Description
Pseudacris nigrita is a small frog with a snout-vent length ranging from 19 - 32 mm. The head and body are narrow, and the snout is pointed. There’s basal webbing between the second, third, and fourth toes. The tips of the digits are moderately expanded (Gates 1988).

At the time of hatching, larvae are approximately 4.5 mm long. The maximum length of larvae can be up to 35.0 mm long. Newly-transformed froglets are between 8.5 and 15.0 mm long (Gates 1988).

Pseudacris nigrita resembles cricket frogs of the genus Acris. However, cricket frogs have prominent stripes near their rear thigh, and these are absent in P. nigrita. Additionally, P. nigrita has a snout that is notably more pointed than other species of chorus frogs (Conant and Collins 1998).

In life, Pseudacris nigrita’s dorsal surface can be between tan and black in color, often with three dark, horizontal stripes or rows of dots. The middle stripe extends up to the snout, but not all individuals have it. The upper lip may have small spots, wavy streaks, or a distinct stripe of white. Pseudacris nigrita has a dark band extending from the snout to the groin, trailing along the side of the body. The limbs appear either striped or spotted, with darker bars along the tibia. The ventral surface is typically a pale yellow and may be speckled with dark spots. Males have smooth, green-ish yellow to orange throats (Gates 1988).

In life, at hatching, P. nigrita larvae have a light lateral stripe that extends from the eye to the tail. Dark melanophore spots can be seen in the dorsal tail fin, and the tail musculature is tan above and a dull yellow below. The chest and abdomen are dull yellow as well. Pseudacris nigrita at Gosner stage 37, have a dark brown dorsal surface with golden specks and black spots. The tail fins are covered with melanophores. The ventral surface is dark, except for the center of the abdomen, which is golden in color. This gold area often forms a triangle pointing anteriorly (Gates 1988).

Pseudacris nigrita is commonly split into two subspecies: Pseudacris nigrita nigrita and Pseudacris nigrita verrucosa. Like most chorus frogs, P. nigrita nigrita has a white upper lip. P. nigrita verrucosa, however, has a black upper lip (Conant and Collins 1998).

Distribution and Habitat

Country distribution from AmphibiaWeb's database: United States

U.S. state distribution from AmphibiaWeb's database: Alabama, Florida, Georgia, Louisiana, Mississippi, North Carolina, South Carolina, Virginia

	View distribution map in BerkeleyMapper.
	View Bd and Bsal data (2 records).

Pseudacris nigrita can be found in most regions of the southeastern United States, including in Alabama, Florida, Georgia, Louisiana, Mississippi, North Carolina, South Carolina, and Virginia. They largely inhibit inner wetlands and forest habitats (IUCN 2014).

Life History, Abundance, Activity, and Special Behaviors
Pseudacris nigrita breeds in a variety of small, shallow waters, including small ponds, puddles, and roadside ditches. Some specimens have also been collected from meadows and woods (Martof and Thompson 1958). Ideal breeding locations have shallow water and many kinds of grass and vegetation. Their breeding season is long, beginning in November and ending in April. The most active breeding occurs during rainy weather (Martof and Thompson 1958).

The P. nigrita call is described as a musical trill (Conant and Collins 1998). Frog calls can be heard at the beginning of the breeding season, in November, but large “choruses” -- used to describe large groups of calling frogs -- are not heard until December and January when it rains. Choruses and breeding behavior may be interrupted by cold weather, but the choruses continue largely-uninterrupted through March. By April, there are notably fewer choruses, but scattered calls can be heard through May (Martof and Thompson 1958).

Trends and Threats
Pseudacris nigrita has an IUCN status of "Least Concern" because of its wide distribution, presumed large population, and apparent tolerance to habitat modification. Local subpopulations are threatened by clear-cutting and urbanization, but overall, the species does not have any major threats.

Comments
Parsimony, Maximum Likelihood, and Bayesian methods were used to analyze 12S, tRNAval, and 16S rRNA mtDNA genes of the Pseudacris genus, with consistent results. Four distinct clades were identified: West Coast, Fat Frogs, Crucifer, and Trilling Frogs. Pseudacris nigrita is a member of the “trilling frog clade,” which includes the nigrita clade and a sister group of P. brimleyi and P. brachyphona (Moriarty and Cannatella 2004). The nigrita clade includes P. clarkii, P. feriarum, P. fouquettei P. kalmi, P. maculata, P. nigrita, and P. triseriata . The nigrita clade was further split into three clades based on geographic divisions: those west of the Mississippi River, including P. maculata and triseriata, those in the southeastern United States, P. fouquettei and P. nigrita, and northeastern US species including P. feriarum, P. kalmi, and P. triseriata. The sister species of P. nigrita is P. fouquettei, which was described in 2008 (Moriarty and Cannatella 2004, Moriarty Lemmon et al. 2008).

Pseudacris nigrita is split into two subspecies: P. nigrita nigrita and P. nigrita verrucosa. However, Moriarty and Cannatella (2004) discourage the recognition and usage of these subspecies, claiming that they are uninformative.

The species epithet, “nigrita” is a reference to the overall dark coloration of Pseudacris nigrita (Gates 1988).

References

Conant, R. and Collins, J.T. (1998). A Field Guide to Reptiles and Amphibians of Eastern and Central North America. 3rd Edition. Houghton Mifflin Company, Boston, Massachusetts.

Gates, W.R. (1988). "Pseudacris nigrita." Catalogue of American Amphibians and Reptiles, (416), 1-3. [link]

IUCN SSC Amphibian Specialist Group. (2014). "Pseudacris nigrita". The IUCN Red List of Threatened Species 2014: e.T55894A64733885. https://dx.doi.org/10.2305/IUCN.UK.2014-3.RLTS.T55894A64733885.en. Downloaded in January 2021

LeConte, J.E. (1825). "Remarks on the American species of the genera Hyla and Rana." Annals of the Lyceum of Natural History of New York, 1, 278-282.

Martof, B.S., Thompson, E.F. (1958). "Reproductive behavior of the chorus frog, Pseudacris nigrita." Behaviour, 13(3-4), 243-257.

Moriarty Lemmon, E., Lemmon, A. R., Collins, J. T., Cannatella, D. C. (2008). "A new North American chorus frog species (Amphibia: Hylidae: Pseudacris) from the south-central United States." Zootaxa, 1675, 1-30. [link]

Moriarty, E.C., Cannatella D.C. (2004). “Phylogenetic relationships of the North American chorus frog (Pseudacris: Hylidae).” Molecular Phylogenetics and Evolution 30: 409-420 [link]

Species Account Citation: AmphibiaWeb 2021 Pseudacris nigrita: Southern Chorus Frog <https://amphibiaweb.org/species/1057> University of California, Berkeley, CA, USA. Accessed Oct 4, 2023.

Citation: AmphibiaWeb. 2023. <https://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 4 Oct 2023.

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