Fifty years after: A taxonomic revision of the amphibian species from the Ecuadorian biodiversity hotspot Abra de Zamora, with description of two new Pristimantis species

fringes; webbing basal; (13) in life, dorsum gray to brown with sparse darker markings or chev- rons; venter white to cream with brown reticulations; hindlimbs usually with dark transverse bars; axilla, groin, anterior and posterior surfaces of thighs, and concealed surfaces of shanks black bordered by white, yellow or orange blotches; iris dark bronze with a reddish median horizontal streak; (14) SVL 28.9–45.7 mm in adult females (35.3 ± 9.06 SD, n = 3) and 25.6– 31.2 mm in adult males (n = 2). Variation. Morphometric variation is shown in Table 3. The females are significantly larger than the males, with one female (MUTPL 168, Fig 22A) having 45.7 mm SVL. All encountered specimens had the groin (but frequently also the axilla, anterior and posterior surfaces of thighs, and concealed surfaces of shanks) black, with the bordering blotches (or stripes) vary- ing from reddish orange (Fig 22A and 22C), yellow (Fig 22B) to whitish yellow (Fig 22D). Manny encountered individuals had the coloration of the female MUTPL 168 (Fig 22A), with brown or light brown dorsum and whitish, light markings. A few individuals had some white, branch-like white markings on their flanks and dorsum like in the case of the male MUTPL 470 (Fig 22B), and several individuals had the head and snout distinctly colored (white or beige) compared to the rest of the brownish body (MUTPL 135, Fig 22C). The juveniles had a more rugged general appearance and it seems that they lack the intense yellow or orange color- ation of the inguinal and axial blotches (MUTPL 493, Fig 22D). Advertisement call. Unknown.

Distribution. Pristimantis cryptomelas presence is confirmed (with DNA samples) from Reserva Tapichalaca, Parque Nacional Podocarpus (Cajanuma entrance), Abra de Zamora, Huacapamba (5 km north to the city of Loja) and Bosque Protector Washapamba, in Loja and Zamora Chinchipe provinces (Fig 23). The species has been reported from Morona Santiago province [9] and Peru [25]; however, due to the large distance between the sites, we recom- mend genetic analyses to confirm that these populations in fact belong to P. cryptomelas. The species was encountered at an altitudinal range between 2480 and 2960 m a.s.l. in montane cloud forest, evergreen upper montane forest (Fig 2C) and subpa´ramo ecosystems. Natural history. This is a common species, even in habitats with anthropic disturbance. All specimens were encountered during the night, perching on the vegetation (usually at 30 cm–2 m above the ground), sometimes in the vicinity of streams. No calling males were heard. Conservation status. Pristimantis cryptomelas is currently categorized as Near Threatened following the IUCN criteria [51]. We consider this category as adequate due the fact that it is a relatively abundant species and some of its populations are inside protected areas (Parque Nacional Podocarpus, Bosque Protector Washapamba), but also because it is currently known from only 5 localities, the existing populations are severely fragmented and there is a continu- ing decline in the extent and quality of its habitat due to cattle grazing and deforestation.

Remarks. Lynch [9] provides a detailed description of this species. Our diagnosis concurs with most of the morphological features described by the author, and we add descriptions of the characters that are more evident in life. Some of the differences that we observed are: tym- panum oval (in contrast to the round tympanum described by Lynch); discoidal fold weak (discoidal folds prominent); upper eyelid bearing 1 to 3 larger tubercles (upper eyelids tuber- culate, no tubercle greatly enlarged). The diagnosis provided herein is based on 8 specimens from the original description (KU 141992, 141993, 120095, 120096, 198480–83), one adult male (MUTPL 470) and two subadults (MUTPL 135, 471) collected from the type locality and 10 specimens collected from the other localities. Pristimantis phoxocephalus species group Three species of this species group were described from Abra de Zamora. PLOS ONE Taxonomic revision of the amphibian species from Abra de Zamora PLOS ONE | https://doi.org/10.1371/journal.pone.0238306 September 10, 2020 40 / 59