Cophixalus pakayakulangun, Hoskin, Conrad J. & Aland, Kieran, 2011

Hoskin, Conrad J. & Aland, Kieran, 2011, Two new frog species (Microhylidae: Cophixalus) from boulder habitats on Cape York Peninsula, north-east Australia, Zootaxa 3027, pp. 39-51 : 46-49

publication ID	https://doi.org/ 10.5281/zenodo.206707
DOI	https://doi.org/10.5281/zenodo.6193252
persistent identifier	https://treatment.plazi.org/id/0394566B-FFCF-FF24-F8EA-EC799AAAB130
treatment provided by	Plazi
scientific name	Cophixalus pakayakulangun
status	sp. nov.

Treatment

Cophixalus pakayakulangun View in CoL sp. nov.

Golden-capped Boulder-frog ( Fig. 6 View FIGURE 6 )

Material examined. Holotype: QMJ88547, female, boulder field just south of Stanley Hill (12°27′50S, 143°16′14″E, elevation 40 m), Cape York Peninsula, north-east Queensland, C. J. Hoskin and K. Aland, 18 April 2010. Paratypes: QMJ88548 (female), QMJ88545 (male), QMJ88546 (male), QMJ88534 (juvenile), QMJ88535 (juvenile), collection details as for holotype. Additional material: An additional three individuals from the type locality were measured in the field.

Diagnosis. A medium sized frog with long, slender fingers and large, obviously truncated finger pads. Cophixalus pakayakulangun sp. nov. can be distinguished from its congeners by a combination of the following characters: large size (SVL: 42–53 mm, average 47 mm); no red/orange in groin or axilla or on posterior thigh; golden tinge to eyelids and forehead; dorsum and flanks fairly uniform pale, grey or brown.

Etymology. From the Kuuku Ya’u words pakaya – down/inside/under, kul’a – rocks/boulders, ngun – belonging to. The name translates approximately to ‘belonging among the boulders’. The specific epithet was suggested by Mrs Suzie Pascoe and Mrs Lucy Hobson in liaison with Rev. David Thompson. Mrs S. Pascoe and L. Hobson are recognised among the custodians of Kuuku Ya’u country. The species epithet is used as a noun in apposition.

Measurements of holotype. QMJ88547, female; SVL 51.7 mm; TL 23.7 mm; FL 11.8; HW 18.6 mm; HL 12.7 mm; ED 4.5 mm; EN 3.8 mm; IN 4.4 mm; 3DW 3.7 mm; 3FL 8.7 mm; 4TL 11.0 mm.

Description of type series. Data presented as range followed by mean in brackets. Adult measurements (mm): SVL 42.2–51.7 (46.8); TL 19.4–24.8 (22.3); FL 10.2–12.9 (11.6); HW 15.7–18.6 (17.2); HL 10.8–12.7 (11.8); ED 4.1–4.5 (4.3); EN 3.6–3.9 (3.7); IN 3.2–4.4 (3.8); 3DW 2.6–3.7 (3.2); 3FL 6.8–8.7 (7.9); 4TL 9.3–11.1 (10.4). Adult proportions: TL/SVL 0.46–0.49 (0.48); FL/SVL 0.23–0.27 (0.25); FL/TL 0.50–0.54 (0.52); HW/ SVL 0.36–0.39 (0.37); HL/SVL 0.25–0.26 (0.25); HW/HL 1.41–1.51 (1.45); ED/SVL 0.09–0.10 (0.09); EN/IN 0.86–1.15 (1.00); EN/ED 0.83–0.90 (0.87); 3DW/SVL 0.062–0.071 (0.068); 3FL/SVL 0.16–0.17 (0.17); 4TL/SVL 0.21–0.23 (0.22). Comparison of sexes: Females (average SVL = 51.3 mm, range = 49.0–52.9) are larger than males (average SVL = 43.8 mm, range = 42.2–46.7). No differences in proportions were detected between the sexes. Juvenile measurements (mm): SVL 24.0–24.6 (24.3); TL 12.2–12.7 (12.4); FL 5.4–6.0 (5.7); HW 8.4–8.8 (8.6); HL 6.7–6.7 (6.7); ED 2.7–2.9 (2.8); EN 1.8–2.0 (1.9); IN 1.9–2.2 (2.0); 3DW 1.3–1.4 (1.4); 3FL 4.0–4.0 (4.0); 4TL 5.6–5.9 (5.8). Juvenile proportions: TL/SVL 0.51–0.52 (0.51); FL/SVL 0.22–0.25 (0.23); FL/TL 0.44–0.47 (0.46); HW/SVL 0.35–0.36 (0.35); HL/SVL 0.27–0.28 (0.28); HW/HL 1.26–1.31 (1.28); ED/SVL 0.11– 0.12 (0.12); EN/IN 0.90–0.95 (0.93); EN/ED 0.63–0.72 (0.68); 3DW/SVL 0.056–0.058 (0.057); 3FL/SVL 0.16– 0.17 (0.16); 4TL/SVL 0.23–0.24 (0.24). Compared to adults, juveniles have a proportionally longer head, larger eyes, longer hindlegs, shorter forearms and smaller finger discs. Head: Narrower than body, triangular in dorsal view; snout truncated at the nares, noticeably projecting in profile; canthus rostralis angular, loreal region steep; nares much closer to tip of snout than to eye, nares anterolateral on tip of snout; eyes large; eye diameter greater than eye to naris distance; internarial distance about equal to distance from eye to naris; tympanum large (approximately half diameter of eye) but indistinct beneath overlying skin, bordered dorsally by supra-tympanic fold. Body: Rotund. Limbs: Hindlimbs and forearms relatively long; fingers and toes unwebbed; relative finger length 3>4>2>1; fingers 2, 3 and 4 long and slender with very large and obviously truncated discs, first finger short with disc expanded but small and only slightly truncated; rounded outer palmar tubercle and smaller, ovoid inner palmar tubercle; subarticular tubercles low, moderately prominent; relative length of toes 4>3>5>2>1, toe 4 very long and slender; large, obviously truncated discs on toes 2, 3 and 4, discs smaller and more rounded on toes 1 and 5; low, rounded inner metatarsal tubercle, no outer metatarsal tubercle; subarticular tubercles low and rounded, moderately prominent; discs on longest fingers larger than discs on longest toes. Skin: Ventral surface smooth; dorsal surfaces covered in fine tubercles; distinct supra-tympanic fold. Colour pattern in preservative: Even brown dorsally; tympanum paler; forehead triangle and eyelids heavily flecked with grey. White patches at the base of the finger and toe discs. Brown merges to paler ventral colour on the lower flanks. Ventral surfaces of chest, belly and hindlimbs pale; throat, forearms and feet brown. Tubercles and discs pale.

Measurements of live individuals. Seven adults and two juveniles were measured in the field: adults SVL 43.0– 52.9 mm (average = 47.4), WT 6.9–12.6 g (average = 9.4); juveniles SVL 24.8–26.4 mm (average = 25.6), WT 1.3–1.6 g (average = 1.45).

Colour pattern in life ( Fig. 6 View FIGURE 6 ). Adults. No sexual dimorphism in colour pattern evident. Dorsal colour most often even brown ( Fig. 6 View FIGURE 6 A), but sometimes uneven or diffusely mottled brown or grey ( Fig. 6 View FIGURE 6 B). Forehead and eyelids usually gold or yellowish ( Fig. 6 View FIGURE 6 A, 6B), but silver or grey in some individuals. Gold or silver flecking particularly conspicuous on eyelids. Sometimes also yellowish colouration to tympanum ( Fig. 6 View FIGURE 6 B). Loreal region dark; in pale individuals this appears as a dark canthal streak ( Fig. 6 View FIGURE 6 B). Dark supratympanic fold and sometimes also dark marking below the tympanum. Tympanum pale. Pale lumbar ocelli indistinctly visible in some individuals. Ventral surfaces pale with grey wash to throat, armpits and forelimbs, and darker palms and soles of feet ( Fig. 6 View FIGURE 6 C). Generally no orange colouration to groin, posterior thigh and inner calf; where this is present it is at most a pale salmon wash. Juveniles. Sandy yellow dorsal surfaces with dark blotches on the back, flanks and limbs ( Fig. 6 View FIGURE 6 D). There is a yellow forehead triangle and yellow lumbar ocelli. A dark canthal streak extends behind the eye above and below the tympanum. The groin, posterior thigh, calf and top of foot have a salmon orange wash. The ventral surfaces are grey, flecked with white.

Call. The call of C. pakayakulangun sp. nov. is not known.

Comparison. Cophixalus pakayakulangun sp. nov. does not co-occur with any other Cophixalus . It could only be confused with the other three boulder-adapted Cophixalus : C. kulakula sp. nov. ( Fig. 3 View FIGURE 3 ), C. zweifeli ( Figs 1 View FIGURE 1 C, 1D) and C. saxatilis ( Figs 1 View FIGURE 1 A, 1B). See the C. kulakula sp. nov. ‘Comparison’ section for a comparison of these four species.

Genetics. Average sequence divergence (for 944 bp 12S and 16S rRNA) between C. pakayakulangun sp. nov. and all other Australian Cophixalus is 12.9% (range = 8.3–17.1%) (Hoskin et al. unpublished). Phylogenetic analyses suggest that Cophixalus pakayakulangun sp. nov. is most closely related to C. kulakula sp. nov., and that both are allied to C. ornatus (Hoskin et al. unpublished). A 16S sequence for C. pakayakulangun sp. nov. was deposited in GenBank (accession number JN208372 View Materials ).

Distribution. Cophixalus pakayakulangun sp. nov. is known only from the type locality, just south of Stanley Hill in north-east Queensland ( Fig. 2 View FIGURE 2 ). This is north of the Pascoe River and approximately 30 km north of the C. kulakula sp. nov. sites.

Habitat and habits. Cophixalus pakayakulangun sp. nov. inhabits deeply piled granite boulder field habitat that is festooned with vegetation such as vines, creepers, ferns and umbrella trees ( Schefflera ) ( Fig. 7 View FIGURE 7 ). As for C. kulakula sp. nov., this species appears to be restricted to boulder habitat and no individuals were found away from rocks. The frogs emerge from the jumbled boulders on dusk to forage at night on the rocks and associated vegetation. No other frog species were observed utilizing boulder habitat at this site. As for C. kulakula sp. nov., analysis of scats of C. pakayakulangun sp. nov. revealed that they feed primarily on ants (including Polyrachis , Camponotus and Odontomachus ), as well as Coleoptera and Blattodea. This diet conforms broadly to that recorded for other Australian Cophixalus ( Williams et al. 2006) .

Cophixalus pakayakulangun sp. nov. was abundant at the site during wet weather towards the end of the wet season (April 2010), with males and females being observed in approximately equal abundance. However, no calling was heard and this suggests that breeding occurs earlier in the wet season. This is supported by the abundance of juveniles (approx. 25 mm) at the site in April. Cophixalus pakayakulangun sp. nov. almost certainly lays a clutch of terrestrial eggs, as seen in other Australian microhylid frogs ( Hoskin 2004).

Two tubular structures are visible under the skin on the ventral surface of adult male C. pakayakulangun sp. nov. and C. kulakula sp. nov. (visible in Fig. 3 View FIGURE 3 D). These structures lie on either side of the midline, are easy to observe and allow for immediate determination of sex of live individuals (but are less obvious in preservative). We have subsequently observed these on males of other Australian frogs (e.g. Uperoleia ). On dissection, these structures appear to lie within the muscular layers of the abdominal wall. We do not know what these structures are but we hypothesize that they might be involved in calling.