Saturday, May 29, 2021

[Herpetology • 2021] Rhinella chullachaki • Genetic and Morphological Evidence reveal Another New Toad of the Rhinella festae Species Group (Anura: Bufonidae) from the Cordillera Azul in central Peru

Rhinella chullachaki  
Castillo-Urbina, Glaw, Aguilar-Puntriano, Vences & Köhler, 2021

Chullachaki Beaked Toad | Sapo picudo Chullachaki || SALAMANDRA. 57(2)

 We studied the status of toads of the genus Rhinella collected in the southern Cordillera Azul, central Peru. Molecular analysis of the mitochondrial 16S rRNA gene revealed them to be members of the recently proposed Rhinella festae species group, and sister to R. lilyrodriguezae, a species known from northern areas of the Cordillera Azul. The new specimens are differentiated from R. lilyrodriguezae and other species of Rhinella by substantial genetic divergence in the studied gene fragment (> 5% uncorrected pairwise distance) and several qualitative morphological characters, providing combined evidence for a divergent evolutionary lineage. We consequently describe the specimens from the southern part of the Cordillera Azul in Departamento Huánuco as a new species, Rhinella chullachaki sp. n. We briefly discuss the definition and content of species groups in Rhinella as well as the difficulties hampering taxonomic resolution within this species-rich genus. 

Key words. Amphibia, Rhinella, new species, species groups, morphology, molecular genetics, systematics, taxonomy.

Male holotype (MUSM 40293) of Rhinella chullachaki sp. n. in life (SVL 44.2 mm);
 (a) dorsolateral view; (b) lateral close-up view of head; (c) ventral view.

Male paratypes of Rhinella chullachaki sp. n. in life.
 Left column shows MUSM 40292, right column shows ZSM 237/2019,
each in (a, b) dorsolateral, (c, d) ventral, and (e, f) close-up lateral head views.

Rhinella chullachaki sp. n. 

Diagnosis. A medium-sized species of the Rhinella festae species group, based on morphological similarities and phylogenetic relationships. The new species is characterized by (1) medium size, SVL 42.1–44.2 mm in adult males (n = 3), females are unknown; (2) eight presacral vertebrae; (3) bicondylar articulation of sacral vertebrae and coccyx; (4) snout long, acuminate, pointed to rounded terminally in dorsal view; snout protuberant, directed slightly anteroventrally in profile as a ‘shark snout’; nostrils at level or only slightly beyond anterior margin of lower jaw in lateral profile; (5) cranial crests moderately developed; (6) canthal, supraorbital, postorbital and supratympanic crests distinctly elevated and continuous; pretympanic crest present, occipital crest weakly developed; (7) tympanum and tympanic annulus absent, middle ear cavity and columella present; (8) mandibular angle protruding; (9) parotoid glands moderately large, roughly rectangular and rounded in outline, swollen laterally, incorporated into the lateral row of tubercles; (10) dorsolateral rows of large, conical tubercles extending from parotoid gland to groin; (11) hands and feet with long digits, fingers basally webbed and toes moderately webbed; (12) skin on dorsum tubercular with scattered large tubercles in the lateral and lumbar regions in males; (13) subarticular tubercles distinct, round to ovoid; (14) supernumerary tubercles present, round and well developed; (15) cloacal sheath absent; (16) in life, dorsum yellowish green with irregular black and dark brown markings; venter pale cream to white with black blotches and spots; black spots and flecking on ventral surfaces of limbs and scattered black spots on throat; iris bronze with irregular black reticulation.

 Etymology. The specific epithet is derived from the Quechuan language. The Chullachaki is a mythical creature of the Peruvian and Brazilian Amazon region said to be living in the jungle, being able to turn into any creature, and guarding the forest by punishing people acting unwisely in the forest. Many depictive representations of the Chullachaki show it as having a large nose. We chose the name as a plea for a more respectful and sustainable treatment of Peruvian forests. The specific name is an invariable noun in apposition. 

Proposed common names. Chullachaki Beaked Toad; Sapo picudo Chullachaki. 

Ernesto Castillo-Urbina, Frank Glaw, César Aguilar-Puntriano, Miguel Vences and Jörn Köhler. 2021. Genetic and Morphological Evidence reveal Another New Toad of the Rhinella festae Species Group (Anura: Bufonidae) from the Cordillera Azul in central Peru. SALAMANDRA. 57(2); 181-195.