Hyloscirtus elbakyanae Varela-Jaramillo, Streicher, Venegas & Ron, 2025, sp. nov.
Creators: name: Varela-Jaramillo, Andrea
name: Streicher, Jeffrey W.
name: Venegas, Pablo J.
name: Ron, Santiago R.
Publisher: name: Zenodo
Year: 2025
Subjects: Biodiversity
Taxonomy
Animalia
Chordata
Amphibia
Anura
Hylidae
Hyloscirtus
Hyloscirtus elbakyanae

description: Hyloscirtus elbakyanae sp. nov.
Figs 5, 7, 9, 11, 18, 19 Common name: Proposed standard English name: Elbakyan stream frog Proposed standard Spanish name: Rana de Torrente de Elbakyan
Type material.
Holotype. • QCAZ 53808 (Figs 18, 19), field no. SC 39260, adult male from Ecuador, Provincia Morona Santiago, Comunidad Shaime, near Mirador de la Virgen (2.975540 ° S, 77.80346 ° W), 622 m above sea level, collected by SRR, A. Merino, F. Ayala, T. Camacho, and M. Cohen on 23 July 2012. A 3 D model of the holotype is available at Sketchfab platform (https://skfb.ly/oSXSH). Paratypes. • All collected in Ecuador, Provincia Morona Santiago. Same locality and collection data as the holotype, QCAZ 53807, 53831 adult males. Surroundings of Río Shaime (2.9409 ° S, 77.8012 ° W), 511 m, QCAZ 72665 –66 adult males, collected on 6 June 2018; • Tiwintza-Shaime road (2.9750 ° S, 77.7957 ° W), 211 m, QCAZ 72667, collected on 8 June 2018; • Mirador de la Virgen, Tiwintza-Shaime road (2.9756 ° S, 77.8015 ° W), 529 m, QCAZ 72668 adult male, collected on 8 June 2018; • Peñas-Shaime road (2.9663 ° S, 77.8468 ° W), 363 m, QCAZ 72669, collected on 9 June 2018; • Peñas-Shaime road, 2.8 km E Río Yaupi (2.9663 ° S, 77.8468 ° W), 363 m, QCAZ 73709 adult male. F. Ayala, D. Núñez, K. Nusirquia and A. Carvajal collected all specimens from 2018.
Definition.
In this section, coloration and characters refer to preserved specimens unless otherwise mentioned. The Definition and Diagnosis are based on eight adult males, females are unknown. Hyloscirtus elbakyanae sp. nov. can be diagnosed by the combination of the following characters: (1) male mean SVL 36.3 mm (range 34.5–37.6; n = 9; Suppl. material 1: table S 5, Fig. 7); (2) white supralabial stripe absent; (3) tympanum round, inconspicuous; supratympanic fold inconspicuous and unpigmented; (4) white ulnar and cloacal folds present; white tarsal fold present, inconspicuous to conspicuous; (5) subarticular tubercles conspicuous in hands and feet; (6) supernumerary tubercles inconspicuous; (7) calcar tubercle absent; (8) pericloacal spots well-defined; (9) all surface plain cream with inconspicuous or absent white spots and minute or thick black spots or flecks in the dorsum; (10) in life, dorsal surfaces and flanks olive green, brownish green or greyish green with or without white flecks and with minute or thick black spots or flecks; axillar and inguinal regions silver or brownish; venter and posterior surfaces of tights yellow; other ventral surfaces silver or brownish; pericloacal spots ill-defined, unpigmented; webbing yellow orange; iris pearl to clam shell with pinkish drown or leather reticulations; (11) the advertisement call consists of a single note, with a mean duration of 0.056 ± 0.001 s and a dominant frequency of 2321.29 ± 127.86 Hz and fundamental frequency of 1184.35 ± 30.48 Hz. The call can be repeated in a series of 4–13 calls.
Diagnosis.
Characters in this section pertain to preserved specimens unless otherwise noticed. Coloration refers to live specimens. The most similar species to Hyloscirtus elbakyanae sp. nov. in the Amazon basin are Hyloscirtus albopunctulatus, H. maycu sp. nov., H. dispersus sp. nov., H. phyllognathus, and H. torrenticola. Hyloscirtus elbakyanae sp. nov. differs by the absence of a white supralabial stripe (present in H. albopunctulatus, H. phyllognathus and H. torrenticola), an absent supratympanic fold (present in H. albopunctulatus and H. dispersus sp. nov.), an inconspicuous tarsal fold (conspicuous in H. albopunctulatus, H. phyllognathus, and H. torrenticola), conspicuous subarticular tubercles in hands and feet (inconspicuous in hands and feet in H. albopunctulatus, Fig. 11), inconspicuous supernumerary tubercles in hands and feet (conspicuous in hands in H. dispersus sp. nov.), absent pericloacal spots (present in H. albopunctulatus and H. phyllognathus), absent calcar tubercle (present in H. dispersus sp. nov. and H. phyllognathus), and a clam shell or pearl iris (clam shell with black or sand dune reticulations in H. albopunctulatus and a bronze iris in H. torrenticola, Fig. 12).
The advertisement call of Hyloscirtus elbakyanae sp. nov. has a rise time of 0.57 ± 0.05 s (longer in H. albopunctulatus with 2.28 ± 0.80 s and in H. torrenticola with 0.16 ± 0.017 s), a dominant frequency of 2321.29 ± 127.86 Hz and a fundamental frequency of 1184.35 ± 30.48 Hz (higher dominant frequency of 2795.41 ± 138.68 Hz and fundamental frequency of 2700.63 ± 195.66 Hz in H. dispersus sp. nov.). Hyloscirtus torrenticola also has a higher dominant frequency of 2743.79 ± 48.22 Hz and a fundamental frequency of 2743.75 ± 48.16 Hz. Hyloscirtus elbakyanae sp. nov. has a call duration of 0.06 ± 0.001 s (longer in H. dispersus sp. nov. with 0.11 ± 0.015 s) and an intercall duration of 0.12 ± 0.007 s (shorter in H. torrenticola with 0.07 ± 0.007 and longer in H. albopunctulatus with 0.30 ± 0.06 s and in H. dispersus sp. nov. of 0.33 ± 0.044 s) (Table 4, Fig. 9; Melin 1941; Duellman and Altig 1978; Rivera-Correa 2016).
Moreover, H. elbakyanae sp. nov. inhabits elevations between 214 and 622 m, while H. maycu sp. nov. lives higher between 882 and 1183 m, in colder and dryer environments (Figs 5 and 10). The available evidence indicates that H. elbakyanae sp. nov. is larger than H. maycu sp. nov. (Fig. 7).
Description of the holotype.
Description of characters based on preserved specimen. Adult male (Figs 18, 19). Measurements (in mm): SVL 36.1; foot length 14.3, head length 10.5, head width 11.7, eye diameter 3.4, tympanum diameter 1.6, tibia length 16.9, femur length 16.7, internarial distance 3.0, inter-orbital distance 5.5. Head wider than long; body slender; snout rounded in dorsal and lateral views; distance from nostril to eye shorter than diameter of eye; canthus rostralis distinct; loreal region concave; internarial region nearly flat; top of the head flat; nostrils not protuberant, round, directed anterolaterally; lips rounded, not flared; interorbital area slightly concave, longer than upper eyelid; tympanum inconspicuous, with upper and posterior margins barely covered by a curved and thin inconspicuous supratympanic fold reaching anterior margin of insertion of arm; tympanic annulus absent; tympanic membrane absent; mental gland present, oval-shaped, very distinct, extending ~ 1 / 2 the length of the head; dentigerous processes of vomers straight, in transverse row posterior to level of choanae, which is round, each process narrowly separated from each other and bearing 4 teeth; tongue slightly cordiform, widely attached to mouth floor; vocal slits and vocal sac present.
Forearms slender; axillary membrane absent; fingers bearing dermal fringes and rounded discs; relative lengths of fingers I <II <IV <III; webbing formula I basal II 2 – — 3 – III 2 + — 2 – IV; subarticular tubercles prominent, round, single; supernumerary tubercles inconspicuous; thenar and palmar tubercles absent; small prepollex, not modified as a spine; nuptial pads absent; ulnar tubercles absent; outer ulnar fold present. Hindlimbs moderately robust; toes bearing rounded discs; relative length of toes I <II <III <V <IV; extensive toe webbing, formula I 1 – — 1 3 / 4 II 1 – — 2 – III 1 + — 1 – IV 1 – — 1 – V; outer tarsal fold present; tarsal tubercles absent; calcar tubercle absent; subarticular tubercles round and single; supernumerary tubercles not distinctive; inner metatarsal tubercle present and ovoid, outer absent. Skin on dorsal surfaces and flanks smooth and ventral surfaces granular; cloacal opening directed posteriorly at upper level of thighs, rounded tubercles below; cloacal fold thick.
Color of holotype in preservative
(Fig. 18). Dorsal surfaces of the dorsum, flanks and limbs cream covered with minute black spots, more abundant in the head. Very few white spots barely visible dispersed on the posterior dorsum and dorsal surfaces of the hindlimbs. Venter, throat, and ventral surfaces of limbs plain cream. Mental gland cream with small black spots. White supralabial stripe absent. Ulnar, tarsal, and cloacal folds white. Webbing cream.
Color of holotype in life
(Fig. 19). Based on digital photographs. Dorsal surfaces and flanks dark brownish green with minute black spots, more abundant on the anterior part of the head and limbs, as if those areas were dark brown. Few barely visible white flecks spread on the hindlimbs. Venter and posterior surfaces of thighs yellow, other ventral surfaces whitish. Throat greenish white. Tympanum pale green. Mental gland calico. Ulnar, tarsal, and cloacal folds white. Webbing yellow. Iris pearl with pinkish-brown reticulations.
Variation.
Dorsal and ventral variation of adult specimens is illustrated on Figs 18, 19. In preservative, dorsum varies from cream with scattered white spots through the body and limbs and minute and thick black pots scattered across the body and limbs (e. g., QCAZ 73669) or barely visible black spots or marks (e. g., QCAZ 72666), without white spots and brownish black flecks dispersed in the body and limbs, more accumulated in the anterior part of the body (e. g., QCAZ 72668) or spots covering the entire body and limbs (e. g., QCAZ 72665) to paler cream without white spots and few black marks in the anterior part of the body (e. g., QCAZ 73709). Ventral surfaces vary from darker cream (e. g., QCAZ 72666) to paler cream (e. g., QCAZ 73709). Mental gland varies from cream (e. g., QCAZ 73669) to whitish (e. g., QCAZ 72665). White supralabial stripe varies from inconspicuous (e. g., QCAZ 72665) to absent (e. g., QCAZ 73709).
In life (Fig. 19), dorsum varies from pale olive green, olive green, brownish green, darker brownish green to greyish green with barely visible white spots scattered throughout the body and few black marks in the anterior part of the body (e. g., QCAZ 53831) or without black marks or spots (e. g., QCAZ 53807), to absent white or black spots (QCAZ 72665, 72667, 72669 and 73709). Ventral surfaces, besides venter and posterior thighs, vary from silver (e. g., QCAZ 53807) to whitish (e. g., QCAZ 73709). Iris varies from clam shell with thin reticulations (e. g., QCAZ 73709) to pearl with thicker reticulations (e. g., QCAZ 72667). White supralabial stripe varies from present (e. g., QCAZ 72665) to absent (e. g., QCAZ 72667).
Distribution and natural history.
Hyloscirtus elbakyanae sp. nov. is known from seven localities, nearby the type locality, Comunidad Shaime, Provincia Morona Santiago, Ecuador, at elevations between 214–622 m (Fig. 5). Biogeographic regions are Amazon Humid Tropical Forest and Eastern Lower Montane Forest (Ron et al. 2022). This species lives in hillside forest, with varying levels of anthropogenic disturbance. The habitat is dominated by palms (Iriartea deltoidea) and trees up to 20–30 m high (collectors’ observations). They are nocturnal and have been found on ravines with shrub vegetation on the edge of torrent rivers and streams. Hyloscirtus elbakyanae sp. nov. calls from under rocks in streams with little water and cracks. There are no records of individuals perching on riparian vegetation.
Advertisement call.
We analyzed ten calls from two individuals. Both calls (QCAZ 53807 –08) from Comunidad Shaime, Provincia Morona Santiago, recorded on 23 July 2012 by SRR and T. Camacho, water temperature 20–21 ° C. The advertisement call consists of a single tonal note, repeated in series of 4–13 calls (Fig. 9 C). Average call duration is 0.06 ± 0.05 s with an average inter-call interval of 0.12 ± 0.007 s. The average dominant frequency is 2321.29 ± 127.86. Other call parameters are listed in Table 4.
Conservation status.
The distribution polygon of H. elbakyanae sp. nov. is 11 km 2. There is evidence of deforestation due to logging and it is not known to occur in protected areas. There might be undiscovered populations because the region where it occurs has not been thoroughly sampled. However, in response to its distribution range being less than 20000 km 2 and having fewer than ten known localities, we propose assigning H. elbakyanae sp. nov. to the Red List category Vulnerable (VUB 1 abiii).
Etymology.
The specific name elbakyanae sp. nov. is a noun in the genitive case and is a patronym for Alexandra Elbakyan. She is a computer programmer and creator of Sci-Hub, a website which provides free access to scientific articles. Sci-Hub allows scientists worldwide to access articles that, otherwise, are behind paywalls and unaffordable in low- and middle-income countries. Our research has greatly benefited from access to relevant literature using Sci-Hub through the years.
description: Published as part of Varela-Jaramillo, Andrea, Streicher, Jeffrey W., Venegas, Pablo J. & Ron, Santiago R., 2025, Three new species of torrent treefrogs (Anura, Hylidae) of the Hyloscirtus bogotensis group from the eastern Andean slopes and the biogeographic history of the genus, pp. 233-292 in ZooKeys 1231 on pages 233-292, DOI: 10.3897/zookeys.1231.124926