Pristimantis postducheminorum, Palacios-Rodríguez & Daza & Mazariegos-H & Rendón & Amézquita, 2022

Palacios-Rodríguez, Pablo, Daza, Juan M., Mazariegos-H, Luis A., Rendón, Ubiel & Amézquita, Adolfo, 2022, A new species of Pristimantis (Anura: Strabomantidae) with a colourful venter from the cloud forests of Colombian western Andes, Zootaxa 5092 (1), pp. 67-84 : 69-79

Pristimantis postducheminorum sp. nov.

Figures 3 –, 4 , 5 ; Table 2 .

Holotype. MHUA-A11550 ( Figs. 3 and 4 ). An adult female, at the Mesenia-Paramillo Nature Reserve (5.496º N, 75.889º W), about 1.5 km south of the field station at 2800 m.a.s.l., 14 km southwest of the municipality of Jardín, vereda La Mesenia, municipality of Andes, department of Antioquia, Colombia; collected on July 2, 2018, by Luis A. Mazariegos-H. and Ubiel Rendón.

Paratypes. ( Figs. 3 , 5 ) Three males ( ANDES-A4425 , MHUA-A11551 , MHUA-A12715 ), and five females ( ANDES-A4427 , ANDES-A4428 , MHUA-A11549 , MHUA-A12715 ), collected at the type locality, between June 2017 and October 2019 by Luis A. Mazariegos-H. and Ubiel Rendón. An unsexed specimen ( MHUA-A11313 ), El Centello Nature Reserve (5.504º N, 75.849º W, 2400 m.a.s.l.), vereda Macanas, municipality of Jardín, department of Antioquia, Colombia less than 5 km northeast (bearing 68º) from the type locality, collected on September 5, 2018 by Fredy A. Grisales .

Etymology. We propose the specific epithet postducheminorum as a patronym to honour Dr. Gerald Post, veterinary oncologist and conservation biologist, and his husband David Duchemin. Both are avid conservationists and supporters of non-profit organisations dedicated to raise awareness and take conservation actions to help biodiversity.

Definition and diagnosis. We assign the new species to the genus Pristimantis on the basis of the phylogenetic results ( Fig. 1 ). Pristimantis postducheminorum sp. nov. is characterised by (1) body dorsal surface of the skin with sparse conical tubercles, much coarser towards the posterior end of the dorsum, without any apparent distribution pattern; discoidal fold barely visible; dorsolateral folds absent; paravertebral folds absent; postocular folds short, extending posteromedially from the eyes, barely reaching the line connecting the axillae, often fragmented into pustules; lateral surfaces of the body intermediate between dorsum and belly, albeit more similar to the dorsum; all the ventral surfaces are areolate, including belly, proximal surface of the thighs, throat and chest; (2) tympanic membrane and tympanic annulus prominent; supratympanic folds present, arc-shaped, diagonal, and ventrally bordered by a diagonal black band; horizontal diameter of tympanum 40–50% of eye diameter ( Table 1 ); (3) snout rounded from both dorsal and lateral views ( Fig. 4 ); snout tubercle absent; interocular fold absent; (4) upper eyelid tubercle present and conical, often with 1–3 smaller subconical tubercles on the eyelid; 1–2 postrictal tubercles, subconical and low, ovoid at the base; cranial crests absent; (5) vomerine odontophores triangular in shape, oblique, and widely separated; choanae ovoid; (6) males with barely visible vocal slits; nuptial pads absent, very small and whitish testis; (7) finger I slightly shorter than finger II ( Fig. 4 ); webbing short and basal among the fingers; finger discs with pads, expanded and truncate (wider than long); (8) lateral fringes of fingers present; one subarticular tubercle in fingers I (thumb) and II, two on fingers III and IV; all subarticular tubercles low and rounded, and slightly oval on the base; thenar tubercle oval or somehow elongate; palmar tubercle oval; supernumerary tubercles in hand present, and small ( Fig. 4 ); (9) between 1–5 ulnar tubercles, subconical, not forming a fold, notorious in larger individuals, without a distinctive coloration; (10) heel tubercles present, as long as wide; (11) inner metatarsal tubercle longer than wide, and oval; outer metatarsal tubercle about half in area compared to inner metatarsal tubercle, and oval in shape; between 1–3 supernumerary tubercles at the base of toes II–IV ( Fig. 4 ); (12) toe V longer than toe III; toes without fringes but with barely noticeable basal webbing; toes I and II with a single subarticular tubercle; toes III and V with two subarticular tubercles; and toe IV with three subarticular tubercles; toe discs with pads, expanded and truncate ( Fig. 4 ); (13) in life ( Fig. 3 ) the dorsum is predominantly dark brown, with black marks of variable shape; throat cream, yellow, or orange, with V-shaped longitudinal black bars or dark blotches; belly and often legs conspicuously coloured, in shades of orange, yellow to reddish, sometimes lighter than throat; limbs brown, often with dark spots or traversed by dark bars; uniform and distinctive dark grey coloration in the inguinal area and in the concealed surfaces of the thighs; iris bronze to dark brown; (14) adults medium in size ( Table 1 ), SVL in males 22.5–23.2 mm (n = 3), SVL in females 27.5–30.3 mm (n = 5).

Comparison with related species. The new species is phylogenetically closest to P. satagius ( Lynch 1995) , to the sympatric P. ferwerdai ( Amézquita et al. 2019) , as well as to the clade formed by P. kelephus ( Lynch 1998) and P. calcaratus ( Boulenger 1908) ( Table 2 ). It is also phenotypically similar to P. orpacobates ( Lynch et al. 1994) , P. quicato ( Ospina-Sarria et al. 2011) , P. cremnobates ( Lynch & Duellman 1980) , and P. jubatus (García & Lynch 2006) . It can be distinguished externally from all these species but P. jubatus by the conspicuous orange, yellow or reddish cream ventral coloration (versus black, brown or cream in other species); ventral coloration is cream or yellow golden with brown or gray spotting in P. jubatus , but this species exhibits dorsolateral folds and finger lateral fringes, both of which are absent in P. postducheminorum sp. nov. It can also be distinguished by the uniformly dark grey coloration of groin and concealed surface of the thighs (versus brown with cream in P. satagius , black with white blotches in P. ferwerdai , with many pale spots in P. calcaratus , uniformly brown in P. kelephus , alternating dark and brown bars in P. orpacobates , white with dark bars in P. quicato , and pale yellow or yellow-cream with brown spotting in P. jubatus ). No other species of Pristimantis with conspicuous ventral coloration has been found at or near the study area. For a comparison of character states among similar species see Table 3 .

Description of the holotype ( Figs. 3 , 4 ).An adult female, 28.7 mm in snout-vent length (SVL). Head width 41% of SVL; 9% wider than long, head length 34.8% of SVL. Snout rounded in dorsal and lateral views; boreal region concave with very small tubercles; interorbital distance 94.1% of eye-to-nostril distance; canthus rostralis concave in dorsal view and angular in cross-section; eye-to-nostril distance 97.1% of eye-length. Upper eyelid width slightly narrower than IOD, 76.5% of IOD; upper eyelid with one distinctive large, conical tubercle and four smaller ones, cranial crest absent. Tympanic annulus prominent, its diameter 37.1% of eye diameter, supratympanic fold arcshaped, diagonal, and ventrally bordered by a diagonal black band, one postrictal tubercle subconical and low, ovoid at the base; choanae ovoid; vomerine odontophores triangular in shape, oblique, and widely separated; tongue longer than wide. Skin on dorsum granular with some conical tubercles sparsely and irregularly distributed; dorsolateral folds absent; ventral skin areolate, discoidal fold visible, throat with similar pattern as venter but slightly darker and more redish, with V-shaped dark bands; ulnar tubercles present, without forming a distinct fold; thenar tubercle elongate; supernumerary palmar tubercles present; subarticular tubercles visible; fingers with lateral fringes; finger I slightly shorter than finger II; finger discs with pads, expanded and truncate (wider than long), except for finger I, which is rounded; inner digits bearing much narrower discs; hind limbs moderate; tibia long 46.9% of SVL; foot long 41.1% of SVL; relative length of adpressed toes IV> V> III> II> I; tip of toe V extending to base of distal subarticular tubercle of toe IV; tip of toe III extending beyond distal border of penultimate subarticular tubercle on toe IV, but before last subarticular tubercle of toe IV; discs of toes smaller than discs on outer fingers, without lateral fringes; webbing basal; heel bearing small tubercles, one slightly larger and conical; subconical tubercles along outer border of tarsus; inner metatarsal tubercle longer than wide, and oval; outer metatarsal tubercle about half in area compared to inner metatarsal tubercle, and oval in shape; between 1–3 supernumerary plantar tubercles present, at bases of toes II–V; prominent subarticular tubercles.

Coloration of the holotype. ( Fig. 3 ). In life, the holotype dorsum was predominantly dark brown, with a mid dorsal yellowish line, and black marks of variable shape; the throat exhibited essentially the same pattern as the belly, but darker, more reddish, and with V-shaped longitudinal black bars; the belly and legs conspicuously coloured in white to reddish, with a mid dorsal ventral line; limbs with essentially the same pattern as the dorsum, except by the distinctive dark grey coloration in the concealed surfaces of the thighs; the flanks darker than the dorsum; the iris bronze to dark brown.

Variation of type series. ( Figs. 3 , 5 ). Morphometric variation among individuals of the type series is depicted in Table 1 . There is strong sexual dimorphism in body length, with males ( SVL = 22.8 ± 0.3 mm, N = 3 individuals) attaining 79% % of females’ body size (28.8 ± 1.0 mm, N = 5 individuals). No other measurement appears to differ among the sexes, once allometry is considered, but the low number of individuals preclude any formal statistical comparison. Among standard morphological traits, we found remarkable variation between 1–4 in the number of minor tubercles besides the eyelid tubercle, as well as in the shape of the thenar tubercle: elongate in the holotype ( MHUA-A11550 ), and a second female ( MHUA-A11549 ), but oval in other females and in all males. Regarding coloration, the dorsum of most individuals in the type series is predominantly dark but light brown in male MHUA- A12715 , and female MHUA-A12716 , always with irregular black marks. The ventral surface was yellow to orange in ANDES-A4428 and ANDES-A4427 , light orange in MHUA-A 1549 , and white to reddish in MHUA-A11550 (holotype) and MHUA-A11551 . Three out of the eight individuals exhibit a mid-ventral and only two a mid-dorsal whitish line; the holotype MHUA-A11550 and MHUA-A11551 exhibited both lines. The throat of three individuals was crossed by the oblique V-shaped anteromedial dark bars (two of them in Fig. 3 ). We found no sign of sexual dichromatism, but the sample size is too low at this point to infer any generalisation in this regard. In preservative (1–4 years in 70% ethanol), the dorsum looks dark grey with irregular black marks ( Fig. 5 ). Limbs are dark dorsally, and black with creamy areas ventrally. Fingers 1 and 2 are creamy yellow. The belly looks light orange, yellow or cream, with black blotches or reticulation. Both patterning and medial lines remain recognisable in preservative. The gular area looks lighter than in life. The concealed surfaces of the thighs and groin remain uniformly dark grey. The forelimbs they have a greyish green dorsal coloration and a creamy yellow ventral coloration; the limbs posteriors have a creamy yellow coloration on the ventral part of the femur .

Natural history, distribution, and conservation status. The specimens of Pristimantis postducheminorum sp. nov. were found sitting on the moss covering tree trunks, branches and roots, and on the outer surface of epiphyte bromeliads ( Fig. 6 ). No individual was seen calling, although a single-note, barely modulated, call was heard in the capture area and often led us to find males of this species. Individuals were far from any pool, puddle, or stream, and only syntopic with Pristimantis peraticus and another unidentified species of Pristimantis .

To the best of our knowledge, the species is known only from two localities separated by less than 4.5 km in straight line, both situated within protected forests, yet surrounded by severely fragmented habitats. The species seems also to be rare despite four intensive searches by three people, throughout one week each, at the type locality; the reserve has been also searched for this and other Pristimantis species during the rainy and dry seasons on five different years. Therefore, based on the known area of occupancy of less than 500 km 2, the number of known locations being less than five, and the low number of encountered mature individuals, we proposed to declare this new species as Endangered [IUCN; B2a, 2c. (IV)] until new information is gathered.

Figures

FIGURE 1. Phylogenetic analysis on the relationship between Pristimantis postducheminorum sp. nov. and related species of Pristimantis based on the mitochondrial gene 16S (see Supplementary Table 1). Numbers at nodes represent ultrafast bootstrap support after 5000 pseudoreplicates, replaced by green-filled circles when the values are above 95. The taxon composed by P. euphronides and P. shrevei was used as external group. Photos: P. ferwerdai and P. postducheminorum sp. nov. by Luis A. Mazariegos-H., and P. satagius by Juan M. Daza.

FIGURE 3. Variation in dorsolateral and ventral coloration among some individuals of the type series. From top to down: A. MHUA-A11550 (holotype), B: ANDES-A4428, C: MHUA-A11551, D: ANDES-A4427, E: MHUA-A 1549. Photographs not to scale.

FIGURE 4. Schematic lateral (A) and dorsal (B) views of the snout of Pristimantis postducheminorum sp. nov.; ventral view of the hand (C) and foot (D). All illustrations by Luis A. Mazariegos-H. based on his own photographs on the holotype (MHUA- A11550).

FIGURE 5. Representative examples of among-individuals variation in ventral colouration of Pristimantis postducheminorum sp. nov. after preservation in 70% ethanol during at least one-year. Regarding the gular area, individuals may lack patterning (A), or present a V-shaped band (C) or a blotched (B, D) pattern. Some keep the belly orange pigment (B), and some exhibit a mid-ventral white line (D). From left to right and top to down: MHUA-A 11549, ANDES-A4425, MHUA-A 11550, ANDES- A4428. Photographs not to scale.

FIGURE 6. General (above) and detailed (below) representative pictures of the habitat of Pristimantis postducheminorum sp. nov. in the cloud forests of the Colombian northwestern Andes. Individuals were found perched on the moss covering tree branches or (one) directly sitting on bromeliad leaves. Photos by Luis A. Mazariegos-H.

Tables

TABLE 3. Comparison of external features that allow the recognition of P. postducheminorum sp. nov. against the phylogenetically closest species of Pristimantis from the Colombian western Andes. Data from Lynch (1995, 1998), Amézquita et al. (2019), and Cuellar-Valencia & Bernal-Rivera (2020). Asterisks denote traits in which the new species differ from the other ones

Species	Ventral coloration	Concealed thighs	Snout in dorsal	Dorsal	Dorsum
		surface	view	folds	tubercles
P. postducheminorum	orange to pink reticula-	uniform dark grey	rounded	absent	uniform
sp. nov.	tion
P. satagius	cream with brown	brown with cream*	subacuminate*	present*	uniform
	reticulation*
P. ferwerdai	black with white	black with white	rounded	present*	uniform
	blotches*	blotches*
P. calcaratus	mostly cream*	many pale spots*	subacuminate*	absent	uniform
P. kelephus	pale gold with heavy	Hblack markings to black	uniformly brown*	rounded	absent	pale and in Hblack markings to black shaped figure*	shaped figure*
	Hblack markings to black				shaped figure*
	with cream to white
	spotting*

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