Description
Brachycephalus pernix is a very minute frog, very bufoniform in appearance with short robust arms and legs. The coloration in this species is rather uniquely patterned. The head is orange with black blotches (except for eyes and surrounding areas which are black), the dorsum of body , forearm, arm, knee, heel, and foot are orange as well; lateral surfaces of body, anal region and legs are black. Black stains are also present on arms. Dermal ossofication above the vertebral column is absent in this species (present in B. ephippium). Head is very round in dorsal and lateral aspect. Canthus rostralis faintly distinct, tympanum is not visible externally, and eyes do not project above the dorsal border of head. Vomerine teeth are absent. This is a relatively "small" species, males measuring 12-13.3 mm and females 14.1-15.8 mm SVL. Relative finger lenghts are 4<1<2<3, toes are 2<3<4 (digits 1 and 5 are not visible externally, but are present beneath epidermis). Pectoral girdle is completely ossified (Pombal Jr. et al 1998).

Distribution and Habitat

Country distribution from AmphibiaWeb's database: Brazil

View distribution map in BerkeleyMapper.

Only found in Morretes, State of Parana, Brazil and the type locality at Morro Anhangava, in Serra da Baitaca, Conjunto Marumbi (1400 m), Municipality of Quatro Barras, State of Parana, Brazil. They are found in shady forested areas with thick leaf litter.

Life History, Abundance, Activity, and Special Behaviors
Brachycephalus pernix is active by day. Some were found on leaf litter 10-15 cm thick! Clutch and vocalizations unknown.

Trends and Threats
The IUCN Red List 2004 assessment lists this species as Data Deficient; however, Bornschein et al (2019) analyzed the Brachycephalus species using the IUCN Red List criteria with newer locality information and concluded this species should be listed as Vulnerable (criteria D2).

Possible reasons for amphibian decline

General habitat alteration and loss
Habitat modification from deforestation, or logging related activities
Habitat fragmentation
Climate change, increased UVB or increased sensitivity to it, etc.

Comments

Brachycephalus pernix by Richard L. EssnerJr. et al 2022

This species was featured in News of the Week 25 July 2022:

Frogs are famous for being accomplished leapers. In addition to their take-off, nearly all frogs control their trajectory through the air and the eventual landing. However, Essner et al. (2022) found that this is not true for the tiniest of frogs where size limitations have performance consequences. They demonstrate the small pumpkin toadlets (genus Brachycephalus) from Brazil do not control their posture after take-off, resulting in sometimes wildly uncontrolled landings. The authors hypothesize that the extremely tiny semicircular canals— the smallest yet recorded for an adult vertebrate— result in low sensitivity making it difficult for the frogs to sense their position as they move through the air. (David C. Blackburn)

References

Bornschein, M. R., Pie, M. R., Teixeira, L. (2019). "Conservation status of Brachycephalus toadlets (Anura: Brachycephalidae) from the Brazilian Atlantic rainforest.” Diversity, 11(150), 1-29. doi: 10.3390/d11090150 [link]

Pombal, J. P., Jr., Wistuba, E. M., and Bornschein, M. R. (1998). ''A new species of brachycephalid (Anura) from the Atlantic rainforest of Brazil.'' Journal of Herpetology, 32(1), 70-74.

Species Account Citation: AmphibiaWeb 2022 Brachycephalus pernix <https://amphibiaweb.org/species/5421> University of California, Berkeley, CA, USA. Accessed Nov 22, 2024.

Citation: AmphibiaWeb. 2024. <https://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 22 Nov 2024.

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