Austrochaperina blumi, 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 : 20-27

Austrochaperina blumi , new species Figure 9

HOLOTYPE: MZB 3562 , also tagged UPNG 9538 (field no. Blum l979-59), collected in July 1979 by J. Paul Blum at Kosarek, elevation 1400 m, Jayawijaya District , Irian Jaya, Indonesia. This locality is on the north slope of the central dividing range of Irian Jaya, west of Nipsan and northeast of Anguruk.

PARATYPES: All collected by J. Paul Blum in Jayawijaya District, Irian Jaya. AMNH A157795 , 157796 , UPNG 9529–9531 , 9534 , 9537 , same data as holotype ; UPNG 9514 , 9515 , Bime , 1500 m, May 1975 ; UPNG 9546–9548 , 9550 (C&S), Bime Valley , 1500 m, May 1975. See Referred Specimen, below .

ETYMOLOGY: I name this species for Dr. J. P. Blum in recognition of his important collections of frogs from Irian Jaya (e.g., Blum and Menzies, 1988).

DIAGNOSIS: The following characteristics, in combination, distinguish A. blumi from other Austrochaperina : size moderately small, maximum SVL about 26 mm; fingers with moderately large terminal discs (3rd finger disc/SVL 0.031 –0.040), only that of the first finger not broader than the penultimate phalanx; hands moderately large (HD/SVL 0.23–0.26).

DESCRIPTION OF HOLOTYPE: Adult female (ova 2.2 mm in diameter) with the following measurements and proportions: SVL 26.3, HW 9.0, TL 11.3, EY 3.05, EN 2.15, IN 2.8, third finger disc 1.0 (penultimate phalanx 0.6), fourth toe disc 1.0 (appears slightly shrunken; penultimate phalanx 0.6), HD 6.3, FT 11.3; TL/SVL 0.430, HW/SVL 0.342, EY/SVL 0.116, EN/SVL 0.082, IN/SVL 0.106, EN/IN O.768, FD/SVL 0.038, TD/ SVL 0.038, HD/SVL 0.240, FT/SVL 0.430.

Head relatively narrow; snout rounded, verging on truncate in dorsal aspect, high, rounded, and slightly projecting seen laterally; nostrils lateral, barely visible from above, widely separated but appearing close to tip of snout in lateral view; loreal region nearly vertical, shallowly concave, canthus rostralis rounded. Eyes moderately large, laterally placed and visible from beneath, EY greater than EN, interorbital span slightly greater than width of an eyelid. Tympanum small and indistinct, horizontal diameter of annulus less than one-half that of eye. Relative lengths of fingers 4> 3> 2> 1, first well developed, all with rounded, grooved terminal discs, that on first finger scarcely broader than penultimate phalanx, others better developed, disc on third finger about 1.7X width of penultimate phalanx; subarticular and inner metacarpal elevations low, round- ed, inconspicuous (fig. 56F). Toes unwebbed, relative lengths 4> 3> 5> 2> 1, all with rounded, grooved terminal discs, that on first toe scarcely broader than penultimate phalanx, others better developed, disc on fourth toe about 1.7X width of penultimate phalanx and equal to disc on third finger but apparently a bit dried and shrunken; subarticular elevations low and rounded, slightly more evident than those on fingers, a low, rounded, elongate inner metatarsal tubercle, no outer (fig. 56F). Dorsal surface of body nearly smooth, a slightly raised midvertebral line and a shallow fold from posterior corner of eye across upper edge of tympanum to forelimb insertion, no other conspicuous folds on dorsum; venter smooth.

The dorsal surfaces of head, body, and limbs are pale tan with numerous small, somewhat darker, irregular spots. The end of the snout and the upper loreal region are darker than the dorsal ground color, and there is a hint of this darker color on the postocular fold. The lips are pale with darker spotting. The groin and anterior and upper posterior surfaces of the thighs are dusky. The lower posterior surfaces of the thighs are colored and patterned like the dorsum, but with a pal- er ground color and more conspicuous spotting. There is no dark seat patch. The ventral ground color is pale tan, almost white, with numerous small, slightly darker spots on the throat and chest and a sparser scattering of these on the abdomen. The soles are dark and unspotted.

VARIATION IN TYPE SERIES: Averages and ranges of selected proportions are in table 2, and regression statistics are in table 3. The largest of 13 specimens is the holotype, a gravid female 26.3 mm SVL. Females at 22.1 and 22.9 mm are possibly immature, but one of 22.7 mm is gravid and other larger individuals are mature. Four males 22.6 to 24.4 mm SVL have vocal sac openings and thus are presumably mature.

Except for minor differences, the description of the holotype could stand for the other specimens as well. The dorsal surfaces are not always as smooth as in the holotype, but may bear a scattering of inconspicuous, tiny warts. In 11 of 13 specimens the disc on the fourth toe is slightly but distinctly broader than on the third finger, and in one of the exceptional cases the toe disc appears to be shrunken. There is no significant variation in color or pattern.

ILLUSTRATIONS: 3rd finger terminal phalanx, fig. 71L; premaxilla, fig. 64C; sacral region, fig. 73E; vomer, fig. 65K; hands and feet, fig. 56F.

CALL: This has not been described.

COMPARISONS WITH OTHER SPECIES: The description and illustration of Chaperina punctata van Kampen (here considered a synonym of Austrochaperina macrorhyncha ) resemble Austrochaperina blumi in several respects, and the type series of punctata comes from the upper reaches of the Lorentz River, not greatly distant (though across the central divide) from the localities for blumi . The most striking difference between blumi and macrorhyncha is their size. The largest of 14 blumi is only 26.3 mm SVL, and both males and females of less than 23 mm are mature. In contrast, macrorhyncha matures at about 30 mm and reaches 36.8 mm.

Three species that resemble blumi in most proportions are A. gracilipes , A. novaebritanniae , and A. yelaensis . These are smaller species reaching maximum size at 22–23 mm SVL, whereas this is approximately the minimum size at maturity of blumi . In addition, blumi has relatively larger finger discs (table 3). The species are widely separated geographically, with novaebritanniae and yelaensis being insular and gracilis being an Australian species found also in the southern lowlands of Papua New Guinea.

REFERRED SPECIMEN: A single specimen from western Papua New Guinea agrees with the type series in most respects, although it has slightly larger EN and HW measurements and a greater IN than do others of similar size. I tentatively refer this specimen to this species, but exclude it from paratype status because of its geographic remoteness (some 250 km east of the localities in Irian Jaya) and because I had no opportunity to compare it directly with the specimens from Irian Jaya.

HABITAT AND HABITS: Dr. Harold Cogger (personal commun.) found the referred specimen, a male, on an egg mass in a fissure in a clay bank in a regrowth area.

DISTRIBUTION: The type-series localities for Austrochaperina blumi lie at 1400–1500 m on the north slope of the central dividing range of Irian Jaya (fig. 10).

LOCALITY RECORDS AND SPECIMENS EXAMINED: Localities of the holotype and paratype specimens are cited above. The referred specimen, AMS R127758 , has the following data: Papua New Guinea: West Sepik Prov. ; ca 2 km W Atemkinkin Village , itself ca 7 km W Telefomin, 141°34′E, 05°06′S, collected April 13, 1987 .

REMARKS: Dr. Blum noted the native names for this frog as ‘‘tanaofoge’’ at Kosarek and ‘‘calap’’ at Bime Valley.

Austrochaperina brevipes (Boulenger) ,

new combination

Figures 11 , 31B

Liophryne brevipes Boulenger, 1897: 11 (type locality, ‘‘ Mount Victoria , Owen Stanley Range, New Guinea ’’; holotype, BMNH 1947.2 .12.50, formerly 1896.10.31.31, collected by A. S. Anthony; see account of Liophryne rhododactyla for information on locality and date of collection).

Sphenophryne brevipes : Parker, 1934: 158 (first use of combination).

TYPE MATERIAL: The holotype is in moderately good condition though somewhat fad- ed. It has not been sexed. Parker (1934) referred to it as juvenile, although from its size (20.5 mm SVL by my measurement, 22 mm by Parker’s earlier measurement) it could be an adult male or subadult female (see below). There are no paratypes. Measurements and proportions of the holotype are: SVL 20.5, TL 7.4, HW 8.4, HD 4.3, FT 8.2, EY 2.65, EN 1.69, IN 1.93; TL/SVL 0.361, HW/SVL 0.410, HD/SVL 0.210, FT/SVL 0.400, EY/ SVL 0.129, EN/SVL 0.082, IN/SVL 0.094, EN/IN 0.876. The finger and toe tips are too dried to be measured with accuracy.

DIAGNOSIS: Distinguished from most of its congeners by its relatively small digital discs: those of the fingers not (or scarcely) broader than the penultimate phalanges; those of the toes broader than on the fingers but still only slightly expanded. Austrochaperina kosarek has even less development of finger discs, with indistinct terminal grooves and only the disc of the third finger slightly expanded. Two species, A. aquilonia and A. mehelyi , have finger discs similar to those of brevipes but differ in body size and other proportions (see Comparisons).

MORPHOLOGY: A small (SVL up to 28 mm), stocky, relatively broad-headed frog (HW/SVL mean 0.412) with hind legs of moderate length (TL/SVL mean 0.408) and relatively large eyes (EY/SVL mean 0.123). Snout bluntly pointed to almost rounded seen from above, high and almost vertical but slightly rounded in profile; nostrils lateral, almost terminal in profile, scarcely visible from above; loreal region a moderately steep slope, canthus rostralis abrupt but not sharp. Eyes prominent, visible from beneath, upper lid about 60% of interorbital distance. Tympanum indistinct, horizontal diameter half that of the eye or less. Relative lengths of fingers 3> 4> 2> 1, first well developed, more than half the length of second; finger tips flattened and disclike with (except possibly the first) terminal grooves, equal in width to penultimate phalanges or scarcely broader (fig. 54B); subarticular and metacarpal elevations low, rounded, not at all obvious. Relative lengths of toes 4> 3> 5> 2> 1, all unwebbed and with flattened, grooved, slightly broadened terminal discs distinctly larger than those of fingers (fig. 54B); subarticular and inner metacarpal elevations low, rounded; no outer metacarpal elevation. A straight fold of skin diagonally downward from posterior corner of eye, touching upper edge of tympanum and becoming obscure on flank. Dorsal surfaces of hind legs somewhat warty; a few scattered, small protuberances on back; ventral surfaces smooth.

COLOR AND PATTERN: Dorsal surfaces of preserved specimens range from pale yellowish tan to dark grayish brown, more often tending to the darker shades. Usually there is little dorsal pattern except for a thin, pale, midvertebral line that is always at least partly evident. There may be a few dark spots, often associated with small warts. Lumbar eye spots are present in a few specimens but are indistinct. The facial region, including upper and lower lips, is dusky but rarely dark enough to produce a face-mask effect. A narrow area below the canthus rostralis is darkened, and a similarly situated dark band follows the postocular fold. Many individuals have a more or less distinct light line along the canthus rostralis. The ventral surfaces are mottled with brown on pale gray, more densely so on the chin and coarser under the hind limbs. A dark, triangular area has its apex just below the vent.

The colors in life are not greatly different from those of the preserved specimens. A frog from Myola (field notes) was reddish brown on all dorsal surfaces with a yellow vertebral line. The loreal area was dark brown, almost black, and the chin, chest, and undersurfaces of hind limbs gray had lighter gray flecks, palms gray, and soles dark gray. The abdominal region is similar to the other ventral surfaces except for being somewhat translucent. Other individuals as seen in col- or photographs had a brown to yellowish brown dorsal ground color rather than reddish brown. The iris is golden above the horizontal pupil and dark gray elsewhere except for a gold spot beneath the pupil.

VARIATION IN SIZE AND PROPORTIONS: The largest specimen among 37 measured is a female 28.0 mm SVL. Females of 20.0 and 21.9 mm appear to be maturing, and others 21.9 mm or longer (n = 12) are adult. The largest of 18 males measures 23.9 mm. Specimens 18.3 mm and smaller lack vocal slits and thus presumably are immature, whereas those 19.7 mm and larger have slits. (See table 2 for statistics on proportions, and table 3 for regression data.)

ILLUSTRATIONS: 3rd finger terminal phalanx, fig. 71E; premaxilla, fig. 63D; hyoid, fig. 69B; sacral region, fig. 72D; vomer, fig. 65D; skull, fig. 67C; ear, fig. 60; hand and foot, fig. 57E.

CALL: The call is a series of short, harsh chirps uttered at intervals of one to several minutes (fig. 77E). Based on 20 tape-record- ed calls of six frogs (table 4), calls range from about 1.4 to 3.4 sec and include 20–37 notes, with each note being 0.03–0.05 sec long. Notes are pulsed, with 11–13 pulses in a note and the first two or three pulses more widely spaced than the remaining ones. The dominant frequency lies at 2900–3200 Hz. Note repetition rate ranges from 10.1 to 14.4 notes per sec. The expected positive correlation with temperature is evident: Calls of one frog recorded at 16.7°C had a mean of 14.3 notes per sec, whereas those of four others recorded at 12.5–12.9° averaged 10.4– 11.4 notes per sec. The correlation (negative) of duration with temperature is less close, and that of notes per call (positive) is even poorer.

COMPARISONS WITH OTHER SPECIES: Austrochaperina aquilonia and A. mehelyi resemble A. brevipes in disc proportions, although they have larger toe discs. Austrochaperina is distinguished by relatively shorter legs and longer eye-naris distance that, in combination, afford clear separation (fig. 2).

Austrochaperina brevipes is microsympatric with Liophryne similis and probably also with its sibling L. rhododactyla , larger species that otherwise look much like brevipes . Juvenile similis can easily be confused with brevipes , alive or preserved. The undersurfaces of similis tend to be more heavily pigmented, with the throat and chest appearing dark with light flecks in contrast to the paler, mottled pigmentation of brevipes . A narrow, pale vertical stripe on the snout of similis bifurcates at the level of the nares, whereas in brevipes the pale color of the top of the snout typically converges to a point below the level of the nares. These features, and the tendency for similis to have much darker loreal and postocular regions, should permit correct identification of questionable specimens. Confirming the sexual maturity of specimens in the problematic size range is also a helpful approach.

HABITAT AND HABITS: Austrochaperina brevipes lives on the floor of mossy montane rain forest. While collecting in August 1987 (Zweifel and Parker, 1989), we took most of our specimens from beneath logs during the daytime and found the balance at night as we searched through the leaf litter for calling individuals. We saw none active on the surface of the leaf litter, although such small frogs might easily be overlooked.

A male, SVL 23.9 mm SVL, was found associated with a clutch of 14 eggs (fig. 11) on the verge of hatching (most of the capsules ruptured when preserved). The dimensions of an intact egg (external capsule) are 5.8 X 5.2 mm. A female of 22.9 mm contained 10 well-yolked eggs about 2 mm in diameter.

DISTRIBUTION: Austrochaperina brevipes is known from only two localities 38 km apart: Mount Victoria and Myola Guest House in the Owen Stanley Mountains (fig. 42). It likely has a wider range in these mountains than is known at present, but it has not been taken in seemingly appropriate habitat in Morobe Province to the northwest, and it may be replaced by Oxydactyla crassa in mountains to the southeast.

LOCALITY RECORDS AND SPECIMENS EXAMINED: PAPUA NEW GUINEA: Central Prov. (?): Mt. Victoria ( BMNH 1947.2 .12.50, holotype). Northern Prov.: Myola Guest House, 2080 m, 7 km S, 6 km W Mt. Bellamy ( AMNH A130512–130523 , A130525– 130541 ; UPNG 7084–7091 , 8276 ). 4

REMARKS: This species, described in 1896, was known only from the type specimen until rediscovered by James Menzies at Myola Guest House in 1986.

Inasmuch as A. brevipes and L. rhododactyla are similar morphologically at the size of the holotype of brevipes , and the two species share a common type locality, I have considered the possibility that the holotype of brevipes may be a juvenile rhododactyla . In some measurements, in fact, the holotype does hew more closely to the rhododactyla regression lines. As the holotype has faded somewhat, the characters of pigmentation are not available. There is, however, no firm basis for identifying brevipes with rhododactyla . That Boulenger, with fresh specimens at hand, recognized a close affinity of the two but regarded them as distinct is sufficient reason for not complicating the nomenclature.

Figures

Fig. 9. Austrochaperina blumi, holotype, MZB 3562, SVL 26.3 mm.

Fig. 11. Austrochaperina brevipes, AMNH A130535, SVL 23.9 mm male and associated eggs.

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.