Description
Previously known as Hyla erythromma (Duellman 1970) and Ptychohyla erythromma (Campbell and Smith 1992). This species is lime-green dorsally, with a a white iris exhibiting reddish-brown reticulations. Other males examined in life displayed a more conspicuous gray to almost maroon mottling on the dorsum. Nares are edged with black or tan, and the dorsal surfaces of the digital discs are yellowish, but heavily covered with smoky gray. A tarsal fold is present. There are 10-20 enlarged white tubercles below the vent which extend along the proximal 1/2 - 3/4 of the ventrolateral surface of the thigh. Head is slightly wider than body, equally wide as is long. Head width and head length are 36% SVL. Lips moderately thick and slightly flared. Ventrolateral edge of forearm fringed with distinctly raised dermal ridge punctuated with enlarged tubercles. Width of the disc on third finger about equal to diameter of tympanum. Hind limbs moderately long and slender. Tibia length is 56% SVL. Several conical tubercles are present on foot. Toes are two-thirds webbed.

Tadpoles. Thirty six tadpoles were collected. The following measurements are from specimens from Gosner (1960) Stages 25-37: total lengths of tadpoles ranged from 18.8 mm (Stage 25) to 37.9 (Stage 37), and the maximum body length ranged from 7.8 mm (Stage 25) to 12.5 mm (Stage 37). Mouth is ventral, eyes moderately small and directed dorsolaterally. Nostrils situated approximately two fifths distance from the eyes to the tip of the snout. One or two rows of small papillae border the periphery of the mouth, oral disc is bordered by two rows of papillae laterally and posteriorly; there are also 4 upper and 6 lower rows of labial denticles. In life, tadpoles are dark brown with whitish, lichen-like markings and with coppery flecks. The tadpole of Ptychohyla acrochorda (as Hyla erythromma) from the Sierra Juarez has been drawn in Duellman (1970 figs. 260D and 261B).

Distribution and Habitat

View distribution map in BerkeleyMapper.

Only known from the mesic forest of the Atlantic sloopes of Sierra Juarez. Has been collected from elevations ranging from 594 and 900 m along small streams flowing through the montane forests. The males have been caught at night as they sit perched on streamside vegetation. Tadpoles are present year round; this species may also be active year round. Campbell and Duellman (2000) state that "one has to practically be in the bushes with these froms to hear them" due to their very low vocalization. Duellman (1970) described the call to sound like a "single note, and call groups are repeated at intervals of about 30 to 50 seconds." The duration of a note was 0.62 seconds. There were 26 pulses, with a fundamental frequency at 87 Hz, and the dominant frequency at 2266 Hz.

Life History, Abundance, Activity, and Special Behaviors
Sexual dimorphism occurs in size, where males reach a maximum SVL of 36.3 mm and females reach 57.6 mm. Males in breeding condition develop a distinctive chest gland, dark nuptial pads consisting of several hundred tiny spines, and a call consisting of al ong, moderately low-pitched, slowly pulsed note. Males have 4-7 and females have 7-9 teeth on each process of the vomers.

References

Campbell, J. A., and Duellman, W.E. (2000). ''New species of stream-breeding hylid frogs from the northern versant of the highlands of Oaxaca, Mexico.'' Scientific Papers of the Natural History Museum of the University of Kansas, 16, 1-28.

Campbell, J. A., and Smith, E.N. (1992). ''A new frog of the genus Ptychohyla (Hylidae) from the Sierra de Santa Cruz, Guatemala, and description of a new genus of Middle American stream-breeding treefrogs.'' Herpetologica, 48, 153-167.

Duellman, W.E. (1970). The Hylid Frogs of Middle America. Monograph of the Museum of Natural History, University of Kansas.

Gosner, K. L. (1960). ''A simplified table for staging anuran embryos and larvae with notes on identification.'' Herpetologica, 16(3), 183-190.

Species Account Citation: AmphibiaWeb 2008 Ptychohyla acrochorda <https://amphibiaweb.org/species/6135> University of California, Berkeley, CA, USA. Accessed Feb 12, 2025.

Citation: AmphibiaWeb. 2025. <https://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 12 Feb 2025.

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