Pristimantis cajanuma, Urgiles, Veronica L., Szekely, Paul, Szekely, Diana, Christodoulides, Nicholas, Sanchez-Nivicela, Juan C. & Savage, Anna E., 2019

Urgiles, Veronica L., Szekely, Paul, Szekely, Diana, Christodoulides, Nicholas, Sanchez-Nivicela, Juan C. & Savage, Anna E., 2019, Genetic delimitation of Pristimantis orestes (Lynch, 1979) and P. saturninoi Brito et al., 2017 and description of two new terrestrial frogs from the Pristimantis orestes species group (Anura, Strabomantidae), ZooKeys 864, pp. 111-146 : 123-129

Pristimantis cajanuma sp. nov. Figs 5 , 6 , 7 , 8

Type material.

Holotype. MUTPL 346 ( Figs 5 - 7 ), field no. SC 159, adult female from Ecuador, Loja Province, Loja canton, Cajanuma entrance to the Podocarpus National Park, on Los Miradores trail (4.1176S, 79.1663W; datum WGS84), 3022 m above sea level, collected by Diana Székely and Paul Székely on 28 June 2018.

Paratypes ( Fig. 8 ) 16 specimens collected in the type locality: MUTPL 343 (SC 156) an adult female and MUTPL 344 (SC 157) a juvenile (4.1170S, 79.1668W; datum WGS84), 2974 m, MUTPL 345 (SC 158) a juvenile (4.1176S, 79.1663W; datum WGS84), 3022 m, MUTPL 347 (SC 160) an adult female and MUTPL 353 (SC 166) a subadult male (4.1177S, 79.1658W; datum WGS84), 3042 m, and MUTPL 352 (SC 165) a subadult male and MUTPL 355 (SC 168) an adult male (4.1177S, 79.1647W; datum WGS84), 3098 m collected by Diana Székely and Paul Székely on 28 June 2018; MUTPL 573 (SC 331) a subadult female (4.1166S, 79.1691W; datum WGS84), 2890 m collected by Diana Székely and Paul Székely on 09 December 2018; MUTPL 583 (SC 903) an adult female and MUTPL 584 (SC 904) a subadult female (4.1167S, 79.1690W; datum WGS84), 2883, MUTPL 588 (SC 908) and MUTPL 592 (SC 912) two juveniles, MUTPL 589 (SC 909) and MUTPL 591 (SC 911) two subadult females, and MUTPL 593 (SC 913) and MUTPL 594 (SC 914) two adult males (4.1169S, 79.1666W; datum WGS84), 2984 m collected by Diana Székely and Paul Székely on 05 January 2019.

Diagnosis.

Pristimantis cajanuma is a small species distinguished by the following combination of traits: (1) skin on dorsum shagreen; skin on venter areolate (trait more visible in life); discoidal fold weak; dorsolateral folds present; low middorsal fold present; (2) tympanic membrane absent but tympanic annulus evident, its length about 45% of the length of eye; supratympanic fold present; (3) snout short, subacuminate in dorsal view, rounded in profile; canthus rostralis concave in dorsal view, angular in profile; (4) upper eyelid bearing several small tubercles, about 60% IOD in females and 65% IOD in males; cranial crests absent; (5) dentigerous processes of vomers prominent, triangular, without space between the processes; each processes bearing 4 to 7 teeth; (6) males with subgular vocal sac and vocal slits; nuptial pads absent; (7) Finger I shorter than Finger II; discs on fingers expanded, rounded; circumferential grooves present; (8) fingers lacking lateral fringes; subarticular tubercles prominent; supernumerary palmar tubercles present, rounded, smaller than subarticular tubercles; palmar tubercle bifurcated (partially divided distally); thenar tubercle oval; (9) small, inconspicuous, ulnar tubercles present (trait more visible in life); (10) heel with small tubercles; outer edge of tarsus with a row of small tubercles; inner tarsal tubercles coalesced into a short tarsal fold; (11) inner metatarsal tubercle broadly ovoid, about 2 × round, subconical (in profile) outer metatarsal tubercle; supernumerary plantar tubercles present; (12) toes lacking lateral fringes; webbing basal; Toe V slightly longer than Toe III; discs on toes expanded, rounded, about same size as those on fingers; circumferential grooves present; (13) in life, dorsum of various shades of brown, gray or sometimes green, with or without darker bands or bars; flanks various shades of brown or gray, usually lighter than the dorsum coloration; venter light gray with or without dark flecks; groin, anterior and posterior surfaces of thighs, concealed shanks and axillae are black enclosing large white spots; iris bronze with a reddish broad median horizontal streak, and with fine black reticulations; SVL 17.6-22.1 mm in adult females (19.8 ± 1.81 SD, N = 8) and 14.4-16.4 mm in adult males (15.4 ± 0.83 SD, N = 5).

Comparison with similar species.

Pristimantis cajanuma is morphologically similar to its closest relatives, the species from the recently redefined P. orestes group (sensu Brito et al. 2017), but its characteristic morphological features readily distinguish it from all resembling species. Pristimantis cajanuma is most similar to P. orestes sensu stricto but can be easily distinguished by having evident dorsolateral folds (absent in P. orestes ), a shagreen skin on dorsum (finely tuberculated in P. orestes ), broader discs on the fingers and toes (e.g. width of disc on Finger III in P. cajanuma : 0.8-1 mm, N = 3; in P. orestes : 0.6-0.7 mm, N = 3), palmar tubercle bifurcated, only partially divided distally (completely divided into a larger and a smaller tubercle in P. orestes ) and by the more widespread black coloration in the groin and concealed shanks ( Fig. 9 ). Its sister species, P. andinognomus is significantly smaller (females up to 17 mm, males up to 14 mm; Lehr and Coloma 2008), has the Toe V much longer than Toe III (Toe V slightly longer than Toe III in P. cajanuma ) and lacks the typical black enclosing large white spots coloration of the groin, anterior and posterior surfaces of thighs, concealed shanks and axillae of P. cajanuma .

Pristimantis simonbolivari has a similar coloration of the groin, anterior and posterior surfaces of thighs, concealed shanks and axillae but lacks dorsolateral folds (present in P. cajanuma ) and its venter coloration is darker, orange or brown (light gray in P. cajanuma ). Pristimantis saturninoi and P. quintanai sp. nov. also have similar coloration of the groin, thighs and shanks but P. saturninoi has a black or blackish-amber venter (venter light gray in P. cajanuma ) and green iris (bronze in P. cajanuma ). Pristimantis quintanai sp. nov. is different by having a finely tubercular dorsum skin (shagreen in P. cajanuma ), and by having a black, reddish-brown or reddish-cream venter coloration.

All other species of the P. orestes group (sensu Brito et al. 2017) lack the typical coloration of the groin, thighs, shanks and axillae of P. cajanuma : Pristimantis bambu has large yellow spots; P. mazar has a reticulated pattern, P. tiktik presents a black reticulum in the females and whitish/pinkish yellow coloration in the males and P. muranunka shows a brown or dark brown uniform coloration.

Description of holotype.

Adult female (MUTPL 346) ( Figs 5 - 7 ) with head narrower than body, wider than long, HL 92% of HW, HW 36% of SVL; HL 33% of SVL; snout short (snout to eye distance 16% of SVL), subacuminate in dorsal view, rounded in profile ( Fig. 7A, B ); canthus rostralis concave in dorsal view, angular in profile; loreal region flat; ED notably greater than eye-nostril distance; nostrils not protuberant; lips not flared; cranial crests absent; upper eyelid bearing several small tubercles (one slightly larger than the others), width of upper eyelid 64% of IOD; half of tympanic annulus evident ( Fig. 7B ), oval (slightly higher than wider), its upper and posterodorsal part obscured by rounded supratympanic fold; tympanic membrane absent; diameter of tympanum 52% of the length of eye; postrictal tubercles are fused and form a short ridge situated posteroventrally to tympanic annulus; choanae small, round, partially concealed by palatal shelf of maxillary arch; dentigerous processes of vomers prominent, triangular in outline, much larger than the choanae, without space between the processes, each bearing 4 or 5 teeth; tongue 1.5 × as long as wide, slightly notched posteriorly, posterior half not adherent to floor of mouth.

Skin on dorsum shagreen, that on flanks is finely tuberculated; thin, low middorsal fold starting at tip of snout and ending at cloaca; long, continuous dorsolateral folds present ( Fig. 6A ); skin of throat shagreen, that on chest and belly areolate; discoidal fold weak, barely visible ( Fig. 6B ); ornamentation in cloacal region absent.

Ulnar tubercles small, inconspicuous (trait more visible in life); outer palmar tubercle inconspicuous, bifurcated (partially divided distally); thenar tubercle oval; subarticular tubercles prominent, round and subconical in section; supernumerary palmar tubercles rounded, smaller than subarticular tubercles; fingers lacking lateral fringes; Finger I shorter than Finger II; discs on fingers expanded, rounded; all fingers bearing pads well defined by circumferential grooves ( Fig. 7C ).

Hindlimbs short; TL 50% of SVL; FL 47% of SVL; heel with small tubercles (one slightly larger than the others); outer edge of tarsus with a row of small tubercles (trait more visible in life); inner edge of tarsus bearing a short fold; inner metatarsal tubercle broadly ovoid, about 2 × round and subconical (in profile) outer metatarsal tubercle; subarticular tubercles prominent, round and subconical in section; plantar supernumerary tubercles rounded, smaller than subarticular tubercles; toes lacking lateral fringes; webbing basal; discs on toes expanded, rounded, about same size as those on fingers; toes with ventral pads well defined by circumferential grooves; relative length of toes I <II <III <V <IV; Toe V slightly longer than Toe III (tip of Toe III not reaching the penultimate subarticular tubercle on Toe IV, tip of Toe V not reaching the proximal edge of distal subarticular tubercle on Toe IV) ( Fig. 7D ).

Measurements of holotype.

SVL 20.6; HW 7.5; HL 6.9; IOD 2.4; internarial distance 1.7; upper EW 1.5; ED 2.3; eye-nostril distance 1.8; snout to eye distance 3.2; TD 1.2; TL 10.2; FL 9.7.

Body mass of holotype: 1.01 g.

Coloration of holotype.

In life ( Fig. 5 ) the dorsum is brown with dark mottling and with the dorsolateral folds blackish-dark brown. Flanks grayish-brown with white flecks. Dorsal surfaces of hindlimbs and arms the same color as the dorsum but with dark brown transverse bars. The head bears blackish-dark brown canthal, labial and supratympanic stripes. The throat is whitish gray and the venter is brownish-gray with white flecks. Groin, anterior and posterior surfaces of thighs, concealed shanks and axillae are black enclosing large white spots. The dorsal and ventral surfaces of the hands and feet are reddish-orange. The iris is bronze with a reddish broad median, horizontal streak, and with fine black reticulations.

In preservative ( Figs 6 , 7 ) the dorsum is brownish gray and the flanks whitish gray with white flecks. All the blackish-dark brown coloration of the dorsolateral folds, canthal, labial and supratympanic stripes in life became dark gray in preservative. Also, the black enclosing the large white spots of the groin, anterior and posterior surfaces of thighs, concealed shanks and axillae in life turned to dark gray in preservative. The dorsal and ventral surfaces of the hands and feet are whitish gray.

Variation.

Morphometric variation is shown in Table 4. The dorsolateral folds were fragmented in some of the specimens ( Figs 8E, G, I , 9B ) and thus not so evident, but all encountered individuals (probably more than 50) had dorsolateral folds. Pristimantis cajanuma displays a considerable variation in the dorsal coloration ( Figure 8 ). We encountered individuals with a general gray ( Fig. 8A, E, F, I, K ), light brown ( Fig. 8G ), dark brown ( Fig. 8D, L ), light brown with a dark brown middorsal band ( Fig. 8B, H ) and even green ( Fig. 8C, J ) coloration. Some of the individuals had chevrons on the dorsum ( Fig. 8E ) and/or dark transverse bars on the flanks and limbs ( Fig. 8E, I, J ), white or yellowish dorsolateral folds ( Fig. 8A, C, J ), white middorsal fold ( Fig. 8I ) and even completely whitish-yellow head ( Fig. 8K ). As for the sexual dimorphism, besides the size difference (the males are significantly smaller), the only identified coloration difference is that the males are lacking the characteristic large white spots enclosed by black of the groin, anterior and posterior surfaces of thighs, concealed shanks and axillae. From the encountered individuals, only the specimen MUTPL 353 had a similar coloration of the groin, but significantly fainter.

The dorsolateral folds are already visible in the juveniles ( Fig. 8F, G, H ), but the large white spots enclosed by black in the groin, anterior and posterior surfaces of thighs, concealed shanks and axillae are not so conspicuous and probably become darker and more evident as the animals mature. The identity of all the specimens was confirmed molecularly using the 16S mitochondrial gene.

Etymology.

The specific epithet cajanuma (in Quechua language " cajan " means cold and " uma " peak, or head, in other words the cold peak, referring to the cold climate of the area) is used as a noun in apposition and refers to the region where the species is found. Cajanuma is the highest entrance to the Podocarpus National Park, which is one of the largest and most diverse protected area from Ecuador. By naming this species cajanuma we also want to honor and recognize the Podocarpus National Park rangers for their extraordinary and tireless work protecting this incredible reserve.

Distribution and natural history.

Pristimantis cajanuma is known only from the Cajanuma entrance to the Podocarpus National Park, in an altitudinal range between 2882 and 3097 m a.s.l. in a Mountain Cloud Forest ecosystem. All specimens were encountered during the night, perching on the vegetation (usually at 10-40 cm above the ground), near the Los Miradores trail. No calling males were encountered. Other sympatric frog species include Pristimantis andinognomus , P. vidua and an undescribed species of Pristimantis .

Conservation status.

Even though Pristimantis cajanuma is currently known only from the type locality in the Podocarpus National Park, we recommend that this species to be categorized as Near Threatened following the IUCN criteria. This is due the fact that the species is locally abundant and its habitat does not face any major threats (because it is situated within a national protected area). However, at present its distribution is limited to only one locality, therefore there is some level of threat.

Figures

Figure 5. Holotype of Pristimantis cajanuma sp. nov. in life. A dorsolateral view B ventral view.

Figure 6. Holotype of Pristimantis cajanuma sp. nov. in preservative, adult female MUTPL 346: A dorsal view B ventral view C lateral view.

Figure 7. Holotype of Pristimantis cajanuma sp. nov. in preservative, adult female MUTPL 346: A dorsal view of head B profile view of head C palmar surfaces D plantar surfaces.

Figure 8. Color variation of Pristimantis cajanuma sp. nov. in life. A-E females: A MUTPL 343 B MUTPL 591 C MUTPL 347 D MUTPL 583 E MUTPL 584; F-H juveniles: F MUTPL 345 G MUTPL 588 H MUTPL 592 I-L males: I MUTPL 353 J MUTPL 352 K MUTPL 355 L MUTPL 594.

Figure 9. Morphological differences between Pristimantis orestes sensu stricto (A, C, E) and P. cajanuma sp. nov. (B, D, F): whitish gray iris (A) vs. bronze iris (B) dorsolateral folds absent (C) vs. dorsolateral folds present (D); and limited black coloration in the groin and concealed surfaces of shanks (E) vs. widespread black coloration (F).