A New Forest Frog of the Genus Platymantis (Amphibia: Anura: Ranidae) from the Bicol Peninsula of Luzon Island, Philippines
We describe a new species of forest frog (genus Platymantis) from Mt. Malinao, Bicol Peninsula, southern Luzon Island, The Philippines. The new species is distinguished from congeners by a moderate body size (28.3–39.1 mm for eight males; 49.8–52.7 in two females), slightly expanded terminal finger and toe disks, a distinct color pattern, a unique microhabitat preference, and various spectral and temporal aspects of the advertisement call. The new species is known only from 950–1160 m above sea level on Mt. Malinao and, as such, accentuates this mountain's unrecognized conservation significance as a minor center of herpetological diversity and endemism on southern Luzon. We compare the new species to all presumably related (phenotypically similar) species of Platymantis from the Philippines and comment on apparent trends in morphological evolution and habitat preference in Philippine members of the genus Platymantis. Current understanding of Platymantis species diversity throughout this topographically and geographically complex archipelago is underestimated and in need of comprehensive review. Inilalarawan namin ang bagong uri ng palakang gubat (genus Platymantis) mula sa mababa hanggang sa kalagitnaang bulubunduking dipterocarp ng pagbabagong sonang gubat ng Bundok Malinao sa Peninsula ng Bicol sa katimugang pulo ng Luzon, Pilipinas. Ang bagong uri ay may katangiang katamtamang pangangatawan (28.3–39.1 mm para sa walong lalake; 49.8–52.7 para sa dalawang babae), bahagyang malawak na bahaging mabilog at patag sa dulo ng daliri ng kamay at paa. Ito ay may katangi-tanging kulay dibuho, may walang kahambing na mumunting bahay hayop na kanilang higit na nagustuhan, ang iba't ibang espektrum at pamanahong anyo na kanilang pantawag pansin. Ang bagong uri ay kilala lamang mula sa kalagitnaan ng matayog na lokalidad sa Bundok Malinao, Peninsula ng Bicol at binibigyang diin ang hindi napapansing kahalagahan ng pag-aalaga sa nasabing kabundukan bilang menor na sentro sa pag-aaral ng sari-saring ampibya at reptilya na sa katimugang Luzon lamang matatagpuan. Inihahalintulad namin ang bagong uring ito sa lahat ng inaakala naming may kaugnayan (magkatulad na morpolohiya) sa uri ng Platymantis mula sa Pilipinas at binibigyang puna ang malinaw na takbo ng ebolusyong morpolohiya at ang bahay hayop na higit na nagustuhan sa kaanib na genus sa Pilipinas. Ang kasalukuyang pagkakaintindi sa iba't ibang uri ng Platymantis sa buong kapuluang may hindi maunawaang topograpiya at geograpiya ay ipinagwawalang bahala. Ito ay nangangailangan ng kabuuang pagbabago.Abstract

Known distribution of Platymantis diesmosi on Mt. Malinao (inset), Bicol Peninsula, Luzon Island, Philippines. The capital city of Manila is indicated with a star, and the type locality (Mt. Malinao, municipality of Tiwi, Albay Province) is indicated by a black dot. The volcanic peak of Mt. Mayon (A) is located immediately SE of Mt. Malinao, and Mt. Isarog (B) is located to the NW. Scale bar = 10 km.

Photographs in life of Platymantis diesmosi paratypes exhibiting two color patterns: (A) the marbled black phase (TNHC 62042, male, 36.0 mm SVL; Photo: RMB); and (B) the solid brown phase (UPLB-NHM 22; male, 33.8 mm SVL; Photo: JCG).

Lateral (A) and dorsal (B) view of the head of the Platymantis diesmosi holotype (PNM 8499). Scale bar = 5 mm.

Palmar and plantar view of manus (A) and pes (B) of Platymantis dorsalis (TNHC 21870); (C, D) P. diesmosi holotype PNM 8499; and (E, F) P. banahao (PNM 3640). Scale bars = 2 mm.

The advertisement call of Platymantis diesmosi (paratype TNHC 64042) recorded at ambient temperature of 22.2 C (cloacal temp. 24.0 C) on 11 August 2001: power spectrum (A: Fast Fourier Transformation; relative amplitude vs. frequency in kHz) and an expanded waveform (B: relative amplitude vs. time in ms) of a single call. The sonogram (C: audiospectrogram: frequency in kHz vs. time in s) and an oscillogram (D: relative amplitude vs. time in s) of the final four calls from a single call group. Background signals visible at 1.5, 3–4, and 5 kHz (in C) are insect vocalizations; the four-pulsed call of Platymantis luzonensis (2.1 kHz) overlaps the first P. diesmosi call in this figure. Expanded inset in waveform (B) shows subpulse structure over 100 ms.
Contributor Notes
Section editor: T. W. Reeder.