Friday, June 26, 2020

[Herpetology • 2020] Phyllodytes magnus • A New Large Canopy-dwelling Species of Phyllodytes Wagler, 1930 (Anura, Hylidae) from the Atlantic Forest of the State of Bahia, Northeastern Brazil

Phyllodytes magnus
Dias, Novaes-e-Fagundes, Neto, Zina, Garcia, Recoder, Vechio, Rodrigues & Solé, 2020

The known diversity of treefrogs of the genus Phyllodytes has rapidly increased in recent years, currently comprising 14 species. Recent field work in the Atlantic Rainforest of the state of Bahia lead to the discovery of a new large species of Phyllodytes which is herein described based on multiple evidence including morphological, acoustical and genetic data. Phyllodytes sp. nov. is one of the largest species within the genus and presents immaculate yellowish dorsum and limbs. The advertisement call of the species is composed of 7–31 notes (half pulsed/pulsatile-half harmonic) with frequency-modulated harmonics. Phyllodytes sp. nov. has a karyotype of 2n = 22 chromosomes, as also found in other species of the genus. Genetic distance values of the 16S mitochondrial rRNA among Phyllodytes sp. nov. and its congeners range between 6.4 to 10.2%. The description of another new species for this state reinforces the need for further taxonomic work with Phyllodytes in this region that has been revealed as a priority area for research and conservation of this genus.

Figure 3: Phyllodytes magnus sp. nov. (A, B, C, D), P. maculosus (E) and P. kautskyi (F) in life. Phyllodytes magnus sp. nov, holotype (MZUESC 18264) in (A) dorsal and (C) ventral view and paratype (MZUESC 18265) in (B) dorsal and (D) ventral view. In (E) P. maculosus and (F) P. kautskyi.

Phyllodytes magnus sp. nov.
Phyllodytes kautskyi—(Freitas, 2015)
Phyllodytes cf. kautskyi—(Freitas et al., 2018)
Diagnosis. — A large species (SVL 36.4 to 41.1 mm in males, n = 3) characterized by (1) snout mucronate in dorsal view, acute in profile; (2) mandible with two anterior large odontoids on each side in adults; (3) adults males with dorsum of body and limbs immaculate, uniformly pale yellow; (4) dorsal skin granular; (5) ventral skin cream and evenly granular, lacking distinct rows of tubercles; (6) a row of tubercles along lateral surface of forearm and tarsus; (7) tubercle subarticular from second segment of finger IV single and rounded shape; (8) canthus rostralis immaculate; (9) tympanum size corresponding to 6.6–7.1% of SVL; (10) advertisement call consisting of a series of 7–31 composite notes (half pulsed/pulsatile–half harmonic).

Etymology. — The specific epithet is an adjective from Latin meaning “great” or “large” (Lewis & Short, 1891), and refers to the large size of the adult males collected from this species, which are among the largest known in the genus.

Geographic Distribution and Natural history. — Phyllodytes magnus is known from three localities from the Atlantic Rainforest of Bahia (Fig. S5). Calls of this species have also been heard in the municipalities of Almadina, Ilhéus, Igrapiúna and Camacan, state of Bahia, but as no vouchers or recordings were obtained, these records need to be confirmed.

Although one specimen of Phyllodytes magnus was in a ground bromeliad, most calling males were in canopy bromeliads. At Parque Estadual da Serra do Conduru, Phyllodytes magnus is syntopic with four congeners (P. maculosus, P. megatympanum, P. melanomystax and P. praeceptor), although apparently less abundant than its relatives. In an area of 52 ha we heard only five males in a one-night search. All were calling from epiphytic giant bromeliads of the genus Hohenbergia with diameter superior to 1.50 m and at heights between 3.10 m and 11.30 m (x = 7.72 m ± 3.56 m). We found a male of Phyllodytes melanomystax in the same bromeliad where we collected the paratype MZUESC 18265, though in a different axil.

Almost 60% (nine species) of the known diversity of Phyllodytes can be found in the Atlantic Forest of southern Bahia, the region with the highest concentration of representatives of this genus. Over half of these species are endemic to the state: P. wuchereri, P. praeceptor, P. megatympanum, P. amadoi and P. magnus, the latter three are known from a few localities or only from the type locality (Cruz, Marciano & Napoli, 2014; Marciano-Jr, Lantyer-Silva & Solé, 2017; Vörös, Dias & Solé, 2017; this study). The high diversity of Phyllodytes in this part of the central corridor of the Atlantic Forest (Carnaval et al., 2009) is not unique. Other genera like Adelophryne (Fouquet et al., 2012; Lourenço-de Moraes et al., 2018), Adenomera (Fouquet et al., 2014), Gastrotheca (Teixeira-Jr et al., 2012) or the gymnophthalmid lizard genus Leposoma (Rodrigues et al., 2013), to cite a few, have their highest species diversity in this part of the biome. The high diversity of Phyllodytes and endemism brings support to this pattern and highlights the evolutionary importance of this area. Furthermore, together with the scarce available biological information and habitat specificity (bromeliads), it makes the Atlantic Forest of the state of Bahia a priority area for research and conservation of Phyllodytes.

Iuri R. Dias, Gabriel Novaes-e-Fagundes, Antonio Mollo Neto, Juliana Zina, Caroline Garcia, Renato Sousa Recoder, Francisco Dal Vechio, Miguel Trefaut Rodrigues and Mirco Solé. 2020. A New Large Canopy-dwelling Species of Phyllodytes Wagler, 1930 (Anura, Hylidae) from the Atlantic Forest of the State of Bahia, Northeastern Brazil. PeerJ. 8:e8642. DOI: 10.7717/peerj.8642