Description

DESCRIPTION:

Physalaemus atim is a medium-sized, brown-patterned frog. The species has a snout-vent length range of 28.2 - 30.1 mm in males and 26.0 - 30.5 mm in females. The snout is protruding and roughly pointed, and the head is longer than it is wide. The skin is mostly smooth, with sparse warts and small ridges. The ventral surface is smooth. The hands are longer than the forearms. The leg (thigh and tibia) is slightly longer than the snout-vent length. Various tubercles on the feet are present and are useful for identifying the species (Brasileiro and Haddad 2015) .

DIAGNOSIS:

As of 2015, 47 species of Physalaemus were known and grouped into 4 - 7 species groups based on morphology. Physalaemus atim is larger than members of the P. signifer group, which includes P. angrensis, P. camacan, and P. irroratus. The focal species also has a tarsal tubercle, inner metatarsal tubercle, and lacks a dark arrowhead-shaped mark on its dorsum, which further differentiate it from members of the P. signifer group. They differ from members of the P. deimaticus group, in that P. atim is larger, and has a slender body, a tarsal tubercle, smaller inguinal glands, and a well-developed vocal sac. From the P. henselii group, P. atim is larger, and lacks a ridge of glands between the eyes and the insertion of the arm. From members of the P. olfersii group, which includes P. feioi, P. insperatus, P. lateristriga, and P. orophilus, P. atim has warty skin or longitudinal glandular ridges on the dorsum, a slightly concave loreal region, and lack of planter supernumerary tubercles. To see comparisons with individual species please see Brasileiro and Haddad (2015).

COLORATION:

Dorsally, P. atim is brown and irregularly patterned with dark-brown splotches and stripes. The arms and legs are also brown with dark-brown stripes. There are black stripes running along both sides of the frog, spanning from the rear of the eye to the groin. Ventrally, it is brown, with several light spots near the chest. The ventral surface of the thighs is described as uniformly dark-brown, while the hands, feet and digits are white (Brasileiro and Haddad 2015).

VARIATION:

Variation among individuals includes variation in the dorsal pattern and the coloration of the markings. The stripes and splotches differ in size, shape, and placement. The markings vary in color—some appearing much darker than others—and are sometimes surrounded by a white line. The black line running laterally down the frog differs in width. Some individuals display a stripe between their eyes (Brasileiro and Haddad 2015).

Males and females do not differ in size, but can be distinguished in coloration and secondary sexual characters. Males have a dark gular area, compared to a lighter area on females. Males also have nuptial pads on the thumb and large vocal sacs (Brasileiro and Haddad 2015).

Distribution and Habitat

Country distribution from AmphibiaWeb's database: Brazil

View distribution map in BerkeleyMapper.

Physalaemus atim was first discovered at a farm outside the city of Campo Limpo de Goiás in the State of Goiás, Brazil. The frogs were found in a swampy area and in puddles near a man-made lake amidst an open and undisturbed habitat of mostly pasture. While no other specimens were collected outside of this location, calls of the frog were heard approximately 20 kilometers away. This suggests a very narrow range of distribution for P. atim, in this specific region of Brazil. The specimens were collected at 910 km above sea level (Brasileiro and Haddad 2015).

Life History, Abundance, Activity, and Special Behaviors
Physalaemus atim is found primarily in shallow puddles around ponds dug for agricultural purposes at night. Often cattails can be found around the perimeter of the water, but the ponds themselves were in sparsely vegetated areas (Brasileiro and Haddad 2015).

Like many frogs, males advertise to potential mates using vocalization. Their call is characterized by a single note with multiple harmonies that is made repeatedly, but less frequently throughout the duration of the call. These calls are made while floating on the surface of the water (Brasileiro and Haddad 2015).

Amplexus occurs primarily in the evening around sunset. Following amplexus, the female lays her eggs in floating nests. Central Brazil is very seasonal, with its wet season occurring from October to March. Although the males call during the wet season, floating nests were observed only in the dry season. Most Physalaemus species breed during the wet season, so the observation of nests in the dry season calls typical Physalaemus behavior into question (Brasileiro and Haddad 2015).

Physalaemus atim primarily consumes insects, such as termites and ants. It is suggested that this species feeds opportunistically, and while they are carnivores, plant material—most likely consumed by accident—has also been found in their stomachs (Gambale et al. 2020).

Physalaemus atim is found in sympatric with P. cuvieri (Gambale et al. 2020).

Trends and Threats
Physalaemus atim is found in regions that have been completely modified by agriculture practices and that are relatively close to large cities in the central region of Brazil. It’s unknown whether the agriculture practices benefit or endanger the species, or push them closer to urban areas. Although P. atim was originally found in ponds that had been dug as stock tanks for cattle in agricultural areas relatively close to cities, this does not rule out the possibility of P. atim inhabiting other environments (Brasileiro and Haddad 2015, Gambale et al. 2020).

The eggs of P. atim are only found in dry seasons, which could lead to challenges with climate change that might interfere with their life history and reproduction (Brasileiro and Haddad 2015).

Possible reasons for amphibian decline

Climate change, increased UVB or increased sensitivity to it, etc.

Comments

PHYLOGENETIC RELATIONSHIPS:

Although 16S rRNA and COI mtDNA sequences were obtained, P. atim was described as a new species on the basis of morphology and bioacoustics (Brasileiro and Haddad 2015).

ETYMOLOGY:

The scientific species epithet, “atim” for this species originates from the language of the indigenous people of Brazil known as the Tupi. The word, “atim”, means “big nose,” and refers to this species' prominent snout (Brasileiro and Haddad 2015).

References

Brasileiro, C. A. and Haddad, C. F. (2015). “A new species of Physalaemus from central Brazil (Anura: Leptodactylidae)”. Herpetologica, 71(4), 280–288. [link]

Gambale, P. G., da Silva, M. R., Oda, F. H., Bastos, R. P. (2020). “Diet and trophic niche of two sympatric Physalaemus species in central Brazil”. South American Journal of Herpetology, 17(1), 63. [link]

Nascimento, J., Lima, J. D., Suárez, P., Baldo, D., Andrade, G. V., Pierson, T. W., Fitzpatrick, B. M., Haddad, C. F., Recco-Pimentel, S. M., Lourenço, L. B. (2019). “Extensive cryptic diversity within the Physalaemus cuvieri–Physalaemus ephippifer species complex (Amphibia, Anura) revealed by cytogenetic, mitochondrial, and genomic markers”. Frontiers in Genetics, 10, 719. [link]

Species Account Citation: AmphibiaWeb 2022 Physalaemus atim <https://amphibiaweb.org/species/8394> 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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