We describe a new species of Telmatobius from the Pacific slopes of the Andes in central Peru. Specimens were collected at 3900 m elevation near Huaytará, Huancavelica, in the upper drainage of the Pisco river. The new species has a snout–vent length of 52.5 ± 1.1 mm (49.3–55.7 mm, n = 6) in adult females, and 48.5 mm in the single adult male. The new species has bright yellow and orange coloration ventrally and is readily distinguished from all other central Peruvian Andean species of Telmatobius but T. intermedius by having vomerine teeth but lacking premaxillary and maxillary teeth, and by its slender body shape and long legs. The new species differs from T. intermedius by its larger size, flatter head, and the absence of cutaneous keratinized spicules (present even in immature females of T. intermedius), and in males by the presence of minute, densely packed nuptial spines on dorsal and medial surfaces of thumbs (large, sparsely packed nuptial spines in T. intermedius). The hyper-arid coastal valleys of Peru generally support low species richness, particularly for groups such as aquatic breeding amphibians. The discovery of a new species in this environment, and along a major highway crossing the Andes, shows that much remains to be done to document amphibian diversity in Peru.

Describimos una nueva especie de Telmatobius de la vertiente Pacífica de los Andes en el centro de Perú. Los especímenes tipo fueron colectados a una elevación de 3900 m cerca de Huaytará, Huancavelica, en la parte alta de la cuenca del río Pisco. La nueva especie tiene una longitud hocico–cloaca de 52.5 ± 1.1 mm (49.3–55.7 mm, n = 6) en las hembras adultas y de 48.5 mm en un macho adulto. La nueva especie tiene coloración brillante amarilla y naranja en las partes ventrales y se diferencia fácilmente de todas las demás especies peruanas de Telmatobius de los Andes centrales a excepción de T. intermedius por tener dientes vomerianos y carecer de dientes maxilares y premaxilares, y por su forma del cuerpo delgada y sus patas largas. La nueva especie se diferencia de T. intermedius por su mayor tamaño, por tener la cabeza más plana, y por la ausencia de espículas queratinizadas cutáneas (presentes incluso en hembras inmaduras de T. intermedius), y en los machos por la presencia de pequeñas espinas nupciales compactadas en la superficie dorsal y medial de los pulgares (espinas nupciales grandes y dispersas en T. intermedius). Los valles costeros hiper-áridos de Perú se caracterizan en general por tener baja riqueza de especies, especialmente para grupos como los anfibios de reproducción acuática. El descubrimiento de una nueva especie en este tipo de ecosistema, y a lo largo de una de las carreteras principales que cruzan los Andes, muestra que aún queda mucho por hacer para documentar la diversidad de los anfibios en Perú.

Huancavelica, amphibian, Andean water frog

Huancavelica, anfibio, rana acuática Andina

The Tropical Andes are characterized by a large diversification of the aquatic frogs of the genus Telmatobius Wiegmann, 1834. Sixty-two species are currently recognized in this genus (AmphibiaWeb 2014; Aguilar and Valencia 2009; Frost 2014; including species previously assigned to Batrachophrynus Peters, 1873). The altitudinal distribution of Telmatobius ranges from 1000 m to 5400 m (De la Riva and Harvey 2003; Seimon et al. 2007), and its longitudinal distribution extends from the equator (T. niger Barbour & Noble, 1920, whose populations have been extirpated in Ecuador; Merino-Viteri et al. 2005) to 29°S, on the eastern slopes of the Argentinean Andes (T. contrerasi Cei, 1977). Twenty-eight species of Telmatobius are distributed in Peru (Lehr 2005; AmphibiaWeb 2014), but of these only five [T. arequipensis Vellard, 1955; T. intermedius Vellard, 1955; T. jelskii (Peters, 1873); T. peruvianus Wiegmann, 1834; T. rimac Schmidt, 1954] are known to occur in the hyper-arid coastal valleys that drain directly into the Pacific Ocean.

During October 2012 we made several surveys for the Biodiversity and Monitoring Assessment Program of the Smithsonian Conservation Biology Institute’s Center for Conservation Education and Sustainability (Catenazzi et al. 2013a; Catenazzi et al. 2013b). During one of these surveys, we found a population of Telmatobius in the upper drainage of the Huaytará river (Region of Huancavelica), a tributary of the Pisco river in the Pacific slopes of the central Peruvian Andes. Individuals of this population possess traits that do not correspond to the morphological characteristics of other species found in the arid coastal valleys of central Peru (Fig. 1), namely T. rimac to the north and T. intermedius to the south (Vellard 1951; Schmidt 1954; Lehr 2005). Therefore, here we describe the new species and provide a diagnosis to differentiate it from congeneric forms.

Figure 1. 

Map of Peru indicating the type localities of Telmatobius ventriflavum sp. n. (square), T. rimac (asterisk), T. intermedius (triangle) and T. arequipensis (star). The type locality of T. peruvianus is presumed to be near Tacna.

Specimens were preserved in 10% formol and stored in 70% ethanol. Sex and maturity of specimens were determined externally by observing sexual characters (nuptial spines), and gonads through dissections. Specimens below the SVL of the only male (SVL 48.5 mm) were considered juveniles. We measured the following variables (Table 1) to the nearest 0.1 mm with digital calipers under a stereomicroscope: snout–vent length (SVL), tibia length (TL), foot length (FL, distance from proximal margin of inner metatarsal tubercle to tip of Toe IV), head length (HL, from angle of jaw to tip of snout), head width (HW, at level of angle of jaw), eye diameter (ED), tympanum diameter (TY), interorbital distance (IOD), upper eyelid width (EW), internarial distance (IND), eye–nostril distance (E–N, straight line distance between anterior corner of orbit and posterior margin of external nares). Fingers and toes are numbered preaxially to postaxially from I–IV and I–V respectively. We determined comparative lengths of toes III and V by adpressing both toes against Toe IV; lengths of fingers I and II were determined by adpressing the fingers against each other. Photographs taken by A. Catenazzi were used for descriptions of coloration in life and are available at the Calphoto online database (http://calphotos.berkeley.edu). We used spring scales (Pesola AG, Switzerland) to weigh live specimens in the field. The format of the diagnosis and description follows De la Riva (2005) with the addition of one feature describing head morphology.

We swabbed specimens in the field to measure infection by Batrachochytrium dendrobatidis. Each animal was swabbed with a synthetic dry swab (Medical Wire & Equipment) using a standardized swabbing protocol. In post-metamorphic stages, swabs were stroked across the skin a total of 30 times: 5 strokes on each side of the abdominal midline, 5 strokes on the inner thighs of each hind leg, and 5 strokes on the foot webbing of each hind leg (total of 30 strokes/frog). Tadpoles were swabbed with 10 strokes on the mouthparts. We followed standard DNA extraction and real-time PCR methods (Boyle et al. 2004; Hyatt et al. 2007), except that we analyzed single-swab extracts once instead of three times (Kriger et al. 2006; Vredenburg et al. 2010). We used a real-time Polymerase Chain Reaction (PCR) assay on material collected on swabs to quantify the level of infection (Boyle et al. 2004). This assay compares the sample to a set of standards and calculates a genomic equivalent for each sample, reported as z_e, the amount of zoospore equivalents (referred as “zoospores” in the text).

Specimens examined are listed in Appendix; codes of collections are: CORBIDI = Herpetology Collection, Centro de Ornitología y Biodiversidad, Lima, Peru; KU = Natural History Museum, University of Kansas, Lawrence, Kansas, USA; MUSM = Museo de Historia Natural Universidad Nacional Mayor de San Marcos, Lima, Peru; USNM = National Museum of Natural History, Washington D.C., USA.

Species of Telmatobius are known to exhibit considerable intraspecific variation in morphological and meristic traits, which hinders the use of these traits in taxonomy and systematics (Aguilar and Valencia 2009; De la Riva et al. 2010; Sáez et al. 2014). However, the unique combination of traits and coloration of T. ventriflavum warrants its description as a separate species. The new species bears some similarity with T. intermedius and T. peruvianus. The three species are medium sized, slender with relatively long tibias and feet, head wider than longer and short snout. They also inhabit similar habitats, high-elevation rocky streams that are tributary of coastal rivers draining directly into the Pacific Ocean. However, the new species is larger (the only known male is larger than the largest females of T. intermedius and T. peruvianus), both sexes have smooth skin, and males have small and densely packed nuptial spines.

Admittedly our comparisons of adult specimens are not ideal. For example, only one specimen of T. intermedius was available for comparison. However, this single specimen was a male exhibiting the large nuptial spine and the dorsal skin covered by keratinized spicules (Fig. 3). Concerning T. peruvianus, the original type locality of “Peru” (Wiegmann 1834) had been restricted to the Cordillera de Guatilla in Chile (Schmidt 1928), with several subsequent authors referring to Chilean material for morphological descriptions. The taxonomic status of the Chilean populations of T. peruvianus has recently been questioned (Sáez et al. 2014), and these populations might belong to a different taxon than the Peruvian populations. However, for our present work we only relied on specimen descriptions (Vellard 1951) and direct comparison of material collected near Tacna, Peru (Appendix).

A comparison of the larval stages of these three species could add additional diagnostic characters, but the tadpole of T. intermedius has not been collected and the tadpole of T. peruvianus has been described from specimens collected in Chile. We postpone description of the tadpoles of T. ventriflavum until tadpoles of T. intermedius and of T. peruvianus from Peruvian populations become available. Further research is needed to establish the phylogenetic relationships of these three taxa. Recent research from Chile revealed that species inhabiting the western valleys of the Andes formed an endemic lineage that diverged from lineages of the Altiplano in the late Pleistocene (Sáez et al. 2014).

The discovery of a new species in the species-poor coastal valleys of central Peru is unusual because these areas have been surveyed before and are easily accessible. For example the stream at the type locality of T. ventriflavum is at the crossing with the highway connecting the coastal Panamerican highway to the city of Ayacucho. Furthermore, two other species of Telmatobius were already known from coastal valleys to both the north (~200 km, T. rimac) and the south (~170 km, T. intermedius) of the type locality of T. ventriflavum. In such arid landscape one would not expect to find several species of aquatic frogs. Specimens of the new species had previously been collected from Huaytará, and had been deposited at the MUSM as unidentified Telmatobius. These specimens were not included in the type series because they are not adults, and because the name of collectors, and date and precise location of collection are unknown. Nevertheless, the discovery of a new species in such arid and easily accessible environments shows that much remains to be done to document amphibian diversity in the Andes (Sáez et al. 2014).

In addition to probably having a restricted geographic distribution, T. ventriflavum is threatened by the presence at the type locality of the pathogenic fungus B. dendrobatidis. This fungus causes chytridiomycosis and has been implicated in population declines and species extinctions of species of Telmatobius throughout the Andes (Merino-Viteri et al. 2005; Barrionuevo and Mangione 2006; Seimon et al. 2007; Barrionuevo and Ponssa 2008; Catenazzi et al. 2011; De la Riva and Burrowes 2011; Catenazzi et al. 2014; Catenazzi and von May 2014). For example, the three Telmatobius species known from Ecuador were extirpated in the late 1980s and early 1990s and are now thought to be extinct (Merino-Viteri et al. 2005). The last individuals of Telmatobius found in Ecuador showed symptoms of chytridiomycosis (Merino-Viteri et al. 2005). Moreover, population declines of T. marmoratus and T. timens in Peru (Seimon et al. 2007; von May et al. 2008; Catenazzi et al. 2011) and of three species of Telmatobius in Argentina (Barrionuevo and Ponssa 2008) have been associated with outbreaks of B. dendrobatidis, and high prevalence of infection has been reported from high-elevation populations of T. jelskii in central Peru (Catenazzi et al. 2013b) and T. gigas in Bolivia (De la Riva and Burrowes 2011). Therefore, further studies should monitor infection and assess the susceptibility of T. ventriflavum to chytridiomycosis. Additional threats to the conservation of the species are the damming and regulation of streams, large-scale infrastructure projects (reservoirs, pipelines, roads, etc.) and contamination from mining and agriculture.

We thank two anonymous reviewers for their helpful comments on our manuscript. We thank M. Jaico Huayanay and O. Sissa for assistance in the field, and C. Sahley and K. Ledesma for assistance with logistics and travel arrangements. We thank Peru LNG and the Biodiversity and Monitoring Assessment Program at the Center for Conservation Education and Sustainability (CCES), Smithsonian Conservation Biology Institute. Collecting permit 0605-AG-DGFFS-DGEFFS was issued by the Ministry of Agriculture. This is publication number 32 of the CCES’s Peru Biodiversity Program.

Specimens examined

Telmatobius arequipensis (5 specimens): PERU: Moquegua: Mariscal Nieto, Qda. Torota, MUSM 19491, 19493, 19474, 19492, 19494.

Telmatobius intermedius (1 specimen): PERU: Ayacucho: near Puquio, Allipaca, MUSM 3752 (lectotype).

Telmatobius jelskii (6 specimens): PERU: Ayacucho: Tambo, La Mar, MUSM 7646 (lectotype); Ayacucho: Seccelambra, MUSM 28511; Abra Toccto, MUSM 28513–14, Vinchos, MUM 28517; Huancavelica: Huancavelica, MUSM 7639 (lectotype).

Telmatobius mayoloi (5 specimens): PERU: Ancash: Conococha, MUSM 20470, 20742–74, 20489.

Telmatobius peruvianus (9 specimens): PERU: Tacna: Caplina, MUSM 19604–6, 19608; Putre, FMNH 6385, 6390, 6394–96, 6399–6400.

Telmatobius rimac (17 specimens): PERU: Lima: 6 km WSW Matucana, KU 181474–84; Canta, MUSM 19640–41, 19643, 19646, 19648; Tupe, MUSM 7657.