Description
Hypsiboas cambui has a snout-vent length of 26.3 - 32.8 mm in males. The only known female was 32.7 mm, which, along with the forearm development, appears to be within the same range established for H. cambui males. Its body is slender, with its head being wider than its body, almost as wide as it is long. The snout is rounded both in dorsal and profile views. The canthal ridge is curved in dorsal view. Its lips are thin and not flared. The area between the eyes and nostrils of the species is slightly concave, and its internarial region is very slightly depressed and nostrils do not protrude and are directed dorsolaterally. The area between the eyes is flat, shorter than the width of the eyes and less than a third of the width of the head. The eyes themselves are large and protuberant, with translucent palpebral membranes that lack reticulations and have poorly pigmented lower portions. The tympanum itself is small, distinct, and directed dorsolaterally. The supratympanic fold is poorly developed and it covers the upper part of the tympanic ring, extending all the way to the joint of the arm. The space between the tympanum and the eye is slightly larger than the width of the tympanum. This species’ skin is smooth except in the pectoral and abdominal areas and in the ventral surfaces of the thighs, where it is granular. The pectoral fold is notably absent. The sheath-less cloacal opening is located between the upper thighs and is directed posteroventrally, with a white dermal ridge above it. There are cloacal tubercles scattered down to the midlevel of the thighs (Pinheiro et al. 2016).

The arms in this species are slender, lacking an axillary membrane and not hypertrophied. A single row of small, juxtaposed ulnar tubercles runs along the proximal limit of the hand to the elbow. The fingers in H. cambui are long with round disks, webbing and lateral fringes. The relative finger lengths are I < II < IV < III. There are distinct, nonbifid subarticular tubercles that appear rounded in ventral view, but conical on fingers I and II and flat on fingers III and IV in profile view. Supernumerary tubercles are also present. The inner metacarpal tubercle is flat and elongated and the outer metacarpal tubercle is clefted, flat and large. There is no nuptial pad, but the prepollex is evident in males (less so in females), being enlarged and pointed, and resembling a bony spine that is visible beneath the skin. The hind legs in this species are long and slender with a tarsal fold extending from the inner metatarsal tubercle to the heel. The calcars are large and triangular in dorsal view. The toes are long and webbed with round disks that are slightly smaller than those on the fingers, and lateral fringes. The relative toe lengths are I < II < III = V < IV. Between toes IV and V, there is a noticeably thickened layer of tissue at the midline of webbing. The subarticular tubercles are moderately large and appear round when viewed ventrally and slightly conical when viewed in profile. Supernumerary tubercles have been noted in this species. The inner metatarsal tubercle is distinct, flat and elliptical in ventral view but the outer metatarsal tubercle is absent (Pinheiro et al. 2016).

Hypsiboas cambui tadpoles in life stages 34 – 36, have an oral disk that is approximately a third of the width of its body, along with a distally free spiracle. The body is depressed with the body length being around a third of the length of the tail. The tadpole’s body appears elliptical dorsally, but laterally, the ventral contour appears flat in the peribranchal region and slightly convex in the abdominal region. The head of the H. cambui tadpole is long, flattened and curved with six to eight marginal cusps, with the cusps from the tip being higher than those originating from the base. The snout appears oval dorsally and rounded laterally. The nostrils, located dorsally closer to the snout than the eyes, are large, elliptical, dorsolaterally directed, and kidney-shaped due to a fleshy triangular projection on the medial margin. The tadpole has medium-sized eyes that are located dorsally and are dorsolaterally directed. The spiracle is positioned laterally on the left, and it is visible both dorsally and laterally and projected posteriorly. Its inner wall is only barely separated from the body and it is slightly longer that the external wall with its opening being located at the back third of the body. The lateral line system is not very visible in the tadpole life stages, with the exception of the infraorbital and middle lines, which are located in the dorsal region. There are also cumuli of neuromasts located anterolaterally to the base of the vent tube that are slightly noticeable. The intestinal tube is coiled in a circle, with a switchback point occurring at the center of the abdomen. The large vent tube is fused to the ventral fin on its mid-ventral portion and has a dextral opening. The tadpole’s tail, ventral fin and dorsal fin are considered to be moderately high with the tail being slightly higher than the body. The free margin of the dorsal fin is convex and emerges on the posterior third of the body, whereas in the ventral fin, the free margin is nearly parallel to the longitudinal axis of the tail muscle. Its musculature is somewhat robust and extends to the tip of the tail (Pinheiro et al. 2016).

The cream dorsolateral band on H. cambui resembles that of H. freicanecae and this feature distinguishes these species from the rest of the species in the Hypsiboas pulchellus group. Other differences that occur in H. cambui are having a more slender body, a smaller male snout-vent length, a larger calcar, and orange coloration on the hidden areas of the thighs and webbing. Hypsiboas cambui (26.3 – 32.8) also differs in male snout-vent length with H. aguilari (33.7 – 43.8), H. alboniger (47.0 – 56.0), H. balzani (33.3 – 49.9), H. bischoffi (36.0 – 47.0), H. callipleura (37.2 – 43.3), H. cordobae (39.0 – 50.0), H. cymbalum (44.8 – 46.2), H. gladiator (35.3 – 49.4), H. guentheri (33.0 – 40.0), H. joaquini (40.3 – 56.4), H. latistriatus (34.9 – 40.6), H. marginatus (37.5 – 53.6), H. marianitae (36.5 – 56.8), H. melanopleura (43.6 – 50.0), H. palaestes (36.2 – 50.4), H. poaju (33.5 – 42.7), H. prasinus (41.0 – 47.0), H. pulchellus (37.0 – 49.0), H. riojanus (48.0 – 56.0), H. secedens (55.0 – 57.0), H. semiguttatus (36.1 – 45.2), and H. stellae. Hypsiboas cambui lacks the vertical bars or spots on the hidden parts of the thighs which is seen in H. alboniger, H. balzani, H. bischoffi, H. caingua, H. callipleura, H. cordobae, H. curupi, H. cymbalum, H. gladiator, H. guentheri, H. marianitae, H. prasinus, H. pulchellus, H. riojanus, H. secedens, and H. stellae. Vertical bars or spots on the flanks are also lacking in H. cambui, which differentiates it from H. aguilari, H. alboniger, H. balzani, H. caingua, H. caipora, H. callipleura, H. curupi, H. cymbalum, H. ericae, H.gladiator, H. guentheri, H. joaquini, H. marianitae, H. melanopleura, H. poaju, H. prasinus, H. pulchellus, H. riojanus, H. secedens, H. semiguttatus, and H. stellae. The lack of longitudinal stripes and lines on the dorsum of H. cambui distinguishes it from H. bandeirantes, H. beckeri, H. botumirim, H. buriti, H. caingua, H. cipoensis, H. goianus, H. guentheri, H. jaguariaivensis, H. latistriatus, H. leptolineatus, H. phaeopleura, H. polytaenius, and H. stenocephalus. The presence of a calcar is a trait that H. cambui shares only with H. bischoffi, H. freicanecae, H. polytaenius and H. secedens, but it is also present in some specimens of H. caingua. Hypsiboas cambui differs from H. secedens in that H. cambui does not have nuptial pads on the thumbs or reticulations on the palpebrae, and its vomerine teeth aeries are short and transverse, whereas they are long and oblique, forming an inverted V in H. secedens (Pinheiro et al. 2016).

In the 23 described tadpole species of the Hypsiboas pulchellus species complex, H. cambui varies from H. bischoffi, H. caipora, H. curupi, H. joaquini, H. marianitae, and H. poaju (> 0.45 mm) in the size of the oral disk, which is smaller in H. cambui (0.33 - 0.39 mm). With regard to the spiracle, only the distal portion of the inner wall is free from the body in H. cambui, whereas in H. caingua the inner wall is completely free, and in H. cipoensis, H. goianus, H. leptolineatus, H. marginatus, and H. palaestes, the inner wall is completely fused to the body. The tail coloration allows for distinguishing between H. freicanecae and H. cambui as it is dark brown to black with large dark brown to black spots in H. freicanecae (Pinheiro et al. 2016).

Adults of H. faber and larvae of H. albomarginatus were found in the same pond as H. cambui. Both H. faber and H. albomarginatus have spiracles with their inner walls completely free from their bodies. Tadpoles of H. albomarginatus (0.03 - 0.05 mm) have smaller nostrils than H. cambui. The cumuli of neuromasts are much more noticeable in H. faber, and it also has a brown to black tail and fins with dark blotches, which help distinguish it from H. cambui (Pinheiro et al. 2016).

The call of H. cambui can be distinguished from the calls of H. aguilari, H. balzani, H. bandeirantes, H. beckeri, H. bischoffi, H. botumirim, H. caipora, H. callipleura, H. curupi, H. ericae, H. gladiator, H. joaquini, H. latistriatus, H. leptolineatus, H. marginatus, H. marianitae, H. melanopleura, H. palaestes, H. poaju, H. polytaenius, H. prasinus, H. semiguttatus, and H. stellae, which all emit pulsed notes. The dominant frequency is coincident with the fundamental frequency in H. cordobae, H. goianus, H. phaeo-pleura, H. pulchellus, and H. riojanus, which have between 1160 and 2450, 2925 and 3694, 2557.3 and 3554.8, 1203 and 3428, and 1700 and 2800 Hz, respectively, instead of the dominant frequency being on the second harmonic as in H. cambui. There is no difference in note length in H. cambui, but in H. cordobae and H. pulchellus, the last note is longer than the first and in H. riojanus, the first note is longer than the notes that follow (Pinheiro et al. 2016).

In life, at night, the dorsum of adults appears dark brown with light brown dots and a whitish-cream (female) to light brown (male) dorsolateral band on each side that extends from the posterior outer half of the eyelid to the dorsal surface between the orbits and the tip of the snout where it expands into a triangle. In the female, the entire tympanum is covered by the lateral dark brown stripe. A cream line runs along the dorsolateral band internally and along the triangle proximal to the canthal ridge and then extending to the tip of the snout where it joins with a labial stripe. There is a gradual color change between the cream labial stripe and the dark brown of the upper loreal region. The palpebral membrane follows the pattern of the loreal region, being translucent except in the lower section where it is partially pigmented. A dark brown band, lined in cream, runs laterally from behind the eye to the inguinal region, covering the upper portion of the tympanum. The ulnar tubercles, the tip of the calcar and the cloacal crest are also a whitish-cream in color. The limbs and thickened layer of tissue at the midline of the webbing between toes IV and V of H. cambui are a light brown on the dorsal side. On the dorsal surface of the tibia, small, dark, irregular spots can be seen. The hidden surfaces of the thigh and the foot webbing are orange. The posterior side of the ankle and elbow, and the dorsal side of the cloaca all appear dark brown. The arm and body are cream in color on their ventral sides. The iris of H. cambui ranges in color from copper to gold, with fine black reticulation. The bones are visible through the skin and appear green. Daylight makes the colors appear paler and decreases the contrast between the dark and light areas. Under these conditions, tiny red dots are visible on the dorsal surfaces. The colors fade when the specimen is in preservative, becoming pale tones with scattered melanophores. The red dots are no longer visible and the light brown dots on the dorsal side of the specimen turn whitish. The orange coloration on the thighs and webbing also pales or disappears completely. The contrast between the dark brown dorsum and the cream dorsolateral band decreases as well (Pinheiro et al. 2016).

In life, tadpoles have black marbling covering the brownish body, with the distal portion of the spiracle being lighter in color. On the dorsum, there can be black and silver blotches. The tail muscle is cream in color and finely reticulated with melanophores that contrast with light, unpigmented, rounded spots. The fins of the tadpole are translucent and scattered with small, light blotches and the dorsal region of the dorsal fin is a reddish brown. Stretching from the posterior end of the body to the proximal fourth of the tail is a dark longitudinal stripe that passes between the dorsal and ventral caudal myotomes. There is also a narrow, interrupted brown line along the dorsal margin of the caudal musculature. The iris of the tadpole is copper or gold in the center and greenish in the periphery, with a golden band outlining the pupil. The iris is dark in the anterior, posterior, ventral and dorsal areas. In preservative, the brownish background and the brownish red section of the dorsal fin of the H. cambui tadpole pales, with the spiracle becoming whitish and the silver blotches usually disappearing entirely. The intestinal mass becomes visible ventrally and laterally. The iris becomes completely black (Pinheiro et al. 2016).

The light dots found on the dorsum of most adult specimens as well as the cream band that contours the dorsolateral band of H. cambui may be absent in some specimens. Regarding coloration, the dorsolateral band may appear yellowish or have small dark brown spots/splotches in some specimens and during vocal activity, the colors appear paler and less contrasted on the dorsum of some males. Dark brown blotches on the tibia may be absent, but in one species a lateral dark brown stripe was observed on the tibia with a lateral dark brown blotch on the forearm. A sinuous pattern can be observed to separate a well-defined upper dark brown loreal region from the labial stripe instead of the gradual color change usually present (Pinheiro et al. 2016).

Onward from stage 25 in tadpoles, the inner wall of the spiracle is no longer attached and instead grows and separates. In four specimens, two in Stage 29, and one each in Stages 31 and 37, the switchback point of the intestinal tube is dislocated anteriorly and to the left. In some specimens, mainly Stages 25 through 28, the black line along the axis of the tail muscle is absent (Pinheiro et al. 2016).

Distribution and Habitat

Country distribution from AmphibiaWeb's database: Brazil

View distribution map in BerkeleyMapper.

The species was discovered in a swampy pond off of the stream, Riacho do Funil, in Vilarejo do Funil, Municípo de Rio Preto, State of Minas Gerais, Brazil. The area is known locally as Cambuí, and is in the mountains of Serra Negra, which forms part of the Serra da Mantiqueira. The specific location coordinates are 22°0’19”S, 43°53’20”W, 905 m above sea level. Hypsiboas cambui can frequently be found in the vegetation directly above water (Pinheiro et al. 2016).

Life History, Abundance, Activity, and Special Behaviors

The pond where specimens were found was covered with a large amount of vegetation and surrounded by primary forest. Hypsiboas cambui can often be found at a height of 0.2 - 0.4m, on the grass directly above the water or on lianas or shrubs along the water’s edge. However, calls were also heard from above a height of 3 m, suggesting that H. cambui shelters in the treetops as well.

The advertisement call of H. cambui was observed in March to occur between 2030 and 2300 at air temperatures of 19^oC and 17^oC respectively. The call is made up of two nonpulsed notes, with the second harmonics having the dominant frequency (3382.6 - 5076.7 Hz). The fundamental frequency of the note is 2062.5 Hz and the peak frequency of the call averages 4125 Hz. The note duration ranges from 23 - 54 ms and the silence between the notes, if present, can last between 60 and 121 ms (Pinheiro et al. 2016). Other species present in the pond in which H. cambui was found include adults of Rhinella crucifer, H. faber, H. polytaenius, Dendropsophus berthalutzae, D. microps, D. cf. oliveirai, and Scinax argyreornatus, and tadpoles of H. albomarginatus, D. microps, Dendropsophus sp., Scinax sp. 1 (S. catharinae group), and Scinax sp. 2 (S. ruber clade). No fish were observed in the pond when there was no contact between the stream and the pond, but a number of small fish were found when there was contact between the two bodies of water after a week of heavy rain in early March. Activity of the Hypsiboas cambui increased after a heavy rainfall in late April. However, there was a decrease in tadpole population was noted when small fish were found in the pond (Pinheiro et al. 2016).

Trends and Threats
Hypsiboas cambui is currently only known to exist in one small, unprotected locality within the Atlantic Forest. Around 90% of the original vegetation in the Atlantic Forest has already been removed, threatening many endemic species, including H. cambui (Pinheiro et al. 2016).

Possible reasons for amphibian decline

General habitat alteration and loss
Habitat modification from deforestation, or logging related activities

Comments
The species authority is: Pinheiro, P.D.P., Pezzuti, T.L., Leite, F.S.F., Garcia, P.C.A., Haddad, C.F.B, Faivovich, J. (2016). ''A New Species of the Hypsiboas pulchellus Group from the Serra da Mantiqueira, Southeastern Brazil (Amphibia: Anura: Hylidae).'' Herpetologica, 72(3), 256-270.

Hypsiboas cambui most closely resembles H. freicanecae. The southernmost population of H. freicanecae is located ~1640 km north of the pond in which H. cambui was discovered (Pinheiro et al. 2016).

Hypsiboas cambui is named after the trees of Myrtaceae (known as “Cambuî”, a Portuguese term derived from the tupi “Kābu’i”), which are found next to streams and wet soils in the same areas in which H. cambui is typically located. The local population also knows the region in which the species was found as Cambuí (Pinheiro et al. 2016).

The Serra da Mantiqueira region where H. cambui is found is known for its high degree of endemism amongst the anurans, having many populations that are restricted to a single or very few localities (Pinheiro et al. 2016).

References

Pinheiro, P.D.P., Pezzuti, T.L., Leite, F.S.F., Garcia, P.C.A., Haddad, C.F.B, Faivovich, J. (2016). ''A New Species of the Hypsiboas pulchellus Group from the Serra da Mantiqueira, Southeastern Brazil (Amphibia: Anura: Hylidae).'' Herpetologica, 72(3), 256-270.

Species Account Citation: AmphibiaWeb 2016 Boana cambui <https://amphibiaweb.org/species/8496> University of California, Berkeley, CA, USA. Accessed Apr 19, 2024.

Citation: AmphibiaWeb. 2024. <https://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 19 Apr 2024.

AmphibiaWeb's policy on data use.