Phrynopus apumantarum, Chávez & García-Ayachi & Catenazzi, 2023

Chavez, German, Garcia-Ayachi, Luis A. & Catenazzi, Alessandro, 2023, A new species of frog (Terrarana, Strabomantidae, Phrynopus) from the Peruvian Andean Grasslands, Evolutionary Systematics 7 (1), pp. 105-116 : 105

Phrynopus apumantarum sp. nov.

Figs 3A-E , 4A-H

Type material.

Holotype. Peru • Adult female; Huancavelica Department, Tayacaja Province, the vicinity of San Luis de Rabayoc; 12°10'36.65"S, 74°48'2.49"W; 3715 m; 19 Jun. 2019; L.A. García-Ayachi leg.; CORBIDI 20553 (Figs 3A-E , 4C, D ).

Paratopotypes. Peru • 3 ♀ adults, 4 ♂ adults, collected on 22 Feb. 2019 at the same place as holotype; L.A. García-Ayachi leg.; CORBIDI 20432-35, 20436-39 (Fig. 4A, B, E-H ) • 5 ♀ adults, 2 ♂ adults, collected with the holotype; CORBIDI 20551, 20555-58, 20552, 20554.

Diagnosis.

A species of Phrynopus having the following combination of characters:1) Skin on dorsum coarsely tuberculate, some tubercles enlarged and arranged longitudinally in paravertebral and dorsolateral rows, skin on venter coarsely areolate; discoidal fold absent, thoracic fold absent; postocular fold present, uncomplete dorsolateral ridges present; 2) tympanic membrane and tympanic annulus absent; 3) snout rounded in dorsal and lateral views; 4) upper eyelid with small rounded tubercles; narrower than IOD, cranial crests absent; 5) dentigerous process of vomers absent; 6) vocal slits and nuptial pads absent; 7) Finger I slightly shorter than finger II; tips of digit bulbous, rounded; 8) fingers without lateral fringes; 9) ulnar and tarsal tubercles absent; 10) heels without tubercles; 11) inner metatarsal tubercle rounded, about 1.5 times as large as ovoid outer metatarsal tubercle; supernumerary plantar tubercles absent; 12) toes without lateral fringes, basal webbing absent, toe V slightly longer than toe III, toe tips bulbous; 13) in life, dorsum grayish yellow with black or dark brown mottling and bluish-black or brown blotches, throat pinkish yellow, yellow or yellowish brown, venter grayish yellow with brown mottling and bluish-black blotches, groins grayish white with brown blotches; iris ash gray with black blotches and reticulations; (14) SVL 23.9-25.7 mm in males (n = 4), and 28.4-35.7 mm in females (n=4).

Comparisons.

The absence of tympanic membrane and tympanic annulus distinguishes Phrynopus apumantarum sp. nov. from P. auriculatus Duellman & Hedges, 2008, P. mariellaleo Venegas, Barboza, De la Riva & Padial, 2018 and P. peruanus Peters, 1873, the only three species in the genus with tympanic membrane and tympanic annulus. Also, P. apumantarum sp. nov. resembles externally to P. bufoides , but is easily distinguishable by lacking the discoidal fold (vs present), warts on dorsum absent (vs enlarged warts present), post ocular fold moderately developed (vs prominent), and by having dark canthal and post ocular stripe (vs absent). Furthermore, the dark mottling or blotches on dorsum makes P. apumantarum sp. nov. similar in appearance to P. barthlenae Lehr & Aguilar, 2002, P. horstpauli Lehr, Köhler & Ponce, 2000, P. miroslawae , P. tautzorum , and P. thompsoni Duellman, 2000. However, P. apumantarum is distinguished from them by the following characters (morphological features of the other of species in parenthesis): presence of a postorbital fold (vs absent in P. barthlenae , P. horstpauli , P. tautzorum , and P. thompsoni ), rounded tubercles on the upper eyelid (vs absent in P. horstpauli , P. tautzorum , and P. thompsoni ), having skin on venter coarsely areolate (vs areolate in P. barthlenae , P. horstpauli , P. miroslawae , and P. tautzorum ), lacking discoidal and thoracic fold (vs at least one of them present in P. barthlenae , P. horstpauli , P. miroslawae , and P. thompsoni ), and absence of tubercles on heels (vs present in P. barthlenae and P. miroslawae ). Only P. chaparroi from the other side of the Mantaro River dry valley (51.6 km airline from the type locality of the new species) and P. remotum Chávez, García-Ayachi & Catenazzi, 2020 from the northern Andes of Peru share with P. apumantarum sp. nov. a combination of characters consisting of head rounded, small tubercles on the upper eyelid, skin on venter areolate and the absence of discoidal and thoracic fold, however the lattest could be differentiated by having a bigger size with a maximum SVL in females of 35.7 mm (vs 32.2 mm in P. chaparroi , and 28.3 mm in P. remotum ), canthal and postorbital stripes present (vs absent in P. chaparroi ) a dorsum coarsely tuberculate (vs shagreen with small subconical tubercules in P. remotum ), tubercules on dorsum arranged longitudinally (vs scattered in all dorsum in P. chaparroi and P. remotum ), and heels without tubercles (vs rounded tubercles on heels in P. remotum ). Furthermore, P. apumantarum sp. nov. is similar to P. anancites Rodríguez & Catenazzi, 2017, P. capitalis Rodríguez & Catenazzi, 2017, and P. lapidoides Lehr & Rodríguez, 2017 in having a coarsely areolate or areolate skin on venter, however is differentiable from all of them by bearing tubercles on dorsum arranged paravertebrally and dorsolaterally. Also P. apumantarum has small rounded tubercles on upper eyelid (vs absent in P. anancites and P. capitalis ), skin on dorsum coarsely tuberculate (vs tuberculate in P. capitalis and P. lapidoides ), discoidal and thoracic folds absent (vs at least one of them present in P. anancites , P. capitalis , and P. lapidoides ), and Toe V slightly longer than toe III (vs toe V longer than toe III in P. capitalis ). Despite having a combination of dorsal tubercles arranged paravertebrally as well as dorsolaterally and skin on venter coarsely areolate makes P. apumantarum sp. nov. clearly distinct from the rest of congeners, we consider that P. badius Lehr, Moravec & Cusi, 2012, P. curator Lehr, Moravec & Cusi, 2012, P. daemon Chávez, Santa Cruz, Rodríguez & Lehr, 2015, P. dagmarae Lehr, Aguilar & Köhler, 2002, P. dumicola Rodríguez & Catenazzi, 2017, P. heimorum Lehr, 2001, P. kotosh Lehr, 2007, P. montium (Shreve, 1938), P. paucari Lehr, Lundberg & Aguilar, 2005, P. pesantesi Lehr, Lundberg & Aguilar, 2005, P Phrynopus unchog Lehr & Rodríguez, 2017, and P. vestigiatus Lehr & Oróz, 2012 which are species bearing dorsal ridges (or folds) and/or an areolate venter might not easily distinguished from the new species. Nevertheless, P. apumantarum sp. nov. can be differentiated by having a bigger size with females reaching SVL of 35.7 mm (vs 18.8-28.3 mm in P. badius , P. curator , P. daemon , P. dagmarae , P. dumicola , P. heimorum , P. kotosh , P. montium , P. paucari , P. unchog , and P. vestigiatus ), discoidal fold absent (vs present in P. paucari ), thoracic fold absent (vs present in P. badius , P. curator , P. daemon , P. dagmarae , P. dumicola , P. heimorum , P. kotosh , and P. unchog ), canthal stripe present (vs absent in P. daemon , P. dumicola , P. kotosh , P. paucari , P. unchog , and P. vestigiatus ), postorbital stripe present (vs absent in P. daemon , P. kotosh , P. paucari , P Phrynopus pesantesi and P. unchog ), postocular fold present (vs absent in P. dagmarae , P. kotosh , P. heimorum , and P. paucari ), tubercles on heels absent (vs present in P. dagmarae and P. vestigiatus ), and toe V slightly longer than toe III (vs toe V shorter than toe III in P. dumicola ; toe V slightly shorter than toe III in P. daemon and P. heimorum ). The rest of the species ( P. bracki Hedges, 1990, P. inti Lehr, von May, Moravec & Cusi, 2017, P. interstinctus Lehr & Oróz, 2012, P. juninensis (Shreve, 1938), P. kauneorum Lehr, Aguilar & Köhler, 2002, P. lechriorhynchus Trueb & Lehr, 2008, P. oblivious Lehr, 2007, P. personatus Rodríguez & Catenazzi, 2017, P. tribulosus Duellman & Hedges, 2008, and P. valquii Chávez, Santa Cruz, Rodríguez & Lehr, 2015) lack areolate skin on venter and/or tubercules on dorsum.

Description of the holotype.

Head as wide as body, wider than long, HW 130% of HL; HW 35% of SVL; HL 27% of SVL; snout short, rounded in dorsal and lateral views (Fig. 3A, E ), ED larger than E-N distance (E-N 75% of ED); nostrils protuberant, directed dorsolaterally; canthus rostralis slightly curved in dorsal view, rounded in profile; loreal region slightly concave; lips rounded; upper eyelid with small rounded tubercles; UEW narrower than IOD (EW 72% of IOD); postocular folds low, poorly developed, extending from posterior margin of upper eyelid to level of tympanic region (Fig. 3B ); tympanic membrane and tympanic annulus absent, tympanic re-gion without postrictal tubercles. Choanae small, triangular, close to but not concealed by palatal shelf of maxilla; dentigerous processes of vomers absent; tongue broad, about 1.5 as long as wide, not notched posteriorly, posterior half free; vocal slits absent.

Skin on dorsum coarsely tuberculate with enlarged tubercles arranged paravertebrally and dorsolaterally (Fig. 3A ); skin on flanks shagreen with scat-tered, low tubercles; skin on throat, chest and belly coarsely areolate (Fig. 3B ); discoidal fold absent, thoracic fold absent; cloacal sheath not distinct; cloacal region without tuber-cles. Outer surface of forearm with small rounded tubercles; outer palmar tubercle barely visible, low, ovoid, slightly smaller than ovoid inner palmar tubercle; supernumerary tubercles absent; subarticular tubercles low, ovoid, most prominent on base of fingers; fingers without lateral fringes; Finger I shorter than Finger II (Fig. 3C ); tips of digits rounded, bulbous, lacking circumferential grooves; nuptial pads absent.

Hind limbs long and robust, TL 31% of SVL; FL 37% of SVL; dorsal surface of hind limbs shagreen with scattered low tubercles; anterior surfaces of thighs shagreen with small few tubercles, poste-rior surfaces of thighs coarsely areolate; heel without tubercles; outer surface of tarsus without tubercles; outer metatarsal tubercle rounded and prominent, about as large as prominent ovoid inner metatarsal tubercle; supernumerary plantar tubercles absent; subarticular tubercles low, ovoid in dorsal view, most distinct on base of toes; toes without lateral fringes; basal webbing absent; toe tips bulbous, rounded, lacking circumferential grooves, about as large as those on fingers; relative lengths of toes: 1 <2 <3 <5 <4; Toe V slightly longer than Toe III (Fig. 3C, D ).

Measurements of the holotype

(in mm). SVL 34.3; tibia length 10.8; foot length 12.7; head length 9.3; head width 12.2; eye diameter 2.9; interorbital distance 3.3; upper eyelid width 2.4; internarial distance 2.6; eye-nostril distance 2.2.

Coloration of the holotype in life

(Fig. 4C, D ). Dorsum greyish yellow with dark brown mottling and bluish-brown enlarged blotches. Flanks dark brown with greyish yellow reticulations. Canthal and postorbital stripes brown. Upper lip bearing brown irregular spots. Arms and legs dorsally dark brown with greyish yellow reticulations. Throat and chest greyish yellow with pinkish brown blotches, belly greyish yellow with dark brown mottling. Groin, posterior surfaces of thighs, posterior surfaces of tibias, and dorsal surfaces of feet greyish white with brown blotches or spots. Iris ash grey with fine black reticulations.

Coloration of the holotype in preservative

(Fig. 3A-E ). Dorsum greyish cream with dark brown spots and blotches. Flanks the same color as dorsum, with brown mottling. Canthal and postorbital stripes dark brown. Upper lip with few pale brown spots. Arms and legs dorsally tan with dark brown blotches and spots. Groin greyish cream. Throat, chest, and venter creamy yellow and dark brown mottled. Ventral surfaces of hand and feet pinkish yellow. Iris bluish grey.

Variation.

All paratypes are similar in morphology to the holotype, but males have slightly wider heads than females (HW/SVL in males= 0.3-0.4 vs females=0.3), see Table 1 for variation in measurements and proportions. Main variations are noted on the dorsum coloration (Fig. 4A-H ) which consists of a dark brown background with black spots and enlarged blotches in male CORBIDI 20436; or of an olive-yellow background with dark brown enlarged blotches on scapular and sacral areas, and black spots on the head in female CORBIDI 20433, 20434, and 20435, and of a brownish yellow background with dark brown spots or blotches in male CORBIDI 20439. Also, postorbital stripe is interrupted in female CORBIDI 20435 and male CORBIDI 20437. Supralabial region varies from dark brown in male CORBIDI 20436 to olive yellow in male CORBIDI 20438, and brownish yellow in male CORBIDI 20439. Regarding venter coloration, the throat is usually pinkish yellow, yellow in female CORBIDI 20434, and yellowish brown in male CORBIDI 20436. Also, the belly lacks large dark blotches in female CORBIDI 20439 and bears the largest dark blotches arranged at the edge of the venter in male CORBIDI 20437.

Etymology.

The epithet Phrynopus apumantarum derives from the Quechua word apu (= mountain spirit), and from the name Mantaro which is the main river of the Valley where the new species was discovered. This name means the spirit of the Mantaro Mountains because the occurrence of the new species in the upper areas of that mountain ridge reminds the authors of the Inca legend that says Apus are always taking care of the Andes from the top of every valley in the region.

Distribution, Natural History, and Conservation status.

Phrynopus apumantarum sp. nov. is known only from the type locality at 3714 m a.s.l. (Fig. 1 ). All the specimens were found under rocks and moss, during daytime (around 10:00 am), in an Andean relicted patch of forest under rocks and moss, near a pasture area (Fig. 5 ). The vegetation consisted mainly of small bushes and epiphytes. No sympatric anurans were recorded during sampling, the only other vertebrate recorded was Wilsonosaura josyi which seemed to have diurnal habits, however, none of them was observed sharing the same stone with P. apumantarum sp. nov. In nearby areas, local farmers use the land to grow potatoes which involves burning the ground seasonally, an activity that seems to increase in frequency and that threatens the habitat of this species. Therefore, given its apparent small distribution range (less than 2000 km2 of occurrence), fragmented habitat, and the threats mentioned above which are further fragmenting the habitat at the type locality and nearby areas, we recommend the IUCN Red List Category VU 2ab (iii) for this species. Future field efforts in the area will be needed to confirm its persistence and the possible reduction of its population.

Figures

Figure 1. Map of the distribution of Phrynopus frogs. Type locality of P. apumantarum sp. nov. in orange star. Green circle: distribution area of P. mariellaleo; Red circle: distribution area of P. thompsoni; yellow circles show distribution area of: 1) Phrynopus mariellaleo, 2) P. thompsoni, 3) P. capitalis, 4) P. dumicola, 5) P. personatus, 6) P. anancites, 7) P. valquii, 8) P. remotum, 9) P. daemon, 10) P. vestigiatus, 11) P. lechriorhynchus, 12) P. kauneorum, 13) P. dagmarae, 14) P. interstinctus, 15) P. horstpauli, 16) P. heimorum, 17) P. miroslawae, 18) P. tautzorum, 19) P. barthlenae, 20) P. badius, 21) P. tribulosus, 22) P. pesantesi, 23) P. auriculatus, 24) P. bracki, 25) P. paucari, 26) P. juninensis, 27) P. bufoides, 28) P. kotosh, 29) P. montium, 30) P. peruanus, 31) P. oblivious, 32) P. inti, 33) P. chaparroi, 34) P. lapidoides, 35) P. unchog.

Figure 3. Holotype of Phrynopus apumantarum sp. nov. (CORBIDI 20553). A. Dorsal view of the body; B. Ventral view of the body; C. Ventral view of the right hand; D. ventral view of the right foot; E. Lateral view of the head. Scale bar: 10 mm (A-D); 5 mm (E).

Figure 4. Type series of Phrynopus apumantarum sp. nov. Dorsal (left column) and ventral (right column) view of the type series of Phrynopus apumantarum sp. nov. A, B. Female CORBIDI 20432; C, D. Female CORBIDI 20553 (holotype); E, F. Male CORBIDI 20438; G, H. Male CORBIDI 20439.

Figure 5. Landscape at the type locality of P. apumantarum sp. nov.