenar tubercle oval, inconspicuous; subarticular tubercles round, low; supernumerary palmar tubercles present at the base of all fingers, low, inconspicuous; disc cover of Finger I slightly expanded, those of Fingers II–IV extensively expanded; outer discs of fingers as wide as those of toes; all disc covers with elliptical ventral pads defined by circummarginal grooves. Nuptial pads absent.

Hind limbs relatively slender; tibia length 56% of SVL; foot length 76% of tibia length; tarsal fold and tarsal tubercles absent; heel (tibia-tarsal articulation) without tubercles; toes with narrow lateral fringes; subarticular tubercles round, low; inner metatarsal tubercle oval, about 2x as long as wide; subconical outer tubercle; supernumerary plantar tubercles inconspicuous; disc covers slightly expanded; toes with defined pads; disc pads nearly ellipti- cal; relative lengths of toes I <II <III <V <IV; tip of Toe V reaching distal border of distal subarticular tubercle of Toe IV; tip of Toe III reaching proximal border of medial subarticular tubercle of Toe IV.

Coloration of the holotype. In life, the holotype of Pristimantis zorro sp. nov is yellow dorsally, with some dark brown blotches and spots and yellow-green in the supra-ocular region. The holotype has a well-defined canthal brown stripe covering the front of the face, extending to the inter-nostrils region and forming a facial mask. The inter-orbital brown bar and supra-tympanic brown stripe is present, extending towards the flanks to the middle of the body. The wrist of the hands is intensely pigmented in the dorsal region; the flanks and limbs have scattered brown spots; throat, axillae, undersides and posterior surfaces of thighs immaculate with light yellow coloration; venter is white; palmar and plantar side light yellow; ventral side of limbs and thighs light yellow without spots or marks. The iris is cooper with fine brown reticulation ( Fig. 2A ). In preservative, the yellow of the body turned into pale cream, both on the dorsum and on the flanks; the brown botches o and marks became darker almost black and dorsum show traces of very small black dots throughout the body, only perceptible to stereoscope. In addition, arm and legs cream with dark brown spots and blotches, cream belly without marks.

Measurements of the holotype (in millimeters). SVL: 20.1; HL: 7.5 HW: 7.7; ED: 3.0; END: 2.4; NSD: 0.9; IND: 1.7; AMD: 4.4; TD: 0.8; FAL: 4.0; FAB: 1.2; HAL: 62; THL: 10.7; TL: 11.3; TAL: 5.6; FL: 8.6; TFD: 1.0; FTD: 1.9.

Variation of type series. Pristimantis zorro sp. nov. has dorsum light yellow in (MHUA-A 8815, 8816) to green-yellow (MHUA-A 8814, 8817) and presenting conspicuous brown spots, blotches and marks with variably extension ( Fig. 2 ). Individuals have a well-defined canthal brown stripe and blotch covering the front of the face; in addition to a strong pigmentation in the inter-nostrils region forming a mask-like pattern. The extension and shape of the inter-orbital brown bar and supra-tympanic brown stripe vary between specimens, and is weakly stained in the inter-orbital region in MHUA-A 11165 ( Fig. 3 ) and in the supratimpanic region in MHUA-A 8816, and partially interrupted in MHUA-A 11165, MHUA-A 11167. The brown coloration of the marks on the wrist is less intense in MHUA-A 8814 and MHUA-A 8816. Additionally, in MHUA-A 8813, 8814 there are two spots in both the scapular and the urostil region. Variations in morphometric measurements are shown in Table 1.

Vocalization. The advertisement call of Pristimantis zorro sp. nov. consists of single-pulsed, short note lacking frequency modulation, with a duration of 0.109 ± 0.015 (0.062 –0.155) seconds ( Fig. 4A ). We observed up to three harmonics per note. The interval between notes is 1.258 ± 0.547 (0.179 –3.763) seconds (Table 3). Call rate ranges from 34 to 68 calls per minute. The dominant frequency is 2.954 ± 94.434 (2.842 –3.186 kHz), minimum frequency 2.855 ± 0.091 (2.670 –3.186) kHz, and maximum frequency 3.092 ± 56.584 (2.928 –3.273). In qualitative terms, the amplitude of note suddenly increases and it quickly falls into a funnel at the end of it ( Fig. 4B ).

Geographic distribution and natural history. Pristimantis zorro sp. nov. is known only from the type locality at elevations ca. 1860 m a.s.l., near the Peñol-Guatape hydroelectric reservoir, on the northeastern Cordillera Central, in Antioquia, Colombia ( Fig. 5 ). We found individuals on shrubs at 1.0 to 4.0 m from the ground, in open areas and on the side of the road next to mature forest. We observed and collected active frogs between 1830–2100 h. We heard calls at night, during both clear and full moon nights, and overcast and rainy nights. Reproductive activity of females, and other natural history characteristics remain unknown. Sympatric congeneric species include P. factiosus , P. helvolus , P. lemur , P. permixtus , P. aff. paisa P. aff. suetus , and P. aff. viejas .

Etymology. The specific name is a patronym in reference to the character El Zorro (fox in Spanish). El Zorro is the secret identity of Don Diego de la Vega, a fictional hero created in 1919 by pulp writer Johnston McCulley. The character has a distinctive black garb, coat, hat and a mask that covers the top of the head from eye level upwards. The name alludes to the facial mask of the new species.

Comparison with related species. Pristimantis zorro sp. nov. ( Fig. 6A ) is easily distinguished from most of its congeneric by its color pattern, having a light-green to green-yellow dorsum with well-defined canthal stripe, a blotch covering the front of the face, including inter-nostrils area forming a “mask”, an inter-orbital brown bar or blotches and supra-tympanic brown stripe. Another diagnostic feature that is present in P. zorro sp. nov. is having blotches on the wrist of the hand. Only two related species, P. moro ( Savage 1965) and P. schultei ( Duellman 1990) have a similar pattern on the head, with the “mask” and band to interorbital area in some individuals. However, P. moro has the upper eyelids and area from halfway between eyes to snout bright orange-red and P. schultei having upper eyelids and flanks with tubercles ( Duellman 1990, Beraún et al. 2014), absent structures in P. zorro sp. nov. Pristimantis pluvialis Shepack, von May, Tito and Catenazzi 2016 , having body reddish-brown ( Fig. 6B ), without interocular and canthal stripe and snout rounded in profile (dorsum light yellow to green-yellow; well-defined canthal stripe and snout truncate in profile in P. zorro ). Pristimantis pulchridormientes Chávez and Catenazzi 2016 , has bright red coloration ( Fig. 6C ) on groins and on the posterior surfaces of thighs and shanks, and dentigerous process of the vomer absent (surfaces of thighs and shanks are yellow and dentigerous process are present in P. zorro ). Pristimantis zorro sp. nov. superficially resembles P. bromeliaceus ( Lynch, 1979) and P. mendax ( Duellman 1978) which differs in having prominent tubercles on the eyelid, dorsum and flanks (absent in P. zorro sp. nov.), and P. olivaceus ( Köhler, Morales, Lötters, Reichle, and Aparicio, 1998) which has acuminate and protruding snout (subacuminate in dorsal view and truncate in profile in P. zorro sp. nov.). The “green” Amazonian clade composed by Pristimatis acuminatus , P. limoncochensis , P. padiali , and P. omeviridis have well-defined canthal stripe and some individuals also having supratympanic stripe, but lacking a differentiated tympanic annulus and tympanic membrane, which are covered by muscle ( Ortega-Andrade et al. 2015). Pristimantis enigmaticus has a differentiated tympanic annulus but lacks vocal slits and vocal sac Ortega-Andrade et al. (2015), both present in P. zorro sp. nov.

Figures

FIGURE 2. Adult males of Pristimantis zorro sp. nov. in life: (A) MHUA-A 8813, SVL 20.1 mm, holotype; (B) MHUA-A 8814, SVL 20.5 mm, paratype; (C) MHUA-A 8815, SVL 20.3 mm, paratype, adult male; (D) MHUA-A 8816, SVL 19.5 mm, paratype; (E) MHUA-A 8817, SVL 21.5 mm, paratype; (F) MHUA-A 11165, SVL 20.1 mm, paratype; (G) MHUA-A 11166, SVL 21.3 mm, paratype; (H) MHUA-A 11167, SVL 20.8 mm, paratype. Photos by Adriana Restrepo, Carlos Marín and JMD.

FIGURE 3. Paratype of Pristimantis zorro sp. nov. in preservative. MHUA-A 11165, SVL 20.1 mm, adult male. Photos by MRC.

FIGURE 4. Advertisement call of Pristimantis zorro sp. nov. (MHUA-A 8813, holotype). (A). Spectrogram; (B) Oscillogram; (C) Power spectrum. Photo by JMD.

FIGURE 5. Map showing the type locality of Pristimantis zorro sp. nov. and relatives. Pristimantis zorro sp. nov. (green dot) Antioquia, Colombia; P. pulchridormientes (blue dot) Huánuco, Perú; P. pluvialis (red dot) Cusco, Perú; Pristimantis olivaceus (CORBIDI 17473, orange dot) Cusco, Perú and Pristimantis sp (ROM 43978, purple dot) Potaro-Siparuni, Guyana.

FIGURE 6. Adult males of Pristimantis zorro sp. nov. and related species: (A) Pristimantis zorro sp. nov, paratype (MHUAA12093); (B) Pristimantis olivaceus ZFMK 67132, SVL 19.7 mm, paratype; (C) Pristimantis pluvialis CORBIDI 11862, SVL 20.5 mm, paratype; (D) Pristimantis pulchridormientes CORBIDI 15565, adult male. Photos: (A) MRC; (B) Jörn Köhler; (C) Alessandro Catenazzi; (D) Germán Chávez.