Monday, September 21, 2020

[Herpetology • 2020] Amazophrynella gardai • A New Tiny Toad Species of Amazophrynella (Anura: Bufonidae) from east of the Guiana Shield in Amazonia, Brazil


Amazophrynella gardai 
 Mângia​, Koroiva & Santana, 2020

 
Abstract 
The combination of different approaches has successfully delimited new species within many Neotropical species complexes traditionally classified as a single nominal organism. Recent studies have shown that the Amazonian endemic genus Amazophrynella, currently composed of 12 small-sized species, could harbor several additional species. Based on morphology and molecular data, we describe a new species of Amazophrynella from east of the Guiana Shield, in Pará state, Brazil. The new species is characterized by having one of the biggest size of the genus (SVL of males 16.0–17.8 mm and females 22.9–24.4 mm), presence of a large palmar tubercle (occupying 2/4 of the palmar surface), 5.6–8.1% uncorrected p-distance from its sister clade (including A. teko, A. sp.1, and A. manaos) for the 16S mitochondrial gene, and 8.8% for the COI. The new species described here represents a newly discovered lineage. Of the 12 Amazophrynella species currently recognized, two were describe in the last century (A. bokermanni and A. minuta) and the remaining species were recently discovered and described (in the last six years), which underscores the degree to which species richness of Amazophrynella is underestimated.

Figure 3: Live specimens of Amazophrynella gardai sp. nov. 
(A–B) Amplected couple (ZUFMS-AMP12827, adult male, SVL 16.0 mm; ZUFMS-AMP12826, adult female, 22.9 mm). (C) Amplected couple (ZUFMS-AMP12829, adult male, SVL 16.6 mm; ZUFMS-AMP12828, adult female, SVL 24.0 mm). (D) Adult male (ZUFMS-AMP12822, SVL 16.5 mm). White circle in the (B) indicates the reticulated lower eyelid.

Figure 7: Defensive behavior on Amazophrynella gardai sp. nov. 
(A) Thanatosis and (B) Stiff-legged (ZUFMS-AMP12822, adult male, SVL 8.3 mm).

     

Amazophrynella gardai sp. nov. 

Diagnosis. The new species can be distinguished using the following combination of traits: (1) large size for the genus (SVL of males 16.0–17.8 mm and females 22.9–24.4 mm); (2) snout elongated, acuminated in lateral view and truncated in dorsal view; (3) dorsal skin spiculated (small sized warts with pointed tips); (4) ventral region with dark brown blotches, with a white background; (5) palmar and subarticular tubercles rounded; (6) big palmar tubercle, occupying 2/4 of the palmar surface.


Natural history (Fig. 7). One male individual (ZUFMS-AMP12822) showed stiff-legged behavior and thanatosis (death-feigning) during manipulation for photographs. The stiff-legged behavior is a defensive strategy to avoid detection by predators and thanatosis is used to avoid subjugation (Bertoluci et al., 2007; Toledo, Sazima & Haddad, 2011). Russel (2002) documented death-feigning behavior in Amazophrynella minuta” from Pacaya-Samiria National Reserve, Loreto, Peru (probably A. matses or A. amazonicola, see Rojas et al., 2015). This is the first report of stiff-legged behavior in the genus Amazophrynella.
 
We found individuals of Amazophrynella gardai sp. nov. by visual search and pitfall traps inside the forest (from 500 m up to 2,000 m from the edge). During visual search (both diurnal and nocturnal periods), we found three males (ZUFMS-AMP12822-24), one female (ZUFMS-AMP12821), and an amplected couple (ZUFMS-AMP12828-29) on the leaf litter. The individuals were in “Terra firme”, nearby to rivulets inside the forest, concentrating their activity during the morning, between 8:00–11:00 h am. Using the pitfall traps, we collected one female (ZUFMS-AMP12825) and one amplected couple (ZUFMS-AMP12826-27). February comprises the rainy season in the region and the presence of amplected couples may indicate that Amazophrynela gardai sp. nov. was in its breeding season. However, we have not observed males in calling activity.


Etymology The specific name is a patronym honoring Prof. Adrian Antonio Garda (Universidade Federal do Rio Grande do Norte, UFRN) for his extensive contributions to the knowledge of Neotropical anurans, his friendship, and his mentoring of SM and DJS during their doctorate degrees.

Distribution (Fig. 8). Amazophynella gardai sp. nov. is known only from its type locality, Óbidos municipality, Pará state, Brazil. The area where we found the new species is characterized as a Alluvial Forest type, with smaller trees where it is possible to observe a high concentration of palm trees.


Sarah Mângia​, Ricardo Koroiva and Diego José Santana. 2020. A New Tiny Toad Species of Amazophrynella (Anura: Bufonidae) from east of the Guiana Shield in Amazonia, Brazil. PeerJ. 8:e9887. DOI: 10.7717/peerj.9887