The dorsal ground color of Smilisca cyanosticta is pale green to tan and the venter is creamy white. The dorsum is variously marked with dark olive-green or dark brown spots or blotches (Pl. 6B). An interorbital dark bar usually is present. The most extensive dark area is a V-shaped mark in the occipital region with the anterior branches not reaching the eyelids; this mark is continuous, by means of a narrow mid-dorsal mark, with an inverted V-shaped mark in the sacral region. In many specimens this dorsal marking is interrupted, resulting in irregular spots. In some specimens the dorsum is nearly uniform pale green or tan with a few small, dark spots. The hind limbs are marked by dark transverse bands, usually three or four each on the thigh and shank, and two or three on the tarsus. The webbing on the feet is brown. The loreal region is pale green, bordered above by a narrow, dark brown canthal stripe extending from the nostril to the orbit, which is bordered above by a narrow, bronze-colored stripe extending from the nostril along the edge of the eyelid to a point above the tympanum. The upper lip is white. A broad dark brown mark extends posteriorly from the orbit and encompasses the tympanum to a point above the insertion of the forelimb. The flanks are dark brown with many pale blue, rounded spots, giving the impression of a pale blue ground color with dark brown mottling enclosing spots. The anterior and posterior surfaces of the thighs are dark brown with many small pale blue spots. The inner surfaces of the shank and tarsus are colored like the posterior surfaces of the thighs. Pale blue spots are usually present on the proximal segments of the second and third toes. A distinct white stripe is present on the outer edge of the tarsus and fifth toe; on the tarsus the white stripe is bordered below by dark brown. A white stripe also is present on the outer edge of the forearm and fourth finger. The anal region is dark brown, bordered above by a narrow transverse white stripe. The throat in breeding males is dark, grayish brown with white flecks.
No geographic variation in the dorsal coloration is evident. Specimens from the eastern part of the range (Piedras Negras and Chinajá, Guatemala) have bold, dark reticulations on the flanks enclosing large pale blue or pale green spots, which fade to tan in preservative. Specimens from Oaxaca and Veracruz characteristically have finer dark reticulations on the flanks enclosing smaller blue spots; in many of these specimens the ventrolateral spots are smallest and are white.
All living adults are easily recognized by the presence of pale, usually blue, spots on the flanks and thighs. Individuals under cover by day have a tan dorsum with dark brown markings. A hiding individual at Chinajá, Alta Verapaz, Guatemala (KU 55936), had a pale tan dorsum when found; later the dorsal color changed to chocolate brown. A pale green patch was present below the eye; the spots on the posterior surfaces of the thighs were pale blue, and those on the flanks were yellowish green. A calling male obtained 10 kilometers north-northwest of Chinajá (KU 55934) was reddish brown when found at night; later the dorsal color changed to pale tan. A green patch below the eye was persistent. Usually these frogs are green at night. The coloration of an adult male (KU 87201) from 11 kilometers north of Vista Hermosa, Oaxaca, México, was typical: "When calling dorsum pale green; later changed to dull olive-green. Flanks dark brown with pale blue spots in axilla and groin and bluish white flecks on mid-flank. Anterior and posterior surfaces of thighs, inner surfaces of shanks, and median dorsal surfaces of tarsi dark brown with blue spots. Canthal and postorbital stripes dark chocolate brown; labial stripe creamy white. Forearm, tarsal, and anal stripes pale cream-color. Throat dark brown with yellow flecks; belly and ventral surfaces of limbs creamy buff; webs pinkish tan; iris deep bronze, brown below pupil." (Duellman, field notes, June 24, 1964.)
Some individuals have both green and brown coloration in life. An individual obtained at night on the south slope of Volcán San Martin, Veracruz, México, had a pale tan dorsum changing peripherally to pale green. The dorsal markings were dark brown and dark olive-green.
In contrast to the color-changes noted above, the labial region below the eye is always pale green, and pale spots are always present on the flanks and thighs in adults. The iris is invariably golden or bronze above and darker, usually brown, below. Minute black flecks are present on the iris, and in some individuals these flecks are so numerous that the eye appears gray.
Recently metamorphosed young have pale tan flanks, and the posterior surfaces of the thighs are orange-yellow; pale spots are absent. A juvenile (KU 55935) from Chinajá, Alta Verapaz, Guatemala, having a snout-vent length of 35.0 mm. was pale yellowish tan above with olive-green markings; the flanks were dark brown with pale blue spots, and the anterior and posterior surfaces of the thighs were uniform bright tomato red. A juvenile (UMMZ 121298), 18.6 mm. in snout-vent length, from the southeast slope of Volcán San Martín, Veracruz, México, had pale tan flanks lacking blue spots, but had red thighs. Apparently the ontogenetic changes in coloration proceed as follows: (1) flanks pale tan and thighs orange-yellow, both lacking spots, (2) flanks pale tan and thighs red, both lacking spots, (3) flanks dark brown with blue spots and thighs red, lacking spots, and (4) flanks and thighs dark brown, both having pale blue spots.
Natural History.—Smilisca cyanosticta inhabits humid tropical forest and cloud forest from the lowlands to elevations of about 1200 meters in Los Tuxtlas and to about 900 meters in northern Oaxaca. In these moist environments the frogs apparently are active throughout the year. Active individuals have been obtained in January, July, and August in Los Tuxtlas, Veracruz, in June and July in northern Oaxaca, in February and March at Chinajá, Guatemala, and Taylor and Smith reported (1945:589) activity in May at Piedras Negras, Guatemala. Calling males were observed as follows; in a rain barrel 11 kilometers north of Vista Hermosa, Oaxaca, México, on June 23-28, 1964; in a quiet pool in a stream 8 kilometers south of Yetla, Oaxaca, México, in July, 1963 (Dale L. Hoyt, personal communication); in and near springs flowing into a stream at Dos Amates, Veracruz, México, on August 4, 1959 (Douglas Robinson, personal communication); and in a water-filled depression in a log 10 kilometers west-northwest of Chinajá, Guatemala, on March 13, 1960. Taylor and Smith (1945:589) reported that individuals were found at night on the ground at the edge of temporary pools at Piedras Negras, Guatemala, on May 28-29, 1939. A clasping pair was found on a rock at the edge of a small stream on the south slope of Volcán San Martín, Veracruz, México, on July 11, 1959 (Douglas Robinson, personal communication).
Only one individual has been observed in a tree at night. In the daytime, individuals were found in elephant ear plants (Xanthosoma) at Chinajá, Guatemala.
The breeding call consists of one or two moderately short notes that are lower pitched than those of S. baudini, but higher pitched than those of S. phaeota. Each note has a duration of 0.25 to 0.45 seconds and is repeated at intervals of one-half minute to several minutes. Each note is a vibrant "waunk," having 110 to 180 pulses per second and dominant frequency of 1600 to 2100 cycles per second (Pl. 10B).
Apparently the eggs are deposited as loose clumps in the water. In eggs in the yolk plug stage of development, the diameter of the embryo is about 2.3 mm.; that of the outer envelope is 4.0 mm. Hatchling tadpoles have total lengths of 5.8 to 6.5 mm. and body lengths of 2.8 to 3.1 mm. The external gills are moderately long, slender, and filamentous; the yolk sac is still moderately large. The body and anterior part of the caudal musculature are dark brown; posteriorly the caudal musculature is pale brown. The caudal fins are creamy tan. The oral discs are large and ovoid. The growth of the tadpole is summarized in Table 10.