Description

Platymantis nexipus is a medium-sized frog, with adult males reaching 39.2-42.7 mm in snout-vent length. This frog has a robust body and a broad head. The head is clearly distinct from the neck and considerably wider than the body. There are prominent, spinose tubercles protruding from the jaw margin, adding to the impression of head width. The snout extends beyond the lower jaw and is bluntly pointed when viewed both dorsally and laterally. Nostrils are closer to the tip of the snout than to the eyes. Eyes are relatively large (Eye/SV, 0.138), and protrude well above the dorsal surface of the head. Small tubercles are present between and on the eyelids. The tympanum is visible, with tubercles located ventral to the tympanum. A supratympanic fold extends from the orbit to the postrictal region of the jaw. The canthus rostralis is curved inward. The loreal region is concave and almost vertical. Lips are moderately swollen. The dorsal skin is rough, with numerous low tubercles, and an indistinct row of low tubercles dorsolaterally in some individuals. Faint dorsolateral folds are present in about 40% of specimens. Ventrally the skin is smooth, except for the posterior part of the trunk and part of the femoral segment of the hindlimbs, both of which are glandular. Relative finger lengths are: 3>4>2>1. All fingers and toes have widely enlarged terminal discs. Those on the second and third fingers are slightly more than three times the width of the penultimate phalanx. Relative lengths of the toes are: 4>3>5>2>1. Very slight interdigital webbing is present on both hands and feet (Zweifel 1975; Brown et al. 2006).

Dorsal coloration is gray to light brown. The dark brown markings include two ragged interorbital lines and a sequence of irregular spots on the dorsolateral boundary. There are three broad lines running from the eye to the lip. Limbs and digits are light brown with darker crossbars. The venter is a pale tan with darker mottling. Soles and palms are dark brown with the tubercles conspicuously lighter (Zweifel 1975).

Distribution and Habitat

Country distribution from AmphibiaWeb's database: Papua New Guinea

View distribution map in BerkeleyMapper.

Platymantis nexipus is found in Papua New Guinea. This species is endemic to the island of New Britain, part of the Bismarck Archipelago in the Southwestern Pacific Ocean. The type locality is St. Paul’s, Baining Mountains, New Britain Island, and it has also been found in the Nakanai Mountains, the Wanui River Valley, and Wide Bay. It occurs at altitudes ranging from 350-1200 m. In the Nakanai Mountains, it is found in deep ravines and fog-covered valleys (Brown et al. 2006).

Life History, Abundance, Activity, and Special Behaviors

Males perch in the low understory, on leaves, twigs or branches about 3-5 m above the ground. Calling activity begins at about 1830 h and lasts until 2400 h. Platymantis nexipus has a unique advertisement call, consisting of a repeated series of amplitude-modulated, non-tonal, non-accelerating shrill chirps or bleats. The sound has been described as a "krüh...krüh...krüh...krüh". Each note consists of 4-5 pulses, and individuals sound 2-11 notes per call. Single notes contain equal amounts of energy in two frequency components, so that neither component is consistently dominant from individual to individual. One frequency component peaked at about 1.2 kHz and the other peaked at about 2.5 kHz. There is little to no harmonic structure in the calls (Brown et al. 2006).

This species is thought to be widely distributed in New Britain, in suitable montane habitat. Calling males appeared to be relatively widely spaced in the Nakanai Mountains, as much as 200 m apart (Brown et al. 2006).

Possible reasons for amphibian decline

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

References

Brown, R. M., Foufopoulos, J., and Richards, S. J. (2006). ''New species of Platymantis (Amphibia; Anura; Ranidae) from New Britain and redescription of the poorly known Platymantis nexipus.'' Copeia, 2006(4), 674-695.

zweifel, R.G. (1975). ''Two new frogs of the genus Platymantis (Ranidae) from New Britain.'' American Museum Novitates, 2582, 1-7.

Species Account Citation: AmphibiaWeb 2021 Cornufer nexipus <https://amphibiaweb.org/species/4908> University of California, Berkeley, CA, USA. Accessed Nov 8, 2024.

Citation: AmphibiaWeb. 2024. <https://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 8 Nov 2024.

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