Diagnosis: This species can be distinguished by the following combination of characters: large, robust body (adult males 35.6-44.1 mm SVL); dorsolateral skin densely granular, with large white tubercles; Toe V with moderate fringing on outer side; advertisement call consisting of 4-8 notes, each with 3-6 frequency-modulated pulses (rapid raise and decay); lack of light dorsolateral stripes; males with external vocal sacs; lack of blue or yellow dorsal spotting. H. asper is similar to H. cardosoi but has a different call (more notes per call and longer duration for H. asper); less frequently has a distinct pair of cloacal tubercles on either side of the vent (cloacal tubercles distinct: 7.9%, weak: 67.3%, lacking: 24.8% of H. asper specimens vs. cloacal tubercles distinct: 89.2%, weak: 8.1%, lacking: 2.7% of H. cardosoispecimens); has longer fringe on Toe V (H. asper); posterior thigh almost always brown with scattered cream blotches in H. asper, vs. brown with anastomosed cream blotches (56% of H. cardosoi specimens), or less frequently, brown with scattered cream blotches (22% of H. cardosoi specimens), or equal brown/cream patches (18.0% of H. cardosoi specimens).
Description: The snout-vent length in males is 35.6 mm to 44.1 mm and in females is 36.7 mm to 46.5 mm. The head has a greater length than width. From above, the snout appears rounded and from the lateral view appears protruding, with nostrils directed laterally, a distinct, nearly straight canthus rostralis and a concave loreal region. The tympanum is distinct and is nearly round with a diameter slightly smaller than half the diameter of the eye. A supratympanic fold extends posteriorly from the edge of the orbit and stops before the shoulder. Lateral vocal sacs are well-developed in males. The large tongue is nearly ovoid, and free posteriorly. Vomerine teeth are present in two series between rounded choanae. Maxillary and premaxillary teeth are also present. A row of small, unpigmented tubercles is present on the margin of the upper lip in the male holotype, but never in females. The body is robust, with moderately robust arms and more robust legs. The outer metacarpal tubercle is very large and round, while the inner metacarpal tubercle is small and elliptical. The subarticular tubercles on the fingers are single and round, and the supernumerary tubercles are arranged in rows between fingers. The relative lengths of the fingers are II < I < IV < III. Lateral fringes on the fingers run from the proximal subarticular tubercle to the disc. On the outer margin of finger III is a vestigial fringe, running from the proximal subarticular tubercle to the distal one. The elliptical discs of the fingers are slightly expanded but smaller than the tympanum, with the disc on finger I being the smallest. Well-developed scutes are present on the upper surfaces of discs. The finger discs are as developed as the toe discs. On the legs, the protruding outer metatarsal tubercle is small and round, while the inner metatarsal tubercle is elongated. Subarticular tubercles are single, and can be either rounded or ovoid. The relative lengths of the toes is I < II < V = III < IV. The toes have extensive fringe, and the fringe along the outer margin of toe V extends beyond the end of the subarticular tubercle to a distance almost equal to the tubercle's diameter. Tarsal fringe is also extensive, and continuous distally with the toe fringe of toe I's inner margin on the male holotype. Female paratypes display more poorly developed fringes on the toes, fingers and feet. Slightly expanded toe discs are somewhat elliptical, with a smaller disc on toe V. Well-developed scutes are present on the upper surfaces of discs. The dorsal skin texture of the flanks and thighs are rugose. Ventral surfaces of the thighs and vent are also rugose, but otherwise the venter is smooth. Males lack nuptial asperities or spines on the thumb, but have vocal sacs. Females have weakly developed fringes on fingers, toes, and feet, lack upper lip tubercles, and are slightly larger than males (Lingnau et al. 2008).
The overall coloration is brown, with numerous, small, uniformly distributed brown spots on the dorsum. Thighs have two irregular dark brown stripes on the dorsal surfaces, while the tibia has one irregular dark brown and two irregular light brown stripes on the dorsal surface. The pes has two dark brown stripes as well. Two dark brown stripes mark the dorsal surfaces of the brachium. Arms are marked with brown blotches on the anterior and dorsal surfaces. Tubercles on the flanks are white. The head has irregular brown blotches on the sides. Throat, abdomen, and ventral surfaces of the thighs and arms are uniformly cream. Posterodorsal surfaces of the thighs sometimes vary in coloration between specimens; 22.0% had scattered light blotches, 56.0% presented a brown background with anastomosed light blotches, 18.0% displayed equally distributed brown and cream blotches, and 4.0% had brown blotches on a cream background (Lingnau et al. 2008).
Distribution and Habitat
Country distribution from AmphibiaWeb's database: Brazil
Endemic to the Atlantic Forest of southeastern and southern Brazil, Hylodes cardosoi is known from the localities of Marumbi and São João da Graciosa, Municipality of Morrestes, in the State of Paraná, as well as the Municipalities of Apiaí, Capão Bonito and Iporanga in the State of São Paulo (Lingnau et al. 2008).
Life History, Abundance, Activity, and Special Behaviors
The species tends to act warily, and reacts to disturbances by jumping into water, but returning to the original location a few minutes later (Lingnau et al. 2008).
Males have been observed performing visual displays of body-raising and foot-flagging, and sometimes simultaneously emitting an advertisement call (Lingnau et al. 2008). This behavior has been similarly observed in other species of the Hylodes nasus group, such as Hylodes asper (Haddad and Giaretta 1999).
The call is given sporadically, and consists of 4-8 notes of 3-6 frequency-modulated pulses each, at a dominant frequency of 3.9-5.8 kHz. Generally the dominant frequency is associated with the third harmonic, but sometimes the second and third harmonics have equal amounts of energy, making it difficult to distinguish the dominant frequency (Lingnau et al. 2008).
Hylodes cardosoi males and females appear to practice some site fidelity (Lingnau et al. 2008). Hylodes cardosoi is sometimes sympatric with Hylodes heyeri in stream habitats (Lingnau et al. 2008).
Hylodes cardosoi was named after the late Dr. Adão José Cardoso and his contributions to the information and knowledge on Brasilian anurans.
Haddad, C. F. B., and Giaretta, A. A. (1999). ''Visual and acoustic communication in the Brazilian torrent frog, Hylodes asper (Anura: Leptodactylidae).'' Herpetologica, 55, 324-333.
Lingnau, R., Canedo, C., and Pombal, J. P. Jr. (2008). ''''A new species of Hylodes (Anura: Hylodidae) from the Brazilian Atlantic Forest.'' Copeia, 2008, 595-602.
Originally submitted by: Alexis Leigh Krup (first posted 2009-09-29)
Edited by: Kellie Whittaker (2010-05-05)
Species Account Citation: AmphibiaWeb 2010 Hylodes cardosoi <https://amphibiaweb.org/species/7331> University of California, Berkeley, CA, USA. Accessed Sep 28, 2023.
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Citation: AmphibiaWeb. 2023. <https://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 28 Sep 2023.
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