Cophixalus interruptus, 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 : 19-23

Cophixalus interruptus , sp. nov.

Fig. 11

Holotype. BPBM 11523 (field tag AA 13103), adult male, collected by A. Allison at Oomsis Forestry Camp, 6.6983695ºS, 146.8156702ºE, 400 m, Morobe Province, Papua New Guinea, 3 March 1988.

Paratypes (n = 3). BPBM 11524–25, same data as holotype; BPBM 13448, same data as holotype except 530 m and collected 10 September 1988.

Diagnosis. A small species (male SV = 16.6–18.7 mm) with finger discs smaller than toe discs (3rdF/4thT = 0.72–0.94); first finger of normal size, with disc bearing circum-marginal groove; small finger discs (3rdF/ SV = 0.026–0.040); long legs (TL/SV = 0.55–0.59); short snout (EN/SV = 0.075–0.083); small tympanum (TY/SV = 0.053–0.066); small eye (EY/SV = 0.12–0.13); narrow and short head (HW/SV = 0.36–0.40, HL/ SV = 0.31–0.35); face with a dark subocular blotch but not uniformly black; dorsum and sides uniformly light brown; a short, dark bar behind forearm insertion; and abdomen lighter than chin and throat.

Comparisons with other species. The new species differs from all Papuan congeners except C. melanops and C. misimae in the combination of 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 both of those species in having only a dark subocular blotch instead of the entire face uniformly black. It further differs from C. misimae in having a smaller tympanum (TY/SV = 0.065–0.075 in C. misimae ), smaller eye (EY/SV = 0.13–0.14 in C. misimae ), broader head (HW/SV = 0.31–0.36 in C. misimae ), and lacking a black lateral band. It further differs from C. melanops in its longer leg (TL/SV = 0.46–0.58, mean 0.52 in C. melanopos ), shorter snout (EN/SV = 0.081–0.105 in C. melanops ), smaller eye (EY/SV = 0.14–0.17 in C. melanops ), and narrower and shorter head (HW/SV = 0.41–0.44, HL/SV = 0.38–0.41 in C. melanops ).

Description of holotype. An adult male with vocal slits. Head moderately wide (HW/SV = 0.38), with vertical loreal region; canthus rostralis rounded, swollen, slightly convex when viewed from above; nostrils directed laterally, closer to tip of snout than to eyes; internarial distance larger than distance from naris to eye (EN/IN = 0.78, IN/SV = 0.103, EN/SV = 0.080); snout rounded and slightly projecting when viewed from the side, truncate when viewed from above, with a triangular depression on dorsal surface just posterior to tip; eyes moderately large (EY/SV = 0.13); eyelid approximately 2/3 width of interorbital distance; tympanum distinct and small (TY/SV = 0.063), with a clear 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 and disc well-developed. Finger discs somewhat shrivelled, approximately 2 times widths of penultimate phalanges, except for the first finger disc, which is only slightly wider than penultimate phalanx. Subarticular tubercles absent; metacarpal tubercles poorly developed skin thickenings. Toes unwebbed, bearing discs with terminal grooves; relative lengths 4>3>5>2>1. Toe discs somewhat shrivelled, larger than those of fingers; disc of fourth toe approximately three times width of penultimate phalanx; disc of first toe slightly wider than penultimate phalanx. Subarticular tubercles lacking; inner metatarsal tubercle narrow and elongate, outer lacking. Hind legs long (TL/SV = 0.58).

Dorsum light brown, irregularly stippled with dark-brown; sides lighter. Small, elongate dark-brown postocular bar ending just posterior to tympanum; another short, elongate dark-brown bar following this dorsal to and just behind forearm insertion. Face brown with darker-brown subocular blotch extending to angle of jaw. Venter straw minutely flecked with brown, denser on chin, gradually lessening posteriorly; under thighs same but with more brown flecking than on abdomen. Rear of thighs light brown with dark-brown flecks; front of thighs light straw with brown flecks. Iris black with obscure dark-bronze flecks.

Measurements (in mm). SV = 17.5, TL = 10.1, HW = 6.7, HL = 6.1, IN = 1.8, EN = 1.4, SN = 2.5, EY = 2.3, TY = 1.1, 3rd F = 0.70, 4th T = 0.85.

Variation. Mensural variation for the type series is shown in Table 9 . The three paratypes have a vague, brown, chevron-shaped smudge in the suprascapular region. One has a narrow, dark-brown vertebral line extending posteriorly from snout before dissolving on rear of body. One has the second dark-brown lateral bar followed by another than extends posteroventrally and is weakly connected to the former.

Color in life. Holotype: “Dorsum brownish, head darker; whole upper body slightly mottled, variegated; venter ca. cream/yellowish suffused with fine brown/black reticulum; thighs and groin bright orange; flanks similar to dorsum; dark (black) patch just above ear, slightly smaller one just behind; thigh ca. black.” BPBM 11525 resembled the holotype except in having a yellowish mid-vertebral line.

Character Males (n = 4)

Call. The call consists of a moderately slow series of peeps. The single call that we recorded from the holotype (BPBM 11523) consisted of 24 call notes and lasted 11.88 s. The mean note duration was 0.1533 s (range 0.1277–0.1678). The internote interval was about twice this, averaging 0.3567 s (range 0.2677–0.4456). The call note abruptly reaches maximum amplitude and decreases less abruptly at termination ( Fig. 12 A). Notes are unpulsed. The notes are finely tuned with a dominant frequency of 4300 Hz ( Fig. 12 B), with no frequency modulation ( Fig. 12 C).

Etymology. The name is a Latin adjective meaning “broken apart” in reference to the broken line of two brown dashes behind the eye.

Range. Known only from Oomsis, ~ 20 km W of Lae, Morobe Province, Papua New Guinea ( Fig. 7 ).

Ecological notes. Animals were found at night in the interior of lowland forest perched on low vegetation, such as ferns, a meter or less from the ground.

Figures

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 11. (A) Dorsal, and (B) lateral view of holotype of Cophixalus interruptus (BPBM 11523).

FIGURE 12. (A) Waveform, (B) power spectrum, and (C) spectrogram of the call of holotype of Cophixalus interruptus (BPBM 11523) recorded by A. Allison in the hills above Oomsis Forestry Station, 400 m elevation, Morobe Province, Papua New Guinea, at 2050 h, 3 March 1988. Air temperature 25.2 ° C.

Tables

TABLE 9. Mensural data for type series of Cophixalus interruptus sp. nov.

	mean	range
SV (mm)	17.7	16.6–18.7
TL/SV	0.57	0.55–0.59
EN/SV	0.079	0.075–0.083
IN/SV	0.109	0.103–0.114
SN/SV	0.14	0.14–0.14
TY/SV	0.062	0.053–0.066
EY/SV	0.13	0.12–0.13
HW/SV	0.39	0.36–0.40
HL/SV	0.33	0.31–0.35
3rdF/SV	0.034	0.026–0.040
4thT/SV	0.041	0.036–0.049
EN/IN	0.73	0.68–0.78
3rd F/4th T	0.83	0.72–0.94
HL/HW	0.86	0.82–0.91