Monday, November 13, 2023

[Herpetology • 2023] Arthroleptis nyungwensis • A New Miniature Species of Arthroleptis (Anura: Arthroleptidae) from Nyungwe National Park, Rwanda


Arthroleptis nyungwensis
 Dehling, 2023

 
Abstract
A new, very small-sized species of Arthroleptis is described from western Rwanda. The new species occurs locally endemic in Nyungwe Forest and Cyamudongo Forest, where it inhabits the leaf litter of montane forests between 1800 and 2200 m a.s.l. It differs from all other members of the genus by a unique combination of morphological characters, including size (SVL of adult males 16.0–16.5 mm), skin texture, length of hindlimbs, and ventral colour pattern; by characteristics of its advertisement call that consists of a single note lasting 17.4 ± 6.4 [11–32] ms and has a dominant frequency of 5861 ± 188 [5531–6029] Hz; and also in the sequence of the 16S rRNA gene that differs from available homologous sequences of other species of the genus by an uncorrected p-distance of at least 4.6%. Details of the natural history as well as two additional call types are described.

Keywords: amphibians; diversity; bioacoustics; phylogenetics; Arthroleptis schubotzi; Nyungwe Forest; Cyamudongo Forest

Arthroleptis nyungwensis sp. nov.
(A) Dorsolateral view and (B) ventral view of the holotype (ZFMK 104075) in life.
(C) Dorsolateral view and (D) ventral view of an adult male (JMD 599) in life.
(E) Dorsolateral view and (F) ventral view of one of the subadult paratypes (SMNS 15743) in life.

Arthroleptis nyungwensis sp. nov.
Nyungwe Squeaker

Diagnosis: The species is assigned to the genus Arthroleptis for exhibiting the following morphological characteristics [28]: pedal webbing absent, median dorsal skin raphe present, third finger elongate in adult males, dermal spines present on third finger. The new species differs from all other members of the genus by the combination of the following characteristics: small size (SVL of adult males 16.0–16.5 mm); dorsal surfaces of head, trunk, and limbs and lateral surfaces of trunk finely shagreened; tympanum well visible externally; median lingual process absent; legs long, tibiotarsal joint reaching to eye; tibiofibular length equal to foot length; tip of third finger and tips of toes slightly enlarged; inner metatarsal tubercle very small and rounded, outer metatarsal tubercle absent; ventral colour reddish to orange with two slightly concave longitudinal yellow stripes and white dots; advertisement call consisting of single note, lasting 17.4 ± 6.4 [11–32] ms and dominant frequency at 5861 ± 188 [5531–6029] Hz; sequence of the 16S rRNA gene differing from available homologous sequences of other species by uncorrected p-distance of at least 4.6%.

Etymology: The species is named after Nyungwe Forest in southern Rwanda.


 J. Maximilian Dehling. 2023. A New Miniature Species of Arthroleptis (Anura: Arthroleptidae) from Nyungwe National Park, Rwanda.  Diversity. 15(10); 1104. DOI: 10.3390/d15101104