Description
Lankanectes pera is a moderate-sized frog with snout vent length of 66.0 – 68.7 mm in males and 42.4 -55.8 mm in females. Body stout. Head flat dorsally. Snout rounded when viewed dorsally and laterally. Canthal edges indistinct. Loreal region convex. Edges of upper lip with distinct tubercles; interorbital and internasal spaces convex. Nostrils oval; close to each other; placed dorsally on snout; edges fleshy. Tympanum absent; pineal ocellus absent. Vomerine teeth present; the vomerine teeth are tusk-like (more prominent in males), with an angle of 60º relative to body axis; less close to choanae than to each other. Tongue large; emarginated; not bearing a lingual papilla; two tubercles on posterior base of tongue. Two fang-like processes on the mandible. Internal vocal slits present, close to gape. Supratympanic fold absent. Parotid glands absent. Head wide. Cephalic ridges absent. Cephalic knob on head. Skin on head not co-ossified. Dorsal surface of head and body covered in numerous prominent dermal folds (corrugations) and glandular, white-tipped warts. Corrugations present also on ventral surface of head and throat. Manus robust. Forearms short, strong; fingers thin. Tips of fingers rounded, enlarged; discs absent; finger-tips not wide compared to finger width; no dermal fringe on inner or outer sides of fingers; no webbing on fingers; subarticular tubercles on fingers prominent, oval, single; prepollex distinct. Two palmar tubercles, oval, distinct, convex. Supernumerary tubercles on palm very small. Nuptial pad absent. Pes robust. Thigh and shank stout. Toes thin. Tips of toes rounded, enlarged, discs absent; tips of toes not wide compared to toe width. Toes fully webbed. Dermal folds present on inner edge of toe I and outer edge of toe V. Subarticular tubercles on toes prominent, rounded or oval, single. Inner metatarsal tubercle long, prominent, oval. Tarsal fold present. Outer metatarsal tubercle absent. Supernumerary tubercles on foot absent. Tarsal tubercle absent. Snout between eyes and side of head with folds and fine tubercles. Anterior and posterior part of back, and upper and lower flank with dermal folds. Dorsolateral fold absent on body. Corrugations and glandular warts present on dorsal surface of legs, but are less prominent; ventral surface of legs smooth. Lateral-line system present. Dorsal parts of forelimb and thigh with corrugations. Dorsal part of shank and tarsus with corrugations and tiny tubercles. Chest, belly and ventral part of thigh smooth. A cluster of macroglands (femoral glands) on inner surface of thigh. Vocal sacs and nuptial pads are present (Senevirathne et al., 2018).

Color in life: Dorsally chocolate brown with unequal dark-brown patches. Ridges of the numerous prominent corrugations lighter in color, with interspersed light-brown spots. A light-brown bar edged with dark brown/black colors in the interorbital area. Flank, inguinal zone, loreal region and sides of back of head light brown. Throat, margin of throat and vocal sacs white with pale brown patches. Chest, belly ventral sides white. Ventral sides of thighs light brown, with white patches. Underside of webbing light brown. Disks and tubercles of pes and manus grey-brown (Senevirathne et al., 2018).

Color in alcohol: Dorsally dark brown with unequal dark patches, edges of corrugations lighter in color, some pale spots on dorsum. A pale-yellow bar with dark edges on inter-orbital area. Flank, inguinal zone, loreal region and sides of back of head light brown, edges of corrugations pale. Throat, margin of throat and vocal sacs pale brown with lighter spots. Chest, belly, ventral sides of thighs and webbing light brown (Senevirathne et al., 2018).

Diagnosis: The genus Lankanectes is endemic to Sri Lanka and it comprises of two species, L. pera and L. corrugatus (Batuwita et al.,2019). Lankanectes pera can be distinguished from L. corrugatus by the following characters: ventrally greyish (vs white with dark brown patches in L. corrugatus); white tubercles on throat (vs smooth throat in L. corrugatus); edge of the upper lip uniform grey (vs white border with dark brown patches in L. corrugatus); inner edge of toes grey (vs inner edge of I, II, III and IV toes white in L. corrugatus); inner edge of foot grey (vs white in L. corrugatus); flank grey (vs. flank with dark brown and white patches inL. corrugatus). Molecular phylogenetic analysis revealed that the uncorrected pairwise genetic distance between L. corrugatus and L. pera is 3.5–3.7% confirming them as two distinct species (Senevirathne et al., 2018).

Distribution and Habitat

Country distribution from AmphibiaWeb's database: Sri Lanka

View distribution map in BerkeleyMapper.

Lankanectes pera is restricted to streams flowing through the cloud forests of the Knuckles Mountain range at elevations of 1100 m above sea level in Dothalugala and Bamabarella and Riverston regions of Sri Lanka (Senevirathne et al., 2018; Batuwita et al.,2019).

Life History, Abundance, Activity, and Special Behaviors
This species has only been observed inhabiting pristine streams flowing through closed-canopy montane forests. These streams are characterized by clear, shallow and slow-flowing water, and sand and rock-strewn substrates. Males are found under rocks or rock-crevices in flowing water. Occasionally males call haltingly during daytime, but several males frequently vocalize in chorus at night, especially after light rain. Tadpoles of these frogs are large and occur in deeper regions where decaying vegetation gathers (Senevirathne et al., 2018).

Comments
The species authority is: Senevirathne G., Samarawickrama P., Wijayathilaka N., Manamendra-Arachchi K., Bowatte, G., Samarawickrama S. and Meegaskumbura M. (2018).

Etymology: Lankanectes pera is named after the University of Peradeniya, Sri Lanka, affectionately referred to as “Pera” by its alumni (Senevirathne et al., 2018).

References

Batuwita S, Udugampala S, DeSilva M, Diao J and Edirisinghe U. (2019). "A review of amphibian fauna of Sri Lanka: distribution, recent taxonomic changes and conservation." Journal of Animal Diversity, 1(2), 44-82. [link]

Senevirathne G., Samarawickrama P., Wijayathilaka N., Manamendra-Arachchi K., Bowatte, G., Samarawickrama S. and Meegaskumbura M. (2018). "A new frog species from rapidly dwindling cloud forest streams of Sri Lanka- Lankanectes pera (Anura, Nyctibatrachidae)." Zootaxa, 4461(4), 519-538. [link]

Species Account Citation: AmphibiaWeb 2021 Lankanectes pera <https://amphibiaweb.org/species/8900> University of California, Berkeley, CA, USA. Accessed Nov 21, 2024.

Citation: AmphibiaWeb. 2024. <https://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 21 Nov 2024.

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