Description
Mantophryne insignis is a slender frog with males having a snout-urostyle length of 35.0 - 36.2 mm. No female measurements were reported. The head is slightly longer than it is broad. The snout is truncated, and narrows slightly at the tip from the dorsal view but protrudes in the lateral view. The canthus rostralis is rounded, but is straight anterior to the eyes and then bends laterally above the nares. The loreal region is flat and the nares are laterally facing and are near the end of the snout. The nares cannot be seen from above, and are farther apart from each other than they are from the eyes. The supratympanic skin fold is not well pronounced while the tympanic annulus is pronounced. The tympanum has a diameter or more than half that of the eye. The eyes have horizontally oval pupils. The small vocal slits are near the jaw’s angle. The fingers do not have webbing, but fingers I and II have one subarticular tubercle and fingers III and IV have two well developed tubercles. There are three metacarpal tubercles. All of the fingers have small disks with grooves, and the relative finger lengths are III > IV > II > I. The legs are long and thin. Toes do not have webbing disks, and their disks are bigger than the finger disks and have circum-marginal grooves. Toes I and II have one subarticular tubercle, toes III and V two, and toe IV has three. There is an inner meratarsal tubercle. Toe lengths are IV > III > V > II > I. All surfaces are smooth except for two small longitudinal ridges from the eyes to occiput, two small chin protuberances that cannot be seen in preservative, and three whitish tubercles on the upper eyelid (Günther and Richards 2016).

Mantophryne insignis is the most arboreal species in its genus, which is mostly terrestrial. It is also different from other species in the genus in that it has a smooth dorsum and coloration including a golden-tan back, black dorsolateral bands edged below with a white stripe, and brown abdomen spots encircled by white. Mantophryne insignis is most similar to Mantophryne lateralis but has a more slender, smaller body, longer shanks, bigger terminal toe disks, and a shorter advertisement call. In contrast, Mantophryne lateralis does not have a golden back and has longer calls. Mantophryne louisiadensis is larger than Mantophryne insignis and has a broader head, more filled out body, lacks lateral bands, a golden back, and brown abdomen spots. Mantophryne axanthogaster is also larger than Mantophryne insignis and has a flecked back, a grey abdomen, no lateral bands, and a call with longer and fewer notes. Mantophryne menziesi is smaller than Mantophryne insignis and has a grey-brown dorsum, a longer call, an arch formed by the squamosal and frontoparietal bones over the prootic region, and lacks dark lateral bands and a blotched abdomen. Hylophorbus infulatus is similar to Mantophryne insignis in body size but has a shorter internarial distance, brown back, poorly defined dorsolateral band, and mottled abdomen. The slender body, expanded toe discs, and long legs of Mantophryne insignis compared to congeners reflect its adaptation for living in arboreal habits instead of terrestrial habits (Günther and Richards 2016).

In life, most specimens had a golden-tan mid-dorsum bordered by black dorsolateral bands. Descriptions are for males only, as no females were collected. The dorsal surfaces of thighs are also golden tan. The dorsal surfaces of shanks are yellow and posterior of thighs are orange-red. A yellow supracanthal stripe extends onto upper eyelids. A black dorsolateral band is underlined with a thin white stripe. The axillary region is yellowish and the inguinal region is orange-red. The tarsi and lateral surfaces of shanks are dark brown, with a dark brown mottled pattern on the ventral parts. The iris is silvery with dark lines and a slight orange hue in the anterior and posterior positions and there are three whitish tubercles on the eyelids. The ground color of ventral surfaces is white. The throat and chest are brown with dark brown spots. The abdomen and lower flanks have dark brown blotches encircled with white, spots on inferior thighs are smaller and without white rings. In preservative, the dorsal surface of the head, shanks, and mid-dorsum are light grey. The dorsal surfaces of the thighs and upper arms are mottled brown. The underside of the lower arm, dorsal side of the hand and tarsi are brown. Brown spots edged with white extend to posterior lower arm and anterior tarsus and metatarsus. A white supracanthal stripe stretches from snout tip to middle eyelid. The dorsolateral bands start at the orbital opening and end at the cloacal opening. The ground color of ventral surfaces is white (Günther and Richards 2016).

No female specimens were collected. Body size of the three adult males (snout-urostyle length) varied only slightly, and differences in coloration were also negligible. An additional three males were collected by F. Kraus on Woodlark Island, and of these the only noticeable variation was a creamy tan dorsal band (instead of golden tan) in one specimen (Günther and Richards 2016).

Distribution and Habitat

Country distribution from AmphibiaWeb's database: Papua New Guinea

View distribution map in BerkeleyMapper.

The specimens were collected from lowland rainforest in south-central Woodlark Island in Milne Bay Province, Papua New Guinea. The holotype and one paratype were found on the slopes of Talpos Mountain on the island. The other paratype was collected from the island’s Upper Muniai Creek. All three specimens were found through their calls, which they made at night from perches (a limestone block, a tree buttress, and a fallen log) 50 - 80 cm off the ground. Two of the three additional specimens found by F. Kraus on Woodlark Island were around 4 meters above the ground in climbing plants, and the other was under a leaf on the forest floor. Because the island habitat is fairly uniform, the species is likely spread across the majority of the island that can be categorized as lowland rainforest. It has not been found on other islands in the region (Günther and Richards 2016).

Life History, Abundance, Activity, and Special Behaviors
The species has only been found on Woodlark Island. Males call from perches (including climbing plants, tree buttresses, limestone crevices, and fallen logs) up to four meters above ground (Günther and Richards 2016).

Their calls at 26.5^oC are rattles that last for 4.6 - 6.5 seconds and do not contain harmonies. The call frequencies range from 1.0 - 3.5 kHz. Internote interval increased over the course of the call and ranged from 41 - 153 ms. Calls contain 38 - 52 notes and lasted a mean duration of 50 ms with a repetition rate of 8.1 notes per second(Günther and Richards 2016).

Comments
The Species Authority is: Günther, R., Richards, S. (2016) Description of a striking new Mantophryne species (Amphibia, Anura, Microhylidae) from Woodlark Island, Papua New Guinea. Zoosystematics and Evolution 92(1). 111-118

The species epithet “insignis” comes from the Latin “insignis”, which means remarkable or conspicuous. It was chosen for the species for the species’ distinct color pattern and irregular arboreal ecology (Günther and Richards 2016).

All three specimens from which data were collected were males, due to the fact that their calls made them much easier to collect than females (Günther and Richards 2016).

References

Günther, R., Richards, S. (2016). ''Description of a striking new Mantophryne species (Amphibia, Anura, Microhylidae) from Woodlark Island, Papua New Guinea.'' Zoosystematics and Evolution, 92(1), 111-118.

Species Account Citation: AmphibiaWeb 2016 Mantophryne insignis <https://amphibiaweb.org/species/8482> University of California, Berkeley, CA, USA. Accessed Nov 22, 2024.

Citation: AmphibiaWeb. 2024. <https://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 22 Nov 2024.

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