Vocalizations and comments on the relationships of Hypsiboas ericae ( Amphibia , Hylidae )

The vocalizations of Hypsiboas ericae (Caramaschi & Cruz, 2000) are described and new information on the external morphology and osteology of the species are presented. H. ericae presents a bony spine in the prepolex and the individuals can present green or brown dorsal color, as other species of the Hypsiboas pulchellus (Duméril & Bibron, 1841) species group. The vocalizations of H. ericae are similar to the vocalizations of Hypsiboas bischoffi (Boulenger, 1887), Hypsiboas guentheri (Boulenger, 1886), and other species in the H. polytaenius (Cope, 1870 “1869”) clade of the H. pulchellus species group, but some osteological aspects are different to those found in the majority of the species of this group.

Hypsiboas ericae (Caramaschi & Cruz, 2000) was described based on specimens obtained at Chapada dos Veadeiros, Alto Paraíso de Goiás, Goiás, Brazil (CARAMASCHI & CRUZ, 2000).In the original description, the species was included in the group of Hyla pulchella Duméril & Bibron, 1841 (now Hypsiboas pulchellus group sensu FAIVOVICH et al., 2005) and related to Hyla marginata Boulenger, 1887, and Hyla semiguttata A. Lutz, 1925(now Hypsiboas marginatus (Boulenger, 1887) and H. semiguttatus (A.Lutz, 1925)).During field studies realized at the type-locality of the species, we did new observations about H. ericae, including the vocalization recordings of some specimens.Some information about the diagnosis of the species were also verified by the study of part of the skeleton of some individuals.In this work, we describe the vocalization of H. ericae and comment on the species relationships according to the new informations obtained.
In a recent work, FAIVOVICH et al. (2005) transferred the Hyla pulchella species group to genus Hypsiboas and included the species of the Hyla polytaenia group as a clade in the H. pulchellus species group.
The osteological characters were analyzed in cleared and stained specimens using the technique of TAYLOR & VAN DYKE (1985).Vocalizations of H. ericae, obtained from Rio dos Couros, Alto Paraíso de Goiás, central Brazil, in January 2001, were recorded using a Nagra E tape recorder and Sennheiser microphone ME-66, and analyzed using the software Canary 1.2.4 in Power Macintosh computer.The sounds were digitalized in 22.1 kHz and the spectrograms and waveforms were produced using frame length and fast Fourier transform (FFT) of 256 points, frame overlap of 50% and window function Hamming.

RESULTS
Vocalization.Two males were recorded on 17 January 2001.Three distinct calls were observed in H. ericae (Fig. 1).The first of them, here denominated call "A" (Fig. 2), was the most frequent, being emitted 43 times in nine minutes of recording ( x = 4.8 calls/min).It is composed by an isolated note ("a" note), with pulsed structure of 8-20 pulses/note ( =14.5 ± 2.74), with duration of 33.6-92 ms ( =67.5 ± 13) and frequency between 2.03 -3.6kHz ( =2.7 ± 1).The second call, denominated "B" call (Fig. 3), was the less frequent, being emitted 16 times in nine minutes ( =1.8 call/min), with duration of 229.8-317.9ms ( =283.6 ± 20.3).This call is composed by two notes of pulsed structure: the first note is similar to "a" note of "A" call, with mean duration slightly larger, between 59.4 and 89.5ms ( =75.5 ± 9.1), and frequency and number of pulses similar (Tab. 1) to those of note "a"; the second note, denominated "b" note, had smaller duration, between 40.9 e 62.5ms ( =49.6 ± 7.3), frequency between 2.09-3.54kHz( =2.8 ± 0.6), and 7-10 pulses/note ( =8.2 ± 1.1).The third call, "C" call (Fig. 4), was emitted 29 times in nine minutes ( =3.2 call/ min), had a simple note, denominated "c" note, with pulsed structure, from 2-11 pulses/note ( =4.8 ± 2.1), duration between 103.6-560.3ms (239.3 ± 138.4), and frequency between 2.12-3.54( =2.8 ± 0.4).The "c" note is a trill, composed by pulses better defined than the previous notes, with duration of 6.1-49.9ms( =13.8 ± 7.92).The three calls are emitted independently from each other.The "C" call can be preceded by another "C" call, by an "A" call or a "B" call, occurring the same with the other calls.The calls "B" and "C" are more frequent when there are more individuals vocalizing.The function of each call is not clear, but judging for the constancy, the "A" call might correspond to the advertisement call and the "C" call to the territorial call; the function of the "B" call is unknown.
Color in life of the examined specimens.Dorsal color brown or green, with or without dark blotches.When there are blotches, these are rounded, large, and distributed irregularly along the dorsal surfaces of body and limbs.Dark brown dorsal blotches in brown specimens and dark green in green ones.A white dorsolateral stripe delimited inferiorly by a brown line, both from the superior eyelid to the inguinal region.Flanks dark brown (even in green specimens) with many small blotches, framed by a dark brown line.Some of the blotches fused, making larger and extended blotches.A whitish stripe on the upper lip, from the tip of snout to the arm insertion.Posterior surface of thigh not pigmented.Supra cloacal region with white and a dark brown stripe.Venter whitish, slightly darker in the chest and throat.Iris gold or tan, slightly lighter on the upper area.
Natural history.Specimens of H. ericae were found vocalizing on bushes and trees, always close to water, between 0.1 to 1m above the ground along limpid water streams inside or near gallery forest.The vocalization begins in the sunset.Males were found vocalizing in December and January.Males showed scars on the back (Fig. 5), probably a consequence of fights between males, with the use of prepollical spines.Females, clutches, and tadpoles were not found.

DISCUSSION
CARAMASCHI & CRUZ ( 2000) included Hypsiboas ericae in the group of Hypsiboas pulchellus, considering it more closely related with H. marginatus and H. semiguttatus, due to the robust aspect of the body and the presence of a longitudinal white stripe situated dorsolaterally.The pointed differences between H. ericae and those species were: smaller size, absence of spine on the prepollex, and white bones.However, males of H. ericae have prepollical spine and, apparently, use it in fights in the same way as reported for other species in the group of H. pulchellus (GARCIA et al., 2001(GARCIA et al., , 2003) ) and in the clade Hypsiboas polytaenius (Cope, 1870 "1869") (MENIN et al., 2004), judging by the scars on the back of some males.The presence of green bones in H. semiguttatus was mentioned by LUTZ (1973); LANGONE (1997) quoted this characteristic to H. marginatus.Even though this character is evident in live specimens, in preserved ones it disappears.Moreover, in the same population of H. joaquini (B.Lutz, 1968) (another species of the H. pulchellus species group), GARCIA et al. (2003) noticed the presence of some specimens with green or white bones, showing that this character can be polymorphic among specimens of the same population.
Related to the external morphology, the characteristics that indicate a close relationship between H. ericae and the species of H. pulchellus group are: (1) white stripe in the upper lip; (2) dorsolateral white stripe; (3) brown or green colored body; (4) pronounced prepollex ending in curved spine; (5) small white rounded blotches on the flanks (absent in H. marginatus and species of H. polytaenius clade); (6) absence of blotches in the concealed areas of thigh; and (7) presence of green or white bones.
The vocalization of H. ericae differs from all other species of the H. pulchellus group with known vocalization.However, some elements might be similar.The "A" and "B" calls of H. ericae are structurally similar to the calls of H. pulchellus, with the difference that in H. pulchellus the notes have lower duration and are not pulsed (see GARCIA et al. 2003).The "C" call is similar to a part of the call of H. caingua (Carrizo, 1990) (pers. obs.) and of H. prasinus (see BARRIO, 1965) (both species included in the group of H. pulchellus sensu DUELLMAN et al., 1997).However, the call of H. ericae shows more similarities with the advertisement calls of species in the clade of H. polytaenius (Cope, 1870), as H. leptolineatus (Braun & Braun, 1977) (personal observation), Hypsiboas sp.(aff.polytaenius) (Heyer et al., 1990, as H. polytaenius), and H. goianus (B. Lutz, 1968) (GUIMARÃES et al., 2001;MENIN et al., 2004).Also shows similarities with the vocalizations of other species that were not included in formal groups, but eventually appear quoted in the groups of H. pulchellus or of H. polytaenius, as H. guentheri (Boulenger, 1886) (pers.obs.) and H. bischoffi (Boulenger, 1887) (see HEYER et al., 1990, as H. multilineatus B. Lutz, 1939).These species have the call with one or two pulsed notes and a trill emitted in the sequence.
Although the general skeleton of H. ericae is relatively similar to some species of the H. pulchellus group (which is expected in Hylinae, since the skeletons of the majority of species are very similar; see Duellman, 2001), many differences were observed among H. ericae, H. marginatus, H. prasinus, H. pulchellus, and H. semiguttatus.
A recent phylogenetic study based on mitochondrial DNA showed that the group of Hyla pulchella was paraphiletic related to the group of Hyla polytaenia and also to the species Hyla bischoffi and Hyla guentheri Boulenger, 1886 (FAIVOVICH et al., 2004).In this work, Hyla ericae appears as the sister taxon of the group, which is represented by two clades, one of which involving two species of Hyla polytaenia group + Hyla semiguttata and H. joaquini; and other involving the other specimens analyzed in the group of H. pulchella (lato sensu).More recently, FAIVOVICH et al. (2005) formalized the proposal, transferring the Hyla pulchella species group to the revalidated genus Hypsiboas, where Hypsiboas pulchellus group, including all species of the group of Hyla pulchella, plus Hyla bischoffi, Hyla guentheri, and all species of the Hyla polytaenia species group (sensu CRUZ & CARAMASCHI, 1998) as a clade of the Hypsiboas pulchellus group.These results corroborate the observations made here.By one side, H. ericae presents morphological and biological characteristics shared with specimens considered in the group of H. pulchellus (GARCIA et al., 2001(GARCIA et al., , 2003)); on the other side, presents vocalization with similar characteristics to the vocalizations of species included in the group of H. polytaenius (sensu CRUZ & CARAMASCHI, 1998).However, H. ericae presents exclusive osteological characteristics, which is in agreement to its position as sister group of all the other species of the Hypsiboas pulchellus species group.