Description
Brachycephalus bufonoides is a robust frog with a snout-vent length range of 12.0 - 14.5 mm for males and 14.7 - 16.3 mm for females. The skin on the head is ossified. They have rough, hyperossified skin on the dorsum with warts on their dorsolateral surfaces, and they lack osteoderms. Their digits have arrow-shaped terminal phalanges. For a more complete description, please see Folly et al. 2020.

DIAGNOSIS:

The presences of ossified skin on the head and vertebrae, and a hyperossified process of the fourth vertebra distinguish B. bufonoides from B. atelopoide, B. darkside, B. didactylus, B. ephippium, B. garbeanus, B. hermogenesi, B. margaritatus,B. pernix, B. pulex, and B. sulfuratus that lack hyperossification. The orange coloration with different intensities of dark orange blotches on the dorsum of B. bufonoides differentiates them from B. alipioi, B. guarani, B. pitanga, and B. toby. Not having warts on the dorsal surface distinguishes B. bufonoides from B. crispus and B. nodoterga (Folly et al. 2020).

COLORATION:

In life, B. bufonoides is pumpkin orange with different intensities of dark orange blotches. For a more complete description of color, please see Folly et al. 2020.

VARIATION:

Females of this genus are typically larger than their male counterparts (Dorigo et al. 2012).

Distribution and Habitat

Country distribution from AmphibiaWeb's database: Brazil

View distribution map in BerkeleyMapper.

Brachycephalus bufonoides is only known only from the type locality, Serra de Macaé, Rio de Janeiro, Brazil. They are found in moist, high altitude forests at an elevation of 1169 meters above sea level (Folly et al. 2020). The montane forest where this species is found contains large canopies with steep terrain (Pie et al. 2018). The area is characterized by patchy outcrops and rocky streams with a dry season around April to August and a wet season from September to March (Nunes et al. 2021).

Life History, Abundance, Activity, and Special Behaviors
Brachycephalus bufonoides is a diurnal and terrestrial species that is often observed roaming forest floors or leaf litter and in high moisture areas along tree trunks in moist, high-altitude forests. Both males and females are active by day during the rainy seasons and move slowly through leaf litter and low perches (Pombal et al. 1994). Males have been observed exposed in forests on either leaves or timber during cloudy or rainy days, vocalizing (Folly et al. 2020).

The vocal activity is more pronounced in the morning and later during the day. Males of this genus call at high densities, usually under leaf litter and move occasionally. Vocalizations were recorded for B. bufonides at an air humidity of 78% and a temperature of 20.8 °C. These calls lasted around 3 minutes and were described as a sequence of low intensity buzzing with a consistent amplitude of about 120 dB at 1 meter of recording distance. Notes generally contained multiple pulses that range from 13 to 17 pulses per note and lasted 0.22 - 0.31 seconds with a period of pulse modulation. During the second quarter of these notes, the amplitude increased with shorter duration periods ranging from 4.13 to 4.88 kHz (Folly et al. 2020).

Breeding behavior in this genus include male-male confrontations through vocalization and displays where the intruder often retreated without any physical contact. Territorial displays include wiping their heads with their forelimbs, which can also serve as multiple functions that can indicate cleaning. If intruded upon, males pursue and embrace each other and even mount in various instances (Pombal et al. 1994).

In general, this genus utilizes inguinal amplexus in which the male clasps the female’s waist. Males have also been recorded to switch from inguinal to axillary amplexus during oviposition, which lasted about 30 minutes (Pombal et al. 1994).

Females have unpigmented ovarian eggs that are few, but often large (Pombal 2001). Clutches in this genus consist of about five eggs that are yellow/white in coloration and are about 5.1 - 5.3 mm in diameter. After oviposition, the female covers the surface of the eggs with soil to conceal them, assuming no parental care (Pombal et al. 1994).

Frogs of the Brachycephalus genus breed through direct development (Pombal 2001). Small toadlets hatch from eggs that are laid on the forest floor or under logs (Folly et al. 2020).

Their diet consists of a variety of arthropods and invertebrates, including seasonal differences in prey, but mites and ants seem to be the preference during both the wet and dry seasons (Dorigo et al. 2012)

Brachycephalus species are often recognized by their bright yellow or orange hue that is related to aposematism as a warning coloration to predators. They have a tetradotoxin compound called ephippiotoxin in their skin which is considered noxious if ingested (Pombal et al. 1994).

Larva
Species of the genus Brachycephalus have direct development (Pombal 2001, Folly et al. 2020).

Trends and Threats
IUCN Red List has not yet assessed this species; however, Bornschein et al. (2019) analyzed the Brachycephalus species using the IUCN Red List criteria with newer information and concluded this species should be listed as Data Deficient until more information is available.

Brachycephalus bufonoides was originally described in 1909, and then wasn’t seen again until 2020. As a result, there is too little data on this species to determine any trends. However, as of 2022, a mere 21 individuals of B. bufonoides have ever been recorded (two from Ernest Garbe’s initial collection and 19 from the Folly et al. collection). Due to its small distribution and unique habitat (high altitude forests), B. bufonoides is particularly vulnerable to the effects of habitat loss, fragmentation and climate change. More research needs to be done to determine its current conservation status (Folly et al. 2020).

Possible reasons for amphibian decline

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

Comments

PHYLOGENETIC RELATIONSHIPS:

Based on Bayesian Inference of 16S mtDNA, B. bufonoides belongs to the Brachycephalidae family. Within Brachycephalidae there are two genera: Brachycephalus and Ischnocnema. Brachycephalus bufonoides belongs to the former genus. Within its genus, its sister to the clade composed of B. alipioi, B. nodoterga, B. pitanga, B. toby, and B. vertebralis (Folly et al. 2020).

ETYMOLOGY:

The genus name of “Brachycephalus” comes from the Latin and Greek words “brachy,” meaning “short,” and “cephalic”, which pertains to the head (Folly et al. 2020).

The species epithet “bufonoides” is a reference to the true toad family Bufonidae, but is a misnomer because B. bufonoides is actually from the family Brachycephalidae (Folly et al. 2020).

OTHER INTERESTING INFORMATION:

There was a 111 year gap between the first and second recorded sightings of B. bufonoides (Folly et al. 2020).

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]

Dorigo, T.A., Siqueira, C.C., Vrcibradic, D., Maia-Carneiro, T., Almeida-Santos, Rocha, C.F.D. (2012). “Ecological aspects of the pumpkin toadlet, Brachycephalus garbeanus Miranda-Ribeiro, 1920 (Anura: Neobatrachia: Brachycephalidae), in a highland forest of southeastern Brazil.” Journal of Natural History 46(39-40), 2497-2507 [link]

Folly, M., Amaral, L.C., Carvalho-E-Silva, S.P. de, Pombal Jr., J.P. (2020) “Rediscovery of the toadlet Brachycephalus bufonoides Miranda-Ribeiro, 1920 (Anura: Brachycephalidae) with osteological and acoustic descriptions.” Zootaxa 4819(2), 265–294. [link]

Nunes, I., Guimarães, C.S., Moura, P.H.A.G., Pedrozo, M., Moroti, M.d.T., Castro, L.M., Stuginsk, D.R., Muscat, E. (2021). “Hidden by the name: A new fluorescent pumpkin toadlet from the Brachycephalus ephippium group (Anura: Brachycephalidae).” PloS One 16(4): e0244812 [link]

Pie, M.R., Ribeiro, L.F., Confetti, A.E., Nadaline, M.J., Bornschein, M.R. (2018). “A new species of Brachycephalus (Anura: Brachycephalidae) from Southern Brazil.” PeerJ 6, e5683 [link]

Pombal Jr., J.P. (2001). “A new species of Brachycephalus (Anura: Brachycephalidae) from Atlantic Rain Forest of southeastern Brazil.” Amphibia-Reptilia 22(2), 179-185 [link]

Pombal, J. P. Jr., Sazima, I., and Haddad, C. F. B. (1994). "Breeding behavior of the pumpkin toadlet, Brachycephalus ephippium (Brachycephalidae)." Journal of Herpetology, 28, 516-519. [link]

Species Account Citation: AmphibiaWeb 2022 Brachycephalus bufonoides <https://amphibiaweb.org/species/7850> University of California, Berkeley, CA, USA. Accessed Nov 21, 2024.

Citation: AmphibiaWeb. 2024. <https://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 21 Nov 2024.

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