Description

Diagnosis: Cycloramphus faustoi (males 31.2–37.9 mm snout-vent length (SVL), females 41.6–44.0 mm SVL) is characterized by: (1) snout truncate in dorsal and lateral views, (2) head wider than long, (3) eyes protruding, (4) upper eyelid lacking tubercles or with a few small tubercles; (5) tympanum not visible externally, but present under skin; (6) lack of vocal slits; (7) vocal sac indistinct, (8) dentigerous process of vomer triangular, each bearing six teeth, (9) tibia shorter than thigh, (10) tibia + thigh size same size as SVL, (11) toes free, (12) dorsal skin slightly smooth, and (13) in life, dorsum dark brown with yellow or white scattered spots (Brasileiro et al. 2007).

Cycloramphus faustoi can be distinguished from the similar species C. diringshofeni by the following combination of characteristics: larger size (males to 37.9 mm SVL, vs. C. diringshofeni males up to 31 mm), lack of vocal slits (present in C. diringshofeni), and lack of dorsolateral ridges (present in C. diringshofeni). From C. eleutherodactylus, the new species differs by having a wider and shorter head; smaller relative interorbital distance; shorter eye-nostril distance; truncated snout in dorsal, ventral, and lateral views (rounded snout in C. eleutherodactylus); less protruding eyes; less concave loreal region; tibia shorter or the same size as thigh, such that when compressing the tibia against the thigh, the knees do not touch each other; vs. knees touching each other in C. eleutherodactylus); and darker, less patterned dorsal coloration in C. faustoi than in C. eleutherodactylus (Brasileiro et al. 2007).

Description: Robust, elliptical body when viewed from above. Head wider than long. Internarial distance is less than eye-nostril distance and less than eye diameter. Snout is truncate with protuberant nostrils and a concave loreal region. Eyes are protuberant. Some individuals have a few upper eyelid tubercles. Tympanum not visible externally. Discrete supratympanic fold extends from tympanic region to shoulder. Tongue smooth and elliptical with an anterior notch. Vomerine dentigerous processes are triangular and each has six vomerine teeth. Choanae are medium-size, rounded, and visible. Arm is slender but forearm is slightly robust. No ulnar fold is present. Fingers lack webbing or fringes. Relative finger lengths III>IV>II>I. Outer metacarpal tubercle is rounded and slightly bigger than the inner metacarpal tubercle, which is elliptical. Toes lack webbing or fringes. Relative toe length is IV>III>V>II>I. No tarsal fold or tarsal tubercles are present. Inner metatarsal tubercle is elliptical and is larger than the outer metatarsal tubercle, which is rounded. Inguinal glands are visible and round. Dorsal and ventral skin are mostly smooth in texture. Males have inguinal glands, an indistinct vocal sac, lack vocal slits, and are smaller than females, plus having relatively longer head, and greater arm, hand, foot, and tibial length (Brasileiro et al. 2007).

The dorsum is brown to dark brown, with sparse white to yellowish spots, a narrow light yellow interorbital bar, light bars on the arm, thigh, and tibia, phalangeal articulations lacking pigmentation, throat white with sparsely scattered brown spots; generally immaculate whitish belly (sometimes with a few brown spots) (Brasileiro et al. 2007).

In preservative, coloration of adults is variable, especially in males. Females have a dark brown dorsum with small white spots, indistinct labial bars, and a uniform brown ventral thigh surface. In both genders, bars are present on dorsal thighs and arms, the throat may be uniform brown or mottled, and an interorbital narrow light stripe may be continuous or broken. Males vary, with some having a dark brown dorsum with small white spots (50%), others having large dark blotches that coalesce (35%), and some with a broken pattern (15%) (Brasileiro et al. 2007).

Distribution and Habitat

Country distribution from AmphibiaWeb's database: Brazil

View distribution map in BerkeleyMapper.

This species is known from a single population at Saco do Funil, municipality of São Sebastiao, on the Ilha dos Alcatrazes, a 149 ha island about 35 km off the northern coast of the State of São Paulo, southeastern Brazil (Brasileiro et al. 2007). The maximum elevation on the island is 150 m asl; the species has been recorded from 20-100 m asl but may occur higher than that (Brasileiro pers. comm., cited in Stuart et al. 2008). The type locality is a valley bordered by Atlantic forest, with a dry to trickling stream bed that has large rocks (Brasileiro et al. 2007).

Life History, Abundance, Activity, and Special Behaviors
C. faustoi has a specialized reproductive mode (terrestrial eggs in crevices). Almost all frog species presently recorded in islands off the coast of the state of São Paulo have specialized reproductive modes. Other Ilha dos Alcatrazes amphibian species include Leptodactylus marmoratus and the endemic Scinax alcatraz, but these frogs occur in different habitats (Brasileiro et al. 2007).

Both males and females have been found in rock crevices. Calling activity was recorded following a rainy afternoon in August 2005, with five males calling from rock crevices. The advertisement call consists of two different types of notes: two shorter initial notes (median 15 ms, range 11-21 ms) followed by longer subsequent notes (median 69 ms, range 39-94 ms), with a total of 4-7 notes. The median call duration is 368 ms (range 253-417 ms), with a median interval of 69 s between calls (range 52-87 s). The dominant frequency ranged from 0.9-22 kHz (N=9 calls recorded). This species also has a territorial call, with more notes but the same duration as the advertisement call. The territorial call consists of a sequence of 9-16 notes, also with initial notes shorter (range 5-8 ms) than those following (third note range 6-9 ms, and then 13-19 ms for the last note) In the territorial call, the median call duration was 552 ms (range 452-652 ms). The dominant frequency was also 0.9-2.2 kHz (Brasileiro et al. 2007).

In March 2004 two females with well-developed oocytes (mean diameter 3.4 mm, mean number of ovules per female = 23) were collected. In August 2005, one female was found guarding a clutch in a rock crevice, on the same night that the calling males were recorded. The female did not leave the eggs even after being disturbed. The female's throat was swollen, possibly with stored water, and was in direct contact with the egg mass. The clutch contained 31 eggs, which were large and white with a mean diameter of 3.8 mm. (Brasileiro et al. 2007).

Trends and Threats
C. faustoi is known only from a single locality on the Isla dos Alcatrazes and does not appear to be abundant there. The maximum number of individuals recorded in one night was 11. The main threats are the extremely restricted range, habitat specificity, and military activity. The vicinity of the Saco do Funil (the only known place of occurrence) has been used by the Brazilian Navy for artillery training activities. This practice on occasion ignites the vegetation (Brasileiro et al. 2007).

Relation to Humans
Threatened by military activities at the type locality (Brasileiro et al. 2007).

Possible reasons for amphibian decline

General habitat alteration and loss
Subtle changes to necessary specialized habitat
Loss of genetic diversity from small population phenomena

Comments
First described by Brasileiro et al. (2007). The specific name faustoi honors Fausto Pires de Campos for his focus on scientific research and conservation in the Ilha dos Alcatrazes.

References

Brasileiro, C.A., Haddad, C.F.B., Sawaya, R., and Sazima I. (2007). ''A new and threatened island-dwelling species of Cycloramphus (Anura: Cycloramphidae) of southeastern Brazil.'' Herpetologica, 63, 501-510.

Stuart, S., Hoffmann, M., Chanson, J., Cox, N., Berridge, R., Ramani, P., Young, B. (eds) (2008). Threatened Amphibians of the World. Lynx Edicions, IUCN, and Conservation International, Barcelona, Spain; Gland, Switzerland; and Arlington, Virginia, USA.

Species Account Citation: AmphibiaWeb 2011 Cycloramphus faustoi <https://amphibiaweb.org/species/7041> University of California, Berkeley, CA, USA. Accessed Dec 26, 2024.

Citation: AmphibiaWeb. 2024. <https://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 26 Dec 2024.

AmphibiaWeb's policy on data use.