Hyloscirtus albopunctulatus
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 albopunctulatus

description: Hyloscirtus albopunctulatus (Boulenger, 1882)
Figs 4, 5, 7, 9, 11, 13, 14, 15 Common name: Standard English name: White-speckled tree frog Standard Spanish name: Rana de torrente de puntos blancos (Frank and Ramus 1996)
Hyla albopunctulata Boulenger, 1882: 385, fig. 4. Type locality: Sarayacu, Ecuador.
Type material.
Designated lectotype (Fig. 4 A): BMNH 1880.12.5.230, adult male, from “ Sarayacu, Ecuador ”. Paralectotypes: BMNH 1880.12.5.159 –162 adult males from “ Ecuador ”
Definition.
In this section, coloration and characters refer to preserved specimens unless otherwise mentioned, based on four adult females and 17 adult males, including the paralectotypes. Hyloscirtus albopunctulatus can be diagnosed by the combination of the following characters: (1) mean SVL 32.3 mm in adult males (range 30.3–35.5; n = 17) and mean SVL 37.8 mm in adult females (range 37.1–38.1; n = 4) (Suppl. material 1: table S 5, Fig. 7); (2) white supralabial stripe present; (3) tympanum round, inconspicuous in males and distinct in females, supratympanic fold present and unpigmented; (4) white ulnar and tarsal folds present and thick; (5) subarticular tubercles varying from small to inconspicuous in hands and feet; (6) supernumerary tubercles inconspicuous in hands and feet; (7) calcar tubercle absent; (8) pericloacal spots well-defined; (9) all surfaces plain cream with a combination of black and white spots in the dorsum; (10) in life, dorsal surfaces and flanks olive green to yellowish green, covered with white spots and with or without sparce or clumped black spots; axillar and inguinal regions yellowish or blueish; venter and anterior and posterior surfaces of thighs yellow; other ventral surfaces silver, brownish or greenish; yellow pericloacal spots; webbing yellow orange; iris clam shell with black or sand dune reticulations; (11) the advertisement call consist of a single note, with a mean duration of 0.051 ± 0.005 s, a mean dominant frequency of 2147.84 ± 137.36 Hz and a fundamental frequency of 1214.12 ± 184.71 Hz. The call can be repeated consecutively for an indefinite number of times (2 –> 70) in a series of calls.
Diagnosis.
Characters in this section pertain to preserved specimens unless otherwise noticed. Coloration refers to live specimens. The most similar species to Hyloscirtus albopunctulatus living in the Amazon basin are H. maycu sp. nov., H. elbakyanae sp. nov., H. dispersus sp. nov., H. phyllognathus, and H. torrenticola. Hyloscirtus albopunctulatus differs by having a white supralabial stripe (absent in H. elbakyanae sp. nov.), a supratympanic fold (absent in all species except in H. dispersus sp. nov.), a thick tarsal fold (rudimentary in H. maycu sp. nov., H. elbakyanae sp. nov., and H. phyllognathus), small to inconspicuous subarticular tubercles in hands and feet (conspicuous in hands and feet in H. maycu sp. nov., H. elbakyanae sp. nov., and H. dispersus sp. nov.; Fig. 11), inconspicuous supernumerary tubercles in hands and feet (conspicuous in hands in H. dispersus sp. nov.), an absent calcar tubercle (present in H. dispersus sp. nov. and H. phyllognathus), well-defined pericloacal spots (ill-defined or absent in H. maycu sp. nov., H. elbakyanae sp. nov., and H. torrenticola), and a clam shell iris with black or sand dune reticulations (a clam shell iris with dark pinkish or leather reticulations in H. maycu sp. nov. and H. elbakyanae sp. nov., pearl or pinkish iris with leather reticulations in H. dispersus sp. nov. and bronze iris in H. torrenticola, Fig. 12).
The advertisement call of H. albopunctulatus has a rise time of 2.28 ± 0.80 s (shorter in H. maycu sp. nov. with 0.832 s and in H. elbakyanae sp. nov. with 0.57 ± 0.05 s), a dominant frequency of 2149.84 ± 137.36 Hz and a fundamental frequency of 1214.12 ± 184.71 Hz (higher dominant frequency of 2795.41 ± 138.68 Hz and fundamental frequency of 2210.8–2924.2 Hz in Hyloscirtus 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 albopunctulatus has a call duration of 0.051 ± 0.005 s (longer in H. dispersus sp. nov. with 0.11 ± 0.015 s). Hyloscirtus albopunctulatus has an intercall duration of 0.30 ± 0.06 s (shorter in H. phyllognathus with 0.05 s and in H. torrenticola with 0.07 ± 0.007 s) (Table 4, Fig. 9; Melin 1941; Duellman and Altig 1978; Rivera-Correa 2016). Moreover, all males of H. albopunctulatus were registered calling from under rocks next to streams (n = 5; Pontificia Universidad Católica del Ecuador 2024), while all males of H. dispersus sp. nov. have been found calling while perching in vegetation over streams (n = 14; Pontificia Universidad Católica del Ecuador 2024).
Variation.
Dorsal and ventral variation of adult preserved specimens is illustrated on Fig. 13. In preservative, dorsum varies from cream with white spots distributed throughout the body and limbs and thick black spots scattered across the body (e. g., QCAZ 59825) and limbs (e. g., QCAZ 59823), with minute black spots scattered in the entire body (e. g., QCAZ 59817) or accumulated in the head (e. g., QCAZ 59824), with dark flecks in body and limbs (e. g., QCAZ 59809), with barely visible minute black spots (e. g., QCAZ 62188) or absent black spots (e. g., QCAZ 59827), to cream with barely visible white spots and minute and thick black spots covering almost the entire dorsum (e. g., QCAZ 59814). We found evidence of conspicuous intraindividual phenotypic plasticity in color. Photos of QCAZ 59825 taken within 14 days of each other show variation in the presence of black spots on the dorsum, head, and snout. Similarly, QCAZ 59822, after 17 days, gained abundant black spots on the dorsum and head and increased the conspicuousness of the dark reticulations on the iris (Fig. 14 A, B). We did not find phenotypic plasticity in ventral coloration. Ventral surfaces vary from cream (e. g., QCAZ 59825) to darker cream (e. g., QCAZ 59817). Mental gland in males varies from whitish cream (e. g., QCAZ 59814) to darker cream (e. g., QCAZ 59827).
In life (Fig. 15), the dorsum varies from light green with white spots scattered throughout the body and limbs, and few spread black marks (e. g., QCAZ 59825) or without black spots or marks (e. g., QCAZ 59811), yellowish green with white spots covering the entire body and limbs and spread black marks, accumulated in the anterior part of the body (e. g., QCAZ 59824) or minute and thick blacks spots across the body (e. g., QCAZ 59823) to brownish green with white spots in all the body and limbs and few black marks randomly dispersed (e. g., QCAZ 59808). Venter and posterior surfaces of thighs vary from yellow (e. g., QCAZ 59811) to greenish yellow (e. g., QCAZ 59808). Other ventral surfaces vary from whitish (e. g., QCAZ 59823) to brownish green (e. g., QCAZ 59824). Iris varies from clam shell with thin (e. g., QCAZ 59825) to thick black or sand dune reticulations (e. g., QCAZ 59823). Examined specimens are listed in Suppl. material 1: tables S 1, S 9.
Distribution and natural history.
Hyloscirtus albopunctulatus is known from seven localities, from North to Central eastern Ecuador at elevations between 389 and 1391 m (Fig. 5). Biogeographic regions are Amazon Humid Tropical Forest, Eastern Foothill Forest, and Eastern Montane Forest (Ron et al. 2022). They are nocturnal and associated with streams near ravines. Males call under rocks in ravines, leaf litter, streams, small creeks, caves, or cracks. Several individuals have been found perching on vegetation up to 2.5 m but have not been found calling there. The species occurs in sympatry with Hyloscirtus dispersus sp. nov.
Advertisement call.
We analyzed 26 calls from seven individuals. Six males (QCAZ 59813, 59815, 59817 and three non-collected males) from Comunidad Zarentza, Llanganates National Park, Provincia Pastaza, on 17–24 February 2017, air temperature 19–21 ° C, recorded by D. Velalcázar and D. Rivadeneira. One individual (QCAZ 48503) from Reserva Río Bigal, Provincia Orellana, recorded by M. Read, on 22 May 2010. The advertisement call consists of a single tonal note, repeated a highly variable number of times in a series of calls (Fig. 9 A). We found from two to more than 70 consecutive calls before long silence periods. One male (QCAZ 59815) called with short pauses during 4.08 s, broadcasting 926 calls. The average call duration is 0.051 + 0.005 s with an average inter-call interval of 0.30 ± 0.06 s. The average dominant frequency of the call is 2149.8 ± 137.36 Hz. Other call parameters are listed in Table 4.
Conservation status.
The distribution polygon of Hyloscirtus albopunctulatus is 7921 km 2. Habitat destruction for agriculture and cattle is rising within its distribution range (Ministerio del Ambiente 2013). However, they also inhabit undisturbed and protected areas like Parque Nacional Llanganates. Its tolerance to disturbed forests is unknown. Given its distribution range being less than 20000 km 2 and by having less than 10 known localities, we propose that H. albopunctulatus remains assigned to the Red List category Vulnerable (B 1 abiii).
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