Bioacoustics of Phyllodytes praeceptor

Advertisement call . The advertisement call ( Fig. 5 ) of Phyllodytes praeceptor has a total duration of 3.02– 9.41 s (5.34 ± 1.53, n = 28). It is emitted at intervals of 29.5– 99.2 s (48.5 ± 21.2, n = 27) and with a dominant frequency of 2928.5–3273.0 Hz (3045.4 ± 115.3, n = 28). Each call is composed of 6–12 notes (8.39 ± 1.55, n = 28) with structured pulses lasting 0.141– 0.538 s (0.295 ± 0.075, n = 235), emitted at intervals of 0.236– 1.057 s (0.389 ± 0.102, n = 207), resulting in a note rate of 1.28–2.02 (1.61 ± 0.2, n = 28) notes/s. The interval between the final two notes of the call is generally much larger than the previous intervals. The notes dominant frequency range is 1378.1–3617.6 Hz (2998.1 ± 275.1, n = 235). Notes are composed by isolated pulses and/or by 1–11 pulse groups with 2–8 pulses in each group. Usually, the last pulse group is the largest among them and always composed of 6–15 more aggregated pulses. The total number of pulses per note is 17–58 (28.7 ± 9.4, n = 89) and pulse emission rate is 67.2–141.8 pulses/s (98.9 ± 15.8, n = 89). The notes exhibit amplitude modulation, usually starting with low intensity and increasing during the note. Bioacoustic comparisons with other species. The advertisement call of Phyllodytes praeceptor has a pulsed structure being readily distinguishable from the call of P. acuminatus , P. kautskyi , P. megatympanum and P. melanomystax , which show unpulsed structure (Campos et al. , 2014; Nunes et al. , 2007; Simon & Gasparini, 2003, Marciano Jr. et al. 2017). The calls of Phyllodytes amadoi , P. luteolus , P. edelmoi , P. tuberculosus , P. gyrinaethes and P wuchereri (Weygoldt 1981; Lima et al. 2008; Juncá et al. 2012; Roberto & Ávila 2013 Cruz et al. 2014 ; Magalhães et al. 2015 ; Vörös et al. 2017) are more similar to P. praeceptor because all of them consist of a series of multipulsionated notes and present overlap in some acoustic parameters, mainly in dominant frequency and call duration (except P. gyrinaethes , with shorter call and P. amadoi with high dominant frequency). The number of notes per call is higher in P. edelmoi (22–29), P. amadoi (13-17) and P. tuberculosus (14–23), and their ranges do not overlap with the variation of P. praeceptor (6–12). The mean number of notes of P. praeceptor (8.39 ± 1.55, 6–12) is smaller than the mean of P. wuchereri (16.18±3.25, 10–21) and larger than of P. gyrinaethes (4.90 ± 0.60, 4–6). The note duration in P. praeceptor (0.295 ± 0.075) is longer than in all species of the genus with described calls: P. luteolus (0.125, no range available), P. edelmoi (0.10 ± 0.003, 0.04–0.16), P. tuberculosus (0.17 ± 0.047, 0.07–0.25), P. gyrinaethes (0.04 ± 0.01, 0.02–0.07), P. wuchereri (0.19 ± 0.04, 0.11–0.32 and 0.12 ± 0.013, 0.04–0.14), P. kautskyi (0.08 ± 0.012, no range available), P. melanomystax (0.07 ± 0.04, no range available), P. acuminatus (0.10 ± 0.03, 0.03–0.17), P. megatympanum (0.092 ± 0.08, 0.009–0.24) and P. amadoi (0.043 ± 0.02, 0.008–0.119). Finally, the call of Phyllodytes praeceptor differs from all species of the genus by having an accentuated increase in amplitude from the first to the last pulse of each note ( Fig. 5 ), concentrating energy at the last cluster of pulses. Molecular data. Uncorrected pairwise genetic distances of 803 pb of 16S generated in this study are 1 % in relation to Phyllodytes sp. ( AY843722 ; voucher MRT 6144) and 9.6 % to P. luteolus ( AY843721 ). Given this results, we conclude that the specimen MRT 6144, sequenced by Faivovich et al. (2005) , should be identified as P. praeceptor .

Diagnosis . A medium-sized species (SVL 20.7–25.8 mm in males) characterized by: (1) dorsum of body, arms, and legs cream with scattered dark brown spots; (2) a dark brown stripe extending from the eyes; (3) snout short, semicircular (to truncated) in dorsal view, vertical (to truncated) in profile; (4) vomerine teeth in two dense patches, disposed in a transverse plane, behind the choanae; (5) one anterior large, and additional smaller subequal odontoids on each side of the mandible; (6) dorsal skin smooth; (7) vocal sac externally visible; (8) venter areolate with two paramedial rows of developed tubercles; (9) small tubercles in the ventral side of the thighs, the most medial more developed; (10) a tubercle at the tibio-tarsal articulation; (11) unpigmented nuptial pad visible, rounded, moderately expanded, (12) advertisement call consisting of a series of 6–12 pulsed notes, average duration of 5.34 s with notes lasting 0.295 s and dominant frequency ranging between 2928.5–3273.0 Hz. Comparison with other species. Character states of Phyllodytes praeceptor in parentheses. All species of Phyllodytes have multiple tubercles on the tarsus in various arrangements (a single large tubercle on posteroventral internal margin of tarsus, near to the junction with shank) and, with the exception of P. tuberculosus , different snout shapes in dorsal view (semicircular to truncated). Below we list other diagnostic morphological characters. Specimens of P. amadoi have snout with a small apical tubercle (absent) and two large anterior odontoids on both sides of the mandible (one larger odontoid). Specimens of P. acuminatus and P. megatympanum have a large tympanum, TD> 7 % of SVL, (small, TD ~ 6 % of SVL). Specimens of P. brevirostris , P. edelmoi , P. kautskyi , P. luteolus and P. megatympanum have an immaculate dorsum (spots and blotches on dorsum). Specimens of P. gyrinaethes have a hidden tympanum (distinct) and a mottled dorsal pattern (spots and blotches on dorsum). Male specimens of P. kautskyi and P . maculosus are larger, combined SVL = 38.0– 43.5 mm (SVL = 20.7–25.8 mm ). Specimens of P. luteolus have a snout mucronated in dorsal view (semicircular to truncated) and acute in lateral view (vertical to truncated), rows of tubercles in the forearm (inconspicuous), venter with various rows of developed tubercles (only the two paramedial are well-developed). Specimens of P. maculosus have a deeply mottled dorsal pattern (spots and blotches on dorsum). Specimens of P. megatympanum have a bright yellow groin in live specimens (no conspicuous coloration). Specimens of P. melanomystax have a conspicuous large dark brown stripe on the snout and canthus rostralis (absent or thin faded stripe in P. praeceptor ) and lack organized paramedial ventral rows of enlarged tubercles (present). Specimens of P. punctatus lack organized paramedial ventral rows of enlarged tubercles (present). Specimens of P. tuberculosus lack organized paramedial ventral rows of enlarged tubercles (present) and have supranumerary tubercles in the plantar surface (absent). Specimens of P. wuchereri have a dorsal pattern consisting of large black and white stripes and blotches (spots and blotches on dorsum).