Bioacoustics of Pseudopaludicola giarettai

Etymology. The name is a noun in the genitive case honoring Ariovaldo A. Giaretta for his extensive contribution to the knowledge of Brazilian anurans. Pseudopaludicola giarettai advertisement call. Eight males recorded (N = 247 advertisement call samples). Quantitative variables are summarized in Table 3 . Advertisement call (fig. 4) consists of a whistled structure (nonpulsed note) with 4 detected harmonics with ascendant frequency modulation along its extent. Advertisement call may present a slight or a strong descendant intensity modulation in the first third or in the half of calls so that sound energy may even be barely identified. Advertisement call is emitted at a rate of 117–153 calls/minute (mean 136.2, SD = 14.8), and at a rate of 2.0–2.6 calls/second (mean 2.3, SD = 0.2). Call duration was 117–187 ms (mean 153.9, SD = 15.8) with intercall interval from 181–1,316 ms (mean 302.1, SD = 54.1). Ascendant dominant frequency modulation was emphasized from less than 4,000 Hz to more than 5,000 Hz along each call. Peak of sound energy was 3,981–4,719 Hz (mean 4,374, SD = 150.0). Dominant frequency coincided with the fundamental harmonic, the other three harmonics were increasingly weaker in sound intensity, emphasized from 8,278–9,337 Hz (mean 8,847, SD = 321.0), from 11,871–13,931 Hz (mean 12,977, SD = 742.0), and from 15,703–18,189 Hz (mean 17,320, SD = 672.0), being the third and fourth harmonics invisible in sound figures (less than -36 dB in the relative amplitude scale bar). Advertisement call variables P. giarettai sp. nov. (N=8) Call duration (ms) 153.9+15.8 (117–187) Intercall interval (ms) 302.1+54.1 (181–1,316) Peak of sound energy (Hz) 4,374+150.0 (3,981–4,719) Call rate (calls/minute) 136.2+14.8 (117–153) Call rate (calls/second) 2.0+2.6 (2.3–0.2)

Remarks. One population of Pseudopaludicola sp. from the Municipality of Muriaé, State of Minas Gerais, was also reported to emit whistled calls (non-pulsed note structure) ( Santana et al. 2010 ). Morphological/bioacoustic evaluation is required to assess the species identity of that population so as to assign it as being conspecific to P. giarettai sp. nov. or to an additional undescribed species. Assessment of the richness in the Neotropical genus Pseudopaludicola species is particularly difficult due to the conservative morphology of its species. Hence, bioacoustic data are essential for the recognition of cryptic lineages currently assigned to a few available specific names within the genus. FIGURE 4. A. Oscillogram (5 seconds) of a sequence of ten advertisement calls of Pseudopaludicola giarettai sp. nov. from the Municipality of Curvelo, State of Minas Gerais, Brazil . B. Audiospectrogram (above) and corresponding oscillogram (below) detailing two advertisement calls (fifth and sixth calls delimited by a red rectangle outline) of the sequence of ten advertisement call of Pseudopaludicola giarettai sp. nov. Sound file: Pseudop_giarettaiMG8TRC_AAGmt; 18:21h, 23 February 2011 ; air 24ºC, water 26ºC. Vouchered recording.

Diagnosis. Pseudopaludicola giarettai sp. nov. is assigned to the genus by possessing hypertrophied antebrachial tubercle. The new taxon is diagnosed by the following combination of characters: (1) large size (SVL 16.2– 18.0 mm in adult males); (2) absence of either T-shaped terminal phalanges or expanded toe tips (disks or pads); (3) short hindlimbs (tibiotarsal articulation reaching the eye); and (4) distinctive whistled advertisement call possessing a non-pulsed structure. Comparison with other species. The new taxon (SVL 16.2–18.0 mm in adult males) is diagnosed from the species of the P. pusilla group ( P. boliviana , P. ceratophyes , P. canga , P. llanera , and P. pusilla ) by the absence of either T-shaped terminal phalanges or expanded toe tips (disks or pads). Pseudopaludicola giarettai sp. nov. is diagnosed from almost all congeners by possessing a unique advertisement call (fig. 4) with non-pulsed pattern in comparison with that of congeners [pulsed advertisement calls: P. boliviana ( Duré et al. 2004 ) , P. saltica and P. falcipes ( Haddad & Cardoso 1987 ) , P. m y s t a c a l i s (A. Pansonato unpubl. data), P. murundu (Toledo et al. 2010) , P. serrana (Toledo 2010) , P. m i n e i r a ( Pereira & Nascimento 2004 ), P. riopiedadensis (L.D. Vizotto pers. comm.; A. Pansonato unpubl. data), and P. t e r n e t z i (A. Pansonato unpublished data)]; and from the non-pulsed pattern of P. canga ( Giaretta & Kokubum 2003 ) by the emission of isolated long (117–187 ms) non-pulsed notes, whereas P. canga releases sequences of up to nine short (~ 52 ms; Giaretta & Kokubum 2003 ) non-pulsed notes.

Description of holotype . Snout rounded in dorsal and lateral (figs. 3A–B) views ( Heyer et al. 1990 ). Dorsal surfaces of body and limbs smooth. Lateral of head (upper lip and under the eyes and tympanum area) and flanks with white granules. Cloacal region granular. Vomerine teeth absent; tongue ovoid, free behind; dorsal surface smooth; belly and throat smooth; tympanic ring undefined; outer and inner metacarpal tubercles ovoid; small supernumerary tubercle indistinct (fig. 3C); relative length of fingers I <II ~ IV <III; inner metatarsal tubercle oval; outer metatarsal tubercle round and conical (fig. 3D); relative length of toes I <II <III ~ V <IV; finger and toe tips not expanded; finely keratinized nuptial asperities on the base of thumbs; toes barely webbed and with extensive fringing; one round antebrachial tubercle present on distal portion of forearms, no distinctive tubercle on heel; outer edge of tarsus and forearm smooth; a dermal ridge present from inner metatarsal tubercle to mid-length of tarsus; no pigmentation on the base of tongue; body elliptical. Nostrils subtly protuberant, directed anterolaterally. Canthus rostralis rounded. Loreal region slightly concave. Choanae rounded. Eye protuberant, its diameter larger than interorbital distance. Interorbital area flat. Vocal sac single, externally expanded, large, and with longitudinal folds; vocal slits present. Measurements of holotype . Snout-vent length 17.1 mm , head length 7.5 mm , head width 5.9 mm , internarial distance 1.2 mm , eye-nostril distance 1.3 mm , eye diameter 2.0 mm, hand length 4.5 mm , thigh length 7.9 mm , shank length 8.5 mm , and foot length 9.1 mm . Color of holotype in preservative (fig. 2). In preservative, dorsal surfaces of dorsum and limbs pale brown with dark brown spots or irregularly shaped stripes; belly cream; vocal sac yellowish cream. White spots on upper lips extending to the flanks. Color in life. Color in life (fig. 1) was based on three adult male paratopotypes (AAG-UFU 0309–0311). Dorsal surfaces of body and limbs light brown. Dorsum smooth with a few granules, some of them larger on scapular region, tending to red. Dorsum and flanks with irregular dark brown blotches. Lateral of head bordering upper jaw and flanks with white spots, extending to the flanks. Belly cream, vocal sac yellowish. Ill-defined dark brown stripes on dorsal surface of thighs (a few) and interorbital region (single). Variation. The female (AAG-UFU 0318) has a more robust body, nuptial pads absent, and gular region without longitudinal folds. The specimens AAG-UFU 0309–0311, 0 314, and 0 316 have undulating-like paravertebral stripes from the posterior corner of eyes to the half of dorsum. The specimens AAG-UFU 0 311 and 0 315 have copper color stains on scapular region. The specimens AAG-UFU 0 309, 0 311, 0314–0315, and 0 319 have a chevronlike stripe between eyes. The specimen AAG-UFU 0 316 has cream broad longitudinal stripes from the posterior corner of eyes to the half of dorsum. Natural history. Males call during daytime and decrease call activity after nightfall. Males call on the margins of artificial ponds and slow-flowing streamlets with clean water and muddy bottom. Several males were in calling activity during a period with no precipitation for about two months long in the study site in February/2011. Syntopic species include Leptodactylus fuscus , Physalaemus cuvieri , Pseudopaludicola sp., Dendropsophus rubicundulus , Hypsiboas albopunctatus , Hypsiboas crepitans , Scinax sp. (gr. ruber ), Elachistocleis cesarii , and Rhinella schneideri .