[Herpetology • 2019] Pristimantis mallii • A New Species of Terrestrial Frog Pristimantis (Strabomantidae) from the upper Basin of the Pastaza River, Ecuador

Pristimantis mallii 

 Reyes-Puig, Reyes-Puig, Velarde-Garcéz, Dávalos, Mancero, Navarrete, Yánez-Muñoz, Cisneros-Heredia & Ron, 2019

DOI: 10.3897/zookeys.832.30874 

Abstract
We describe a new species of Pristimantis from the montane forest of the Río Zuñag Ecological Reserve, upper basin of the Pastaza River, Ecuador. Pristimantis mallii sp. n. is characterized by a snout-vent length of 11.6–21.3 mm in adult males (n = 12), 22.6–34.3 mm in adult females (n = 8), and is compared morphologically and genetically with Pristimantis miktos and with other relevant species of Pristimantis. The new species is characterized by having skin on dorsum and flanks shagreen, distinctive scapular folds, snout broadly rounded in dorsal view, upper eyelid bearing one or two subconical tubercles and some rounded tubercles, dorsum and flanks light brown to brown, with irregular dark brown marks bounded by dirty cream and groin with irregular yellowish marks.

Keywords: Montane forest, Pristimantis mallii sp. n., Río Zuñag Reserve, Terrarana

Figure 1. Phylogeny of Pristimantis showing the relationships of Pristimantis mallii sp. n. (red). The phylogram was derived from analysis of 2968 bp of mitochondrial (gene fragments 12S and 16S) and nuclear (gene fragment RAG) DNA sequences. Branch support is presented for each clade as Bayesian posterior probabilities × 100 (left of the slash) and non-parametric bootstrap (right of the slash). Asterisks indicate support values of 100. The external group is not shown. For each specimen, museum catalog number, locality, and GenBank accession number (in parentheses) are reported. Abbreviations: E. R. = Ecological Reserve.

Figure 2. Coloration in life of Pristimantis mallii sp. n. Dorsal view.
A ZSFQ 1305, SVL = 34.3 mm, adult female B DHMECN 5236, SVL = 30.9 mm, adult female C QCAZ 52473, SVL = 28.8 mm, holotype, adult female;
Second line from left to right D QCAZ 52494, SVL = 29.3 mm, adult female E QCAZ 52512, SVL = 10.3 mm, subadult male F QCAZ 52474, SVL = 11.6 mm, adult male.
Ventral view G DHMECN 5236, SVL = 30.9 mm, adult female H QCAZ 52473, SVL = 28.8 mm, holotype, adult female I QCAZ 52474, SVL = 11.6 mm, adult male. Pictures are not to scale.

Pristimantis mallii sp. n. 

Proposed standard English name: Malli’s Rain Frog

Proposed standard Spanish name: Cutín de Malli

Diagnosis: A new species of Pristimantis having the following combination of characters: (1) skin on dorsum and flanks shagreen, with rounded tubercles scattered towards the axillary region, with “) (” shaped scapular folds (evident in life); dorsolateral folds absent; skin on venter areolate; discoidal fold slightly defined; (2) tympanic membrane and tympanic annulus present, round, equivalent to 45% of ED; supratympanic fold present; (3) snout broadly rounded in dorsal view, moderate in length and rounded in lateral view; (4) upper eyelid with one or two subconical tubercles on the center of eyelid and some rounded tubercles (less evident in preserved specimens); EW 100% of IOD; cranial crests absent (5) dentigerous processes of vomers oblique in outline, with five to seven teeth, moderately separated, posteromedial to choanae; (6) vocals slits and nuptial pads present; (7) Finger I shorter that Finger II; discs of digits expanded, truncate; two times the width of the digits on Fingers III and IV; (8) fingers with lateral fringes; (9) ulnar tubercles present, rounded; (10) heel bearing one or two subconical tubercles (less evident in preserved specimens) surrounded by few lower rounded tubercles; inner tarsal fold present, it extends up to 1/4 of the tarsus; (11) inner metatarsal tubercle oval, 5–6× as large as outer metatarsal tubercle that is subconical; supernumerary plantar tubercles indistinct; (12) toes with slightly defined lateral fringes; webbing absent; Toe V longer that Toe III, disc on Toe V reach the distal subarticular tubercle on Toe IV; (13) in life, dorsum and flanks light brown to brown, with irregular dark brown marks bounded by dirty cream, light brown or greenish cream; hidden surfaces of thighs brown splashed with dirty cream; groin with irregular yellowish marks; venter light gray or cream, spotted to densely spotted with brown. Golden coppery iris with black reticulations and a reddish-brown horizontal stripe; (14) SVL in adult males 16.7 ± 4.5 (11.6–21.3 mm); females with 27.6 ± 3.9 (22.6–34.3).

Distribution and natural history:

Pristimantis mallii is only known from Fundación EcoMinga’s Río Zuñag Ecological Reserve, which is located in the southeastern buffer zone of the Llanganates National Park, in Baños, Río Negro, Tungurahua province, in the upper basin of the Pastaza River, on the east-central slope of the Andes in Ecuador. This locality comprises montane cloud forest (MAE 2012). The elevation range is 1300–2190 m above sea level.

All specimens were found on herbaceous and shrub vegetation inside mature forest, where they perched on herbs, shrubs, palms, ferns, bromeliads and Araceae between 100 and 450 cm above the ground. A couple in amplexus was found in January 2012, and the female deposited an egg clutch in a field bag, in the time passed between being collected in the field and reaching the base camp. Additionally, two couples in amplexus and an adult female were found in October 2017.

Etymology: The new species is named in honor of the late Dr V. N. Mallikarjuna “Malli” Rao, of Wilmington, Delaware, USA. A winner of the Lavosier Medal at DuPont, he helped develop an environmentally safe alternative to the fluorocarbons that were depleting the ozone layer. His donation to EcoMinga in 2007 started the Río Zuñag Reserve, the type locality of P. mallii.


 Carolina Reyes-Puig, Juan Pablo Reyes-Puig, Daniel A. Velarde-Garcéz, Nicolás Dávalos, Emilio Mancero, María José Navarrete, Mario H. Yánez-Muñoz, Diego F. Cisneros-Heredia and Santiago R. Ron. 2019. A New Species of Terrestrial Frog Pristimantis (Strabomantidae) from the upper Basin of the Pastaza River, Ecuador.  ZooKeys. 832: 113-133.  DOI: 10.3897/zookeys.832.30874

Resumen: Describimos una nueva especie de Pristimantis del bosque montano de la Reserva Ecológica Río Zuñag, cuenca alta del río Pastaza, Ecuador. Pristimantis mallii sp. n. es caracterizada por una longitud rostro-cloacal de 11.6–21.3 mm en machos adultos (n = 12), 22.6–34.3 mm en hembras adultas (n = 8), y es comparada morfológica y genéticamente con Pristimantis miktos y con otras especies relevantes de Pristimantis. La especie nueva se caracteriza por tener la piel del dorso y flancos finamente granular, pliegues escapulares distintivos, hocico redondeado en vista dorsal, párpado superior con uno dos tubérculos subcónicos y algunos redondeados, dorso y flancos café claro a café, con marcas irregulares café oscuras bordeadas de crema sucio y marcas irregulares amarillentas en las ingles.

Palabras clave: Bosque montano, Pristimantis mallii sp. n., Reserva Río Zuñag, Terrarana