Spinomantis brunae ( Andreone et al., 1998 )

Cramer, Abigail F., Rabibisoa, Nirhy H. C. & Raxworthy, Christopher J., 2008, Descriptions of two new Spinomantis frogs from Madagascar (Amphibia: Mantellidae), and new morphological data for S. brunae and S. massorum, American Museum Novitates 3618 (3618), pp. 1-24 : 4-7

Spinomantis brunae ( Andreone et al., 1998)

Figures 1A–B , 2

Mantidactylus brunae Andreone et al., 1998 Spinomantis brunae: Glaw and Vences, 2006

HOLOTYPE: MRSN A1649 from between the villages of Isaka-Ivondro and Eminiminy, Andohahela Strict Reserve , Toliara (Tulear) Province , elevation about 600 m, 24 ° 45 9 30 0 S, 46 ° 51 9 15 0 E.

SPECIMENS EXAMINED: UMMZ 198404–11 ( RAN 36211, RAN 36241–3, RAN 36279, RAN 36375, RAN 36517, RAN 36540), collected 19–28 December 1990, at Ampamakiesiny Pass , Tolagnaro Fivondronana, Toliara Province, Madagascar, between 700– 800 m, 46.85 ° E, 2 24.53 ° S, by J.B. Ramanamanjato, A. Raselimanana, and C.J. Raxworthy .

DIAGNOSIS: A medium-sized Spinomantis (adult male SLV 32–35 mm), with type 2 femoral glands; vomerine teeth; a reticulated dorsal pattern composed of dark round spots on a lighter background; a dark throat with light spots; a singular subgular vocal sac in males; inner and outer metatarsal tubercles; SVL/FT $ 1.4; webbing formula I 0.5 to 1 – 0.75 to 1 II 0 to 0.5 – 1 to 1.5 III 0.5 to 1 – 2 IV 2 – 0.25 to 0.75 V; and no dermal spines on fore or hind limbs (table 1).

Spinomantis brunae can be distinguished from all other Spinomantis species by the following characters. S. aglavei , S. fimbriatus , S. massorum , S. tavaratra sp. nov., and S. phantasticus all have hind limb dermal spines that are absent in S. brunae . Spinomantis bertini is much smaller (males SVL 22– 23 mm), and has only rudimentary webbing on the hind feet. Spinomantis elegans and S. microtis are larger (male SVL 34–60 mm) and males lack femoral glands. In addition, S. elegans lacks an outer metatarsal tubercle, and S. microtis has completely webbed feet. Spinomantis guibei has distinctive markings: the ventral limbs are white with black blotches, and the dorsal body has longitudinal dark lines (both marking features absent in S. brunae ). Spinomantis guibei also has more reduced webbing: the 4th internal toe has 3 phalanges without webbing compared to 1–2 for S. brunae . Spinomantis nussbaumi sp. nov., and S. peraccae can be distinguished from S. brunae by their large adult male body size (SVL 35–57 mm); throat color ( S. nussbaumi sp. nov. brilliant white with dark spots, S. peraccae pale yellowish white with or without dark spots); and smaller foot in relation to body size ( S. nussbaumi sp. nov. and S. peraccae SVL /FT # 1.4).

DESCRIPTION OF UMMZ 198411: Adult male in an excellent state of preservation with a singular subgular vocal sac, distinct femoral glands, and mature testes, measuring 6.0 X 0.9 mm, and whitish yellow in color.

Head dorsally finely granular and lacking an interocular longitudinal ridge. Head 1.18 times wider than long. Head length 0.32 times SVL. Canthus rostrum with a rounded edge. A weak ridge starts posterior to nostril and runs through the loreal region to the lower anterior eye orbit. Internarial distance 0.30 times head width. Nostrils open laterally. Pupil round. Eye to nostril distance 1.87 times nostril to snout distance and 0.86 times eye diameter. Tympanum well defined, diameter 0.61 times eye diameter. Supratympanic ridge arches smoothly from posterior of eye to above the forelimb insertion point. Vomerine teeth present, vomerine bone triangular in shape.

Arms slender and smooth with forearm length 0.24 times SVL. No dermal spines on arms, legs, or body. Hand length (including disks) 0.32 times SVL and free of webbing. Relative finger lengths 1, 2, 4, 3. Fingers and toes with enlarged, triangular disks. Disk of third toe two times wider than terminal phalange. Body dorsally granular. Flanks and belly weakly granular. No enlarged tubercles on body or around anal region.

Tibio-tarsal extension reaches past snout. Thigh length 0.51 times SVL. Ventral surface of thigh granular, and all other leg surfaces smooth. Type 2 oval femoral glands clearly differentiated and distended, measuring 8.7 X 3.5 mm, separated by 0.8 mm. Approximately 90 granules with no central pore visible in external view. Approximately 300 touching granules in internal view. Granules translucent with opaque centers. Lower leg 0.55 times SVL. Foot, including tarsus, 0.73 times SVL. Inner and outer metatarsal tubercles present on foot, with round outer metatarsal tubercle 0.4 mm in diameter and elliptical inner metatarsal tubercle 1.3 mm in length. Relative toe lengths 1, 2, 3, 5, 4. Foot webbing I 1 – 1 II 0.5 – 1.25 III 0.75 – 2 IV 2 – 0.75 V.

COLORATION IN PRESERVATIVE: Head and dorsum pale brown, with a reticulated pattern of dark brown spots (approximately the diameter of the tympanum) closely spaced together. Iris dark brown. Tympanum light brown. Flanks dark brown with light brown small spots. Arms with five dorsal dark brown transverse stripes of uneven width. Legs light brown with 12 dark brown transverse stripes of uneven width. Some of the broader pale brown bands contain within them additional darker brown blotches. In the natural resting posture, the dorsal stripes on the hind limbs line up to form three longitudinal stripes. Ventral arms and legs light brown. Throat light brown with yellowish-white spots. Venter brown. Femoral glands light brown in external view and yellowish white in internal view.

COLORATION IN LIFE: The dorsal pale brown coloration (in preservative) is olive green in life, and the pale flank spots are white in life. The digit and toe pads are each marked

TABLE 1 Morphometric data for Spinomantis brunae . All measurements in mm. MRSN specimen data from Andreone et al., (1998).

with a pair of white spots. The iris is creamy white in color.

VARIATION: Morphometric variation is summarized in table 1, which includes the holotype. All specimens agree with the description of UMMZ 198411 with the following exceptions. Femoral glands vary in size from 8.5–9.1 mm in length and 3.4–3.7 mm width, separated by 0.8–1.3 mm, with approximately 75–110 granules visible in external view. Inner metatarsal tubercle range from 1.2–1.4 mm in length. Foot webbing variation: I 0.5 to 1 – 0.75 to 1 II 0 to 0.5 – 1 to 1.5 III 0.5 to 1 – 2 IV 2 – 0.25 to 0.75 V. The holotype END and NSD measurements given by Andreone et al. (1998) are not within the range of the adult males examined by us (see table 1), possibly due to difference in measurement methodology.

Characters of adult females are unknown. Juveniles UMMZ 198404 and 198406 have poorly defined supratympanic ridges, yellowish-white venters in preservation, and a dorsal pattern of reticulate spots that are not as closely spaced together compared to the adult coloration.

DISTRIBUTION: Known only from humid forests in the Anosy Mountains, SE Madagascar, between 600–800 m elevation.

REMARKS: One UMMZ specimen was collected during the day (1100 hours) on a leaf, but all others were collected at night (2100–2300 hours) on leaves, branches, or rocks. All specimens were found in close proximity to small fast-flowing streams, in areas with large to massive rock boulders and rock crevices at the waters edge. One male (RAN 36729, UMMZ 198408) was found vocalizing at 2100 hours on a branch at 0.5 m height off the ground by a small stream. The call is a short one-second pulse, sounding like a rapid metallic trill, which is repeated every 5–10 seconds.

Figures

Fig. 1. Photos of selected live Spinomantis species. A. Spinomantis brunae, UMMZ 198405, Ampamakiesiny Pass (photo: C.J. Raxworthy). B. S. brunae, UMMZ 198407, Ampamakiesiny Pass (photo: C.J. Raxworthy). C. S. massorum, UMMZ 212362, Antsahabe River, Manongarivo Special Reserve (photo: C.J. Raxworthy). D. S. massorum, AMNH A167941, Ramena River, Tsaratanana Strict Nature Reserve (photo: C.J. Raxworthy). E. S. tavaratra, new species, AMNH A167937, Sorata Mountain (photo: C.J. Raxworthy). F. S. aglavei, UMMZ 212374, Andringitra Strict Nature Reserve (photo: C.J. Raxworthy).

Fig. 2. Localities for the new and redescribed Spinomantis species.