Physalaemus nattereri

The species was described in 1863 by Austrian researcher Franz Steindachner in a publication of the Austrian Academy of Sciences that same year. It was identified as a new species based on its smooth skin; absence of vomerine teeth, parotoid glands, or hypertrophied forearm tubercles (a protrusion on the front of the forearm); lack of a visible tympanum; and the formation of foam nests for its eggs. At the time, the species was known only from Cuiabá, Mato Grosso. It was originally named Eupemphix nattereri, but the genus Eupemphix was later merged into Physalaemus following studies by Hampton Parker in 1927 and John Lynch in 1970. The species received the epithet nattereri in honor of Johann Natterer. == Distribution and conservation ==

Physalaemus nattereri is found in the Central-West, Southeast, and Northeast regions of Brazil, as well as eastern Paraguay and Bolivia, in areas with altitudes ranging from sea level to . It is fossorial and seasonal, highly adapted to the continental semi-arid climate. The species inhabits savanna and low-vegetation areas of the Cerrado, typically near permanent or temporary water bodies such as ponds and swamps, where it nests. It is not adapted to areas degraded by human activity. The International Union for Conservation of Nature (IUCN) classifies it as a least concern species, due to its common occurrence. However, its population is declining and threatened by the expansion of intensive agriculture in its range. Some portions of its distribution area are encompassed by environmental parks, which reduces the risk to the species. Including this species, the genus Physalaemus comprises a total of 47 species. ==Description==

The frog's dorsum varies from light brown to dark brown or reddish, with a mosaic of darker spots and stripes. A distinctive feature is the presence of two large black ocelli over glands in the inguinal region. The inner thigh is white with black, vermiform spots. Its abdomen is light brown with darker spots of the same hue. Males average in length, while females average . A rare characteristic of the species is that males have brightly colored testicles, often with spots of other colors, a trait known in only five other amphibian species, such as Physalaemus cuvieri. This pigmentation also occurs in other organs, including the kidneys, peritoneum, and spleen. It results from a high concentration of melanocytes, possibly due to an interaction between these cells and the vascular system of these tissues. The species can be easily distinguished from other anurans in the same region due to its unique and readily observable traits, such as the pair of ocelli on its dorsum, File:Eupemphix nattereri01a.jpg File:Eupemphix nattereri.jpg == Dietary habits ==

'') preying on an individual. The frog exhibits a generalist and opportunistic feeding behavior, consuming whatever food is available without specific preferences. Studies conducted in Jaboticabal and Guaíra, São Paulo, showed that the species primarily feeds on termites, which constitute 85.65% of the diet in adults. In juveniles, this percentage drops to 69.75%, with an increase in consumption of ants, rising from 14.01% to 29.74%. These data indicate that, despite its generalist nature, the species prefers social insects, such as ants and termites. Despite its deimatic behaviour and toxins for defense, it is often attacked by several predators, including birds and hemipterans. Its most common predators are giant water bugs, particularly Lethocerus delpontei and Lethocerus annulipes. Such predation occurs in water ponds where individuals reproduce or tadpoles undergo metamorphosis, indicating greater vulnerability during these periods. This makes giant water bugs significant in population control during the reproductive season and in regulating the structure of the ecological community. == Reproduction ==

A study in Bodoquena (in Mato Grosso do Sul, state of Brazil) found Physalaemus nattereri to be an explosive breeder, meaning all individuals gather synchronously for a few days, typically between October and January. Males form choruses to attract females, vocalizing after heavy rainfall (exceeding daily). During amplexus, which is axillary, the pair moves to the pond's edge, laying approximately 3 500 eggs in a foam nest. The nest is formed from mucus secreted by the female, with the male increasing its volume by whipping it with his hind legs, similar to whisking egg whites. They may produce communal egg masses. According to the list of anuran reproductive modes by Célio Haddad and Cynthia Prado, this species employs Mode 11. File:Group of tadpoles of Physalaemus nattereri.jpg| Tadpoles File:Eupemphix nattereri03.jpg|eggs == Behavior ==

These frogs are terrestrial and nocturnal. The venom is not lethal to humans, as its maximum toxicity affects smaller animals, but it may cause irritation if the secretion reaches the eyes. == References ==