Litoria graminea ( Boulenger 1905 )

Richards, Stephen J. & Oliver, Paul M., 2006, Two new species of large green canopy­dwelling frogs (Anura: Hylidae: Litoria) from Papua New Guinea, Zootaxa 1295, pp. 41-60 : 44-46

Litoria graminea ( Boulenger 1905) ( Figs 1–2 , 8 )

Material examined

BMNH 1947.2.23.31, ‘Northern British New Guinea’, holotype; SAMA R55521 20­ Jan­2001, Ivimka Camp, Lakekamu basin, Gulf Province, Papua New Guinea (07°44.05'S, 146°29'45E, ~ 100 m asl) collected by Devi Stuart­Fox.

Description

A large green Litoria (an adult male 73.0 mm) with fully webbed fingers. These two specimens are associated on the basis of their broad heads (HW/SVL ratios of 0.404 (holotype) and 0.379 (SAMA R55521), above the range of variation reported for two new species described below). Both specimens also share a prominent white stripe along the upper eyelid, a character that distinguishes L. graminea from members of this complex found north of the main cordillera, but not from the new taxon described below from south of the cordillera. Pigmentation on the nictitating membrane of the Lakekamu specimen is restricted to a thin band of speckling along the upper edge; the nictitating membrane is not clearly visible in the holotype.

In preservative the holotype and the Lakekamu specimen are very similar in appearance. Both specimens are a dull greyish­blue dorsally, the ventral surfaces are yellowish (holotype) or cream (SAMA R55521). Prominent white dermal ridges are apparent on the postero­lateral edges of the legs and arms of both animals.

Boulenger (1905) did not provide a description of L. graminea in life. Photographs of the Lakekamu specimen ( Fig. 2 ) show it to be uniform bright green on most dorsal surfaces including the legs, with the exceptions of a thin orange area on the uppermost portion of the forelimbs, and a thin but distinctive white stripe along the outer edge of the upper eyelid. The dorsal surfaces of digital disks are dull yellowish green and the finger and toe webbing is purple with extensive orange markings, especially towards the distal edges. Dorso­lateral surfaces are green, tending towards reddish orange interspersed with patches of green or cream midlaterally and ventrally. Ventral surfaces are largely cream with a distinctive purple patch around the upper third of the arm and posterior edge of throat. Photographs taken during the day and night indicate that colouration is considerably more intense at night, however the overall colour pattern remains unchanged. The pupil is horizontal, the iris is coarsely mottled with approximately equal amounts of black and brownish orange; the sclera is bright blue.

Assignment of the Lakekamu specimen to L. graminea provides several potentially diagnostic characters for the species, namely: iris coarsely mottled with black and orange; a blue sclera; extensive orange pigmentation on the ventro­lateral surfaces of the body, and distinctive elongate nuptial pads that extend nearly halfway up the proximal edge of finger I. The Lakekamu specimen is also the largest male L. graminea complex animal examined, suggesting that this species may be slightly larger than the other two taxa described herein. The single Lakekamu specimen was collected while calling in primary rainforest five metres above the ground. Numerous other individuals were heard calling from high (> 20 m) in the canopy throughout the duration of a survey at Lakekamu (15­Oct to 15­Nov­ 1996).

Figures

FIGURE 1. Dorsal photograph of holotype of L. graminea (BMNH 1947.2.23.31). Scale = 10 mm.

FIGURE 2. Male L. graminea (SAMA R 55521) from the Lakekamu Basin in life. Photo: Geordie Torr.

FIGURE 8. Dorsal views of adult males of the three species discussed in this paper. From left to right Litoria graminea, L. sauroni and L. dux. Note the very broad head of L. graminea.