Description
Pristimantis campinarana is a small species of frog. Males have a snout-to-vent length ranging from 17.3 to 20.1 millimeters, while females have a snout-to-vent length ranging from 23.2 to 26.5 millimeters. The long snout is subacuminate in the dorsal view and moderately truncated in the lateral view. The oval nostrils are slightly raised and directed dorsolaterally. The internarial region is straight. The loreal region is concave. The eyes are large. The pupil is elliptical and wider than it is tall. There is a small tubercle on the upper eyelid. There is a supratympanic fold, but it is not obvious. Their tympanum is visible and is less than half the diameter of the frog’s eye. There are no cranial crests. Males have vocal slits. The dorsum is shagreen. The hand is longer than the forearm. This species has finger discs, which are larger on fingers III and IV. The relative finger lengths are I < II < IV < III. The fingers do not have lateral fringes, and males do not have nuptial pads. Toes III, IV, and V have lateral fringes, and there is basal webbing between toes IV and V. The relative toe lengths are I < II < III < V < IV. The toe discs are larger in toes III, IV, and V (Mônico et al. 2023, for a more complete description, please see the citation).

DIAGNOSIS:

At the time of the species description, P. campinarana was placed in the P. unistrigatus species group, which includes: P. aaptus, P. academicus, P. altamazonicus, P. brevicrus, P. carvalhoi, P. crepitaculus, P. croceoinguinis, P. delius, P. diadematus, P. divnae, P. espedeus, P. eurydactylus, P. grandoculis, P. guianensis, P. inguinalis, P. kichwarum, P. librarius, P. luscombei, P. martiae, P. matidiktyo, P. miktos, P. ockendeni, P. orcus, P. variabilis, and P. ventrimarmoratus, but can be differentiated by size, presence of vocal slits, presence of dentigerous processes of vomers, presence of eyelid tubercles, two-toned irises, visible tympanum, male tarsal tubercles, coloration, and call characters. More specifically, P. campinarana females have a smaller snout-vent length than P. aaptus, P. altamazonicus, P. brevicrus, P. delius, P. diadematus, P. espedeus, P. eurydactylus, P. miktos, P. ockendeni, P. orcus, and P. ventrimarmoratus. Male P. campinarana have a smaller snout-vent length than P. aaptus, P. diadematus, P. divnae, P. espedeus and P. orcus, but a larger snout-vent length than P. academicus, P. carvalhoi, P. martiae and P. grandoculis. The presences of male vocal slits in P. campinarana differentiate it from P. altamazonicus, P. brevicrus, P. carvalhoi, P. croceoinguinis, P. diadematus, P. divnae, P. eurydactylus, P. grandoculis, P. miktos, P. orcus, and P. ventrimarmoratus. The presence of dentigerous processes of vomers in P. campinarana distinguishes it from P. delius and P. guianensis, which both lack this feature. Eyelid tubercles in P. campinarana differentiate the species from P. carvalhoi, P. delius, P. diadematus, P. lythrodes, P. variabilis, and P. ventrimarmoratus, which lack eyelid tubercles. Pristimantis campinarana have two-toned irises that differ from the monochromatic irises of P. academicus, P. altamazonicus, P. brevicrus, P. carvalhoi, P. croceoinguinis, P. divnae, P. lythrodes, P. miktos, P. orcus, and P. ventrimarmoratus. A visible tympanum in P. campinarana separates it from P. brevicrus, P. carvalhoi, P. croceoinguinis, P. grandoculis, P. martiae, and P. ventrimarmoratus. Pristimants campinarana males have tarsal tubercles, which are not found in P. diadematus, P. librarius, P. lythrodes, P. kichwarum, P. martiae, P. matidiktyo, or P. ventrimarmoratus. The lack of brightly colored marks on the groin in P. campinarana differentiates it from P. aaptus, P. academicus, P. altamazonicus, P. brevicrus, P. carvalhoi, P. crepitaculus, P. croceoinguinis, P. diadematus, P. divnae, P. espedeus, P. eurydactylus, P. grandoculis, P. inguinalis, P. librarius, P. lythrodes, P. martiae, P. matidiktyo, P. miktos, and P. orcus. The focal species has a call that is similar to P. espedeus, P. guianensis and P. ockendeni, but has a longer call duration than P. espedeus and P. guianensis, longer inter-note interval than P. guianensis, and higher dominate frequency than P. espedeus and P. ockendeni. The multi-note call of P. campinarana also distinguishes it from the single note call of P. inguinalis and P. orcus (Mônico et al. 2023).

COLORATION:

In life, the dorsal surface is dark yellow to light brown. A dark brown dorsal stripe may be present that runs the length of the frog from snout to the cloaca (see next paragraph for variation among specimens). This species of frog has a dark brown mid-dorsal stripe. The dorsolateral stripes start behind the eyes and run to the cloaca, but are not solid as they are formed by small, brown spots and blotches. On the head, a black stripe runs from the snout to the anterior edge of the eyelid. The upper lip has dark brown stripes below the eye and above the tympanum. The iris of this frog is pale bronze with dark brown irregular line patterns and a mahogany-red horizontal stripe through the middle, some may have a golden coloration at the base. The forelimbs have dark brown transversal bars. The thigh and tibia have a light brown transversal bar, while the posterior side of the thigh is brown with no stripes or bars. The ventrum is gray during the day but becomes whitish at night when the melanophores expand. Small, dark melanophores can be seen on the white and translucent groin, which otherwise does not have any bright markings (Mônico et al. 2023).

In preserved specimens, the dorsal side has three types of patterns: dark brown mottling, a light dorsum with stark contrast to dark sides, and the dark brown dorsal stripes as described above. Most specimens have a dark brown stripe between the eyes. Some have a W-shaped line on the dorsal side between the shoulders. Various dark brown striping patterns across the body are generally visible in most preserved specimens, but can be less obvious or not present. The ventral side is off-white with dark melanophores present in most specimens (Mônico et al. 2023).

VARIATION:

There is individual morphological variation and variation by time of day within the same individual. When looking down on this species from above, the canthus rostralis can either be straight or have a slight curve. Males have three or four ulnar tubercles, while females do not have any. The texture of the dorsal surface can vary in terms of granularity and in the presence or absence of tubercles; both of these characters are probably influenced by the activity of the frog at the time of interaction. The melanophores on the ventrum expand at night causing the ventrum to turn from gray to white. There is also variation in coloration, which is described above (Mônico et al. 2023).

Distribution and Habitat

Country distribution from AmphibiaWeb's database: Brazil

View distribution map in BerkeleyMapper.

At the time of the species description the species was found in two localities in the Municipality of Iranduba in the state of Amazonas, Brazil. Their habitat consists of anthropized white-sand forest with thin-trunked trees and a canopy lower than 20 m, which are locally called “campinarana”. Specimens were found at elevations between 61 and 83 meters above sea level, and was absent from the nearby “campina” habitat, which is composed white-sand forests with a canopy below 10 m and large patches of white-sand soils (Mônico et al. 2023).

Life History, Abundance, Activity, and Special Behaviors
This species is active during twilight and night hours, with most activity happening at twilight. They tend to breed during the rainy months of the year, and males will stay amongst the leaves of bromeliads during drier months (Mônico et al. 2023).

When breeding, males begin their calls at dusk and continue consistently until nighttime, around 20:00h, and end completely at 22:00h. The calls will continue throughout the night during the rainier days. These males call while resting on plants about 1 meter from the floor, usually in groups of around 10 males, about 4 - 5 meters from each other. When their groups are smaller, of 3 - 4 males, they will often spread out further (Mônico et al. 2023).

Their advertisement calls have between 5 to 10 notes. However, they will usually advertise with 6 to 8 notes for 694 ms (± 115 ms), for a call duration range between 550 to 1061 ms. These notes tend to be tonal, lasting 26.5 ms (± 7.1 ms), and the time between their notes being 82.7 ms (± 11.9 ms). The minimum frequency of the calls are 2,853 Hz (± 141 Hz) and the maximum is 4,490 Hz (± 413 Hz). Their dominating frequency is 3,587 Hz (± 204 Hz) (Mônico et al. 2023).

They utilize the axillary amplexus position, with the female being grasped at the forelimbs (Mônico et al. 2023).

Females produce oocytes, usually about 14 - 17 (Mônico et al. 2023).

Larva
Pristimantis campinarana is in the Strabomantidae family, which is direct developing (Hedges et al. 2008).

Trends and Threats
At the time of the species description, trends and threats were unknown and an "Data Deficient" list was recommended based the IUCN’s criteria. However, this species is endemic to the anthropized Negro-Solimões interfluve (Mônico et al. 2023).

Relation to Humans
This species can be found in forests that have been slightly modified for human use (Mônico et al. 2023).

Possible reasons for amphibian decline

General habitat alteration and loss
Habitat modification from deforestation, or logging related activities
Intensified agriculture or grazing
Climate change, increased UVB or increased sensitivity to it, etc.

Comments

PHYLOGENETIC RELATIONSHIPS:

References
Hedges, S.B., Duellman, W.E., and Heinicke, M.P. (2008). New World direct-developing frogs (Anura: Terrarana): molecular phylogeny, classification, biogeography, and conservation. Zootaxa 1737, 127-128. [link]

Mônico, A.T., Ferrão, M., Moravec, J., Fouquet, A., and Lima, A.P. (2023). A new species of Pristimantis (Anura: Strabomantidae) from white-sand forests of central Amazonia, Brazil. Peerj 11, e15399. [link]

Species Account Citation: AmphibiaWeb 2024 Pristimantis campinarana <https://amphibiaweb.org/species/9756> University of California, Berkeley, CA, USA. Accessed May 5, 2025.

Citation: AmphibiaWeb. 2025. <https://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 5 May 2025.

AmphibiaWeb's policy on data use.