Bioacoustics of Myersiohyla neblinaria

DIAGNOSIS: Myersiohyla neblinaria is characterized by: (1) SVL of male 47.7–52.3; female SVL 54.0–61.6; (2) a single, thick, nuptial pad; (3) a row of tubercles in the forearm; (4) mental gland present but evident only through dissection; (5) thighs with longitudinal bars; (6) dorsum brown, with variable presence of a dorsal line and blotches; (7) m. depressor mandibulae without an origin on the dorsal fascia at the level of the m. levator scapulae; (8) unpigmented eggs; (9) tadpoles with a dorsoventrally flattened body; (10) fins reaching the base of the tail; (11) labial toothrow formula (LTRF) 16 (16)/21(1). COMPARISON WITH OTHER SPECIES: Myersiohyla neblinaria is most similar to M. inparquesi but differs in having: hand and toe discs without sagittal black lines (present in M. inparquesi ); larvae with dorsal and ventral tail fins reaching the base of the tail (extending only a third in M. inparquesi ); larvae with scattered submarginal papillae in the upper and lower labium (apparently absent in M. inparquesi ); and larval oral disc with a single row of marginal papillae (three rows in M. inparquesi ). Furthermore, the advertisement call of M. neblinaria is composed of a single note with 7–9 pulses and a duration of 295–382 ms; in contrast, the advertisement call of M. inparquesi is composed of two notes, one of 6 pulses and a duration of 90 ms, and the other with 7 pulses and a duration of 80 ms (Ayarzagüena and Señaris, “1993” [1994]). Myersiohyla neblinaria differs from M. loveridgei in its larger SVL ( M. neblinaria 47.7– 52.0 mm; M. loveridgei 42–45 mm ; Rivero, 1961 ; “ 1971 ” [1972]), and in having a single nuptial pad (two in M. loveridgei ). From M. aromatica it differs in having a single nuptial pad, instead of two (Ayarzagüena and Señaris, “1993” [1994]: 130); larger SVL ( M. aromatica , 43.6–46.6 mm ; M. neblinaria 47.7–52.0 mm); tadpole with dorsoventrally flattened body (globular in M. aromatica ) and more rows of labial teeth (LTRF 10-13/ 14-18 in M. aromatica ). M. neblinaria is distinguished from M. kanaima by its larger SVL (males: 37.0– 37.8 mm , ẍ= 37.4, n = 5; females: 46.3–48.0 mm, ẍ= 47.05, n = 4; Goin and Woodley, 1969 , and this paper), more robust body (slender in M. kanaima ), more developed prepollex (proportionally reduced in M. kanaima ), more extensive and thick nuptial pad (reduced to the dorsal margin of the prepollex, and composed of a thin layer of glandular tissue, apparently without colored epidermal projections), unpigmented eggs (completely pigmented in M. kanaima ), color pattern, tadpole with dorsoventrally flattened body (depressed in M. kanaima ) and more rows of labial teeth (LTRF 2/ 4 in M. kanaima , but see discussion).

ECOLOGY AND NATURAL HISTORY: Near Camp I, Buck found an adult female (USNM 562070) asleep during the day in a leaf axil of Bonnetia maguireorum (Theaceae) on a small ridge northeast of Camp I (fig. 23). At Camp VII, a gravid female (USNM 562072) was collected on a vine in the forest and produced copious amounts of a milky white exudate on its back after capture. Specimens from Camp XI were collected by McDiarmid, Cocroft, and Paolillo along a small ( 1–4 m wide) forest stream with large boulders and cascades. On February 25, 1985 , USNM 562073 was recorded as it called beside a cascade in a clump of grass growing out of a sloping, mossy rock face about 1 m from the water; three other males (USNM 562074, USNM 562077–78) were on leaves and in grass clumps near cascades on sloping rocks along the same stream. USNM 562075– 76, USNM 562079–80, USNM 562082 were all collected from a rocky grotto along the same stream on the following night. An immature male (see below) was collected on a leaf of a small plant about 15 m from the stream that same night. Two of three females (USNM 562070, SVL 59.8; USNM 562072, SVL 60.2) collected on February 10, 1984 , and February 10, 1985 , respectively, were gravid. A comparable-sized female (AMNH A-123715, SVL 61.6 mm ) collected on November 29, 1984 also was gravid. The fourth female (AMNH A-131172), collected February 9–11, 1984 , was smaller (SVL 54.0 mm) and had oocytes in very early stages of development, suggesting that she was approaching maturity. Most collected males (SVL 47.7–52.3 mm , n = 10) had well-developed nuptial pads and presumably were capable of breeding. Calling males were heard in late February 1985 at Camp XI. A single smaller male (USNM 562081, SVL 40.0 mm) collected at the same time and place lacked nuptial pads and likely was immature. VOCALIZATION: The advertisement call of a male paratype (USNM 562073) calling alone was recorded in February along a cascading stream near Camp XI (fig. 24). The frog was calling at the base of a clump of grass, about 1 m from the water. The recording includes 31 notes being continuously given in 80 sec of tape (the recording may contain only the terminal part of a long call). 1 2 3 1- USNM 562071 — — — 2- USNM 562072 0.002 — — 3- USNM 562074 0.000 0.002 — 4- USNM 562732* 0.000 0.002 0.000 The call is a long train of well-spaced notes given at a rate of 23.4 notes/min. Note duration is about 0.3–0.4 sec (295–382 ms, ẍ = 338 ± 21 ms, n = 20). The individual note is composed of 7–9 pulses (ẍ = 8.05 ± 0.69, n = 20 notes) that are resolvable even by narrowband analysis (fig. 24C). The individual note is a brief musical trill, being narrowly tuned with frequency rising about 113–151 Hz throughout the note from 1522–1560 Hz at initiation to 1673 Hz at the end ( n = 9 notes analyzed). Ayarzagüena and Señaris (“1993” [1994]) described the advertisement call of Myersiohyla inparquesi as a train of 240 ms, composed of two notes, the first with six pulses (90 ms) and the second with seven pulses (70 ms). The call was described as spanning the spectrum between 1200–2000 Hz, with a harmonic at 4400 Hz and the fundamental frequency at 1740 Hz. The call repetition rate was 20 notes/min. While no illustrations or temperature data were provided by Ayarzagüena and Señaris, their description suggests a call quite different from that of M. neblinaria . Although Myersiohyla neblinaria and M. aromatica are readily diagnosable by several morphological characters (see diagnosis), the calls seem similar. The call of M. aromatica was described by Ayarzagüena and Señaris (“1993” [1994]), on the basis of recordings done at 19° C. The call was composed of single notes with an average duration of 420 ms, with 10–11 wellspaced pulses, a dominant frequency of 2000 Hz, and a bandwidth between 1250 and 2600 Hz. The note repetition rate was 44 notes/min.