Description
Melanophryniscus peritus ​​is a medium-sized frog, belonging to the Melanophryniscus tumifrons group, that was described from one female specimen with a snout-vent length of 39.3 mm. The head is just slightly wider than it is long with a head length of 9.0 mm and a head width of 9.3 mm. This species has small, lateral nostrils with an internarial distance of 2.5 mm and an eye to nostril distance of 2.7 mm. Beginning above the snout, the frog has a pronounced bump that extends to about the middle of the upper eyelid and rises to a height above the eyelids. The canthus rostralis has a rounded shape due to this distinct bump. The eye diameter is 2.1 mm, the upper eyelid width is 2.5 mm, and the interorbital distance is 4.7 mm. The tympanum is not visible in this species. The arms are slender, while the legs are short and sturdy. The thigh length is 10.3 mm, the tibia length is 11.7 mm, and the foot length is 12.5 mm. Neither the fore- or hind limbs have folds in the ulnar or tarsal regions. The relative finger lengths are I < II < IV < III. The fingers are fringed but not webbed, and the fingertips are slim and round. The relative toe lengths are I < II < V < III < IV. The toes are short in length, and half webbed, and the tips of the toes are also slim and round like the fingertips. On both the hands and feet, there are tubercles present, with the tubercles on the feet being larger in size. The skin is covered with spiny warts both on the lateral and ventral sides of the body (Caramaschi and Cruz 2011).

Diagnosis:

Melanophryniscus peritus is differentiated from M. admirabilis, M. moreirae, M. stelzneri, and M. vilavelhensis by the pronounced bump on its snout, which the other species do not have. Melanophryniscus peritus can also be differentiated from M. cambaraensis, M. devincenzii, M. macrogranulosus, M. simplex, and M. tumifrons through the presence of tubercles on its skin, as well as the irregular patterning on the venter, and the light and dark spotting throughout its body. Melanophryniscus peritus is differentiated from M. pachyrhynchus by the absence of a distinct glandular swelling on the 4th and 5th toes as well as by the presence of the spiny bump on its snout. Melanophryniscus peritus can be distinguished from M. spectabilis by its distinctive light brown coloration on its dorsum and flanks, as well as by the two round light brown spots on the shoulders, the large white spot on the loreal region, and the uniform dark brown coloration on the dorsal surface of the arms and legs. And finally, M. peritus can be differentiated from M. orejasmirandai by the height of the snout bump, which is lower in M. orejasmirandai, as well as coloration and patterning, which is uniform dorsally and with black reticulations on the ventrum in M. orejasmirandai (Caramaschi and Cruz 2011).

Coloration:

In preservative, M. peritus, is dark brown on the dorsal surfaces and flanks. On the dorsum there is an irregular pattern of light brown spots. On the shoulders there are two rounded light brown spots. The dorsal surfaces of the arms and legs are uniformly dark brown. On the loreal region, there is a large white spot. Overall, the gular region, belly, chest, palmar and plantar surfaces, and the ventral surfaces of forearms and thighs are light brown. The gular region has darker brown spots and the chest and belly both have irregular dark brown spots (Caramaschi and Cruz 2011).

Variation:

There is no known variations in the species as it’s only know from one specimen (Caramaschi and Cruz 2011).

Distribution and Habitat

Country distribution from AmphibiaWeb's database: Brazil

	View distribution map in BerkeleyMapper.
	View Bd and Bsal data (1 records).

Melanophryniscus peritus is known only from a single locality, which is the summit of Pico do Selado in Monte Verde in the state of Minas Gerais, southeastern Brazil at an elevation of 2,000 m asl. Although the habitat and ecology is currently unknown there is a possibility that M. peritus could be associated with the montane forest habitat around Pico do Selado in Monte Verde. Members of the same taxonomic group are known to inhabit small ponds and flooded areas suggesting M. peritus may do the same (IUCN 2013).

Life History, Abundance, Activity, and Special Behaviors
The holotype, discovered in 1953 by German-Brazilian naturalist Helmut Sick, is the only documentation of this species. Although scientists made multiple attempts since then to relocate this species, no new records have been made (Caramaschi and Cruz 2011). Due to the lack of documentation and significant human disturbance in this area, this species may already be extinct and information on this species’ behavior and ecology remains unknown. However, taxa within their genus are known to reproduce in shallow streams, so it is likely that M. peritus have an aquatic larval stage (IUCN 2013).

Trends and Threats
Due to the lack of documentation and significant human disturbance in this area, this species may already be extinct. The primary threat to M. peritus is habitat loss. Eucalyptus and pine plantations for paper production have replaced native fields and forests at the base of Pico do Selado. While M. peritus primarily occurs at higher elevations, and may be less affected by these plantations, its natural habitat is disrupted by other human activities such as tourism and cattle-ranching. Trails leading up to the summit of Pico do Selado are frequented by horses, cattle, hikers, and motorcycles (IUCN 2013).

Relation to Humans
There are currently no accounts of this species being utilized or traded by humans (IUCN 2013).

Possible reasons for amphibian decline

General habitat alteration and loss
Intensified agriculture or grazing

Comments

Phylogenetic Relationships:

Etymology:

The species epithet, “peritus”, is a Latin adjective that means “vanish or disappear”. The name was given to the species as a reflection of the current status of M. peritus (Caramaschi and Cruz 2011).

References

Caramaschi, U., Cruz, C. A. G. (2011). “A new, possibly threatened species of Melanophryniscus Gallardo, 1961 from the state of Minas Gerais, southeastern Brazil (Amphibia, Anura, Bufonidae). Boletim do Museu Nacional.” Nova Serie, Zoologia. Rio de Janeiro 528: 1–9.

IUCN SSC Amphibian Specialist Group (2013). “Melanophryniscus peritus.” The IUCN Red List of Threatened Species. Version 2015.2. . Downloaded on 19 January 2022

Species Account Citation: AmphibiaWeb 2022 Melanophryniscus peritus <https://amphibiaweb.org/species/7847> University of California, Berkeley, CA, USA. Accessed Dec 26, 2024.

Citation: AmphibiaWeb. 2024. <https://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 26 Dec 2024.

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