Cophixalus phaeobalius, Kraus, Fred & Allison, Allen, 2009

Kraus, Fred & Allison, Allen, 2009, New species of Cophixalus (Anura: Microhylidae) from Papua New Guinea, Zootaxa 2128, pp. 1-38 : 29-31

Cophixalus phaeobalius , sp. nov.

Fig. 2 D

Holotype. BPBM 26193 (field tag AA 17562), adult female, collected by A. Allison at Kamiali Wildlife Management Area, 3 km N and 12.9 km W of Cape Dinga, 7.277998011ºS, 147.033451568ºE, 1520 m, Morobe Province, Papua New Guinea, 6 April 2005.

Paratype. BPBM 26194, same data as holotype.

Diagnosis. A small species (male SV = 15.3 mm, female SV = 19.2 mm) with finger discs smaller than toe discs (3rdF/4thT = 0.68–0.80); first finger of normal size, with disc bearing circum-marginal groove; small finger discs (3rdF/SV = 0.026–0.029); short legs (TL/SV = 0.44–0.48); short snout (EN/SV = 0.072–0.073, EN/IN = 0.61–0.67); small tympanum (TY/SV = 0.052–0.057); large eye (EY/SV = 0.15); narrow and short head (HW/SV = 0.38–0.41, HL/SV = 0.35–0.37); face with a dark subocular blotch but not uniformly black; dark-brown lateral stripe extending to at least midbody; no dark bar behind forearm insertion; bold dark-brown spotting on legs; venter uniformly dark, and a moderately slow peeping call of 3–7 notes.

Comparisons with other species. The new species differs from all Papuan congeners except C. interruptus , C. linnaeus , C. melanops and C. misimae in having finger discs distinctly smaller than toe discs and a first finger of normal size, bearing a disc with a circum-marginal groove. It differs from C. melanops and C. misimae in having only a dark subocular blotch instead of the entire face uniformly black; in having a narrow, interrupted black lateral stripe (absent in C. melanops or a broad continuous band in C. misimae ); and bold dark brown spotting on the legs (absent in C. melanops and C. misimae ). Cophixalus phaeobalius is most similar to C. interruptus and C. linnaeus . It differs from both in having shorter legs (TL/SV = 0.55–0.59 in C. interruptus , 0.50–0.57 in C. linnaeus ); shorter snout (EN/SV = 0.075–0.083 in C. interruptus , 0.082–0.099 in C. linnaeus ; EN/IN = 0.68–0.78 in C. interruptus , 0.87–0.93 in C. linnaeus ); the entire venter stippled uniformly dark, overlain with a few scattered dark brown blotches (vs. abdomen light straw, lighter than darkly flecked chin and throat in C. interruptus and C. linnaeus ); having a dark lateral stripe (absent in C.

interruptus , and absent or irregularly developed in C. linnaeus ); having bold dark-brown spotting on the legs (vs. obscure brown mottling in C. interruptus and C. linnaeus ; and in having a call with seven or fewer notes (call of C. interruptus consists of 24 notes and that of C. linnaeus consists of 21–48 notes).

Description of holotype. An adult female. Head moderately wide (HW/SV = 0.38), with oblique loreal region; canthus rostralis rounded, straight when viewed from above; nostrils directed laterally, closer to tip of snout than to eyes; internarial distance considerably larger than distance from naris to eye (EN/IN = 0.67, IN/ SV = 0.11, EN/SV = 0.073); snout slightly rounded when viewed from the side, rounded when viewed from above; eyes large (EY/SV = 0.15); eyelid approximately 2/3 the width of the interorbital distance; tympanum small (TY/SV = 0.057), with a clear, raised annulus. Dorsal, lateral, and ventral surfaces smooth; supratympanic fold absent. Fingers unwebbed, bearing discs with terminal grooves; relative lengths 3>4>2>1; first finger well-developed, disc poorly developed. Finger discs approximately 1.5 times widths of penultimate phalanges, except for the first finger disc, which is barely wider than penultimate phalanx. Subarticular and metacarpal tubercles poorly developed. Toes unwebbed, bearing discs with terminal grooves; relative lengths 4>3>5>2>1. Toe discs larger than those of fingers (3rd F/4thT = 0.68); disc of fourth toe approximately 1.5 times as wide as penultimate phalanx; disc of first toe approximately same width as penultimate phalanx. Subarticular and metatarsal tubercles not obvious. Hind legs rather short (TL/SV = 0.44).

Dorsum dark brown with curved darker-brown dorsolateral stripe from eye to groin, and darker-brown lateral line from behind eye to mid-body, fusing with the dark dorsolateral stripe at point behind eye. Darkbrown interocular bar followed posteriorly by few dark-brown spots above shoulders. Face and snout darker brown, darkest below eye, this continuing to above forearm insertion. Irregular light-brown stripe extending posteriorly from anterior of tympanum and expanding in width above forearm insertion. Dorsal surfaces of limbs with many large darker-brown spots. Front and rear of thighs uniform dark brown, with few darkerbrown spots at knee. Venter dirty white, heavily stippled with dark brown, imparting appearance of a uniformly dark-brown venter; with few darker-brown round spots scattered on chin and chest. Iris black.

Measurements (in mm). SV = 19.2, TL= 8.4, HW = 7.2, HL = 6.8, IN = 2.1, EN = 1.4, SN = 2.6, EY = 2.8, TY = 1.1, 3rd F = 0.50, 4th T = 0.73.

Variation. Measurements of the paratype are: SV = 15.3 TL = 7.3, HW = 6.2, HL = 5.7, IN = 1.8, EN = 1.1, SN = 2.2, EY = 2.3, TY = 0.8, 3rd F = 0.44, 4th T = 0.55. Ground color is lighter, with more numerous dark spots and the lateral and dorsolateral dark lines heavily broken. Venter more heavily mottled with dark brown. Rear of thighs brown blotched with dark brown.

Color in life. Holotype (BPBM 26193): “Dorsum russet-brown except for area between eyes to parietal region which is suffused with black; dorsolateral area mostly lighter, bounded laterally by a black line separating flanks which are light brown; black stripe from ear to about half way along the body where it merges with the belly; white line from eye to insertion of front leg; chin and throat black, rest of venter heavily covered with black and white specks, appearing gray. Iris dark rust”.

The paratype, BPBM 26194, was similar to the holotype: “Dorsum more or less tan with rufescent cast and black mottling, dorso-lateral area light tan, forming a line, flanks similar to dorsum but lighter; oblique black band from above the front leg to venter at mid-body; lateral area with large black blotch; white band from corner of eye to front leg; face, chin and throat black; rest of venter with gray and white speckling, mottled with black; iris dark bronze-rust.

Call. We recorded calls from three individuals ( Table 12 ). They called from within cracks and crevices in peaty substrate for several hours in the early evening. We did not hear them in the morning but spent only a limited time at the field site.

The call consists of a series of three to seven peeps (duration 1.30– 2.73 s, depending on the number of peeps). The repetition rate was 1.7–2.3 notes/s. The mean note duration was 0.1458 s (range 0.1123–0.2020) and the internote duration was more than twice this, with a mean of 0.3744 (range 0.1440–0.4706). The call begins at about 75% of its maximum amplitude and steadily builds to maximum amplitude just before termination ( Fig. 14 A). The notes are unpulsed and are finely tuned (Fig. 17A), with a dominant frequency of 3970 Hz (range 3910–4040) ( Fig. 14 B) and no frequency modulation ( Fig. 14 C).

Etymology. The name is a latinized Greek compound adjective from “phaios”, meaning “darkish”, and “balios”, meaning “dappled”, in reference to the distinctive patterning on the sides and legs.

Range. Known only from upper elevations at Kamiali, Bowutu Mts., Morobe Province, Papua New Guinea ( Fig. 7 ).

Ecological notes. Animals were found on the floor of heavily mossed forest, mostly on steep slopes. They called from within cracks and crevices in thick, peaty substrate, and were very shy, quickly retreating down cracks and holes in the substrate when pursued. They appeared to be uncommon.

Wildlife Management Area, Morobe Province, Papua New Guinea. Uncaptured-1 was recorded from 1400 m on 2 April

2005; Uncaptured-2 and BPBM 26194 were recorded from 1520 m on 6 April 2005.

Mean Mean

Call Note Internote Repetition Dominant

Figures

FIGURE 2. Photos in life of (A) holotype of Cophixalus melanops (BPBM 20198), (B) paratype of Cophixalus melanops (BPBM 20197), (C) holotype of Cophixalus linnaeus (BPBM 31836), (D) paratype of Cophixalus phaeobalius (BPBM 26194), (E) paratype of Cophixalus tomaiodactylus (BPBM 26182), and (F) holotype of Cophixalus tomaiodactylus (BPBM 26185).

FIGURE 7. Map showing known distributions for Cophixalus interruptus (circle), C. kethuk (inverted triangles), C. linnaeus (star), and C. phaeobalius (square). Filled symbols are type localities; open symbols are additional localities, as relevant.

FIGURE 14. (A) Waveform, (B) power spectrum, and (C) spectrogram of the call “ D ” (see Table 12) of paratype of Cophixalus phaeobalius (BPBM 26194) recorded by A. Allison at “ Top Camp ”, Kamiali Wildlife Management Area, 3 km N and 12.9 km W of Cape Dinga, 1520 m elevation, Morobe Province, Papua New Guinea, at 2200 h on 6 April 2005. Air temperature 19.6 ° C.