Amolops panhai Matsui & Nabhitabhata, 2006
Peninsular Torrent Frog
|Species Description: Matsui M, Nabhitabhata 2006 A new species of Amolops from Thailand (Amphibia, Anura, Ranidae).Zoolog Sci. 23: 727-32|
© 2017 Mark Aartse-Tuyn (1 of 1)
Amolops panhai is a small-bodied ranid frog, with males reaching 31-34 mm in SVL and females 48-58 mm in SVL. The head is slightly triangular, longer than wide, with a moderately short snout. The eyes are large and elevated, with horizontal pupils. The tympanum is distinct and half the width of the eye. A small supratympanic fold runs above the tympanum from the eye. Vomerine teeth are present in short, oblique patches. The frog's dorsum is granulated with a scattered row of tubercles dorsolaterally. The dorsolateral fold is indistinct and not always present; some individuals have interrupted, bead-like dorsolateral folds, but other individuals completely lack dorsolateral folds. The sides of the trunk are also tuberculate. Axillary glands are present. Throat and chest are both smooth, and weak creases and wrinkles alternate on the abdomen. Hindlimbs are three times longer than the length of the forelimbs. Fingers are moderately slender, with the first finger shorter than the second finger, and the second finger much shorter than the fourth. Fingertips expand into large discs that have circummarginal grooves. The first finger disc is smaller than that of the second finger, There is no webbing between fingers, but there are very narrow fringes of skin along the third and fourth fingers. There is full webbing between the toes, with fringes of skin medially along the first toe and laterally along the fifth toe. An outer metatarsal tubercle is present on the foot. In males, asperities form cream-colored nuptial pads which cover the dorsal and medial surfaces of the first finger, from the base up to the subarticular tubercle. Males also have paired gular pouches.
The dorsum of the frog is dark brown, with an indistinct dark band below the canthus. Another blackish brown band begins behind the eye and reaches the inguinal area. The throat is light brown with indistinct spots and the lower lip is weakly barred with light brown. Limbs are marked dorsally with alternating crossbands of light and dark brown. The posterior of the thigh is dark brown with irregular light spots. The abdomen and ventral surfaces are cream, with slight dots of melanophores on the ventral surfaces of the limbs. Individuals can vary slightly in coloration; females generally have more dark spots on their throats and backs, while males usually do not have any throat spotting. A difference is also recorded in the dorsal color pattern between northern and southern populations of Thailand, as specimens from Ranong have much clearer dorsal markings than those from Phetchaburi.
Tadpoles at stage 28 reach 39.6 mm in total length. The head is oval and broadly rounded at the snout, while flat below. Eyes point upward and are dorsolateral. The nostrils are closer to the eye than the tip of the snout. The mouth is ventral. The lips contain a single row of papillae at the corners of the oral disc, with a second larger row of papillae antero-medially. Denticles are present and the beaks are heavy, with a smooth outer surface and a finely serrated margin of about 60 serrae on the upper beak. The larval dental formula is 7(4-7)/3(1). The upper beak is M-shaped and the lower is V-shaped, neither of them being divided. The spiracle is ventral and sinistral. The dorsal fin is behind the body while the ventral fin is located at the end of the proximal third of the tail. The tail tapers to a slightly pointed tip. A large suctorial abdominal disc is present.
The tadpole has a dark brown head and body, with occasional small, black spots scattered dorsally. The caudal muscle is dark with light specks and the fins are dark as well. In tadpole samples from Ranong, there are distinct dark and light markings on the tail.
Distribution and Habitat
Amolops panhai has a disjunct distribution around the Isthmus of Kra. Besides the type locality, Pa Lao U, Prachuap Khiri Khan, in northern peninsular Thailand, the species is also known from Pilok (western Thailand) and Punyaban waterfall, Ranong (central peninsular Thailand). It has been found at up to 113 m above sea level. Adults are found along the banks of streams, perching on rocks. Groups of tadpoles cling to bare rocks on the bottom of shallow parts of riverbeds and wide streams.
Life History, Abundance, Activity, and Special Behaviors
These frogs are torrent-dwelling and generally associate with bodies of flowing water such as streams and rivers.
There is not much information available on the breeding season of this species. Males in Ranong have been heard calling in January, from rocks along the bank of a stream. The call consists of two unpulsed short notes, lasting for about 68-76 msec each, at a dominant frequency of 6500 hz.
Eggs are creamy white in color, with mature ova recovered from one female having a diameter of 1.3-1.4 mm each. Females are likely to be able to breed at least twice in a season, as tadpoles at Kanchanaburi were in two groups: those without limb buds and those just beginning metamorphosis. Newly metamorphosed juveniles were collected among stones on riverbeds and on rocks in a wide stream in early December, at Kanchanaburi. At this location, very few adults were seen in early December. In mid-December, females were collected at Prachuap Khiri Khan that had small ovaries with developing ova.
The species name A. panhai is dedicated to Dr. Somsak Panha of Chulalongkorn University, Bangkok who assisted in the survey of Matsumi and Nabhitabhata (2006) in Thailand.
High sequence divergence (5.5%) has been found between Amolops panhai northern populations from Prachuap Khiri Khan and Kanchanaburi (Matsui et al. 2006). There is also a divergence in color pattern between northern and southern populations (in Ranong); clearly these differences warrant further study (Matsumi and Nabhitabhata 2006).
Matsui, M. and Nabhitabhata, J. (2006). ''A new species of Amolops from Thailand (Amphibia, Anura, Ranidae).'' Zoological Science, 23, 727-732.
Matsui, M., Shimada, T., Liu, M. Z., Manyati, M., Khomsue, W., and Orlov, N. (2006). ''Phylogenetic relationships of Oriental torrent frogs in the genus Amolops and its allies (Amphibia, Anura, Ranidae).'' Molecular Phylogenetics and Evolution, 38, 659-666.
Originally submitted by: Alamelu Natesan (first posted 2008-05-07)
Edited by: Kellie Whittaker (2008-05-22)
Species Account Citation: AmphibiaWeb 2008 Amolops panhai: Peninsular Torrent Frog <https://amphibiaweb.org/species/6822> University of California, Berkeley, CA, USA. Accessed Sep 25, 2023.
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Citation: AmphibiaWeb. 2023. <https://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 25 Sep 2023.
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