Calls of five species of the Scinax ruber (Anura: Hylidae) clade from Brazil with comments on their taxonomy

Abstract

As currently defined, tree frogs of the genus Scinax comprises the most species-rich genus within Hylinae. Although in the last decades there have been an increasing number of taxonomic studies on Scinax, populations of several species still deserve further studies to assess their taxonomic status. The purpose of this paper is to contribute to the taxonomy and zoogeography of some species of Scinax from Brazil assigned to the Scinax ruber clade through the description/redescription of their advertisement calls. The advertisement call of S. duartei from topotypic specimens and the call of S. acuminatus are described here for the first time. The call of S. duartei is in disagreement with descriptions from the literature what suggests that an unnamed species is hidden under this specific name. Redescriptions of the calls of S. crospedospilus, S. eurydice, and S. hayii are also provided and compared with previous studies. In order to better assess the taxonomic status of species with advertisement calls that present more than one emphasized frequency, as in some species of the Scinax ruber clade, we recommend special attention in the descriptions of the spectral components of these calls.

Cytogenetic analysis of Scinax auratus and Scinax eurydice (Anura, Hylidae) with emphasis on cytotaxonomy

“…The interpopulation variation of NOR and C-banding pattern among populations of Scinax eurydice , associated with slight differences in vocalization between samples from northeastern and southeastern Brazil (Magrini et al 2011), reinforces the necessity of a taxonomic review of this species.…”

“…Scinax euridyce (Bokermann, 1968) is also widespread in Brazil with records in five states of northeastern and southeastern Brazil (Bahia, Espírito Santo, Minas Gerais, Rio de Janeiro and São Paulo) (Pombal et al 1995, Hartmann 2002, Canelas and Bertolucci 2007, Araújo et al 2009, Magrini et al 2011). Cytogenetic analyses in samples from southeastern Brazil have shown polymorphic NORs since two specimens presented terminal marks on 11q while a single female presented interstitial Ag-NORs (Cardozo et al 2011).…”

Vocalization of Scinax haddadorum (Anura: Hylidae), with further notes on the vocalization of the morphologically similar Scinax rupestris

“…Call duration of S. haddadorum is relatively short (102-328 ms) compared to that of S. rupestris (334-708 ms; Table 2; 290-420 ms [7]). In addition, these species exhibit distinct spectral structure in their calls (under 256-point FFT): the call of S. haddadorum has most energy distributed in a 'J-shaped' pattern for each pulse, whereas the call of S. rupestris has two emphasized frequency bands with different bandwidths throughout the call ( Table 2, Figures 3 and 4) (see a discussion on frequency bands in calls of other Scinax species in Magrini et al [13]). Additionally, S. rupestris has a distinct temporal envelope (a progressive increase in amplitude along the call) in relation to that of S. haddadorum (increment in amplitude in the first pulses, followed by a sustained amplitude throughout call duration).…”

“…Specimens from Alto Paraíso de Goiás (Figure 1(b)) were identified as S. rupestris (Araujo-Vieira et al [7]) based on the following traits: (1) relatively small size (adult male SVL 23.6-27.4 mm; 25.3 ± 1.4; n = 6); (2) dorsal coloration consisting of irregularly-shaped blotches and/or spots with variable extent with no distinctive dorsal color patterns of longitudinal stripes, longitudinally arranged blotches, or spots; (3) expanded, median subgular vocal sac; and (4) advertisement call composed of one type of long-lasting (334-708 ms) multipulsed (11)(12)(13)(14)(15)(16)(17)(18) note.…”

“…Temporal traits were measured directly from the oscillogram; the dominant frequency was obtained through 'Peak Frequency' measurement function; call rise time was obtained through 'Peak Time' measurement function. See Table 1 We arbitrarily adopted the straightforward definition for the advertisement call of both species as a single quasi-periodic pulse train (sensu Littlejohn [11]) to facilitate acoustic comparisons among Scinax species, even though we observed regular amplitude modulations (AMs) within the so-called 'pulse unit' for the advertisement calls of both studied species, and some other Scinax species ( Figure 2) (see also Magrini and Giaretta [12]; Magrini et al [13]; Nunes et al [14]). It is worth pointing out that there are not any available studies for the genus, in which homologies between acoustic units, such as call, note, and pulse, might be established based on the mechanisms of sound production (see Martin [15,16]; Gans [17]).…”