Description
Arthroleptis nlonakoensis are small frogs with male snout-vent ranges from 17.2 - 22.2 mm and females from 17.9 - 20.0 mm. Characteristics include round nostrils, visible from above, closer to snout than eyes; snout shape varies from long and rounded to broad, convex, and slightly triangular; round tympanum visible; small hands; no webbing between fingers; large round and/or oval subarticular tubercles present on all fingers; when long hind limb is adpressed, tibiotarsal joint touches snout tip; very rudimentary webbing between toes; expanded toe discs, smaller size than those on fingers; subarticular tubercles present but much smaller on toes; single inner metatarsal tubercle; smooth dorsal and ventral skin, including gular region. Males lack femoral glands.

Coloration: Head is dark brown to black; dorsum, outer upper arms (and lower arms in females), and outer side of legs are olive green-brown; ventrum and inner legs are beige to yellowish white. Distinguishing characteristics include spotted white lips and a distinct white band between the eyes, in various forms (solid, dashed, linear, triangular). White spots also cover forelegs and flanks. Tibia decorated by one to two medium size bars or large spots.

Males differ from females in that the white spots from the lips continue to the tympanum and in darker coloration of the tympanum, forearms, back of neck, and throat. In contrast, females have black spots on the green-brown forearms and are lighter in coloration on the ventrum, gular region, and forelegs.

Distribution and Habitat

Country distribution from AmphibiaWeb's database: Cameroon

	View distribution map in BerkeleyMapper.
	View Bd and Bsal data (1 records).

The species is known only from the type locality in Cameroon, in the vicinity of the village Ekomtolo, on the southwestern slope of Mt. Nlonako at 450m asl. The area is composed of submontane secondary rain forest. The holotype was collected on the bank of a small creek adjacent to the Nkébé waterfall of Mt. Nlonako in December of 2000.

Life History, Abundance, Activity, and Special Behaviors
Arthroleptis nlonakoensis is a secretive and rarely seen species, found primarily in leaf litter. During a six year survey period from 1998-2004, this species was found only twice. Three habitat types were surveyed: creek, forest, and logging road. Two frogs were found at night perched on low vegetation 12-35cm above ground and in proximity of a still creek 3-11cm in depth. The other nine frogs were found among leaf litter in the same general area, but further away from any creeks. No frogs were found in the vicinity of logging roads. All specimens were found in the dry season. After the first heavy rains which filled up the creek and caused fast flowing water, no specimens were observed.

Trends and Threats
Habitat fragmentation due to logging and human encroachment threatens the amphibians of Mt. Nlonako, including A. nlonakoensis.

Possible reasons for amphibian decline

Habitat modification from deforestation, or logging related activities
Intensified agriculture or grazing

Comments
This species is named after its type locality on Mt. Nlonako.

Arthroleptis nlonakoensis was originally placed in the genus Phrynobatrachus. However in 2008, Fretey reviewed morphological differences in the two genus and placed the species within Arthroleptis. This was further supported by Zimkus and Larson (2009) based on direct measurements of A. nlonakoensis specimens.

References

Fretey, T. 2008. Review of African genera Arthroleptis Smith, 1849 and Phrynobatrachus Gunther, 1862 (Amphibia, Anura). Alytes 25(3-4):99-172

Plath, M., Herrmann, H-W., and Böhme, W. (2006). ''New frog species of the genus Phrynobatrachus (Anura: Phrynobatrachidae) from Mt. Nlonako, Cameroon.'' Journal of Herpetology, 40(4), 486-495.

Zimkus, B.M., Larson, J.G. 2009. External morphology and osteology support the placement of Phrynobatrachus nlonakoensis Plath, Herrmann & Bohme, 2006 within the genus Arthroleptis. African Journal of Herpetology 58(1):36-38

Species Account Citation: AmphibiaWeb 2013 Arthroleptis nlonakoensis <https://amphibiaweb.org/species/6863> 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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