Tuesday, September 28, 2021

[Herpetology • 2021] Pristimantis achupalla • A New Minute Species of Direct-developing Frog (Anura, Strabomantidae) inhabiting Bromeliads of the Montane Forest of the Amazonian Andes of Puno, Peru



 Pristimantis achupalla  
Ttito​ & Catenazzi, 2021


Abstract 
We describe a new species of bromeliad-dwelling Pristimantis from primary montane forest (2,225 m a.s.l.) in southern Peru. The type locality is near Thiuni, in the Department of Puno (province of Carabaya) in the upper watershed of a tributary of the Inambari River. Pristimantis achupalla sp. n. is characterized by a snout-vent length of 10.0–12.8 mm in adult males (n = 4), unknown in adult females, and is compared morphologically and genetically with species in the Pristimantis lacrimosus group, and with other similar species of Pristimantis. The new species is characterized by having skin on dorsum and flanks rugose, green brownish color, distinctive scapular folds, subacuminate or acuminate snout profile, upper eyelid bearing two or three subconical tubercles and some rounded tubercles, rostral papilla, flanks light brown to brown, with irregular dark brown marks.


Figure 3: Holotype of  Pristimantis achupalla sp. n., male CORBIDI 18736 (SVL 12.8 mm).
 In dorsolateral view (A); dorsal (B) and ventral (C) views of specimen alive.
Photographs by A. Catenazzi.

Figure 6: Dorsolateral views of holotype and three paratypes of  Pristimantis achupalla sp. n. showing detail of coloration patterns and morphological feactures.
Male CORBIDI 18736 (A), SVL = 12.8 mm. Male CORBIDI 18737 (B), SVL = 11.7 mm.
Male MUBI 17604 (C), SVL = 10.0 mm. Juvenile MUBI 17605 (D), SVL = 10.4 mm
Photographs by A. Catenazzi.

Pristimantis achupalla sp. n.

Definition: The new species is distinguished by the following combination of characters: (1) skin on dorsum rugose, that on venter areolate, discoidal fold absent, dorsolateral folds absent; (2) tympanic membrane differentiated, tympanic annulus visible, slightly robust supratympanic fold covering dorsal and posterior edges of tympanum; (3) snout acuminate in dorsal view, truncated and posteroventrally inclined in lateral view, canthus rostralis weakly concave in dorsal view, angular in lateral view, loreal region concave, rostral papilla present; (4) upper eyelid bearing two or three subconical tubercles and some rounded tubercles, cranial crests absent, and postrical turbercles present; (5) dentigerous process of vomers absent; (6) males with vocal sacs and vocal slits, nuptial excrescences absent; (7) Fingers I and II of equal length, fingers II and III bearing rounded discs about 1.2 times wider than digits, Finger IV bearing a rounded disc about twice as wide as its digit; (8) fingers with narrow lateral fringes; (9) antebrachial tubercle present; (10) ulnar and tarsal tubercles present (11) inner metatarsal tubercle oval twice as long as round outer metatarsal tubercle, low supernumerary plantar tubercles at the base of toes I, II, and III; (12) toes with narrow lateral fringes, webbing absent, Toe V longer than Toe III; (13) in life, males with dorsum brownish green; canthal stripe brown extending to the orbits; dorsolateral stripe brown; throat and belly pale green; groins, posterior surfaces of thighs, and shanks bright pale green; iris bronze with fine black reticulations; (14) SVL in adult males 10–12.8 mm; SVL in females unknown. 

Etymology: The name of the new species is a Quechua noun, used in apposition, “achupalla” = bromeliads, in reference to the use of bromeliads as its microhabitats.


Conclusions: 
We describe a new species of terrestrial breeding frog in the genus Pristimantis. We justify the generic location-based on morphological similarity and phylogenetic analyses. The new species P. achupalla is nested within the P. lacrimosus group and is closely related to an undescribed species P. sp. from Peru, P. amagunae, P. sp. from Ecuador, and P. bromeliaceus. These species of minute, bromeliad-living frogs form a clade well supported in the phylogeny. Additionally, several meristic traits distinguish P. achupalla from similar species in P. lacrimosus group. We discuss the difficulty of justifying the position of P. achupalla within groups such as P. lacrimosus, but we also confirm the evolutionary unicity of P. achupalla which supports our taxonomic decision to describe it as new species. Our contribution increases the knowledge of the rich diversity of terrestrial breeding frogs found at high elevations on the eastern slopes of the Cordillera de Carabaya. 
  


Alex Ttito​ and Alessandro Catenazzi. 2021. Pristimantis achupalla sp. n., A New Minute Species of Direct-developing Frog (Amphibia, Anura, Strabomantidae) inhabiting Bromeliads of the Montane Forest of the Amazonian Andes of Puno, Peru. PeerJ. 9:e11878. DOI: 10.7717/peerj.11878