Spinomantis massorum

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 : 7-10

Spinomantis massorum

( Glaw and Vences, 1994)

Figures 1C–D , 2 , 3

Mantidactylus massi Glaw and Vences, 1994 Mantidactylus massorum: Vences et al., 2003 Spinomantis massorum: Glaw and Vences 2006

HOLOTYPE: ZFMK 57442 from Benavony

(near Ambanja), about 300 m altitude.

SPECIMENS EXAMINED: AMNH A167938– 39 ( RAX 2865 , 2959 ), collected 11–12 April 2001 , at Ramena River Camp, Tsaratanana Reserve, Ambanja Fivondronana , Antsiranana Province, 740 m, 13 ° 55 9 04 0 S, 48 ° 53 9 16 0 E, by S.D. Mahaviasy, N. Rabibisoa, C.J. Raxworthy, A. Razafimanantsoa, and A. Razafimanantsoa ; AMNH A167940–41 ( RAX 2965–66 ) as AMNH A167938 , except 12 April 2001 , 1150 m; AMNH A167942–45 ( RAX 3190 , 3238–39 , 3298 ), collected 15–19 April 2001 , at Antsaravy Ridge, Tsaratanana Reserve, Ambanja Fivondronana , Antsiranana Province, 1050–1200 m, 13 ° 55 9 34 0 S, 48 ° 54 9 21 0 E, by S.D. Mahaviasy, N. Rabibisoa, A. Razafimanantsoa, and A. Razafimanantsoa ; AMNH A167946 ( RAX 6581 ), collected 2 April 2003 at Irony River Relict Forest, Antsohihy Fivondronana , Mahajanga Province, 950 m, 14 ° 45 9 8 0 S, 48 ° 29 9 41 0 E, by S.D. Mahaviasy, N. Rabibisoa, and C.J. Raxworthy ; UMMZ 212358–63 ( RAN 39379–80 , 39434–37 ), collected 1–4 March 1992 at Antsahabe River, Manongarivo Reserve, Ambanja Fivondronana , Antsiranana Province, 650 m, 48.342 ° E 14.433 ° S, by J.B. Ramanamanjato, A. Raselimanana, and C.J. Raxworthy .

DIAGNOSIS: A medium-sized Spinomantis (adult male SLV 33–42 mm), type 2 femoral glands in adult males; vomerine teeth; no dark markings on throat or venter; a singular subgular vocal sac in males; adult NSD. 2.1 mm, inner and outer metatarsal tubercles; a tibio-tarsal extension that reaches between the eye and nostril, 1–2 phalanges free of webbing on the exterior 4th toe; and simple dermal spines, 1 mm in length (table 2).

Spinomantis massorum can be distinguished from the following species: S. peraccae , S. brunae , S. elegans , S. microtis , S. bertini and S. nussbaumi sp. nov. by the presence of dermal spines on the tarsus. Spinomantis massorum can be distinguished from S. phantasticus by the lack of supraocular dermal spines $ 0.5 mm and lack of other prominent spines on the head or dorsum. Spinomantis massorum can be distinguished from S. aglavei and S. fimbriatus by adult dermal spines on its hind limbs that do not exceed 1 mm in length ( Glaw and Vences, 1997); and lacking dermal spines with multiple points. Spinomantis massorum can be distinguished from S. tavaratra sp. nov. by a lack of markings on venter and

TABLE 2 Morphometric data for Spinomantis massorum . All measurements in mm. ZFMK specimen data from Glaw and Vences (1994, 1997).

throat ( S. tavaratra sp. nov. with dark spots on venter and throat); a longer adult snout ( S. massorum with NSD. 2.1 mm; S. tavaratra sp. nov. NSD, 2 mm); a tibio-tarsal extension that reaches between the eye and nostril ( S. tavaratra sp. nov. tibio-tarsal extension may extend past snout); and more developed webbing on toe 4 ( S. massorum 0.75 to 2: IV: 1 to 2; S. tavaratra sp. nov. 2 to 2.5: IV: 2 to 2.5).

DESCRIPTION OF AMNH A167944: Adult male in an excellent state of preservation with a singular subgular vocal sac, distinct femoral glands, and mature testes, measuring 2.2 X 1.0 mm, and whitish yellow in color. The skin, femoral gland, and muscle have been removed from the right thigh for a tissue sample.

Head width 1.33 times wider than long, head length 0.30 times SVL. Canthus rostrum with a rounded edge. Scattered tubercles on the snout and dorsal posterior regions of the head. A weak ridge starts posterior to nostril and runs through the loreal region to the lower anterior eye orbit. Internarial distance 0.29 times head width. Nostrils open laterally. Pupil round. Eye to nostril distance 1.74 times nostril to snout distance and equal to eye diameter. Tympanum well defined, diameter 0.43 times eye diameter. Supratympanic ridge present and broken, arching unevenly from posterior of eye to above mouth corner. Vomerine teeth present, vomerine bone elliptical in shape.

Arms slender and smooth with forearm length 0.25 times SVL, with four dermal spines up to 0.2 mm in length forming a line from elbow to wrist. Hand length (including disks) 0.36 times SVL with a trace of webbing between digits, never extending beyond basal phalange. Relative finger lengths 1, 2, 4, 3. Fingers and toes with enlarged triangular disks. Disk of third toe 1. 7 times wider than terminal phalange. No dermal spines on body. Dorsum and flanks weakly granular. Venter weakly granular. Four enlarged tubercles positioned ventral to the cloaca.

Tibio-tarsal extension reaches between eye and snout. Thigh length 0.55 times SVL. Dorsal hind limbs with weakly developed tubercles, and smooth ventrally. Clearly differentiated and distended type 2 oval femoral glands, measuring 9.5 X 2.5 mm, and separated by 1.7 mm. Externally each gland includes approximately 120 granules with no central pore. Internally there are approximately 120 opaque centered granules in contact with each other. Lower limb 0.56 times SVL. On the posterior surface of the tarsus to fifth toe there are eight simple dermal spines, measuring,1.0 mm in length. Foot, including tarsus 0.77 times SVL. Ventral foot granular. Inner and outer metatarsal tubercle, with round outer metatarsal tubercle 0.4 mm in diameter and elliptical inner metatarsal tubercle 2.1 mm in length. Relative toe lengths 1, 2, 5, 3, 4. Foot webbing I 0.75 – 1 II 0 – 1.25 III 0.5 – 2 IV 2 – 0.75 V.

COLORATION IN PRESERVATIVE: Head dorsally and laterally brownish yellow with a dark brown transversal intraocular stripe and a brown blotchy band on the supratympanic ridge and canthus rostrum. Lower lip bordered by small dark brown spots. Iris dark brown. Dorsum brownish yellow, with a dark brown ‘‘W’’ marking on the shoulder region, and an isolated brown spot in the middle of the back. Posterior dorsal pelvic region marked with four dark brown spots forming an approximate square pattern. Flanks yellowish white with a brown blotchy dorsolateral line. Arms brownish yellow with four dorsal dark brown transverse stripes of uneven width. Legs brownish yellow with nine dark brown transverse stripes of uneven width. When in sitting posture, dorsal stripes on the hind limbs line up, forming three longitudinal stripes. Dermal spines pale yellow. Throat and ventral body yellowish white and unspotted. Ventral arms yellowish white. Ventral thigh light brown, which fades to yellowish white on the lower limb. Femoral glands yellowish white in external and internal view.

COLORATION IN LIFE: The iris is creamy white in color, with a brown border that includes short bars radiating in toward the pupil. Surrounding the brown border is a thin green iris ring. The dorsal body coloration includes green pigment in areas that are brownish yellow in preservation. The lower flanks and groin area have silvery blotches. The hind limb dermal spines are white.

VARIATION: Morphometric variation is summarized in table 2. All specimens agree with AMNH A167944 with the following exceptions. The vomerine bone of all other specimens is triangular in shape. Dermal tubercles ventral to the vent may be absent (AMNH A167938). Femoral glands vary in size from 8.2–11.3 in length and from 2.4 to 3.9 mm width, separated by 1.7 to 4.7 mm, with approximately 50 to 120 granules visible in external view. Inner metatarsal tubercle range from 1.2 to 1.6 mm in length. Foot webbing variation: I 0 to 1 – 0.75 to1.25 II 0 to 0.5 – 1 to 1.5 III 0 to 1 – 0.75 to 2 IV 1 to 2 – 0.25 to 1 V. Female AMNH A167943 lacks femoral glands. Juveniles AMNH A167939– 42, and A167945–46 lack femoral glands but have fore- and hind limb dermal spines present similar in number, placement, and size to those of adults.

DISTRIBUTION: Known only from humid forests in NW Madagascar, in the Sambirano Region, between 300–1200 m elevation.

REMARKS: This species was found active at night between 2000–2100 hours, on leaves, vertical rock surfaces, branches, and tree trunks, up to 2.5 m height above the forest floor, but always at the edges of small streams or rivers. Three specimens were also found during the day by streams: one crouched on a rock surface, and the other two found among grass on the ground.

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.

Fig. 3. Spinomantis massorum and S. tavaratra, new species. A. Dorsal views of S. massorum (above, left to right): AMNH A167944, 167938, UMMZ 212359; and S. tavaratra, new species (below, left to right): AMNH A167935, 167933, 167936. B. Ventral views of S. massorum (above, left to right): AMNH A167944, 167938; and S. tavaratra, new species (below, left to right): AMNH A167935, 167933.