Boana claresignata (A. Lutz & B. Lutz, 1939) Lyra & Lourenço & Pinheiro & Pezzuti & Baêta & Barlow & Hofreiter & Pombal Jr & Haddad & Faivovich, 2020

THE BOANA CLARESIGNATA GROUP

Diagnosis: The Boana claresignata group can be diagnosed by: (1) projected prepollical spine; (2) nuptial pads present, single, light-coloured, without macroscopically evident epidermal projections (Supporting Information, Appendix S2: Fig. S3); (3) palpebral membrane without reticulation; (4) tympanum diameter/eye diameter of the two species combined 0.23–0.54 (N = 26), see comments below; (5) mental gland not evident macroscopically; (6) posterolateral process of the hyoid plate absent; (7) m. depressor mandibulae without origin in the dorsal fascia at the level of the m. levator scapulae (Supporting Information, Appendix S2: Fig. S2); (8) transparent parietal and visceral peritonea; (9) tadpole with expanded snout; (10) larval nostril oval, reduced (diameter 0.02–0.03 body length), with a small medial projection; (11) spiracle located below the midbody line; (12) fins low and parallel to the tail muscle proximally, increasing their height at the medial third of the tail; (13) larval oral disc enlarged (0.80–0.87 of maximum body width); (14) larval oral disc surrounded by a continuous row of marginal papillae; (15) labial tooth-row formula (LTRF) with seven to nine anterior rows and 11–14 posterior rows (7–9/11–14); (16) upper jaw sheath M-shaped, with lateral processes laterally directed; (17) presence of a medial shelf on the anterior jaw sheath; and (18) unpigmented oocytes (2.1–3.3 mm in diameter).

Comparison with other species of Boana : In the context of Boana , the presence of light-coloured nuptial pads without macroscopically evident epidermal projections, the unpigmented mature oocytes and the characters related to the larval oral disc are synapomorphies of the Boana claresignata group. The occurrence of these character states differentiates this group from all other species of Boana . All these characters, in combination with the projected prepollical spine, distinguish the species in the Boana claresignata group from all other genera of Cophomantini . The unpigmented mature oocytes are homoplastic with Boana heilprini (Noble, 1923) , with the Boana benitezi group (when mature oocytes/eggs are known) and with some species of Myersiohyla and Hyloscirtus . In Boana , nuptial pads with dark-coloured epidermal projections are known to occur only in the Boana semilineata group ( Faivovich et al., 2006). The palpebral membrane without reticulation differentiates the Boana claresignata group from the Boana semilineata group (present in this species group; Faivovich et al., 2006; Peloso et al., 2018). The absence of a macroscopically evident mental gland differentiates of the Boana claresignata group from species of the Boana benitezi , Boana punctata and Boana semilineata groups and from Boana heilprini (present in these species; Faivovich et al., 2006; Brunetti et al., 2015). The absence of the posterolateral process of the hyoid plate differentiates the Boana claresignata group from at least some species of the Boana albopunctata and Boana faber groups ( Pinheiro et al., 2018: fig. 3A–C). The absence of the origin of the m. depressor mandibulae in the dorsal fascia at the level of the m. levator scapulae is shared only with species of the Boana pulchella and Boana punctata groups.

The tympanum diameter/eye diameter ratio in the Boana claresignata group is 0.23–0.54, with the larger value represented by the few available specimens of Boana claresignata and the smaller by all those of Boana clepsydra (see comments below). Although the size of the tympanum might be taxonomically relevant for some comparisons, it becomes more challenging to interpret when considering all the diversity in Boana . A large tympanum is present among the species of the Boana albopunctata , Boana faber , Boana pellucens , Boana punctata and Boana semilineata groups, with a combined tympanum diameter/eye diameter ratio varying from 0.48 [ Boana wavrini (Parker, 1936) ; Hoogmoed, 1990] to 0.98 [ Boana rosenbergi (Boulenger, 1898) ; Duellman, 1970]. In the Boana benitezi group, this ratio varies from 0.25 [ Boana ornatissima (Noble, 1923) ; Hoogmoed, 1979] to 0.51 [ Boana nympha ( Faivovich, Moravec, Cisneros-Heredia & Köhler, 2006) ; Faivovich et al., 2006]. In the Boana pulchella group, the sister taxon of the Boana claresignata group, it varies from 0.35 [ Boana caipora ( Antunes, Faivovich & Haddad, 2008) ; Antunes et al., 2008] to 0.68 [ Boana joaquini (Lutz, 1968) ; Garcia et al., 2003]. Several species of this group also have a smaller tympanum, measuring less than half of the eye diameter [e.g. Boana cambui , Boana ericae ( Caramaschi & Cruz, 2000) and Boana semiguttata (A. Lutz, 1925) ; Caramaschi & Cruz, 2000; Garcia et al., 2007; Pinheiro et al., 2016].

The large oral disc with complete marginal papillae and the LTRF of the larvae of the Boana claresignata group (7–9/11–14) differentiate them from all other species of Boana with known tadpoles. The LTRF is higher than any other known larvae of Boana . Until now, the highest known LTRF was from Boana heilprini at 6/9 ( Noble, 1927; Galvis et al., 2014; Díaz et al., 2015), followed by Boana benitezi at 5/8 (this larva was only tentatively assigned to Boana benitezi ; Myers & Donnelly, 1997), Boana hutchinsi ( Pyburn & Hall, 1984) at 4/7, Boana jimenezi (Señaris & Ayarzagüena, 2006) , Boana curupi ( Garcia, Faivovich & Haddad, 2007) and Boana stellae ( Kwet, 2008) at 3/5 ( Faivovich, 1996; Myers & Donnelly, 1997; Myers & Donnelly, 2008; Widholzer & Castroviejo-Fisher, 2018). Most species of Boana have an LTRF of 2/3 or 2/4 ( Kolenc et al., 2008). The same applies to the large oral disc, which is almost equivalent to the body width in the tadpoles of the Boana claresignata clade [oral disc width (ODW) 0.80–0.87 of body width (BW)], whereas it is smaller in the remaining species of Boana (e.g. ODW/BW = 0.48– 0.60 in Boana heilprini ; ODW/BW = 0.60 in Boana curupi, ODW /BW = 0.50–0.53 in Boana jimenezi ; and ODW/BW = 0.50 in Boana stellae ; smaller than 50% of the body width in most species of Boana ; Faivovich, 1996; Myers & Donnelly, 2008; Kolenc et al., 2008; Díaz et al., 2015; Widholzer & Castroviejo-Fisher, 2018; T. L. Pezzuti, pers. obs).

The M-shaped upper jaw sheath, with long lateral processes laterally directed and a shelf on its medial portion, differentiates the tadpoles of the Boana claresignata group from the other species of Boana (upper jaw sheath arc shaped, lateral processes medially directed and medial shelf absent in most species of Boana ; Kolenc et al., 2008). The shapes of body and tail of the tadpoles of the Boana claresignata group are also unique in the genus, being adapted to rheophilic microhabitats in swift or torrential mountain streams. This suctorial morphology (see comments below) comprises a depressed body with an expanded snout and low fins that are parallel to the tail muscle proximally, increasing their height at the medial third of the tail (the other tadpoles of the genus have a benthic-like morphology).

Characterization: Bokermann (1972) and Lutz (1973) provided appropriate characterizations of the two species of the Boana claresignata group. To complement the observations of these authors, we add the occurrence of a light-coloured nuptial pad (Supporting Information, Appendix S2: Fig. S3), the absence of a macroscopically evident mental gland and the occurrence of unpigmented mature oocytes.

Contents: Boana claresignata (A. Lutz & B. Lutz, 1939) and Boana clepsydra (A. Lutz, 1925) .

Natural history: Lutz & Lutz (1939), Lutz & Orton (1946) and Lutz (1949a) provided observations on the natural history of adults and larvae of Boana claresignata and Boana clepsydra , which were summarized by Lutz (1973). The available information on adults of Boana claresignata is restricted to the three specimens of the type series and several specimens raised from tadpoles in captivity. Bokermann (1972) provided information from the series of adults and the tadpoles that he collected. All observations of adults of the two species are in agreement that they inhabit epiphytic bromeliads growing on the sides of swift or torrential mountain streams. All collecting localities are ~ 400– 1200 m a.s.l. The males of Boana clepsydra call from the bromeliads or perched from branches suspended 1–2 m above streams or brooks. Courtship, amplexus and oviposition remain unknown. Lutz (1949a) and our observations on the female holotype of Boana claresignata (AL-MN 1971) , which has a lateral incision on the left flank, and on another female of this species (MZUSP 117074), indicate that mature oocytes are unpigmented (AL-MN 1971, 2.7–3.3 mm, mean = 3.07 mm, SD = 0.22 mm, N = 10; MZUSP 117074, 2.1–2.7 mm, mean = 2.26 mm, SD = 0.26 mm, N = 5). A female of Boana clepsydra (MZUSP 112626) also has unpigmented mature oocytes evident through the skin. Given that the oocytes are distorted owing to preservation, the reported diameter should be taken cautiously.

Tadpoles were reported in fast-flowing streams, using their oral discs to cling to the rocky streambed ( Lutz & Lutz, 1939; Bokermann, 1972). Tadpoles of Boana claresignata were, in all instances, attached to the rocks, more frequently vertically, but also horizontally, near the bottom of the stream, not rising to the surface ( Lutz & Orton, 1946). When disturbed, tadpoles of Boana clepsydra were observed swimming against the current ( Bokermann, 1972).

Vocalization: The advertisement call of Boana clepsydra was briefly described by Bokermann (1972). We re-analysed his recording of two males ( WCAB 42553 and 42554; currently MZUSP 112613 View Materials and 112614, respectively) available at Fonoteca Neotropical Jacques Vielliard (accession number 31798). The recording of MZUSP 112614 View Materials is of lower quality (probably, the individual was more distant); we describe them separately .

As mentioned by Bokermann (1972), Boana clepsydra emits groups of three to five calls, with each call corresponding to one tonal note ( Fig. 2A, B). Notes are irregularly spaced and with a considerable interval between them. The call has bands, similar to a harmonic structure ( Fig. 2B, C), but the peak frequency of each band is not necessarily an exact multiple of the fundamental peak frequency and may vary within each band (see values below). The call has a characteristic metallic or high-pitched tone.

The first individual ( MZUSP 112613 View Materials ) emitted five calls in 15.48 s (N = 1). Each call lasted 130–169 ms (144.4 ± 16.6 ms) and was separated by intervals of 2.60– 4.17 s (3.68 ± 0.72). The fundamental frequency, which was also the dominant, was between 2053.8 and 3010.9 Hz, with the peak frequency at 2437.5 Hz. The minimum frequency at 5% of energy was 2250 Hz (N = 5); maximum frequency at 95% of energy was 2625 Hz (N = 5); and bandwidth 90% was 375 Hz (N = 5). Up to four additional bands were present: the first one had peaks at 4500 (N = 1), 4875 (N = 1) or 5062.5 Hz (N = 3); the second had peaks at 7125 (N = 1) or 7500 Hz (N = 4); the third one, which was absent in the first note and was the band with lower energy, had peaks at 9000 (N = 1), 9937.5 (N = 2) or 10 125 Hz (N = 1); and the fourth and highest band had peaks at 12 000 (N = 1), 12 375 (N = 1) or 12 562.5 Hz (N = 3) .

The second individual ( MZUSP 112614 View Materials ) emitted three calls in 7.58 s (N = 1). Each call lasted 59–89 ms (73 ± 15 ms), and they were separated by intervals of 3.51– 3.85 s. The fundamental frequency, which was also the dominant, was between 2050.6 and 2885 Hz, with the peak frequency at 2437.5 Hz (N = 3). The minimum frequency at 5% of energy was 2250 Hz (N = 3); maximum frequency at 95% of energy was 2625 Hz (N = 3); and bandwidth 90% was 375 Hz (N = 3). Up to four additional bands were present: the first one had peaks at 4500 (N = 2) or 4875 Hz (N = 1); the second one had peaks at 7312.5 (N = 2) or 7687.5 Hz (N = 1); the third one, which was absent in the third note, was found to have a peak at 9562 (N = 1) or 9750 Hz (N = 1) Hz; and the fourth and higher band was found with peaks at 12 000 (N = 1), 12 187.5 (N = 1) or 12 750 Hz (N = 1) .

The call of Boana clepsydra can be distinguished from those of Boana aguilari , Boana balzani , Boana bandeirantes (Caramaschi & Cruz, 2013) , Boana beckeri (Caramaschi & Cruz, 2004) , Boana botumirim ( Caramaschi, Cruz & Nascimento, 2009) , Boana caipora , Boana cipoensis (Lutz, 1968) , Boana curupi , Boana cymbalum (Bokermann, 1963) , Boana ericae , Boana gladiator ( Köhler, Koscinski, Padial, Chaparro, Handford, Lougheed & De la Riva, 2010) , Boana guentheri (Boulenger, 1886) , Boana jaguariaivensis (Caramaschi, Cruz & Segalla, 2010) , Boana latistriata (Caramaschi & Cruz, 2004) , Boana leptolineata (Braun & Braun, 1977) , Boana marianitae ( Carrizo, 1992) , Boana melanopleura , Boana polytaenia (Cope, 1870) , Boana stellae and Boana stenocephala (Caramaschi & Cruz, 1999) by having notes with a tonal structure (pulsed notes in these species; Haddad et al., 1988; Heyer et al., 1990; Duellman et al., 1997; Garcia et al., 2007; Acioli & Toledo, 2008; Antunes et al., 2008; Garcia & Haddad, 2008; Kwet, 2008; Caramaschi et al., 2009; Köhler et al., 2010; Lehr et al., 2010; Guerra et al., 2017; Forti et al., 2019). From, Boana caingua (Carrizo, 1991) , Boana cambui , Boana cordobae (Barrio, 1965) , Boana goiana (Lutz, 1968) , Boana phaeopleura ( Caramaschi & Cruz, 2000) , Boana pulchella and Boana riojana (Koslowsky, 1895) , the call of Boana clepsydra can be distinguished by being composed by one note (call composed by> 1 note in the other species; Barrio, 1965a; Guimarães et al., 2001; Pinheiro et al., 2012, 2016; Baraquet et al., 2013; Batista et al., 2015). The non-pulsed structure of the call of Boana clepsydra differentiates it from those of the closely related Boana pellucens and Boana faber groups, which have calls with a pulsed structure ( Fouquette, 1961; Bokermann, 1967; Duellman, 1970, 2001; Bokermann & Sazima, 1973; Kluge, 1981; Heyer et al., 1990; Loebmann et al., 2008; Martins et al., 2009).

Comments: Lutz & Orton (1946) described the occurrence of green bones in postmetamorphic specimens of Boana claresignata , indicating impregnation with biliverdin ( Barrio, 1965b), which also happens in several other species of Boana from various species groups (e.g. Lutz, 1949 b, 1973; Duellman, 1970; Hoogmoed, 1979; Caminer & Ron, 2014; Taboada et al., 2017: tab. 1). There are no observations regarding the persistence of biliverdin in adults of Boana claresignata , nor any comment regarding its occurrence in Boana clepsydra . Lutz & Orton (1946) reported that specimens of Boana claresignata release a characteristic odour of crushed plants when handled, which also happens in several other species of Cophomantini (see Faivovich et al., 2013; Brunetti et al., 2015, 2016, 2019). There are no reports on odour from Boana clepsydra .

The occurrence of nuptial pads in Boana claresignata and Boana clepsydra is reported here for the first time. The nuptial pad is easily observed in Boana clepsydra (see Supporting Information, Appendix S2: Fig. S3). There are few available males of Boana claresignata in collections, and all of these are poorly fixed. In these, the nuptial pad is evident only through the occurrence of some yellowish acini in the same position as in Boana clepsydra and, for that reason, we interpret that they are present.

Gallardo (1961) reported the occurrence of Hyla claresignata in the Province of Misiones, Argentina. For this reason, Cei (1980) included an account of that species based on the published information and included it in the Hyla claresignata group, without further comments. Carrizo (1992) re-identified the specimens studied by Gallardo (1961) as Hyla semiguttata A. Lutz, 1925 , a species that Cei & Roig (1961) recorded in Misiones. The populations of this species from Argentina were subsequently shown to be a different, new species ( Boana curupi ) by Garcia et al. (2007).

Cochran (1955) included a description of a male paratype of Boana claresignata from ‘Bonito, Serra da Bocaina, Rio de Janeiro’ and the holotype of Boana clepsydra (a male). The latter is an important reference because the holotype specimen, which Cochran (1955: 88) described at that time as a ‘badly faded and mutilated specimen’ with ‘an immaculate drab over its entire surface’, is now reduced to what seems to be an even worse condition to the point that almost no relevant characters are discernible (AL-MN 976; Supporting Information, Appendix S2: Fig. S4). One notable point of her description of Boana clepsydra is her comment on the occurrence of ‘a pair of lateral external vocal sacs’. She did not compare Boana claresignata and Boana clepsydra .

Bokermann (1972) noticed that adults of Boana claresignata and Boana clepsydra were similar, to the point that initially he suspected that the latter corresponded to males of the former species until he collected females of Boana clepsydra . He described the variation in coloration pattern, vocalization and tadpoles of Boana clepsydra and compared it with three newly collected adult specimens and two tadpole series of Boana claresignata from Teresópolis. He differentiated Boana claresignata from Boana clepsydra based on snout shape in profile (rounded in Boana claresignata , truncate in Boana clepsydra ), tympanum size and position (larger in Boana claresignata , in a more posterior position), hindlimb size (smaller in Boana claresignata ), larval body shape (rounder in Boana claresignata , flatter in Boana clepsydra ), ridges on jaw sheaths (present in Boana claresignata , absent in Boana clepsydra ), larval tail size (proportionally larger in Boana claresignata ), larval eye size (slightly larger in Boana clepsydra ) and larval coloration pattern (larger blotches in larvae of Boana claresignata ). He did not comment on the vocal sac morphology of Boana clepsydra nor did he include it as a diagnostic character. Lutz (1973) stressed that Boana claresignata and Boana clepsydra share a small tympanum, inhabit bromeliads and are montane species, but stated that Hyla claresignata showed no marked affinities with other species, being unaware of the paper by Bokermann (1972) and emphasizing differences in dorsal pattern and Cochran’s (1955) reference to a double vocal sac in the holotype of Boana clepsydra .

The information on variation in the dorsal pattern in Boana clepsydra provided by Bokermann (1972) clearly shows that it does not allow differentiation of this species from Boana claresignata . Our observations on all specimens of Boana clepsydra in the MNRJ and MZUSP collections corroborate that statement (Supporting Information, Appendix S2: Fig. S5).

The analyses of available specimens from both species corroborate the differences reported by Bokermann (1972) regarding the snout shape in profile. Boana claresignata has a rounder snout than Boana clepsydra , which has a shorter and truncated snout. Although in both species there is intraspecific variation in snout shape, we do not see an overlap.

Boana claresignata has a tympanum diameter/ eye diameter (TD/ED) ratio of 0.39–0.54 in females (0.44 ± 0.06; N = 4) and 0.41–0.57 in males (0.48 ± 0.08, N = 6) and a tympanum diameter/head length (TD/ HL) ratio of 0.11–0.15 in females (0.13 ± 0.02; N = 4) and 0.12–0.22 in males (0.16 ± 0.03; N = 6). In contrast, Boana clepsydra has a TD/ED ratio of 0.30–0.38 in females (0.34 ± 0.06; N = 2) and 0.23–0.38 in males (0.31 ± 0.04; N = 23) and a TD/HL ratio of 0.09–0.11 in females (0.10 ± 0.01; N = 2) and 0.08–0.12 in males (0.10 ± 0.01; N = 23). Although these measurements tend to corroborate the larger tympanum size in Boana claresignata noticed by Bokermann (1972), the values of the ratios that express tympanum size are continuous. Considering the low number of specimens of Boana claresignata available, this difference in tympanum size should be viewed cautiously, because the lack of overlap between intervals for the ratios could well be a consequence of the small sample size for that species.

With the caveat of the low sample size for Boana claresignata , we observed that in this species the lower margin of the tympanic ring is slightly below the level of the lower margin of the eye. In Boana clepsydra , the lower margin of the tympanic ring is at or above the level of the lower margin of the eye.

Measurements of hindlimbs revealed that in females of both species and in males of Boana clepsydra , the sum of thigh length and tibia length is slightly larger than snout–vent length. The hindlimb length/snout– vent length ratio of Boana claresignata is 1.01–1.08 in females (1.02 ± 0.07; N = 4) and 0.88–1.01 in males (0.94 ± 0.05; N = 6), and in Boana clepsydra it is 1.03– 1.04 in females (1.03 ± 0.01; N = 2) and 1.01–1.11 in males (1.05 ± 0.03; N = 23).

The study of male specimens of Boana clepsydra (N = 22) reveals that the vocal sac is single and subgular. This observation differs from the description by Cochran (1955) of the vocal sac in the now highly deteriorated male holotype as paired and lateral. The vocal sac is now unrecognizable in the holotype.

Our study of the paratypes of Boana claresignata , the only specimens of this species from Serra da Bocaina, indicates that the reasonably preserved specimen (AL-MN 2088) falls within the variation found in the series of topotypes of Boana clepsydra (Supporting Information, Appendix S2: Figs S6, S7). Therefore, we consider that these paratypes of Boana claresignata are misidentified specimens of Boana clepsydra , indicating that there is no evidence of the occurrence of Boana claresignata in the Serra da Bocaina.

Lutz (1973) reported the collection of tadpoles similar to those of Boana claresignata in Marumbi, State of Paraná (~ 550 km south-west from Serra da Bocaina). These tadpoles are the lot MNRJ 68427 (nine tadpoles in stages 25–28 and 38, and one postmetamorphic specimen; Supporting Information, Appendix S2: Fig. S8), with the exact locality given as ‘Rio Taquaral em Marumbi, Serra do Mar, Estrada de ferro Curitiba- Paranaguá’. We interpret this locality as areas nearby the Marumbi railway station (25°26 ′ 19 ʺ S; 48°55 ′ 12 ʺ W; 500 m a.s.l.). We corroborate the striking similarity of these larvae to those of Boana claresignata and Boana clepsydra , but note the presence of conspicuous lateral projections in the upper jaw sheath that we did not find in larvae of the other species. Pending more studies in morphological variation of larvae in the two described species, for the time being, we consider the larvae to belong to an unidentified species of the Boana claresignata group.

Distribution: Both species are endemic to the Atlantic Forest in south-eastern Brazil. Boana clepsydra is known only from three nearby localities in the section of the Serra do Mar mountain range known as Serra da Bocaina. These are the type locality Fazenda do Bonito and the former Campo de Fruticultura da Serra da Bocaina, currently within the limits of the Parque Nacional da Serra da Bocaina, in the State of São Paulo. The third locality is in the south-western boundary of the national park, in the State of Rio de Janeiro, along the road between Paraty (State of Rio de Janeiro) and Cunha (State of São Paulo), ~ 57 km south-west (air line) from the other localities. Boana claresignata is known from the Parque Nacional da Serra dos Órgãos in Teresópolis, where it has been collected in some swift-flowing streams (Beija Flor, Garrafão, Paquequer and Soberbo), and from Nova Friburgo, both in the State of Rio de Janeiro.

SUCTORIAL TADPOLES IN COPHOMANTINI

Tadpoles of the Boana claresignata group have several modified characters typical of a suctorial morphology (suctorial guild, type II; Altig & Johnston, 1989). They have the posterior portion of the body markedly depressed and an expanded snout that supports the ventral and large oral disc. The expanded snout, which forms a rim surrounding the anterior part of the body, is composed of loose connective tissue between the anterior portion of the trabecular horns and the tip of the snout ( Lutz & Orton, 1946). In Cophomantini , a similar condition has been described and illustrated for the Hyloscirtus armatus group ( Haas & Richards, 1998). It may also be present in some species of Myersiohyla [i.e. Myersiohyla neblinaria Faivovich, McDiarmid & Myers, 2013 and Myersiohyla inparquesi ( Ayarzagüena & Señaris, 1994) ; interpreted from the illustrations, Ayarzagüena & Señaris, 1994; Faivovich et al., 2013] and, possibly, in the Hyloscirtus jahni group (whether the larva of this species has the same snout structure is not clear from the information provided by La Marca, 1985). This specialization, already described in other suctorial species of Pelodryadinae ( Gradwell, 1973, 1975), might act in the engagement or disengagement of the oral disc in the substrate ( Gradwell, 1975) or at least in absorbing shocks against the rocky streambed ( Lutz & Orton, 1946). In the current phylogenetic hypothesis of Cophomantini , an expanded snout would have evolved at least three times in the tribe (in some species of Myersiohyla , the Hyloscirtus armatus group and the Boana claresignata group) and would optimize ambiguously in Hyloscirtus , if also present in Hyloscirtus jahni .

Many of the character states present in the larvae of the Boana claresignata group (enlarged oral discs, lack of gaps in the marginal papillae, high values of LTRF and jaw sheaths laterally expanded) have also been described for stream-dwelling tadpoles of Myersiohyla ( Ayarzagüena & Señaris, 1994; Faivovich et al., 2013) and Hyloscirtus (e.g. Duellman & Altig, 1978; La Marca, 1985; Cadle & Altig, 1991; Lötters et al., 2005; Sánchez, 2010; Coloma et al., 2012). Several of these character states have been considered as putative synapomorphies of the former Bok. claresignata group ( Faivovich et al., 2005), and of Hyloscirtus ( Duellman et al., 1997) , and were subsequently inferred as plesiomorphic conditions within Cophomantini ( Faivovich et al., 2005). However, the phylogenetic position of N. kanaima and the morphological differences of its larvae (i.e. smaller larval oral disc, lower LTRF and an anterior gap on marginal papillae; MacCulloch & Lathrop, 2005; Pinheiro et al., 2019) have resulted in changes (i.e. 2/4 as the ancestral LTRF) and some ambiguities (i.e. in the presence/absence of gaps on marginal papillae) in the optimizations of larval ancestral states in the tribe ( Pinheiro et al., 2019).

Faivovich et al. (2005) inferred that transformations of oral disc characters (e.g. reduction of oral disc size and number of tooth rows and the presence of an anterior gap in the marginal papillae) could have evolved in a common ancestor of and of Bokermannohyla , Aplastodiscus and Boana . Besides the ambiguity generated by the tadpole of N. kanaima , stream-related features have been described for some tadpoles of Aplastodiscus , Boana and Bokermannohyla (e.g. oral disc surrounded by marginal papillae without gaps, and an increase in LTRF above 2/ 4 in the Aplastodiscus sibilatus (Cruz, Pimenta and Silvano, 2003) , Bok. pseudopseudis and Bok. martinsi groups, and some species of the Boana albopunctata , Boana benitezi , Boana punctata , Boana pulchella and Boana semilineata groups; Pyburn & Hall, 1984; Faivovich, 1996; Myers & Donnelly, 1997, 2008; Leite & Eterovick, 2010; Mercês & Juncá, 2010; Lins et al., 2018). The plesiomorphic states of these characters in Boana are still uncertain, in part because of the ambiguities commented on above, but also because the relationships among most species groups of Boana are poorly supported ( Faivovich et al., 2013; Pinheiro et al., 2019; our results). Regardless, only the Boana claresignata group and Boana heilprini have tadpoles with enlarged oral discs and LTRF that show an extreme of development when compared with closely related taxa ( Boana heilprini, LTRF 4–6/6–9; Noble, 1927; Galvis et al., 2014; Díaz et al., 2015), indicating that in these particular cases the characters related to the suctorial morphology had evolved independently.