Saturday, August 17, 2019

[Herpetology • 2019] Noblella naturetrekii • A New Species of Terrestrial Frog of the Genus Noblella Barbour, 1930 (Anura: Strabomantidae) from the Llanganates-Sangay Ecological Corridor, Tungurahua, Ecuador


Noblella naturetrekii  
 Reyes-Puig​, Reyes-Puig​​, Ron, Ortega, Guayasamin, Goodrum, Recalde, Vieira, Koch & Yánez-Muñoz, 2019


Abstract
We describe a new species of terrestrial frog of the genus Noblella from the eastern versants of the Ecuadorian Andes in the upper Pastaza watershed. Noblella naturetrekii sp. n. differs from its Ecuadorian congeners by the presence of a differentiated tympanic membrane and a weakly defined tympanic annulus, and eyelids with rounded tubercles. In addition, the new species is characterized by its blackish–dark brown ventral coloration scattered with little white dots and the absence of papillae at the tip of the fingers and toes. We provide a detailed description of the call and osteology of the new species. Finally, we present the most complete phylogeny of the genus, which confirms that Noblella is a non-monophyletic group.

Figure 6: Dorsal and ventral patterns of Noblella naturetrekii sp. n. in life.
 (A) and (D) Dorsal pattern and ventral pattern of DHMECN 13390, holotype, adult female, SVL = 14.2 mm; (B) Dorsal pattern of DHMECN 14420, paratype, adult female, SVL = 13.1 mm; (C) and (E) Dorsal pattern of ZSFQ 934, paratype, adult female, SVL = 14.1 mm.
 Photographs by Juan Pablo Reyes-Puig (A) (B) and (D) and José Vieira (C) and (E).

Figure 5: Detail of the tympanic annulus and tympanic membrane of Noblella from the eastern slopes of Ecuador.
 (A) Noblella naturetrekii sp. n., paratype, female, ZSFQ 934; (B) N. naturetrekii sp. n., paratype, male, ZSFQ 933; (C) N. naturetrekii sp. n., holotype, female, DHMECN 13390;
 (D) N. personina, female, EPN 14329 (Harvey et al., 2013); (E) N. lochites, female, EPN 14254 (Harvey et al., 2013); (F) N. myrmecoides from Jenaro Herrera, Loreto.
 Photographs by José Vieira (A) and (B), Juan Pablo Reyes-Puig (C), 
Jorge Brito M. (D) and (E) and Mauricio Ortega (F).

Noblella naturetrekii new species

Proposed standard English name. Naturetrek Leaf Frog
Proposed standard Spanish name. Cutín Noble de Naturetrek

Generic placement. A species of terrestrial frog of the genus Noblella as defined by Hedges, Duellman & Heinicke (2008): head no wider than body; cranial crests absent; tympanic membrane differentiated (except in N. duellmani); dentigerous processes of vomers absent; terminal discs on digits not or barely expanded; discs and circumferential grooves present distally; terminal phalanges narrowly T-shaped; Finger I shorter than, or equal in length to, Finger II; Finger IV containing only two phalanges in N. carrascoicola, N. lochites, N. myrmecoides, N. ritarasquinae, and in N. naturetrekii. Toe III shorter than Toe V; tips of at least Toes III–IV acuminate; subarticular tubercles not protruding; dorsum pustulate or shagreen; venter smooth; SVL less than 22 mm. N. pygmaea (SVL 11.1–12.4 mm in adults) (Lehr & Catenazzi, 2009) and N. naturetrekii (SVL 12.1–14.2 mm in adults) have the smallest SVL of the genus. Nevertheless, it is important to mention that there are no known synapomorphies for Noblella or for Psychrophrynella. These two genera are morphologically similar and are closely related (De la Riva et al., 2017; Catenazzi & Ttito, 2018).

Diagnosis. The new species differs from its congeners by the combination of the following characteristics: (1) skin of the dorsum and flanks shagreen to tubercular (smooth by preservation effects), with scattered subconical tubercles on the sacral region; finely granular skin on the abdomen; (2) tympanic membrane differentiated; tympanic annulus present, weakly defined (Fig. 5); (3) snout elongated in dorsal view, rounded in lateral view; (4) eyelids with flattened and rounded tubercles; (5) dentigerous processes of the vomers absent; (6) vocal slits and sac present, nuptial pads present; (7) fingers not expanded distally, finger tips acuminate but lacking papillae; Finger I smaller than Finger II, without circumferential grooves and without papillae (Fig. 3); (8) distal phalanges blunt or T-shaped, phalangeal formula of hand 2, 2, 3, 2; (9) supernumerary palmar tubercles absent, ulnar tubercles present (reduced by preservation effects); (10) one subconical tarsal tubercle present (Fig. 3); two prominent metatarsal tubercles; toe tips pointed, with slightly defined circumferential grooves and lacking papillae; (11) Toe V shorter than Toe III; (12) phalangeal formula of feet: 2, 2, 3, 4, 3 (Fig. 9); (13) in ethanol, dorsum brown with dark oblique lateral line that delineates flanks, large suprainguinal marks, dark brown to black scattered with numerous small white dots; in life dorsum predominately light or dark brown with two black suprainguinal marks or a mid-dorsal cream-colored stripe, the venter and throat is light brown to brown interspersed with small white spots; (14) SVL in males 11.2–12.1 (n = 3); and females 13.1–14.4 (n = 6).

Distribution and Natural History. The new species, N. naturetrekii is known from four localities of cloud forest in the upper Pastaza watershed in the Llanganates-Sangay Ecological Corridor (Fig. 1). Three localities are part of the Naturetrek Reserves of the Ecominga Foundation, in Vizcaya and in the Bosque Protector Cerro Candelaria, which are found in the eastern region of the Baños township, Tungurahua Province. N. naturetrekii thus makes itself a symbol of conservation of the ecological corridor between Llanganates National Park and Sangay National Park. The new species is likely to be endemic of this region, which has proven to be an area with high diversity and endemism in other small vertebrates (Ríos-Alvear & Reyes-Puig, 2015).

The collection sites consisted of mature Andean forest (Ecuadorian Ministry of the Environment (MAE), 2012) with emergent trees in a closed canopy and an understory of herbaceous vegetation and abundant leaf litter. The calls of N. naturetrekii were heard throughout the day in these sites. Likewise, the majority of individuals were obtained during the day in pitfall traps in Vizcaya during the month of March, indicating that it is mostly a diurnal species, a characteristic trait of the genus Noblella (Guayasamin & Terán-Valdez, 2009; Harvey et al., 2013). It is noteworthy that one of the specimens (DHMECN 13307) collected in the locality of Vizcaya was found in secondary forest, dominated by Andean bamboo (Chusquea sp). The entrance path to the Naturetrek Reserve in which it was found was destroyed a few weeks later for the opening of a new road.

The ZSFQ specimens were found on the forest floor hidden in the leaf litter. Two males were active at 22:00 in a forest patch next to the road. Both males were vocalizing within a dead trunk each at an approximate height of 50 cm above the ground, where there was abundant litter on the trunk, the female was found among litter on the ground. Other males were heard in the same locality at the same time. At this locality, the species is sympatric with Gastrotheca testudinea, Pristimantis modipeplus, and Anolis orcesi.

Etymology. Noblella naturetrekii is an emblematic species of the mosaic of Naturetrek Reserves, owned and managed by the Ecominga Foundation, which protect the cloud forests in the upper Pastaza River watershed. Naturetrek, a British wildlife tour operator, has fully funded the purchase of these forest reserves, in two of which the new frog species was discovered. These funds were transferred to the Ecominga Foundation via the World Land Trust. The name is the latinized possessive used in apposition to honor the efforts of the company Naturetrek.


    

Conclusions: 
We provide morphological, osteological, genetic, and acoustic evidence that validate the description of a new species, N. naturetrekii. We include a well-supported phylogeny that highlights Noblella as a non-monophyletic genus with two distinctive clades. The discovery of this new species in the upper basin of the Pastaza River watershed demonstrates the importance of conserving the zone and illustrates the need for future studies to help understand the actual biodiversity of these Andean Trans-Amazonian forests. Ecominga and Naturetrek Reserves protect biodiversity that inhabits between two large National Parks. Therefore, strategies to maintain connectivity between these conservation areas can be addressed by the continuing description of new species.


Juan Pablo Reyes-Puig​, Carolina Reyes-Puig​​, Santiago Ron, Jhael A. Ortega, Juan M. Guayasamin, Mindee Goodrum, Fausto Recalde, Jose J. Vieira, Claudia Koch and Mario H. Yánez-Muñoz. 2019. A New Species of Terrestrial Frog of the Genus Noblella Barbour, 1930 (Amphibia: Strabomantidae) from the Llanganates-Sangay Ecological Corridor, Tungurahua, Ecuador. PeerJ. 7:e7405. DOI: 10.7717/peerj.7405