Pristimantis andinogigas, Yanez-Munoz, Mario H., Veintimilla-Yanez, David, Batallas, Diego & Cisneros-Heredia, Diego F., 2019

Yanez-Munoz, Mario H., Veintimilla-Yanez, David, Batallas, Diego & Cisneros-Heredia, Diego F., 2019, A new giant Pristimantis (Anura, Craugastoridae) from the paramos of the Podocarpus National Park, southern Ecuador, ZooKeys 852, pp. 137-156 : 137

Pristimantis andinogigas sp. nov. Figures 1, 2, 3, 4, 5

Pristimantis grp. orcesi : L Aguirre Mendoza et al. 2015: 173, 180; Z Aguirre Mendoza et al. 2017: 534-535.

Common names.

English: Giant paramo rainfrog. Spanish: Cutín Gigante de Páramo.

Holotype.

Adult female; ECUADOR; provincia de Loja, Parque Nacional Podocarpus, Cajanuma; 4.108346°S, 79.162046°W, 3313 m alt.; 27 January 2010; David Veintimilla-Yánez and Karen Salinas leg.; DHMECN 10984 (field number DVY 057).

Paratypes.

Same collection data as for holotype; DHMECN 10985-6, adult males, 09 December 2009; DHMECN 10996, adult female, and DHMECN 10991-2, adult males, 10 December 2009; DHMECN 10993-4, adult males, 06 January 2010; DHMECN 10998-9, adult males, 06 January 2010; DHMECN 11000, adult male, 07 January 2010; DHMECN 11005, adult male, 13 January 2010; DHMECN 11008, adult male, 14 January 2010; DHMECN 11010-1, adult males, 27 January 2010; DHMECN 11012-13, 11115, adult males, 31 March 2010; DHMECN 11016, adult male, 06 April 2010; subadult males: DHMECN 10997, 06 January 2010; DHMECN 11001, 07 January 2010; subadult females: DHMECN 10995, 06 January 2010; DHMECN 11002, 07 January 2010; DHMECN 11006, 13 January 2010; DHMECN 11007, 14 January 2010; DHMECN 11018, 12 April 2010; DHMECN 11021, 22 April 2010; juveniles: DHMECN 10987-8, 10990, 09 December 2009; DHMECN 10989, 10 December 2009; DHMECN 11003-4, 13 January 2010; DHMECN 11009, 26 January 2010; DHMECN 11014, 31 March 2010; DHMECN 11017, 07 April 2010; DHMECN 11019, 14 April 2010; DHMECN 11020, 19 April 2010.

Diagnosis.

A new species of Pristimantis diagnosed by the following combination of characters: (1) Skin on dorsum porous, thick and glandular, with large, flat, glandular warts on flanks; dorsolateral folds absent; thick glandular patch on supra/postympanic region, and on dorsal surfaces of humeral, femoral, tibial and tarsal regions; glandular folds in wrists; skin on venter areolate; discoidal fold weakly defined; (2) tympanic membrane and tympanic annulus prominent; tympanic annulus rounded, 36% of eye length, with posterior margin in contact with supratympatic glandular patch; (3) snout rounded in dorsal view; rounded to slightly protruding in lateral view; (4) upper eyelid without tubercles, IOD wider than upper eyelid; cranial crests absent; (5) dentigerous processes of vomers present, oblique, moderately separated, posteromedial to choanae, with 4 to 5 teeth; (6) males with cream-coloured nuptial pads on dorsum of Finger I and vocal slits; (7) Finger I shorter than Finger II; emarginated discs of fingers broadly expanded and elliptical; (8) fingers without lateral fringes; (9) ulnar tubercle present but low or poorly differentiated; (10) heels without tubercles, inner tarsal wart low and poorly differentiated; (11) inner metatarsal tubercle ovoid, about 5-6x the size of subconical, rounded outer metatarsal tubercle; supernumerary plantar tubercles present; (12) toes with narrow lateral fringes; basal toe webbing between toes II–V; Toe V longer than Toe III (disc of Toe III does not reach distal subarticular tubercle on Toe IV, disc on Toe V reaches middle of distal subarticular tubercle on Toe IV); toe discs elliptical, slightly narrower than those on fingers; (13) in life, dorsal surfaces dark brown, chocolate brown, or orange-brown, with or without dark irregular botches, distinctive head markings absent, ventral surfaces brown with irregular pale flecks and blotches, iris bronze with dense black reticulations; in preservative, brown surfaces turn grey; (14) SVL 50.0-50.5 mm in adult females (n = 2), 34.7-42.5 (38.5 ± 2.1 SD, n = 10) mm in adult males (Table 1).

Comparisons.

Pristimantis andinogigas sp. nov. is readily distinguished from all other species of Pristimantis by its large body size, thick and glandular skin, large warts on flanks, prominent macroglandular patches on head and legs, and dark brown dorsum. The only species showing a similar combination of characters is Pristimantis erythros Sánchez-Nivicela, Celi-Piedra, Posse-Sarmiento, Urgiles, Yánez-Muñoz & Cisneros-Heredía, 2019, which is readily differentiated from P. andinogigas sp. nov. by being smaller (38.8-42.6 mm in adult females), having a conspicuous red coloration, and lacking dentigerous processes of vomers. In addition, P. andinogigas sp. nov. resembles the following species by bearing large, flat, glandular warts on flanks, and expanded discs on fingers and toes: Pristimantis farisorum Mueses-Cisneros, Perdomo-Castillo, & Cepeda-Quilindo, 2013, P. obmutescens (Lynch, 1980), P. orcesi (Lynch, 1972), P. racemus (Lynch, 1980), P. simoterus (Lynch, 1980), P. simoteriscus (Lynch), and P. thymelensis (Lynch, 1972). Pristimantis andinogigas sp. nov. is larger than any of these seven species, and furthermore, they differ from P. andinogigas as follows (characters of P. andinogigas sp. nov. in parentheses): areolate or shagreen dorsal skin (porous), thin supratympanic folds (prominent supra/post-tympanic glandular patch), thin glandular patches on legs (thick), and smaller body size, with adult females having 38.4-42.3 mm SVL in P. farisorum , 28.5-38.4 mm SVL in P. obmutescens , 35.2-36.1 mm SVL in P. orcesi , 29.9-37.9 mm SVL in P. racemus , 32.4-37.1 mm SVL in P. simoterus , 25.7-31.4 mm SVL in P. simoteriscus , and 28.0-33.5 mm SVL in P. thymelensis (versus 50.0-50.5 mm SVL in adult females of P. andinogigas ). In addition, P. farisorum has snout subacuminate in dorsal view (rounded), fingers with narrow lateral fringes (absent), dorsum dark brown to black with irregular and elongated orange marking (brown with or without lighter irregular blotches), and inhabits upper montane forests on the Nudo de Pasto, Andes of southern Colombia ( Mueses-Cisneros et al. 2013). Pristimantis obmutescens has tympanum concealed beneath skin (visible), fingers with lateral fringes present (absent), small, non-conical tubercles on heel and outer edge of tarsus present (absent), lacks vocal sac and vocal slits in males (present), and inhabits on the Páramo de Puracé, Cordillera Central of the Andes in southern Colombia ( Lynch 1980, Lynch et al. 1996). Pristimantis orcesi has skin on head smooth (porous), fingers bearing lateral fringes (absent), lacks dentigerous processses of vomers (present), and inhabits paramos on the Andes of north-central Ecuador ( Lynch 1972, 1981). Pristimantis racemus has fingers with lateral fringes (absent), dorsum reddish-brown with darker marking (brown with or without darker irregular blotches), lacks vocal sac and vocal slits in males (present), and inhabits paramos on the Cordillera Central of the Andes, central Colombia ( Lynch 1980, Lynch et al. 1996). Pristimantis simoterus has fingers with lateral fringes (absent) and inhabits upper montane forests and paramos on the Cordillera Central of the Andes, central Colombia ( Lynch 1980, Lynch et al. 1996). Pristimantis simoteriscus has subacuminate snout in dorsal view, fingers with lateral fringes (absent), dorsum grey with dark markings (brown with or without darker irregular blotches), lacks vocal slits in males, and inhabits paramos on the Cordillera Central of the Andes, central Colombia ( Lynch et al. 1996). Pristimantis thymelensis has tympanum concealed beneath skin (visible), paraventral folds present (absent), finger bearing lateral fringes (absent), grey to brown dorsum speckled to varying degrees with creamy grey, tan, or black (brown with or without darker irregular blotches), and inhabits paramos on Andes of southern Colombia and northern Ecuador ( Lynch 1972, 1981).

Pristimantis loujosti and P. pycnodermis also stand out from other species of the genus by their stout body and thick glandular skin on dorsal surfaces of body and limbs, but they differ from P. andinogigas sp. nov. as follows (characters of P. andinogigas sp. nov. in parentheses): Pristimantis loujosti Yánez-Muñoz, Cisneros-Heredia & Reyes-Puig, 2010 has smooth skin on head and granular skin on dorsum and flanks (porous, with large warts on flanks), thick supratympanic fold (prominent glandular supra/post-tympanic patch), thin glandular patches on legs (thick), subacuminate snout in dorsal view (rounded in dorsal view), fingers bear lateral fringes (absent), black spots on hidden surfaces of limbs (uniformly coloured), light iris with dark reticulation (bronze with dense black reticulations), and it inhabits on cloud forests on the Upper River Pastaza, Cordillera Oriental of the Andes of Ecuador ( Yánez-Muñoz et al. 2010). Pristimantis pycnodermis (Lynch, 1979) differs by having low cranial crests (absent), snout subacuminate in dorsal view and truncate in lateral view (snout rounded in dorsal view; rounded to slightly protruding in lateral view), skin of flanks smooth (with large warts), fingers bear lateral fringes (absent), dark canthal and tympanic marks (head marks absent), large black spots on the flanks (brown with or without dark irregular blotches), 32.5-44.4 mm SVL in adult females (50.0-50.5 mm), and inhabits paramos on the Andes of central-southern Ecuador ( Lynch 1979).

Description of holotype.

Adult female (50.0 mm SVL, Fig. 2); head narrower than body, wider than long (head width 40% of SVL, head length 32% of SVL, head length 80% of head width); snout short (eye nostril 11% of SVL, eye nostril 87% of eye diameter), rounded in dorsal and lateral views; canthus rostralis rounded and weakly concave; loreal area concave; lips flared; eye large (eye diameter 1.14 times eye-nostril distance, eye diameter 38% of head length); nostrils slightly protuberant laterally (Fig. 3). Cranial crest absent; upper eyelids without tubercles; tympanic membrane differentiated, tympanic annulus visible (tympanum diameter 35% of eye diameter), upper and posterior borders of tympanic annulus in contact with prominent, thick glandular patch that covers all dorsal fascia of m. depressor mandibulae; large, glandular postrictal tubercles. Choanas small and widely separated from each other, not concealed by palatal shelf of maxilla; dentigerous processes of vomer present, oblique, moderately separated, posteromedial to choanae, with four or five teeth; tongue longer than wide, posterior half not adherent to floor of mouth.

Skin on dorsum thick and glandular, surface texture porous (Figs 1, 4), with large, flat, glandular warts on flanks; dorsolateral folds absent; thick glandular patch on dorsal surfaces of humeral, femoral, tibial and tarsal regions; glandular folds in wrists (Fig. 4); skin on venter areolate; discoidal fold weakly defined; skin on ventral surfaces of legs granular; cloaca not protuberant, cloacal region with large warts. Ulnar tubercle present but low; palmar tubercle flat and bifurcate; thenar tubercle elongate, about half the size of palmar tubercle; subarticular tubercles prominent, rounded in ventral and lateral views; supernumerary palmar tubercles rounded, smaller than subarticular tubercles; fingers without lateral fringes; Finger I shorter than Finger II; discs on fingers expanded and elliptical, most prominent on fingers II–IV, while disc on Finger I slightly expanded; all discs bearing ventral pads well defined by circumferential grooves (Fig. 3).

Hind limbs robust (tibia length 46% of SVL; foot length 49% of SVL); heel without tubercles; inner edge of tarsus with one wart low and poorly differentiated; inner metatarsal tubercle ovoid, about 5x round outer metatarsal tubercle; subarticular tubercles rounded; plantar supernumerary tubercles low and inconspicuous, smaller than subarticular tubercles; toes with narrow lateral fringes; basal toe webbing between toes II–V; discs of toes expanded, elliptical, slightly narrower than those on fingers, most prominent on fingers II–V, while disc on Finger I slightly expanded; toes with ventral pads well-defined by circumferential grooves; toe lengths, when adpressed, IV> V> III> II> I; Toe V longer than Toe III; disc of Toe III not reaching distal subarticular tubercle on Toe IV, disc on Toe V reaches middle of distal subarticular tubercle on Toe IV (Fig. 3).

Measurements (in mm) of holotype.

Snout-vent length 50.0; head width 20.1; head length 16.0; eye-nostril distance 5.3; internarial distance 4.6; interorbital distance 8.8; tympanum diameter 2.1; eye diameter 6.0; tibia length 23.2; hand length 15.8; foot length 24.3.

Colouration of holotype in life.

Dorsum dark brown; ventral surfaces dark brown with irregular light-yellow flecks and blotches on throat, hands, feet, armpits, and lower venter; iris golden-bronze with dense black reticulations (Fig. 5).

Colouration of holotype in preservative.

Same pattern as in life, but brown surfaces turned dark grey (Fig. 2).

Variation.

Males are smaller than females, measurements of the type series are provided in Table 1. Dorsal colouration of body and legs varies from dark brown, chocolate brown, or orange-brown (Fig. 5.). Females are darker and have a homogeneous coloration pattern, while males are paler and usually with dark irregular blotches. Some individuals have pale pink flanks and dorsal surfaces of legs (Fig. 5D). Venter colouration varies from completely dark brown to dark brown with irregular light-yellow flecks and blotches. Background dorsal colouration of juveniles is paler, and dorsal dark blotches are darker.

Etymology.

The specific epithet is coined from the New Latin adjective andinus (pertaining to the Andes) and the Latin noun gigas (giant). The name alludes to the large and stout body of this new species in comparison with other species of Pristimantis from the high Andes.

Vocalizations.

Males call from grasses at night, in heterogeneous chorus with extensive call superposition. Paratype DHMECN 11016 was calling from bamboos Neurolepis sp. (Tair = 7° C, relative humidity = 96%). The advertisement call (Fig. 6) has dominant frequencies of 1.63-1.98 kHz (1.80 ± 0.14 SD kHz). Calls were 124-428 ms (231.37 ± 142.76 ms) in duration, with intervals of 2138-5239 ms (3393 ± 1107), and emitted 10.80-24.64 calls per minute (16.61 ± 5.35). Calls were formed by one or two notes, each with 117-148 ms (130 ± 10) in duration, at intervals of 90-157 ms (123 ± 34 ms). In calls with two notes, first note had a dominant frequency (1.65 kHz) lower than the second note (1.89 kHz).

Distribution, natural history, conservation status, and extinction risk.

Pristimantis andinogigas sp. nov. is only known from its type locality, the paramos of the Nudo de Cajanuma, at elevations between 3300 and 3400 m, on the Cordillera Oriental of the Andes of southern Ecuador (Fig. 7). Surveys in other localities of the Nudo de Cajanuma, and on the nearby Nudo de Sabanilla, have not recorded the species ( Almendáriz and Orcés 2004, Ron et al. 2019). However, most surveys were conducted at lower elevations, and most paramos in the region lack amphibian inventories. It is possible that P. andinogigas inhabits a larger area at the Cajanuma-Sabanilla mountain ridges; but it is unlikely that it occurs farther north on the Cordillera Oriental (e.g., Nudo de Guagrahuma), because of separation by the valley of the River Zamora, reaching elevations as low as 2800 m that may limit species’ dispersal.

The ecosystem at the type locality is Paramo Bambusoid Meadow (MAE et al. 2013). The most representative plant genera were Bomarea , Miconia , Blechnum , Disterigna , Epidendrum , Gaultheria and Puya ; and the most abundant plant species were Escallonia myrtilloides , Puya nitida , Hypericum lancioides , Tillandsia aequatorialis , Neurolepis nana , Cortaderia bifida , C. jubata , Chusquea neurophylla , Calamagrostris macrophylla , Themistoclesia epiphytica , Senecio tephrosioides , Disterigma pentandrum , and D. empetrifolium , Rubus laegaardii ( Eguiguren et al. 2015).

Pristimantis andinogigas was found active at night (19h00-22h00) at 6-10° C air temperature and 85-98% relative humidity. All males and some subadults and juveniles were observed active on bamboos ( Neurolepis spp.); while both adult females were found active on the floor. During the day, individuals were found hidden inside rosettes ( Senecio spp. and Puya spp.) or at the base of bamboos. Pristimantis andinogigas was the most abundant species during surveys at the type locality, representing 47 out of 108 anuran records. It was found in sympatry with Pristimantis percultus , Pristimantis sp. cf. colodactylus , Pristimantis sp. cf. orestes , and Lynchus sp.

The type locality of P. andinogigas is officially protected as part of the Podocarpus National Park, a national protected area created in 1982. The area has little anthropogenic impact, and in general, paramos of the Nudo de Cajanuma and the nearby Nudo de Sabanilla are reported to have a relatively good conservation status ( Hofstede et al. 2002). Road infrastructure projects have been proposed in the past, but their development was cancelled ( Cisneros et al. 2004, Bernardi de León 2009). However, three expeditions over the last five years have recorded very low numbers of P. andinogigas . Although more data are needed, it may be possible that the population of P. andinogigas has declined. In the absence of further information about the extinction risk on this newly discovered species, we suggest that P. andinogigas should be classified in the IUCN Red List category of Data Deficient ( IUCN 2012).