Pseudopaludicola ibisoroca, Pansonato & Veiga-Menoncello & Mudrek & Jansen & Recco-Pimentel & Martins & Strüssmann, 2016

Pansonato, André, Veiga-Menoncello, Ana Cristina P., Mudrek, Jessica R., Jansen, Martin, Recco-Pimentel, Shirlei M., Martins, Itamar A. & Strüssmann, Christine, 2016, Two New Species of Pseudopaludicola Miranda-Ribeiro, 1926 (Anura: Leptodactylidae: Leiuperinae) from Eastern Bolivia and Western Brazil, Herpetologica 72 (3), pp. 235-255 : 235-255

Pseudopaludicola ibisoroca sp. nov.

( Tables 5 , 6 ; Figs. 8 , 9 )

Pseudopaludicola aff. falcipes Kopp et al. 2010:195–197 .

Holotype. — Adult male ( UFMT 16208 ; Fig. 8 ) collected on 13 October 2007 by A. Pansonato and C. Strüssmann at Fazenda Granada (17°43 ′ 50 ′′ S, 53°17 ′ 23 ′′ W), municipality of Alto Taquari, state of Mato Grosso, Brazil.

Paratopotypes. — Sixteen adult males ( UFMT 6518–9 ; 16140–8 ; 16152 ; 16182–3 ; ZUEC 13986 ; 13990 ) and nine adult females ( UFMT 6520 ; 16139 ; 16150–1 ; 16184 ; ZUEC 13987–9 ; 13991–2 ) collected between 10 and 13 October 2007 by A. Pansonato and C. Strüssmann at the same locality as the holotype.

Diagnosis. — Pseudopaludicola ibisoroca sp. nov. is assigned to the genus Pseudopaludicola based on the presence of a hypertrophied antebrachial tubercle ( Lynch 1989), posterolateral process of the hyoid outlined and epicoracoid cartilages slightly overlapped ( Lobo 1995). The new taxon is diagnosed by the following combination of characters: (1) SVL ¼ 12.8–15.6 mm in males and 15.5–17.6 mm in females; (2) absence of either T-shaped terminal phalanges or expanded toe tips (disks or pads); (3) short hindlimbs, with tibiotarsal articulation only reaching the eye; (4) karyotype, 2n ¼ 18; (5) advertisement call composed of series of 12–287 notes with 3–12 concatenated pulses per note, note with duration of 25–50 ms; (6) dominant frequency of advertisement call 3617.6–4651.2 Hz.

Comparisons. — Pseudopaludicola ibisoroca sp. nov. can be distinguished from all congeneric species (characters of comparative species in parentheses) belonging to the P. pusilla group ( P. boliƲiana , P. ceratophŋes , P. llanera , P. motorzinho , and P. pusilla ) by the absence of either Tshaped terminal phalanges or expanded toe tips.

From Pseudopaludicola species not assigned to any species group, the new species differs from P. ameghini , P. giarettai , and P. ternetzi by the smaller body size ( P. ameghini , 16.3–18.6 mm SVL in males and 18.5–22.7 mm SVL in females; Haddad and Cardoso 1987; Pansonato et al. 2013; P. giarettai , 16.2–18.0 mm SVL in males; Carvalho 2012; P. ternetzi, SVL of males 16.0– 18.6 mm; SVL of females 16.0– 22.2 mm; Lobo 1996); from P. falcipes , by the presence of a complete abdominal fold (abdominal fold interrupted or absent; Lobo 1996; Lavilla and Cei 2001); from P. mineira , by head longer than wide (head as long as wide; Pereira and Nascimento 2004); from P. murundu and P. saltica , by the shorter hindlimbs, with tibio–tarsal articulation reaching the nostrils (presence of very long hindlimbs, with tibio–tarsal articulation reaching beyond the tip of snout; Toledo et al. 2010; Pansonato et al. 2013). The appearance of the vocal sac of male Pseudopaludicola ibisoroca sp. nov. —light cream—distinguishes the new species from P. atragula and P. facureae (whitish, with dark reticulation; Pansonato et al. 2014a), and from P. murundu (uniformly dark; Toledo et al. 2010).

Presently, 5 out of 14 species without T-shaped terminal phalanges cannot be morphologically distinguished from Pseudopaludicola ibisoroca sp. nov.: P. canga , P. hŋleaustralis , P. mŋstacalis , P. parnaiba , and P. pocoto . The advertisement call structure distinguishes the new species from these 5 species, however, as well as from other 11 congeners for which call descriptions are also available ( P. ameghini , P. atragula , P. boliƲiana , P. facureae , P. falcipes , P. giarettai , P. mineira , P. motorzinho , P. murundu , P. saltica , and P. ternetzi ).

The new species differs from P. canga , P. facureae , P. giarettai , P. hŋleaustralis , and P. parnaiba by having note structure with concatenated pulses (nonpulsed note structure in all comparative species; Giaretta and Kokubum 2003; Carvalho 2012; Pansonato et al. 2012; Andrade and Carvalho 2013; Roberto et al. 2013; Pansonato et al. 2014a). It differs from P. ameghini , P. atragula , P. falcipes , P. mineira , P. murundu , P. pocoto , P. saltica , and P. ternetzi by having a call note with concatenated pulses (note with nonconcatenated pulses; 3–6 pulses per note, Pansonato et al. 2013; 9–36 pulses per note, Pansonato et al. 2014a; 2 pulses per note, Haddad and Cardoso 1987; 2 pulses per note, Pereira and Nascimento 2004; 2–6 pulses per note, Toledo et al. 2010, and Pansonato et al. 2014b; 2–3 pulses per note, Magalhães et al. 2014; 1–4 pulses per note, Pansonato et al. 2013; 3–6 pulses per note in populations from Minas Gerais and São Paulo, Cardozo and Toledo 2013) and lower dominant frequency ( P. murundu 4875–6370 Hz, and P. pocoto 5168– 6374 Hz; Magalhães et al. 2014; Pansonato et al. 2014b).

Amongst species for which notes with concatenated pulses have been described, Pseudopaludicola ibisoroca sp. nov. differs from P. mŋstacalis by having a smaller number of pulses per note (12–20 pulses per note; Pansonato et al. 2013, 2014b) and lower mean dominant frequency (4887.4 ± 149.5 Hz; Pansonato et al. 2013, 2014b); from P. boliƲiana by larger number of notes per series (4–5 notes; Duré et al. 2004), longer internote intervals (2–14 ms), lower rate of notes per minute (293.6–1463.4), and lower mean dominant frequency (4581.1 ± 202.4 Hz; present study); from P. motorzinho by larger number of pulses per note (2–6 pulses), longer duration of each note (5–25 ms), and lower mean dominant frequency (5071 ± 242 Hz).

The number of chromosomes (2n ¼ 18) separates Pseudopaludicola ibisoroca sp. nov., from P. mŋstacalis (2n ¼ 16); P. ameghini and P. ternetzi (2n ¼ 20); and P. falcipes , P. mineira , P. motorzinho , P. murundu , and P. saltica (2n ¼ 22; Duarte et al. 2010; Fávero et al. 2011; Veiga-Menoncello et al. 2014).

Description of holotype. —Size small; snout rounded in dorsal and lateral views; head longer than wide; irregular white markings present from upper lips to under the eyes and to tympanic area and on flanks. Tympanum indistinct; nostrils closer to the snout tip than to eyes; pupil rounded; upper eyelids smooth; vomerine teeth absent; tongue ovoid, covering the entire floor of mouth, posteriorly free. Canthus rostralis rounded; vocal sac single (subgular), granular; choanae well-separated from each other; vocal slits present. Dorsal surfaces of body, ventral skin, and cloacal region smooth. Arms robust, with two antebrachial tubercles, the distal one scarcely perceptible; outer metacarpal tubercle round; inner metacarpal tubercle elongated; subarticular finger tubercles rounded; supernumerary finger tubercles indistinct; fingers free, with tips blunt, not expanded; relative lengths of Fingers IV <I ~ II <III. Hindlimbs robust; inner metatarsal tubercle large, elliptical; outer metatarsal tubercle rounded; toes not webbed, but extensively fringed almost to their tips; relative lengths of Toes I <II <III ~ V <IV; subarticular toe tubercles large, rounded; supernumerary tubercles absent.

Measurements of holotype. —SVL 13.1 mm, HL 5.8 mm, HW 4.8 mm, IOD 0.9 mm, ED 1.3 mm, END 1.1 mm, IND 1.3 mm, HAL 4.0 mm, THL 6.0 mm, TL 7.1 mm, TAL 4.1 mm, and FL 7.7 mm.

Coloration. —In preservative ( Fig. 8 ), dorsal surface of body and limbs whitish brown, with dorsolateral light stripes. White markings on upper lips, extending to the dorsal insertion of the forelimbs and to the flanks. Dark transverse stripes on dorsal surfaces of thighs and shanks, tarsi and feet. Belly and vocal sac light cream; legs yellowish cream; ventral surface of hands and feet dark brown.

Variation. — Females larger ( SVL ¼ 15.5–17.6 mm) than males ( SVL ¼ 12.8–15.6 mm; Table 5 ). Dorsal coloration highly variable ( Fig. 9 ), with one-fourth of the 16 specimens examined presenting a broad dorsolateral light stripe on each side, from eye to groin. One-fourth of the specimens have a thin light vertebral stripe from the tip of the snout to vent .

Etymology. —The specific epithet— ibisoroca —is a noun in apposition, resulting from a transliteration of Tupi– Guarani, a language family that comprises many different dialects spoken by South American indigenous people. It is formed by the words ‘‘yby’’ (or ‘‘yvy’’ ¼ earth, ground) and ‘‘sorok’’ (¼ crevice, crack), which together mean ravine or gully. Transliteration to modern Portuguese resulted in the words ‘‘boçoroca’’ or ‘‘voçoroca’’—large gully erosions. In short, a gully erosion ‘‘indicates that the soil is beyond its capacity to cope with the land use or the management practices’’ ( Alt et al. 2009:111). By coining the nomina ibisoroca , we intend to call attention to not only the fact that the topotypical population of our new species inhabits a highly impacted site, but also the urgent need for catchment conservation programs in the Neotropics, as previously suggested by Wantzen (2006). We are particularly concerned about the situation in the Upper Araguaia headwaters, largely converted into agricultural and grazing lands without adequate soil conservation measures, which has already resulted in almost 200 places where gully erosion has been identified (see Filizola et al. 2011).

Geographic distribution. — Pseudopaludicola ibisoroca sp. nov. is currently known from its type locality, in southeastern state of Mato Grosso, and from Mineiros, Goiás ( Kopp et al. 2010), both in midwestern Brazil ( Fig. 6 ). Kopp et al. (2010) recorded the sympatric occurrence of three species of Pseudopaludicola . One of them, referred to by those authors as ‘‘ Pseudopaludicola aff. falcipes , ’’ is here recognized as belonging to our P. ibisoroca sp. nov. Based in bioacoustical analyses of calls provided by K. Kopp, this species occurs at Parque Nacional das Emas, together with P. saltica and P. ternetzi .

(B) adult female (UFMT 6520). A color version of this figure is available on-line.

Conservation issues. —On-going erosion occurs at sites where concentrated water runoff (mostly attributable to urban settlement or farming practice) flows at a velocity sufficient to undermine remaining protective vegetation and scour away the topsoil. Subsequent rains then gradually remove and wash away large amounts of soil, sometimes forming deep gullies that might reach the water table. This is the case at Fazenda Granada, the type-locality of Pseudopaludicola ibisoroca sp. nov., where the soil along the small stream Ribeirão de Cima, belonging to the Upper Araguaia river basin, was carved out and washed downstream, resulting in a gully nearly 400 m long (see Filizola et al. 2011).

Gully erosion has been recognized as an important environmental threat affecting several ecological processes and resulting in land-use restriction, soil degradation, deforestation, siltation, flooding, and general biodiversity loss, among other consequences. Nevertheless, stabilized gullies can provide suitable habitats for organisms usually associated with groundwater upwelling sites, such as many species of Pseudopaludicola ( Pansonato et al. 2014b) . Individuals of the type series of P. ibisoroca sp. nov. were found amidst grass and sedge tussocks on the wet soil of the stabilized gully at Fazenda Granada. The gully floor is situated approximately 45 m below the natural land level, and it seems that the topotypical population of P. ibisoroca sp. nov. successfully recolonized the area after the erosion process slowed to the point that the soil could stabilize.

The type locality of P. ibisoroca sp. nov. at Fazenda Granada is surrounded to the west and south by heavily exploited agricultural lands. Approximately 40 km to the northeast, however, there is a large (130,000-ha) protected area in the savanna of the Brazilian Cerrado, the Emas National Park, in the headwaters of three distinct river basins: Araguaia, Paraná, and Taquari (see Valdujo et al. 2012).

Advertisement call. —We analyzed 560 notes of six specimens of Pseudopaludicola ibisoroca sp. nov. ( Table 6 ). A typical advertisement call of the new species ( Fig. 10 ) consists of series of 12–287 notes with 3–12 concatenated pulses per note. Duration of each pulse varies from 1 to 8 ms (mean ¼ 3.0 ± 0.1 ms). Series duration varies from 2.5 to 59.8 s (mean ¼ 23.5 ± 15.1 s). Series of notes are emitted at irregular intervals from 2.7 to 179.8 s (mean ¼ 91.6 ± 60.1 s). Duration of each note varies from 25 to 50 ms (mean ¼ 34 ± 4 ms), internote interval from 67 to 585 ms (mean ¼ 115 ± 41 ms), and the mean rate of notes per minute from 263.3 to 466.9 (mean ¼ 356.3 ± 64.1). Mean frequency band ranges from 2821.7 (± 193.9) Hz to 5373.8 (± 336.6) Hz. Dominant frequency varies from 3617.6 to 4651.2 Hz (mean ¼ 4167.7 ± 287.5 Hz).

Karyotype description. —The chromosomal complement of Pseudopaludicola ibisoroca sp. nov. is 2n ¼ 18, constituting four metacentric pairs (1, 2, 5, and 6), three submetacentric pairs (3, 4, and 9) and two telocentric pairs (7 and 8; Fig. 11A ).

In all individuals analyzed, the nucleolar organizer region (NOR) was detected in the pericentromeric region of the short arm of Chromosome 3 ( Fig. 11B ). In some metaphases, this region could be observed as a secondary constriction after Giemsa staining. Centromeric regions were found in all chromosomes after C-banding method and slightly marked heterochromatic blocks were also observed in the telomeric regions of some chromosome pairs. No interstitial heterochromatic block was detected on the long arm of Pair 2, even though variations in exposure time with barium hydroxide caustic treatments were tested ( Fig. 11C ). Heteromorphic sexual chromosomes were not observed.

Figures

FIG. 8.—Holotype of Pseudopaludicola ibisoroca sp. nov. (UFMT 16208, male, SVL ¼ 12.3 mm): (A) dorsal and (B) ventral view; (C) ventral view of hand; and, (D) ventral view of foot. Scale bar in panels C and D ¼ 1 mm. A color version of this figure is available on-line.

FIG. 9.—Live specimens of Pseudopaludicola ibisoroca sp. nov. from the municipality of Alto Taquari, Mato Grosso, Brazil: (A) adult male (UFMT 16142);

FIG. 6.—Map of the portions of South America (inset) showing the geographic distribution of Pseudopaludicola motorzinho sp. nov. (circles), P. ibisoroca sp. nov. (triangle), P. ceratophŋes (diamonds), and P. boliƲiana (squares). Stars represent type localities. Closed symbols are records from the present work, and open symbols are records from the literature (Lynch 1989; De la Riva et al. 2000; Duré et al. 2004; Reichle 2006; Cole et al. 2013).

FIG. 10.—(A) Oscillogram of three short advertisement call series of Pseudopaludicola ibisoroca sp. nov. (16, 11, and 9 notes with concatenated pulses, respectively); (B) oscillogram and (C) spectrogram of 3 notes with concatenated pulses. Voucher call LH 40A–03, from specimen UFMT 16208, recorded at 0945 h on 13 October 2007 (air temperature ¼ 23.5°C) at Granada Farm (Alto Taquari, Mato Grosso, Brazil). A color version of this figure is available online.

FIG. 11.—Karyotpes of two specimens of Pseudopaludicola ibisoroca sp. nov. stained with Giemsa (A; ZUEC 13992), submitted to the Ag-NOR technique (B; ZUEC 13987) and C-banded (C; ZUEC 13992). Scale bar ¼ 10 µm.