Holotype.—

ZSM 601/2001, adult male, collected by M. Vences, F. Andreone, F. Mattioli and J. E. Randrianirina on 30 January 2001, in a plantation at the edge of the Sambirano river, approximately 200 m upstream from Antsirasira (on the river side opposite to the larger village of Marovato), Marovato Fivondronana, Antsiranana Faritany (Diégo Suarez Province), northwestern Madagascar (13°56′22″S, 48°33′16″E, less than 100 m above sea level; Figs. 1–2).

Paratypes.—

MRSN A2066 and ZSM 600/2001 (Fig. 3), two adult females, same locality and collecting data as holotype; ZFMK 76103 and ZSM 603/2001–607/2001, five adult males and one adult female, collected by M. Vences on 12 February 2001 at the type locality.

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Diagnosis.—

A member of Mantidactylus based on absence of nuptial pads and presence of distinct femoral glands in males. Assigned to the M. domerguei group in the subgenus Blommersia based on (1) small size (SVL < 20 mm), (2) white single subgular vocal sac, (3) patchlike femoral glands in males (absent in females), intermediate between type 1 and 2 (Glaw et al., 2000a), (4) short relative hand length (21–27% of SVL), (5) relatively small tympanum diameter (< 80% of eye diameter) without sexual dimorphism. From the six other known representatives of the M. domerguei group (see Glaw and Vences, 1994, 2002), it is distinguished as follows: (1) from M. wittei by completely connected lateral metatarsalia (vs separated), presence of a white frenal stripe continued onto the flanks (vs absence), small body size (SVL of males 11–13 mm vs 22–25 mm), short fourth finger (not longer than second finger vs distinctly longer than second finger), absence of webbing between toes (vs presence) and absence of vomerine teeth (vs presence); (2) from M. grandisonae by completely connected lateral metatarsalia (vs separated), small body size (SVL of males 11–13 mm vs 18–23 mm); a silvery white throat (vs yellowish), absence of webbing between toes (vs presence), and a short fourth finger (not longer than second finger vs distinctly longer than second finger); (3) from M. kely by presence of a white frenal stripe continued onto the flanks (vs absence), smaller body size (SVL of males 11–13 mm vs 14–16 mm), absence of a yellowish middorsal stripe (vs presence), smooth dorsal skin (vs granular), and a short fourth finger (not longer than second finger vs distinctly longer than second finger); (4) from M. domerguei by presence of a white frenal stripe continued onto the flanks (vs absence), smaller body size (SVL of males 11–13 mm vs 15–17 mm) , a silvery white throat (vs not white), absence of longitudinal dark markings on the dorsum (vs presence), and a short fourth finger (not longer than second finger vs distinctly longer than second finger); (5) from M. blommersae by presence of a white frenal stripe continued onto the flanks (vs absence), absence of webbing between toes (vs presence), smaller body size (SVL of males 11–13 mm vs 18–21 mm), a silvery white throat (vs not white), and a short fourth finger (not longer than second finger vs distinctly longer than second finger); (6) from M. sarotra by complete absence of webbing between toes (vs presence of rudiments), smaller body size (SVL of males 11–13 mm vs 15–17 mm), and a short fourth finger (not longer than second finger vs distinctly longer than second finger).

Description of the holotype.—

Specimen in good state of preservation. Part of right tibia removed as tissue sample for genetic analysis. SVL 11.9 mm. For measurements, see Table 1. Body slender; head distinctly longer than wide, not wider than body; snout slightly rounded in dorsal and lateral views, nostrils directed laterally, not protuberant, nearer to tip of snout than to eye; canthus rostralis indistinct, straight; loreal region straight; tympanum distinct, rounded, 67% of eye diameter; supratympanic fold indistinct; tongue ovoid, slightly notched posteriorly but not bifid; vomerine teeth absent, maxillary teeth rudimentary; choanae rounded. Arms slender, distinct single subarticular tubercles; inner and outer metacarpal tubercles distinct; fingers without webbing; relative length of fingers 1<4<2<3, fourth finger slightly shorter than second finger; finger disks slightly enlarged; nuptial pads absent. Hind limbs relatively robust; tibiotarsal articulation reaches center of eye when the hind limb is adpressed along the body; lateral metatarsalia connected; inner metatarsal tubercle small, outer metatarsal tubercle indistinct; webbing between toes absent; relative length of toes 1<2<5<3<4. Skin on the dorsal surface smooth, without folds or ridges. No distinct enlarged tubercles in the cloacal region; ventral skin uniformly smooth. Femoral glands distinct in life but not easily recognizable in alcohol.

Table 1.  Morphometric Measurements (All in Millimeters) of Holotype and Paratypes of Mantidactylus madinika. For abbreviations of measured variables, see Materials and Methods. Further abbreviations used: M (male); F (female); HT (holotype); PT (paratype); RHL (relative hind-limb length: point reached by tibiotarsal articulation when the hind limb is adpressed along the body)

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Coloration of the holotype (Figs. 1–2).—

In life, the dorsum was light brown, with a distinct border toward the grayish brown flanks. A grayish X-shaped marking was present on the anterior portion of the dorsum, and an inversed V-shaped marking on the posterior portion of the dorsum. The head was brown laterally with an indistinct whitish frenal stripe running toward the insertion of the forelimb. On the flanks, the color became lighter toward the inguinal region, and several well-delimited black spots were present. A pair of larger blackish spots was also present on the posterior portion of the dorsum close to the inguinal region. The limbs were light brown dorsally, with dark marbling and indistinct dark crossbands. The iris was light brown in its upper half and dark brown in its lower half. The ventral skin was translucent, but the belly appeared silvery because of subcutaneous pigment. The throat was silvery white.

After about five months in preservative, the dorsum was grayish brown with indistinct darker markings, especially on the flanks. Dark crossbands were present on thigh, shank, foot, upper arm, and hand. The ventral surface was uniformly yellowish white; a line of white markings ran along the flanks, separating dorsal from ventral coloration and was continued into a white frenal stripe.

Variation.—

The female paratypes are larger than the available males. Female SVL is 14.7–15.6 mm (mean 15.0 mm), male SVL is 11.3–12.5 mm (mean 11.9 mm). The male paratypes are similar to the holotype in morphology and coloration. In life, the frenal stripe is sometimes prolonged along the entire flank. In females, the frenal stripe is much more distinct, the dorsum is sometimes reddish brown, and no white color is present on the throat. The yellow oocytes are visible through the skin of the belly.

In the male ZSM 605/2001, the femoral gland in internal view (after dissection and reflection of skin; Glaw et al., 2000a) is an ill-defined, ovoid patch of 3.9 × 1.6 mm, consisting of ca. 100 small granules of variable size. The unusual relative finger length of the holotype (fourth finger shorter than second) is not homogeneous in the available sample, but in all specimens, these two fingers are at least of the same length. The state typical for most other Mantidactylus species (also observed in all specimens of M. sarotra examined), in which the fourth finger is distinctly longer than the second finger, is not seen in any M. madinika.

Etymology.—

The name is derived from madinika, meaning small in Malagasy language and referring to the diminutive body size of the species. The name is treated as a noun in apposition to the generic name.

Natural history.—

All specimens of M. madinika were captured in the vicinity of a small pond in a plantation of large trees and scattered cacao plants. The site was only about 100 m from the Sambirano River, but no brook suited for anuran reproduction was nearby. No plants used by phytotelmic breeders were seen (Pandanus, Ravenala). It can therefore be concluded that M. madinika probably reproduces in the pond which was also used by Mantidactylus wittei, Mantella betsileo, Dyscophus cf. insularis, and Boophis tephraeomystax. Furthermore, numerous Stumpffia cf. gimmeli were found in the leaf litter. Although M. wittei were mostly found in the immediate pond surroundings, specimens of M. madinika were most frequent in the leaf litter of a flat area prone to flooding. They were collected both during day and night. At night, one male was seen to emit feeble chirps by slight inflation of its single subgular vocal sac. The female MRSN A2066 contained 28 yellowish oocytes of 0.9 mm in diameter as ascertained by dissection.