Melanophryniscus montevidensis (Philippi, 1902)

Taxonomy

Melanophryniscus montevidensis, commonly known as Darwin's toad, is a species of toad in the family Bufonidae, belonging to the genus Melanophryniscus.

Distribution

It is found in Brazil and Uruguay.

Genus Distinguishing Traits

Like other amphibians in its genus, it is set apart by its bright coloration, defensive behavior, and rapid metamorphosis.

Skin Compounds

Its skin contains a wide range of chemical compounds that may be suitable for biomedical applications.

Dorsal and Lateral Coloration

Darwin's toad is jet black, with yellow patches on its back, sides, forelimbs, and ventral surface.

Ventral and Limb Extremity Coloration

It has a red spot on the ventral side of the thigh and part of the abdomen; the palms of its hands and soles of its feet are also red.

General Habitat Types

Darwin's toad's natural habitats are temperate shrubland, intermittent freshwater marshes, and sandy shores.

Coastal Distribution Range

This species occurs along the coast of the Río de la Plata and the Atlantic Ocean, ranging from Santiago Vázquez in Montevideo to Praia da Alvorada in Rio Grande do Sul.

Preferred Microhabitat

It is most often found in coastal sandbanks with psammophilous vegetation, where it prefers open, vegetated areas, and is occasionally found in flooded grasslands.

Sheltering Behavior

It takes shelter in burrows it digs in the sand among vegetation.

Activity Pattern

Darwin's toad is typically diurnal.

Diet

It feeds mainly on ants, but will also consume small beetles, springtails, and aphids.

Reproductive Period

Its reproductive period is short, and usually takes place after heavy rains from late spring to early autumn.

Male Mating Territoriality

During the mating season, males defend territories.

Male Mating Behavior

Their vocal repertoire changes, and males engage in short fights with one another.

Winter Activity

They can also be found active in winter after heavy rains, when the air temperature is above 15 °C (59 °F).

Defensive Posture

When handled by humans, individual toads usually stay motionless with their belly turned upward, displaying their red and yellow coloration.

Unken Reflex

This defensive behavior is known as the Unken reflex.