Austrochaperina guttata, ZWEIFEL, 2000

ZWEIFEL, RICHARD G., 2000, Partition Of The Australopapuan Microhylid Frog Genus Sphenophryne With Descriptions Of New Species, Bulletin of the American Museum of Natural History 2000 (253), pp. 1-130 : 33-38

Austrochaperina guttata , new species Figures 18 , 31C

HOLOTYPE: MCZ A92812 (field no. Y22785), collected by W. Hutton at 30 km N, 14 km W Kikori , Gulf Province, Papua New Guinea, on September 11, 1975.

PARATYPES: All from Papua New Guinea. MCZ A132842–132846 , AMNH A157842 , collected by Fred Parker at Uraru, 90 m, Simbu Province, Oct. 2, 1967 ; MCZ 132825 , collected by Fred Parker at Ining River, Soliabedo , 360 m, Simbu Province, Sept. 24, 1967 ; BPBM 13107 , 13137 , QM J67256 , collected at Ivimka Field Station , 5.5 km S, 5.6 km W of Tekadu Airstrip, 7°44.10′S, 146°29.77′E, 120 m, Gulf Province, by A. Allison, Oct. 15, 1996 and S. Richards on Nov. 19, 1996. I also designate BPBM 13157 as paratype, which was taken from the last locality. A tape recording of its call and a color transparency examined are sufficient, in my view, to include this specimen in the type series although I did not examine it physically .

ETYMOLOGY: The Latin adjective guttata , meaning ‘‘spotted,’’ refers to the dorsal color pattern.

DIAGNOSIS: A relatively large Austrochaperina —males to 43 mm, females to 44 mm SVL—with large digital discs (FD/SVL ± 0.035), long legs (TL/SVL mean of 0.479), and a dorsal pattern of irregular dark brown spots on a gray-brown background. The call is distinctive and diagnostic (see Call below).

DESCRIPTION OF HOLOTYPE: Adult female with the following measurements and proportions: SVL 42.8, HW 16.1, TL 21.6, EY 4.5, EN 3.4, IN 4.5, HD 11.8, FT 21.4, disc of third finger 1.6 (penultimate phalanx 0.85), disc of fourth toe 1.9 (1.0), TY 2.3; HW/SVL 0.376, TL/SVL 0.505, EY/SVL 0.105, EN/SVL 0.079, IN/SVL 0.105, EN/IN 0.756, HD/SVL 0.276, FT/SVL 0.500, third finger disc/SVL 0.037, fourth toe disc/SVL 0.044.

Head narrower than body. Snout subacute viewed from above, projecting in lateral aspect; nostrils lateral, just visible from above; loreal region a steep slope, slightly concave; canthus rostralis rounded. Eye outline just visible from beneath; eyelid 3.0, interorbital 4.5 mm (space/lid = 1.5). Tympanum small, inconspicuous. Relative lengths of fingers 3> 2> 4> 1; first finger greater than one-half length of appressed second, reaching past subarticular elevation, all-with well developed terminal discs, that of third almost twice width of penultimate phalanx; subarticular elevations low, rounded, inconspicuous; inner metacarpal elevation elongate, rounded, slightly more conspicuous than the subarticular elevations, outer metacarpal elevation barely evident. Toes unwebbed, relative lengths 4> 3> 5> 2> 1, first reaching almost to distal end of subarticular elevation of second, all with well-developed terminal discs, that of fourth toe wider than that of third finger; subarticular elevations low, rounded, inconspicuous; inner metatarsal elevation low, elongate, more conspicuous than subarticular elevations. A moderately conspicuous postocular-supratympanic fold curves downward to the arm insertion; otherwise, body surfaces are smooth.

In preservative, the dorsum is gray-brown with small but distinct, irregular dark brown spots from snout to tip of body; the snout tip is not noticeably paler than the top of the head. The color pattern on the dorsal surfaces of limbs, hands, and feet is similar to that of the body. The loreal region is darker than the dorsal ground color but is not sharply defined. The lips are spotted and barred, and an ill-defined dark mark lies along the postocular fold. The sides of the body and anterior surface of the thighs are spotted, verging on mottling, whereas the posterior surface of thighs has diffuse dark and light spotting. The chin is pale with moderate darker spotting around the rim and diffuse dark spotting elsewhere. The chest, abdomen, and undersides of thighs are pale and unspotted, but the undersides of the shanks are heavily spotted and the soles are darkened.

VARIATION IN TYPE SERIES: Body proportions of the 11 frogs comprising the type series, all adults, are summarized in table 2, and regression data are in table 3. Six adult males range from 37.2 to 43.3 mm SVL, five adult females from 40.9 to 43.8 mm.

There is little variation in color pattern in the paratypes. One has dorsal spotting encroaching on the undersides of the thighs. In another, the smallest male, the dorsal pattern of spots is much denser, almost reticulate, and the anterior and posterior surfaces of the thighs are similarly marked. The snout tip is slightly paler than the rest of the head in some but not all males, but not in two calling males.

As seen in color transparencies, one individual has a gray ground color with dark gray to black spotting, the other has a tan ground color and dark brown to black spotting.

ILLUSTRATIONS: Hand and foot, fig. 55B.

CALL: Through the courtesy of Stephen Richards and Allen Allison, I have tape recordings of the calls of two individuals of this species, QM J67256 and BPBM 13157. The call is a prolonged series of brief, harsh notes given at a rate of about 7 per sec at 24.2° and 26.4°C (fig. 79C, table 5). The mean note duration is 0.048 sec in two calls (range 0.040 –0.052, dominant frequency 2050–2200 Hz). Each note typically has six or seven pulses about equal in length or with the last longer, although one or two weak additional pulses may sometimes be detected (figs. 79C, 80B, see Vocalizations). Two peculiarities of this species’ call are its duration and infrequency of utterance. A nearly complete sequence—S. Richards estimated (personal commun.) that it lacks the initial 3–8 seconds—lasts 1 min 22 sec. Even more striking is the second call, the recording of which lasts 2 min 37 sec and lacks an estimated 10–15 sec (Allen Allison, personal commun.) S. Richards reported that his recorded individual called only three or four times in an hour.

COMPARISONS WITH OTHER SPECIES: The features noted in the Diagnosis render guttata a rather distinctive species. A. archboldi , probably a smaller species, resembles guttata in relative eye size and leg length but has a wider internarial span, smaller hands and finger discs, and a dorsal pattern of finer dark markings. The other most similar species— derongo and hooglandi —differ in critical ratios (table 2), and the latter has a distinctive color pattern. A. guttata and A. derongo occur in sympatry at Uraru, Gulf Prov., Papua New Guinea.

HABITAT AND HABITS: Two of the localities for the species are in areas mapped by Paijmans (1975) as Medium Crowned Lowland Hill Forest, whereas the type locality appears to be in ‘‘small crowned forest on plains and fans.’’ Stephen Richards reports (personal commun.) that a specimen he tape-recorded and collected was ‘‘calling from under litter at the base of a small shrub.... The forest here is lowland alluvial rainforest.’’ Allen Allison (personal commun.) described the calling site of another individual: ‘‘... on the ground in a small, apparently natural ‘shelter’ approx. 10 cm wide, 10 cm deep and 15 cm high formed by a few leaves that had fallen around a clump of grass.’’

DISTRIBUTION: The species is known from localities around the head of the Gulf of Papua (fig. 19), two in Gulf Province and two in Simbu Province; see Holotype and Paratypes for specifics. Three known elevations of capture are 90, 120, and 360 m, and the fourth is likely within or below this range.

Austrochaperina hooglandi (Zweifel) , new combination Figure 20

Sphenophryne hooglandi Zweifel, 1967a: 2 (type locality, ‘‘ Mt. Hunstein , Sepik District, Territory of New Guinea [West Sepik Province, Papua New Guinea], at an elevation of 4000 feet ’’ [1220 m]; holotype, AMNH A77597 , collected by R. D. Hoogland on August 13, 1966).

DIAGNOSIS: A relatively large Austrochaperina , with males and females reaching 43– 44 mm SVL, a size otherwise attained in the hooglandi species group only by guttata . Among other Austrochaperina , this size is attained or exceeded only in some populations of palmipes and rivularis . The color pattern of hooglandi is distinctive, with the dark middorsal region abruptly differentiated from paler lateral areas and with reddish shades prominent, especially laterally and on the groin and thighs.

MORPHOLOGY: The holotype, a male, is described in detail in Zweifel (1967a). Its measurements and proportions are: SVL 40.1, HW 14.5, TL 17.6, EY 3.8, EN 3.1, IN 4.1,

(closed circles), and A. hooglandi (triangles).

HD 9.3, FT 17.6, disc of third finger 1.05 (penultimate phalanx 0.7), disc of fourth toe 1.45 (0.85); TL/SVL 0.439, HW/SVL 0.361, EY/SVL 0.095, EN/SVL 0.077, IN/SVL 0.102, EN/IN 0.756, HD/SVL 0.232, FT/ SVL 0.439, disc of third finger/SVL 0.026, disc of fourth toe/SVL 0.036.

A relatively large Austrochaperina , adults about 40 mm SVL or longer, with narrow head (HW/SVL 0.353) and moderately long hind legs (TL/SVL 0.444). Snout acute but blunt, projecting beyond anterior margin of lip (fig. 21); loreal region nearly vertical, shallowly concave, canthus rostralis rounded but not obscure; nostrils directed laterally, IN greater than EN (EN/IN O.731; IN/SVL 0.105); eyes unusually small (EY/SVL 0.091), interorbital span almost twice eyelid width; tympanum small, obscure. Hands of average size (HD/SVL 0.227); all fingers and toes with distinct discs bearing marginal grooves, those of third finger about 1.6X width of penultimate phalanges, of fourth toe 2.0X (FD/SVL 0.030, TD/SVL 0.041); relative lengths of fingers 3> 4> 2> 1, of toes 4> 3> 5> 2> 1; no trace of webbing on hands or feet; no distinct subarticular, palmar or solar tubercles, only low rounded elevations. Dorsal and ventral surfaces smooth except for slight roughening of the eyelids and top of head; a weak postocular-supratympanic fold. Male has a single subgular vocal sac.

COLOR AND PATTERN: The dorsum was pale pinkish brown after several months in preservative, and the darker markings, flecks, and mottling were dark brown. The groin, anterior and posterior sides of the thighs, and inside of the shank were light peach in color, probably being brighter and redder in life. The ventral surfaces are pale tan, almost white. The chin and hind limbs are lightly spotted and mottled with brown, the chest and abdomen immaculate. James Menzies (personal commun.) described a specimen from the Adelbert Mtns.: ‘‘dorsal mid and light brown, speckled, becoming reddish posteriorly; groins and back of thighs dull red; arms and legs as back; tympanum buffy; iris brown; throat speckled, rest of belly plain white but mottled below arms and legs.’’

VARIATION IN SIZE AND PROPORTIONS: The largest specimen is an adult female 44.2 mm SVL; the largest male is 43.4 mm SVL. A 35.1-mm female is subadult, whereas one of 37.3 mm is adult. Two males are mature at 40.1 mm, but one of 28.6 mm is not. See table 2 for statistics on proportions and table 3 for regression data.

As is true of some other Austrochaperina , males and females of hooglandi differ in that the snout of mature males is pale, almost white, and projects more than the darker, shorter snout of females and immature individuals.

ILLUSTRATIONS: Hand and foot, fig. 55D.

CALL: This has not been described.

COMPARISONS WITH OTHER SPECIES: The chief distinction of A. hooglandi is in the col- or pattern—no other species has the dark middorsal region and pink to reddish shade of the groin and thighs. There is broad overlap of the standard morphological ratios with derongo , a circumstance confused by geographic variation of some proportions in that species. Greater eye size of archboldi (no overlap in ratios) as well as color pattern distinguish that species from hooglandi . A. guttata differs not only in color pattern, but in several proportions.

HABITAT AND HABITS: Nothing specific is on record. The type locality falls in a region mapped by Paijmans (1975) as Medium Crowned Lowland Hill Forest.

DISTRIBUTION: This species is known from the Hunstein, Schrader, and Adelbert Mountains, West Sepik and Madang Provinces, Papua New Guinea (fig. 19).

LOCALITY RECORDS AND SPECIMENS EXAMINED: PAPUA NEW GUINEA: West Sepik Prov.: Mt. Hunstein , 1200 m ( AMNH A77592–77597 ) ; Madang Prov.: Malanga River near Yilu, southwest slope of the Schrader Mountains , 600 m, approximate coordinates 144°9′E, 5°7′S ( UPNG 8396 ) ; Kervat , Adelbert Mtns., 800 m ( UPNG 8135 ) .

REMARKS: The specimen from the Adelbert Mtns., collected by James Menzies on Nov. 14, 1988, resembles topotypic hooglandi closely in color and pattern. Its IN/SVL ratio is smaller than in other hooglandi , but other ratios are within ranges. The identity in color and pattern with other hooglandi leads me to associate it with that species.

Figures

Fig. 18. Holotype of Austrochaperina guttata, MCZ A92812, SVL 42.8 mm.

Fig. 31. Examples of Austrochaperina, Liophryne, and Sphenophryne. A. S. cornuta, AMNH A130544, adult. B. A. brevipes, AMNH A130534, SVL 21.9 mm. C. A. guttata, QM J67256, SVL 43.2 mm. D. A. macrorhyncha, MZB 3564, SVL 36.8 mm. E. A. rivularis, holotype, AMNH A130551, SVL 49.0 mm. F. A. palmipes, AMNH A130550, adult. G. L. similis, AMNH A130564, SVL 40.0 mm. H. A. derongo, MZB 3563, SVL 36.7 mm. Photos C, D, and H by S. Richards.

Fig. 20. Austrochaperina hooglandi, holotype, AMNH A77597, SVL 40.1 mm.