Notes on the distribution of Gastrotheca testudinea ( Jiménez de la Espada , 1870 ) in Ecuador

We present new information on the distribution of the marsupial frog Gastrotheca testudinea (Jiménez de la Espada, 1870) in Ecuador. We provide the first record from the province of Cañar, and the southernmost locality for Ecuador (which also corresponds to the third known report from the province of Zamora-Chinchipe). In addition, we review the elevation range of the species, and propose to change the lowest elevation limit of G. testudinea from 1100 to 700 m.


Introduction
Most members of the family Hemiphractidae are restricted to specific physiographic regions, with narrow latitudinal and elevation ranges (Duellman 2015).The arboreal direct-development marsupial frog, Gastrotheca testudinea (Jiménez de la Espada, 1870), is however an exception, having a widespread latitudinal range along the eastern (Amazonian) slopes of the Andes of Ecuador, Peru, and Bolivia (Duellman 2015, Frost 2016).This species dwells in Foothill, Low Montane, and Cloud forests up to 2775 m (Icochea et al. 2004, Duellman and Chávez 2010, Duellman 2015).Despite its wide distribution, G. testudinea is seldom collected or recorded, probably due to its arboreal habits, and much remains to be known about its distribution and natural history (Duellman 2015).
In Ecuador, G. testudinea has been reported in few localities in the provinces of Orellana, Tungurahua, Pastaza, Morona-Santiago, and Zamora-Chinchipe (Table 1).The first goal of this publication is to report several records that expand the distribution of G. testudinea in Ecuador: the first record from the province of Cañar, and the southernmost Ecuadorian locality.Furthermore, we comment on data regarding the lowest elevation limit of G. testudinea, which at present is controversial.Duellman's (2015) monographic work reported the lowest elevation of G. testudinea as 1100 m, but a previous work cited the species' lowest elevation as 550 m (Duellman and Venegas 2005; Table 1).Thus, the second goal of this paper is to evaluate the lowest elevation limit of G. testudinea.

Methods
Specimens examined for this work are deposited at: Museo de Zoología, Universidad del Azuay, Cuenca, Ecuador (MZUA) and National Museum of Natural History, Smithsonian Institution, Washington, D.C., USA (USNM).Specimens deposited at MZUA were collected under permits 065-DPA-MA-2014 and 019-IC-FAU/ FLO-DPZCH-MA issued by Ministerio del Ambiente, Ecuador.We determined the position most closely related to the locality description using Google Earth™ mapping service (7.1.5.1557

Results
Specimens reported herein were identified as G. testudinea by their large body size; head wider than long; tibia length less than 60% of snout-vent length; skin of dorsum areolate, adherent to the skull but not co-ossified; supraciliary processes absent; heel bearing a tubercle; Finger I > Finger II; finger discs wider than digits proximal to discs; inner tarsal fold present on distal one-third of tarsus; and webbing extending to the distal subarticular tubercle on Toe V (Duellman 2015).Gastrotheca testudinea is the largest member of the subgenus Gastrotheca (sensu Duellman 2015), and the only member with the skin on the head adherent with the underlying dermal bones (Duellman 2015).

Discussion
An adult male G. testudinea (MZUA.An.0572,Fig. 1) was collected along a ravine, 300 m off the Mazar dam (Table 1, Fig. 4), near Guarainag, province of Cañar, Ecuador, on 12 June 2014.This is the first known record of G. testudinea in the province of Cañar, extending the species' distribution ca 57 km north-northwest from the nearest known locality (18.6 km southwest of Plan de Milagro).The frog was found vocalizing from a small branch, 1.5 m over the ground, in a riparian montane forest remnant.
An adult male (MZUA.An.1084,Fig. 2) and an adult female (MZUA.An.1085,Fig. 3) were collected at two different points in the Estación Científica San Francisco (Table 1, Fig. 4), on March and October 2015, respectively.This site is the third known locality in the province of Zamora-Chinchipe and the southernmost record of the species in Ecuador, extending the species' distribution ca 82 km east-southeast from the nearest known locality (Machinaza Alto).These frogs were active at night on shrubs, 3 and 6 m above the ground, respectively.
A specimen of G. testudinea (USNM 258757) collected at Loreto, province of Orellana, Ecuador, in January 1951, corresponds to the lowest known elevation for the species.Based on this specimen, Duellman and Venegas (2005) cited 550 m as the species' lowest elevation (Table 1).However, Duellman (2015) disregarded this locality and reported the lowest elevation of G. testudinea as 1100 m.Although Duellman (2015) did not mention his reasons for invalidating the locality, it was probably because Loreto lies at a much lower elevation than other known localities of G. testudinea.
Specimen USNM 258757 is part of a collection gathered by Carlos A. Olalla and sent by Gustavo Orcés to James A. Peters at the National Museum of Natural History, Smithsonian Institution.The Olalla family worked at Loreto over several decades, gathering large collections that are now deposited in museums of Ecuador, USA, and Brazil (Paynter 1993, Wiley 2010).It is clear that the Olalla family was knowledgeable about the Loreto region, and careful enough as to discriminate Loreto from nearby localities (such as Avila, San José, or Sumaco; Wiley 2010).Collection localities and data by Carlos A. Olalla have been shown to be accurate (Wiley 2010).We thus consider that there is no evidence to discard the validity of the locality of Loreto for G. testudinea.
While the general locality of Loreto is valid, the exact collecting point of USNM 258757 is less clear.Most Olalla's specimens labelled as "Loreto" were collected in the surroundings of the town of Loreto at 400-450 m.However, some specimens were also collected along trails departing from Loreto to nearby areas and reaching up to ca 700 m (e.g., Sumaco volcano, River Suno;Cisneros-Heredia andMcDiarmid 2005, 2007).Consequently, and conservatively, we propose to update the lowest elevation limit of G. testudinea from 1100 to 700 m.

Table 1 .
(Coloma and Duellman 2014)ocalities of Gastrotheca testudinea in Ecuador Additional localities from the provinces of Napo, Morona-Santiago and Zamora-Chinchipe are mentioned in the webpages of AmphibiaWebEcuador(Chasiluisa et al. 2016)and AnfibiosWebEcuador(Coloma and Duellman 2014).They are not included pending confirmation of identification and formal publication.Gastrotheca testudinea as a sympatric species with Phyllomedusa ecuatoriana, but did not provide locality data.The precise locality was provided by one of the coauthors: Jorge Brito (in litt.13 April 2016).