Saturday, May 1, 2021

[Herpetology • 2021] Brachycephalus rotenbergaeHidden by the Name: A New Fluorescent Pumpkin Toadlet from the Brachycephalus ephippium Group (Anura: Brachycephalidae)


Brachycephalus rotenbergae  
Nunes, Guimarães, Moura, Pedrozo, Moroti, Castro, Stuginski & Muscat, 2021

Species of Brachycephalus has been having taxonomical issues due its morphological similarity and genetic conservatism. Herein, we describe a new species of Brachycephalus from the south Mantiqueira mountain range and semidecidual forests in the municipalities of Mogi das Cruzes, Campinas and Jundiaí, state of São Paulo, Brazil, based on an integrative approach. It can be distinguished from all species of the B. ephippium species group based on morphological characters (especially osteology and head shape), advertisement call and divergence in partial mitochondrial DNA gene sequences (16S). The new species is genetically similar to B. margaritatus and morphologically similar to B. ephippium. It can be differentiated from B. ephippium by the presence of dark faded spots on skull and post-cranial plates, presence of black connective tissue connective tissue scattered over dorsal musculature, parotic plate morphology, smaller snout-vent length (adult SVL: males 13.46–15.92 mm; females 16.04–17.69 mm) and 3% genetic distance. We also present natural history data and discuss the robustness of the integrative approach, geographic distribution, genetic data, behaviour, fluorescence in ontogeny, and conservation status.

Brachycephalus rotenbergae sp. nov. lightened by a UV flashlight (395 nm wavelength).
Deatil of fluorescence in dorsal and cephalic shields.

Natural history observations of Brachycephalus rotenbergae sp. nov.
(A) Inguinal amplexus; (B) An amplected couple of hiding under the juçara palm (E. edulis) root system;
(C) Mouth gaping defensive behaviour; (D) One specimen near a yellow/orange mushroom, notice the similarity of color and size;
(E) One juvenile specimen; (F) Two juvenile specimens, but the smaller one is darker.

Brachycephalus rotenbergae sp. Nov.

Diagnosis: Brachycephalus rotenbergae sp. nov. can be assigned to the genus Brachycephalus by observed phalangeal reduction, an arciferal pectoral girdle in which the ossified procoracoid and epicoracoid cartilages are fused to the clavicle, coracoid, and scapula, a suprascapula expanded with a prominent cleithrum, and the absence of a sternum (putative synapomorphies; see Hedges et al. [54]). A member of the B. ephippium species group by the presence of dermal co-ossification (putative synapomorphy; see [55]). The new species can be diagnosed from its congeners by the following combination of characters: (1) bufoniform body; (2) bright orange overall body coloration; (3) presence of skull and post-cranial plates; (4) presence of faded dark spots over skull and post-cranial plates; (5) absence of metacarpal and metatarsal tubercles; (6) rounded snout; (7) paravertebral plates forming a trapezoidal bony shield; (8) absence of osteoderms; (9) laterally expanded parotic plates; (10) flat paravertebral plates; (11) paravertebral plates not projected over vertebral spines; (12) presence of black connective tissue scattered over dorsal musculature; (13) head wider than long (mean HL/HW ~ 90% for both male and females); (14) adult SVL 13.46–15.92 mm for males and 16.04–17.69 mm for females; (15) advertisement call with dominant frequency of 2.84–4.52 kHz, note duration of 0.13–014 s, and at rate 2.50–3.42 note/s, each note had 8–13 pulses, emitted at rate 50.56–71.82 pulses/s.

Etymology: The epithet rotenbergae is a patronym in honor to Elsie Laura K. Rotenberg, founder, and leader of the Projeto Dacnis, a Brazilian NGO dedicated to research and conservation of Atlantic Forest domain.

Study areas for the natural history observations of Brachycephalus rotenbergae sp. nov.
 (A) São Francisco Xavier, Projeto Dacnis, and (B) Reserva das Araucárias.

Ivan Nunes, Carla S. Guimarães, Pedro Henrique A. G. Moura, Mariana Pedrozo, Matheus de Toledo Moroti, Leandro M. Castro, Daniel R. Stuginski and Edelcio Muscat. 2021. Hidden by the Name: A New Fluorescent Pumpkin Toadlet from the Brachycephalus ephippium group (Anura: Brachycephalidae). PLoS ONE. 16(4): e0244812. DOI: 10.1371/journal.pone.0244812