Pristimantis petersioides, Carrión-Olmedo & Ron, 2021

Carrion-Olmedo, Julio C. & Ron, Santiago R., 2021, A new cryptic species of the Pristimantis lacrimosus group (Anura, Strabomantidae) from the eastern slopes of the Ecuadorian Andes, Evolutionary Systematics 5, pp. 151-175 : 151

publication ID

https://dx.doi.org/10.3897/evolsyst.5.62661

publication LSID

lsid:zoobank.org:pub:62F72992-7781-495B-8899-E72AE637ABD0

persistent identifier

https://treatment.plazi.org/id/F2204639-4B59-4071-A033-5BE637144BEE

taxon LSID

lsid:zoobank.org:act:F2204639-4B59-4071-A033-5BE637144BEE

treatment provided by

Evolutionary Systematics by Pensoft

scientific name

Pristimantis petersioides
status

sp. nov.

Pristimantis petersioides sp. nov.

Eleutherodactylus petersi Lynch & Duellman 1980 (in part)

Pristimantis petersi Batallas & Brito 2016

Pristimantis petersi Brito et al. 2017

Holotype.

(Figs 3 View Figure 3 , 4 View Figure 4 ) QCAZ58939, adult female from Ecuador, Morona Santiago Province, Sangay National Park, Sardinayacu (2.0983°S, 78.1555°W), 1406 m. Found in amplexus with QCAZ58940. collected by Daniel Rivadeneira and Santiago R. Ron on 21 January 2015.

Paratypes

(54: 39 adult males, 15 adult females). All individuals are adults unless otherwise noticed. All from Ecuador. Morona Santiago Province: Sangay National Park: QCAZ58871, female, QCAZ58944, male from Río Volcán (2.1008°S, 78.1559°W, 1345 m), collected by Daniel Rivadeneira, David Velalcázar, Javier Pinto, Francy Mora, Darwin Nuñez, Juan Sanchez, and Andrea Correa; QCAZ58936, 58939, QCAZ58941, females, QCAZ58940, 58942-43, males from Refuge 1 (2.0988°S, 78.1561°W, 1406 m), QCAZ58937-38, males from Chimerella lagoon (2.0885°S, 78.2069°W, 1650 m) collected by Daniel Rivadeneira, Francy Mora, Juan Sánchez and Andrea Correa; QCAZ58881, 58950, females, QCAZ58949 male from the proximities of Cormorant lagoon (2.0738°S, 78.2195°W, 1835 m) collected by Javier Pinto, David Velalcázar and Darwin Nuñez, QCAZ58880, 58951, males from El Enmascarado lagoon (2.0600°S, 78.2207°W, 1796 m) collected by Javier Pinto, David Velalcázar and Darwin Nuñez. in January 2015. QCAZ59166, female, QCAZ59167, 58945-48, males from Refuge 3 (2.0757°S, 78.2157°W, 1724 m), collected by Santiago Ron, Diego Paucar, Pablo Venegas, Pamela Baldeón, Marcel Caminer and Kunam Nucirquia; QCAZ59169-71, males from Cormorant lagoon (2.0738°S, 78.2195°W, 1835 m), collected by Santiago Ron, Diego Paucar, Pablo Venegas, Pamela Baldeón, Marcel Caminer and Kunam Nucirquia, in February 2015. Pastaza Province: QCAZ53227, female, from Anzu river (1.4177°S, 78.0485°W, 1272 m a.s.l), collected by Mauricio Ortega in May 2012. Llanganates National Park: QCAZ45846-50, 45892, 45898, males, from Challuwa Yacu river, Ankaku Reserve (1.2792°S, 78.0779°W, 2300 m) collected by Elicio Tapia and Silvia Aldás in October 2009; QCAZ66553, male, from Ankaku Reserve (1.2770°S, 78.0698°W, 2216 m) collected by Diego Almeida, Santiago Guamán, Darwin Nuñez, María Navarrete, Verónica Andrade, Angel Alvarado, Fernando Alvarado in January 2017, QCAZ59625, male, from Nuchimingue river (1.3626°S, 78.0582°W, 1350 m); QCAZ59456, male, from Yurugyacu river (1.3560°S, 78.0592°W, 1354 m); QCAZ59451, 59467-68, 59479, males, from Zarentza community (1.3556°S, 78.0597°W, 1363 m); QCAZ59458-59, females from near Yurugyacu river (1.3527°S, 78.0596°W, 1354 m); QCAZ59457, 59465 females, QCAZ59454-55, 59462-63, 59466, males from the ravines of Yurugyacu river (1.3523°S, 78.0597°W, 1419 m); QCAZ59470, 59472, females, QCAZ59471, 59473, males from Gustavo Ushpa house trail to Yurugyacu river (1.3430°S, 78.0574°W, 1221 m); QCAZ59461, female, from La paila waterfall (1.3397°S, 78.0594°W, 1360 m) collected by Daniel Rivadeneira, Francy Mora, Juan Carlos Sánchez, David Velalcázar, Darwin Nuñez and Javier Pinto in February 2015.

Referred specimens.

Napo Province: QCAZ46159, male, from Salcedo-Tena highway, km 60 (0.9847°S, 78.1928°W, 2253 m), collected by Elicio Tapia and Fernando Núñez in November 2009. Pastaza Province: QCAZ59452-53, 59460, 59464, juveniles from the ravines of Yurugyacu river (1.3523°S, 78.0597°W, 1419 m) collected by Daniel Rivadeneira, Francy Mora, Juan Carlos Sánchez, David Velalcázar, Darwin Nuñez and Javier Pinto in February 2015.

Suggested common name.

English: Sardinayacu’s Rain Frog. Spanish: Cutín de Sardinayacu

Diagnosis.

The assignment of the new species to the genus Pristimantis is based on the phylogeny (Fig. 1 View Figure 1 ). Pristimantis petersioides sp. nov. is characterized by the following combination of characters: (1) Skin on dorsum smooth to shagreen with or without scattered small tubercles, head with or without one interorbital small tubercle, skin of venter shagreened to weakly areolate; discoidal fold present, ill-defined; dorsolateral folds absent; (2) tympanic membrane and tympanic annulus present, round, its length 2/5 to 1/2 of eye diameter; its upper border weakly concealed by inconspicuous supratympanic fold; (3) snout rounded to truncate in dorsal view, truncate in lateral view, bearing a small rostral papilla; (4) interorbital space flat, broader than upper eyelid; upper eyelid with one distinct subconical tubercle surrounded by lower, indistinct rounded tubercles; cranial crests absent; (5) vomerine odontophores low to prominent, oblique, moderately separated, posteromedial to choanae; (6) males with prominent, subgular vocal sac and vocal slits; (7) first finger shorter than second; all fingers long, discs broadly expanded, rounded to truncate; all fingers bearing a hyperdistal tubercle (Fig. 4B View Figure 4 ); (8) fingers with narrow lateral fringes; (9) few ulnar tubercles; (10) no knee and heel tubercles, outer tarsal fold bearing one to three indistinct tubercles; (11) two metatarsal tubercles, inner oval, 3x the size of outer conical and elliptical metatarsal tubercle; supernumerary plantar tubercles numerous; (12) all toes with hyperdistal tubercles; toes with narrow lateral fringes; basal toe webbing absent, discs broadly expanded, Toe IV much longer than Toe III (disc on Toe III reaches proximal edge of penultimate subarticular tubercle on Toe IV, disc on Toe V exceeds the distal edge of penultimate subarticular tubercle on Toe IV), discs as expanded as those on fingers (Fig. 4A View Figure 4 ); (13) SVL 22.8 ± 1.4 mm (20.4-24.8 mm; n = 15) in females, 18.5 ± 1.5 mm (15.8-23.9 mm; n = 39) in males.

Comparison with other species.

Color comparisons are based on digital photos of live specimens, unless otherwise noted. Pristimantis petersioides sp. nov. is most similar to other species of the P. lacrimosus group, especially P. petersi (Lynch & Duellman, 1980), P. bromeliaceus (Lynch, 1979), P. lacrimosus ( Jiménez de la Espada, 1875), P. schultei (Duellman, 1990), P. pastazensis (Andersson, 1945), and P. rhodostichus (Duellman & Pramuk, 1999) (Fig. 5 View Figure 5 ). Pristimantis petersioides sp. nov. can only be distinguished from P. petersi by differences in advertisement calls. Call duration is shorter in P. petersioides sp. nov. 0.25 s (Table 3 View Table 3 ; 0.19-0.32 s; n = 3) than in P. petersi , 0.42 s (0.37-0.46 s; n = 2). Dominant frequencies also differ: 4430.79 Hz (4122-4837.22 Hz; n = 3) in P. petersioides sp. nov. and 3956.75 Hz (3836.67-4076.84 Hz; n = 2) in P. petersi . Call duration and dominant frequency are static call traits and, therefore, are less variable within species and most reliable to define species boundaries ( Köhler et al. 2017). Crucially, the new species and P. petersi are not sister species and are separated by large genetic distances: uncorrected pairwise p -genetic distances for gene 16S range from 7.9% to 8.4%. Pristimantis petersioides sp. nov. can be distinguished from P. bromeliaceus by snout shape (rounded to truncate in P. petersioides sp. nov. vs. subacuminate in P. bromeliaceus ), texture of ventral skin (weakly areolate in P. petersioides sp. nov. vs. coarsely areolate in P. bromeliaceus ), iris coloration (reddish coppery in P. petersioides sp. nov. vs. brown flecked with gold or bronze in P. bromeliaceus ), and by having an eyelid with one conical tubercle surrounded by lower tubercles (two to three non-conical tubercles in P. bromeliaceus ). Pristimantis petersioides sp. nov. differs from P. lacrimosus ( Jiménez de la Espada, 1875) in dorsal coloration (dark greenish brown to pale yellowish green in P. petersioides sp. nov. vs. golden brown in P. lacrimosus ), presence of eyelid tubercles and narrow lateral fringes (both absent in P. lacrimosus ), and size of outer metatarsal tubercle (3 × bigger than the inner metatarsal tubercle in P. petersioides sp. nov. vs. 5-6 × bigger in P. lacrimosus ). Pristimantis petersioides sp. nov. is also similar to P. rhodostichus and P. schultei from Peru and Ecuador. It can be distinguished from both by snout shape in dorsal view (rounded to truncate in P. petersioides sp. nov. vs. long acuminate in P. rhodostichus [Duellman & Pramuk, 1999] and acuminate in P. schultei ). It can be further distinguished from P. schultei by lacking heel tubercles (present in P. schultei ), and from P. rhodostichus by lacking red markings on the dorsum (present in P. rhodostichus , Duellman & Pramuk, 1999). Additionally, P. petersioides sp. nov. differs from P. pastazensis (Andersson, 1945) by snout shape in dorsal view (rounded to truncate in P. petersioides sp. nov. vs. subacuminate in P. pastazensis , Andersson, 1945), tubercles on upper eyelid (one distinct conical tubercle surrounded by lower, indistinct rounded tubercles in P. petersioides sp. nov. vs. several minute rounded tubercles in P. pastazensis , Andersson 1945), and skin of venter (weakly areolate in P. petersioides sp. nov. vs. coarsely granular in P. pastazensis , Andersson 1945). For further comparison see Table 4 View Table 4 .

Description of the holotype.

Adult female (QCAZ58939). Measurements (in mm): SVL 22.02; tibia length 12.07; foot length 10.72; head length 8.82; head width 9.09; eye diameter 2.96; tympanum diameter 1.35; interorbital distance 2.52; upper eyelid width 2.44; internarial distance 1.59; eye-nostril distance 2.59; tympanum-eye distance 0.71. Body slender; head slightly wider than long, wider than body; snout rounded to truncate with rostral papilla in dorsal view, truncate in lateral profile; canthus rostralis distinct, slightly curved in dorsal view; loreal region concave; interorbital space flat, no cranial crests; eye large, protuberant; upper eyelid about 97% of interorbital distance, bearing one subconical tubercle. Tympanic membrane and annulus distinct, rounded, with inconspicuous supratympanic fold, partially obscuring anterodorsal edge; horizontal diameter of tympanum about 13% of head length, separated from eye by a distance about one half tympanum length; choanae large, rounded, not concealed by palatal shelf of maxillary arc; dentigerous processes of vomers prominent, oblique, bearing a transverse row of five teeth; tongue big, elliptical, posterior border slightly notched, 40% of the anterior surface adherent to floor of mouth. Skin on dorsum smooth to shagreen; dorsolateral folds absent; skin on upper flanks bearing scattered low tubercles; skin on belly weakly areolate; skin on throat and chest smooth; discoidal fold ill-defined; skin in upper cloacal region shagreen. Forearms slender bearing low antebrachial tubercle and one subconical ulnar tubercle at the distal half of the forearm; fingers large and slender, all with broadly expanded pads, all fingers with discs; fingers bearing narrow lateral fringes; relative lengths of fingers I <II <IV <III; three subarticular tubercles on finger III (Fig. 4B View Figure 4 ), the most distal we refer as hyperdistal, all the tubercles well defined, round in ventral and lateral view; several supernumerary tubercles present, prominent at the base of the fingers and lower, indistinct at the palmar surface; palmar tubercle bifid, heart-shaped, about the same length and twice the width of elliptical thenar tubercle (Fig. 4B View Figure 4 ).

Hindlimbs slender; tibia length about 55% of SVL; upper surfaces of hindlimbs smooth; foot length about 48% of SVL, posterior surfaces of thighs smooth, ventral surfaces of thighs slightly areolate; knee and heel lacking tubercles; outer surface of tarsus bearing three low, inconspicuous tubercles, equally distributed along tarsus; toes bearing narrow lateral fringes; webbing between toes absent; discs on toes broadly expanded as those on fingers, rounded; relative lengths of toes: I <II <III <V <IV; Toe V much longer than Toe III (disc on Toe III reaches proximal edge of penultimate subarticular tubercle on Toe IV, disc on Toe V exceeds the distal edge of penultimate subarticular tubercle on Toe IV), subarticular tubercles rounded, simple, elevated; plantar surface with low supernumerary tubercles, bearing four subarticular tubercles (Fig. 4A View Figure 4 ), inner metatarsal tubercle prominent, elliptical, approximately 3x size of oval and conical outer metatarsal tubercle (Fig. 4A View Figure 4 ).

Color of holotype in preservative. (Fig. 3C, D View Figure 3 ) Background color pale grayish cream with scattered, irregular dark brown chevrons, head bearing dark brown supratympanic and canthal stripe, upper lip bearing ill-defined stripe formed by irregular dark brown dots; upper flanks bearing dark brown, irregular flecks and blotches densely distributed; venter, ventral surfaces of forearms and hindlimbs pale creamy white, chest and throat with diminutive dark brown dots uniformly distributed (visible under magnification); ventral surfaces of hands and foot with dense minute dark brown dots, posterior surfaces of thighs pale cream to dark brown; iris reddish coppery with fine, dense, black reticulation.

Color of holotype in life. (Fig. 3A, B View Figure 3 ) Dorsal surfaces yellowish green with scattered, irregular dark brown chevrons; canthal stripe and supratympanic fold black, upper flanks pale cream with dark brown irregular flecks and blotches; venter creamy white; axils pinkish white; ventral surfaces of limbs, thighs yellowish green; iris reddish copper with dark bronze faint horizontal streak and thin irregular black reticulations.

Variation in preservative.

(Fig. 6 View Figure 6 ) Adult males (15.79-23.93 mm) are smaller than adult females (20.42-24.81 mm). See Table 5 View Table 5 for measurements of the type series. Males bearing vocal slits and prominent subgular sac, lacking nuptial pads. Skin tuberculation is less noticeable than in live specimens, it can vary from dorsum completely smooth (e.g., QCAZ58943, 59171) to shagreen (e.g., QCAZ59456). Tubercles on flanks remain conspicuous when dorsum is shagreen (e.g., QCAZ59470, 59472) and also upper eyelids tubercles and interorbital tubercle are more evident when dorsum is shagreen or flanks are tuberculated (e.g., QCAZ59456, 59470). Dorsal background coloration in preserved specimens varies from uniform dark brown (e.g., QCAZ58951, 59451, 59461) to pale cream (e.g., QCAZ58881, 58936, 59166). Marks on dorsum varies from scattered, irregular dark brown chevrons that form a triangle extending from the ilium to the scapula (e.g., QCAZ58950, 59468), ill-defined, dark brown flecks and spots (e.g., QCAZ58948, 59472), pale cream middorsal bar from the snout to the cloaca (e.g., QCAZ59456), to black dorsolateral stripes suffused with supratympanic stripes (e.g., QCAZ58943, 59171), with or without dark interorbital bar.

Variation in life.

(Fig. 7 View Figure 7 ). Tuberculation pattern varies from dorsum completely smooth (e.g., QCAZ58943, 58951) to dorsum shagreen (e.g., QCAZ58938, 58939), some individuals bear scattered small tubercles on anterior half of dorsum (e.g., QCAZ58880) or have the dorsum densely tuberculated (e.g., QCAZ59463). When dorsum is tuberculated, flanks and limbs usually bear scattered tubercles more conspicuous than those in the dorsum. Similarly, the interorbital tubercle and upper eyelid tubercles are more prominent when the dorsum is tuberculated. There is extensive variation in dorsal coloration (Fig. 7 View Figure 7 ). Dorsum varies from dark greenish brown (e.g., QCAZ59471), bright orange (e.g., QCAZ58943), olive green (e.g., QCAZ58938), to pale yellowish green (e.g., QCAZ58941). Dark marks on dorsum vary from scattered dark brown flecks to irregular brown chevrons that form a triangle that extends from the ilium to the scapula, to ill-defined, dark brown flecks and spots (e.g., QCAZ58948, 59455). Some individuals bear bright orange blotches limited by dark brown contours (e.g., QCAZ58951, 59458), a bright orange middorsal bar that extends from the snout to the cloaca (e.g., QCAZ59456), black dorsolateral stripes suffused with supratympanic stripes (e.g., QCAZ58943). Bright orange to yellow with a darker contour interorbital stripe or bar may be present (e.g., QCAZ59455, 59458, 59462) or absent (e.g., QCAZ58943, 59456). Snout varies from dark greenish brown, pale yellowish green to bright orange (e.g., QCAZ59455, 59466, 59471).

Advertisement call.

Quantitative measurements of the advertisement call of Pristimantis petersioides sp. nov. (QCAZ58940) are shown in Table 3 View Table 3 . The call is a metallic click with an average duration of 0.25 s (0.19-0.32 s; n = 3; Fig. 8 View Figure 8 ). The amplitude peak occurs at 20-30 ms and then decreases gradually towards the end (Fig. 8 View Figure 8 ). The calls are repeated at a mean rate of 19.89 calls per minute (11.26-25.78; n = 3). Three or four harmonics are visible, but most of the energy is located on the first one. The dominant frequency (= fundamental frequency) is 4430.79 Hz (4122-4837.22 Hz; n = 3).

Distribution and natural history.

Pristimantis petersioides sp. nov. is known from six localities in the eastern Andean slopes of central Ecuador between 1221-2300 m (Fig. 9 View Figure 9 ). It inhabits the Eastern Andean Foothills Forest and Eastern Montane Forest natural regions (as defined by Ron et al. 2019). It has been recorded in primary forest and, less frequently, in secondary forest. Individuals were found during nocturnal surveys, usually perching on ferns, herbs, or Heliconia leaves, branches, or inside bromeliads up to 350 cm above the ground, usually near water bodies. Three amplectant pairs were found on January and February 2015 in Sardinayacu and Zarentza.

Etymology.

The specific epithet is a masculine noun in apposition. The suffix oides is derived from the Greek eidos meaning similar. The name makes reference to the similarity between the new species and its sister species, Pristimantis petersi .

Conservation status.

Four out of six known localities are inside National Parks (Sardinayacu in Parque Nacional Sangay and Ankaku, Zarentza and Salcedo-Tena road in Parque Nacional Llanganates); nonetheless, based on a vegetation cover map ( Ministerio del Ambiente 2018a) and a deforestation map 2016-2018 ( Ministerio del Ambiente 2018b), Zarentza is <1 km from deforested areas for agriculture. At the year of collection (2009) the locality at Salcedo-Tena highway was in a forested region with small, deforested patches at distances> 2.5 km (based on a 2008 deforestation map by Ministerio de Ambiente). Sardinayacu, refuge 3 occur> 6 km from pastures, while Sardinayacu, refuge 1 is <0.5 km from deforested areas for agriculture.

In Sardinayacu, this species was one of the most common during surveys (24 individuals found in 9 days by 13 people) which suggest it can be locally abundant. Brito et al. (2017) also reported abundant populations in the upper basin of the Upano river, Sangay National Park, Morona Santiago Province (referred both as " Pristimantis petersi " and also " P. aff. petersi "). Its extent of occurrence is 1402 km2 (based on a minimum convex polygon). Despite being locally abundant, we consider Pristimantis petersioides sp. nov. to be in the Red List category Vulnerable (VU) following B1, B2ab(iii) IUCN criteria because: (i) it is only known from six localities (sensu IUCN 2017), (ii) its Extent of Ocurrence is less than 5000 km2 (1433 km2); and approximately 9% of its Extent of Ocurrence has been affected by deforestation, human settlements and agriculture (Fig. 10 View Figure 10 ).

Remarks.

Pristimantis petersioides sp. nov. differs from P. sp. (QCAZ 60398, from Bombuscaro) by the snout shape (in dorsal view, rounded in P. petersioides sp. nov., subacuminate in P. sp. QCAZ60398), venter texture (weakly areolate in P. petersioides sp. nov.; coarsely areolate in P. sp. QCAZ60398), presence of small rostral papilla (absent in P. sp. QCAZ60398); furthermore, P. petersioides sp. nov. bears a complete, rounded tympanic annulus, weakly obscured posterodorsally by a thin supratympanic fold (tympanic annulus concealed posterodorsally by a thick supratympanic fold in P. sp. QCAZ60398). It differs from P. nankints by snout shape in dorsal view (rounded to truncate in P. petersioides sp. nov. vs. acuminate in P. nankints ).

Kingdom

Animalia

Phylum

Chordata

Class

Amphibia

Order

Anura

Family

Strabomantidae

Genus

Pristimantis

Loc

Pristimantis petersioides

Carrion-Olmedo, Julio C. & Ron, Santiago R. 2021
2021
Loc

Eleutherodactylus petersi

Carrión-Olmedo & Ron 2021
2021
Loc

Pristimantis petersi

Carrión-Olmedo & Ron 2021
2021
Loc

Pristimantis petersi

Carrión-Olmedo & Ron 2021
2021