|Litoria lakekamu |
Richards & Bickford, 2023
We describe a new species of very small (male body length 22.0–22.8 mm), green treefrog in the pelodryadid genus Litoria Tschudi from lowland rainforest on the southern margin of Papua New Guinea's central cordillera. The new species is morphologically most similar to Litoria leucova, a small green treefrog known only from the north-flowing Sepik River catchment in western Papua New Guinea. It differs from that species by having longer limbs (TL/SVL 0.56–0.60 vs. 0.53–0.55), a poorly defined (vs. prominent) tympanum, in having a distinct lemon yellow mid-lateral line, and in its unique advertisement call comprising a slowly repeated series of short clicks followed by a discrete group of pulses produced rapidly but with highly variable inter-pulse intervals. Although genetic data are not available, the new species' association with a fast-flowing rocky stream suggests that its relationships may lie with other torrent-dwelling Litoria species.
KEYWORDS: advertisement calls, frog, Litoria lakekamu sp. nov, morphology, taxonomy
Litoria lakekamu sp. nov.
(English name: Lakekamu pygmy treefrog)
Diagnosis: The new species is distinguished from all other Litoria by the following unique combination of characters: size very small (SVL of four males 20.0–22.8 mm, females unknown); dorsum in life predominantly green; vomerine teeth absent; tympanum indistinct; finger webbing extensive, reaching distal edge of subarticular tubercle at base of penultimate phalanx on outer edge of Finger 3 and inner edge of Finger 4; finger discs slightly larger than or same size as toe discs; webbing on toes extending nearly to base of all discs except Toe 4 where it reaches midway between subarticular tubercle at base of penultimate phalanx and disc on both sides of digit; dermal fringes on limbs and below vent absent; pigmentation on nictitating membrane restricted to scattered flecks at dorsal margin; advertisement call a series of short (0.017–0.053 s) distinctly pulsed rasping notes repeated at 2.1–6.5 s intervals, followed by a discrete group of rapidly repeated pulses with highly variable inter-pulse intervals.
Etymology: The specific name lakekamu is a noun in apposition referring to the type and only known locality [Lakekamu Basin, Gulf Province, Papua New Guinea] of this species.
|Torrential stream habitat of Litoria lakekamu sp. nov. on the Sapoi River near Ivimka Camp, Lakekamu Basin, Gulf Province, Papua New Guinea. Males were calling from vegetation along the stream bank.|
Photograph by S. Richards.