Platymantis admiraltiensis, Richards, Stephen J., Mack, Andrew L. & Austin, Christopher C., 2007

Richards, Stephen J., Mack, Andrew L. & Austin, Christopher C., 2007, Two new species of Platymantis (Anura: Ceratobatrachidae) from the Admiralty Archipelago, Papua New Guinea, Zootaxa 1639, pp. 41-55 : 43-46

Platymantis admiraltiensis sp. nov.

( Figs 1 – 6)

Type material. Holotype: SAMA R62799, Adult male, Chachuau Camp near Tulu 1 Village, Manus Island, Papua New Guinea (2o01.089' S, 146o47.807' E; ~ 20 m a.s.l.) collected by S.J. Richards on 8 June 2002. Paratypes: UPNG 10049, SAMA R62800– 1 adult females, and UPNG 10050, SAMA R62802– 3 adult males, same location as holotype, collected by S.J. Richards on 7 June 2002; SAMA R62804– 5 adult males, Lorengau, Manus Island (2o01.870' S, 147o15.593'E; 5–10 m a.s.l.) collected by S.J. Richards on 4 June 2002; SAMA R62808– 10 adult males, Tulu 1 Village, Manus Island (1o57.530' S, 146o50.085'E; 5–10 m a.s.l.) collected by S.J. Richards on 5–6 June 2002; SAMA R62806, adult male, Tingau Village, 27 km south-west of Lorengau (02 o 05.76S, 147o 06.33E; 296 m a.s.l.) and SAMA R62807, adult female, Salami Village, Los Negros Island, Manus Province (02o 02.46S, 147 o 24.24E; 5 m a.s.l.) collected by C. Austin on 28 August 2001; SAMA R62812–3, adult females, and R62811, R62814– 6 adult males, Natnewai Camp, Manus Island (2o10.053'S, 147o15.09'E; 150 m a.s.l.) collected by A. Mack on 29 April 2001.

Diagnosis. A moderate sized Platymantis (males 32.7–38.4 mm, females 43.2–46.4 mm SVL) distinguished from congeners in the Papuan region by a combination of relatively long legs (TL/SVL 0.54–0.60), small terminal discs on toes, pronounced dorsal folds, no dark loreal stripe, a mottled pattern on the posterior of the thighs, and an advertisement call consisting of a long series of slowly repeated (0.4–1.9 notes/s) yapping notes.

Description of Holotype. Adult male with vocal slits. Head slightly longer than wide (HL/HW 1.04), canthus rostralis straight, gently rounded; loreal region oblique, slightly concave; nares closer to snout than eye, oriented postero-laterally; tympanum large (TYM/EYE 0.72), prominent, annulus abutting strong supratympanic fold dorsally; vomerine teeth in two large clumps at postero-medial edge of choanae; tongue oval, deeply bifid posteriorly. Skin finely granular dorsally with numerous longitudinal folds, most prominent folds forming four pairs of lyrate-shaped ridges on dorsum. First pair starts behind each eye, subsequent pairs becoming progressively shorter posteriorly. A short (1.8 mm) pair of folds between orbits; scattered low tubercles dorsally and laterally; most of throat and chest minutely roughened; anterior edge of throat, posterior of thighs and abdomen slightly granular; an elongate (1.6 mm) tubercle oriented postero-laterally at rear edge of tympanic membrane. Limbs moderately long (TL/SV 0.58); relative lengths of fingers 1>3>2>4, subarticular tubercles prominent, fingers unwebbed; tips of digits slightly wider than penultimate phalanx, with weak circum-marginal grooves. Relative length of toes 4>3>5>2>1; subarticular tubercles prominent, one tubercle on right foot swollen, deformed; toes with trace of basal webbing; tips of digits expanded with prominent circum-marginal grooves; toe discs larger than finger discs (3FD/4TD 0.56).

Dorsally dark brown with broad, darker brown cross-bars on limbs and two small dark patches in loreal region, one anterior of eye and other posterior of naris. Supratympanic fold with narrow dark line along ventral edge. Laterally paler than dorsum, with pigmentation forming irregular and diffuse brown patches. Upper and lower lips with brown bars, tympanic membrane mottled with dark and pale brown, interior edge of annulus with narrow ring of dark pigment. Snout anterior of midpoint between eyelids paler brown than rest of dorsum. Posterior of thighs mottled with dark and pale brown. Subarticular tubercles less intensely pigmented than palmar and plantar surfaces. Ventrally cream, with scattered and diffuse brown stippling around angle of jaws.

Measurements of the holotype: SV 36.7; TL 21.4; HW 15.2; HL 15.8; EN 4.3; IN 3.6; EYE 5.0; TYM 3.6; 4TD 1.6; 4TP 0.7; 3FD 0.9; 3FP 0.8; 1FD 0.9.

Variation. Variation in measurements and proportions of the paratypes are presented in Table 1 . Males are 32.7–38.4 mm, females 43.2–46.4 mm SV. Dorsal colour pattern is highly variable. Ground colour is pale to dark brown; one specimen is grey. The dorsum may be unicolor or mottled (n = 12), there may be a narrow (0.2–2.0 mm wide, n = 3) or broad (n = 2) mid-vertebral stripe, and/or a pair of pale dorso-lateral stripes (n = 3). Subarticular tubercles on all specimens are conspicuously less pigmented than palmar and plantar surfaces, and pigmentation is nearly absent on tubercles of some paratypes. Pale markings on the posterior surfaces of the thighs form discrete spots or short irregular bars in all specimens. Iris pale brown, usually with narrow darker brown reticulations.

Advertisement call. The advertisement call is a very long (full sequences 21–44 sec) series of slowly repeated (~ 0.4–1.9 notes/s), yapping notes ( Table 2 ; Figure 6). Each series starts slowly and irregularly, and note repetition rate increases in terminal sequences of the series. Notes have two discrete components, a finely pulsed introductory ‘segment’ (sensu Zweifel 1969) followed without pause by a longer unpulsed segment. Call characteristics are presented in Table 2 . Some of the calls analysed did not comprise full sequences, which normally exceeded 20 sec in length but were difficult to record. A single call is illustrated and compared with P.latro sp. nov. and P. papuensis in Figure 6.

Comparisons with other species. The size, general habitus, small finger and toe discs, prominent dorsal folds, and advertisement call structure of P. admiraltiensis sp. nov. suggest affinities with the informal P. papuensis ‘complex’, a morphologically conservative group of predominantly terrestrial Platymantis . From P. bimaculatus , P. cheesmanae and P. wuenscheorum it differs in its much larger size (male SV to 38 mm vs <32 mm), from P. punctatus in its vestigial (vs extensive) webbing between the toes and from P. batantae by its larger size (female SV 46.4 mm vs <40 mm in batantae ; Zweifel 1969), and by having a strongly mottled (vs not mottled) pattern on the posterior of the thighs. P. admiraltiensis is similar morphologically to P. adiastolus , P. c r y p t o t i s, P. papuensis , P. schmidti and P. w e b e r i. It differs from all of these species by the distinctly mottled posterior surfaces of the thighs, and by its advertisement call. The basic structure of individual notes is similar among these species, but note repetition rates at similar temperatures are dramatically different. The calls of P. adiastolus , P. cryptotis , P. papuensis , and P. s c h m i d t i have been analysed and described in detail previously ( Zweifel 1969, Menzies 1982, Günther 1999, Brown et al. 2006). P. admiraltiensis has a call rate (0.4–1.9 notes/s, see Table 2 ) that is much slower than P. adiastolus (4.3 notes/s; Brown et al. 2006), P. cryptotis (~10 notes/s; Günther 1999), P. papuensis (~4.5 notes/s; Günther 1999), P. s c h m i d t i (12.8 notes/s; Brown et al. 2006) and P. w e b e r i (~8 notes/s; Richards unpublished data). The slow call rate of P. admiraltiensis is not attributable to low temperatures. Recordings of this species on Manus Island, an island close to the equator, were made at temperatures of 28o C, much higher than temperatures at which the other taxa were recorded (see references above).

2.9–3.6 3.7–4.4 3.4–4.1 4.7–5.7

P. admiraltiensis male P. admiraltiensis female P. l a t ro male P. l a t ro female n = 13 n = 6 n = 9 n = 6 0.125–0.147 0.12–0.15 0.13–0.16 0.118–0.133 Etymology. The specific name refers to the Admiralty Archipelago, which encompasses the known distribution of this species.

Distribution. Known only from Manus and Los Negros Islands, Manus Province, Papua New Guinea ( Figure 7 ).

Natural history. Males called from exposed or semi-exposed positions in forest litter, or from the base of grass tussocks in disturbed garden habitats, after heavy rain. This species appeared to be at least as abundant in gardens around Tulu 1 Village where canopy cover was severely reduced, as they were in closed canopy forest at Chachuau Camp. Given the ability of this species to persist in heavily degraded habitats, and its wide distribution on Manus and Los Negros Island, we suggests that this species should be listed as ‘Least Concern’ using the criteria of the Global Amphibian Assessment.

Figures

FIGURE 1. Lateral view of heads of A. Platymantis admiraltiensis sp. nov. holotype (SAMA R 62799) and B. P. latro sp. nov. holotype (SAMA R 62819) showing distinct lateral band of P. latro sp. nov. Scale = 10 mm.

FIGURE 7. Map of Manus and surrounding islands showing locations discussed in the text.

Tables

TABLE 1. Measurements and proportions of Platymantis admiraltiensis sp nov. and P. l a t ro sp. nov. Measurements are presented as mean (SD) and range.

	P. admiraltiensis male n = 13	P. admiraltiensis female P. l a t ro male n = 6 n = 9	P. l a t ro female n = 6
SV	35.89 (1.63) 32.7–38.4	44.55 (1.33) 33.49 (2.09) 43.2–46.4 30.9–38.3	52.13 (4.64) 46.2–58.3
TL	20.70 (0.60)	25.53 (0.63) 16.18 (0.93)	25.08 (2.17)
TL/SV	19.7–21.6 0.58 (0.02)	24.6–26.1 15.1–18.2 0.57 (0.02) 0.48 (0.02)	22.0–27.2 0.48 (0.01)

TABLE 2. Call parameters of Platymantis admiraltiensis sp. nov. Data are presented as mean (SD) and range. Time is in seconds.

Frog Number number of calls	T a (o C)	notes / call	call length (sec)	note rep. rate (notes/s)	note length (n = 193)	inter-note length (n = 183)	Dominant Frequency (Hz)
SAMA R62804 2	28	8–21	17.6–19.3	0.4–1.04	0.104 (0.006) 0.096–0.124	1.254 (1.326) 0.272–5.687	2960–3153
SAMA R62808 3 no specimen 1	28 28	23–33 5	12.8–26.6 10.3	0.83–1.82 0.39	0.123 (0.019) 0.075–0.21 0.113 (0.002) 0.111–0.116	0.658 (0.663) 0.208–4.905 2.433 (0.951) 1.667–3.628	3130–3657 3167
SAMA R62799 4	27	7–32	4.7–25	0.36–1.94	0.127 (0.019) 0.1–0.244	0.808 (0.843) 0.241–4.952	2889–3109