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Diagnosis: A medium-sized species of Pseudis with paired vocal sacs in males and thumb with a bulbous base. It can be distinguished from P. paradoxus by its smaller size and paired vocal sacs (larger body size and single vocal sac in P. paradoxus), and from P. minuta by a more robust body, adpressed hind limbs not having metatarsal articulation reach the snout tip, rounded snout, robust bulbous fingers plus a thumb quite widened at its base, and lack of dilated toe tips (in P. minuta, body is less robust, adpressed limbs extend past the snout tip, snout is truncate, fingers are more slender, and toe tips are dilated) (Kwet 2000).
Description: The snout-vent length in males is 33 - 46 mm, and in females is 45 - 56 mm. The head is about as long as it is wide, and is broad and flat. The snout appears rounded in both dorsal and lateral profile, with an indistinct, rounded canthus rostralis and a slightly sloping loreal region. The upper jaw protrudes in profile. Nares are slightly protuberant. Eyes are large and project slightly. The interorbital region is flat and wide. The rounded tympanum is distinct, with a diameter smaller than the diameter of the eye. The supratympanic fold is weak. Vomerine teeth are present in two round, short and well-divided patches between the small and widely-separated choanae. The large tongue is cordiform. The body is robust. The forearms are robust, while the upper arms are more slender and are shorter. All fingers lack webbing. Fingers are robust, and bulbous at the base, and the thumb is also wider at the base. Small raised conical subarticular tubercles are present, especially on the thumb. The relative lengths of the fingers are 2 < 1 = 4 < 3. Hind limbs are short and robust, with extensively webbed toes. Relative lengths of the toes are 1 < 2 < 5 < 3 < 4. The inner metatarsal tubercle is spurlike and elliptical; the outer metatarsal tubercle is absent. Small, raised, conical subarticular tubercles are present. A tarsal fold is present. The skin of the dorsum and hindlimbs is coarsely granulated. Skin on the head is smooth. Longitudinal rows of tubercles are present on the upper surface of the thigh, tibia, and tarsus. The venter is smooth. Males posses paired vocal sacs that are conspicuous in the lateral gular region as two wrinkled dark areas (Kwet 2000).
In preservative, the dorsum and dorsal surfaces of the limbs are olive gray or gray and marked by irregularly shaped blackish blotches. Dark blotches are present on the forelimb, thigh, tibia, and foot. A dark line runs across the nostrils from the tip of the snout to the eyes. Ventral surfaces are white with sparse dotting on the vent. The ventral surface of the thigh has one distinct dark longitudinal band and three or four less distinct, interrupted bands. In life the dorsal surfaces of the body and limbs range in coloration from light to dark green, olive, or brown. Darker irregular spots and blotches are present. A narrow dark green or black stripe is present on the canthus rostralis, although in some specimens this stripe is broad and blotlike. The tympanum is olive, tan or light brown. The lateral surfaces of the head, body, thigh and the anal region are light yellow. The ventral surfaces are white, and the vent region is sometimes scattered with dark brown dots. Several dark brown longitudinal lines of varying number, form and extension mark the ventral surface of the thighs (Kwet 2000).
Tadpoles have ovoid bodies that are widest at the midbody and highest at the posterior half of the body. Medium-sized eyes are laterally situated on the tadpole head. The dorsolateral nostrils are small and nearer to the snout than to the eyes. The snout is broadly rounded in both dorsal and lateral views. The small mouth is terminal, with multiple rows of well-developed marginal papillae. A large median gap is present in the second row of the anterior labium. All tooth rows are about equal length, except the shorter third row in the posterior labium. The large, triangular vent opening is midventral. The spiracle is sinistral. Tail length is about 2/3 the length of the total tadpole, with a height greater than the body height. The dorsal fin extends from the midbody at the level of the eye to the tip of the tail with a uniformly curved margin. The ventral fin extends from the vent to the tip of the tail, which is flagelliform (Kwet 2000).
In preservative, the tadpole body coloration is brown or grey with a few light reticulations. The posterior portion of the tail is dark brown to black (Kwet 2000).
Distribution and Habitat
Life History, Abundance, Activity, and Special Behaviors
Females deposit spawn both separately and in small clumps, attaching them to submerged plants. A single egg clutch may contain up to 200 eggs. Eggs are dark brown and white and are encapsulated by a large, transparent greenish casing. The tadpoles are suspension feeders (Kwet 2000).
This species is a generalist, foraging actively on various arthropod taxa (primarily Diptera, Coleoptera, Hymenoptera, Hemiptera, and Araneae). Non-insect arthropod prey taxa comprised only 3.7% of stomach contents and included Arachnida, Crustacea, and Chordata (male P. cardosoi were occasionally found to have consumed another frog). Annelids and nematodes were also occasionally consumed. Naiads (Plecoptera) are an important component of the diet and indicate that this species can feed underwater. Plant matter was frequently found in stomach contents, particularly in summer months (Miranda et al. 2006).
Miranda et al. (2005) carried out an 11-month population study at São Francisco de Paula, RS, using photographs of the thigh color pattern to recognize individuals. The population size was estimated at 129 individuals using the Jolly-Seber method. Photographs were deemed more effective than toe clipping methods as Miranda et al. (2005) found that this species is able to easily regenerate the first phalanx.
Trends and Threats
Kwet, A. (2000). ''The genus Pseudis (Anura: Pseudidae) in Rio Grande do Sul, southern Brazil, with description of a new species.'' Amphibia-Reptilia, 21, 39-55.
Kwet, A. (2004). Pseudis cardosoi. In: IUCN 2010. IUCN Red List of Threatened Species. Version 2010.1. www.iucnredlist.org. Downloaded on 05 May 2010.
Miranda, T., Ebner, M., Solé, M., and Kwet, A. (2005). ''Estimativa populacional de Pseudis cardosoi (Anura, Hylidae), com emprego de método fotográfico para reconhecimento individual.'' Biociências, 13, 49-54.
Miranda, T., Ebner, M., Solé, M., and Kwet, A. (2006). ''Spatial, seasonal and intrapopulational variation in the diet of Pseudis cardosoi (Anura: Hylidae) from the Araucária Plateau of Rio Grande do Sul, Brazil.'' South American Journal of Herpetology, 1, 121-130.
Written by Alexis Leigh Krup (akrup1 AT berkeley.edu), UC Berkeley
First submitted 2009-10-20
Edited by Kellie Whittaker (2010-05-04)
Species Account Citation: AmphibiaWeb 2010 Pseudis cardosoi <http://amphibiaweb.org/species/6093> University of California, Berkeley, CA, USA. Accessed Oct 24, 2020.
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Citation: AmphibiaWeb. 2020. <http://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 24 Oct 2020.
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