Mantidactylus madecassus ( Millot & Guibé, 1950 )

Scherz, Mark D., Crottini, Angelica, Hutter, Carl R., Hildenbrand, Andrea, Andreone, Franco, Fulgence, Thio Rosin, Köhler, Gunther, Ndriantsoa, Serge Herilala, Ohler, Annemarie, Preick, Michaela, Rakotoarison, Andolalao, Rancilhac, Loïs, Raselimanana, Achille P., Riemann, Jana C., Rödel, Mark-Oliver, Rosa, Gonçalo M., Streicher, Jeffrey W., Vieites, David R., Köhler, Jörn, Hofreiter, Michael, Glaw, Frank & Vences, Miguel, 2022, An inordinate fondness for inconspicuous brown frogs: integration of phylogenomics, archival DNA analysis, morphology, and bioacoustics yields 24 new taxa in the subgenus Brygoomantis (genus Mantidactylus) from Madagascar, Megataxa 7 (2), pp. 113-311 : 189-190

Mantidactylus madecassus ( Millot & Guibé, 1950)

Type material.—The taxon Racophorus [misspelling of Rhacophorus in the original description] (Philautus) madecassus Millot and Guibé, 1950 is based on the lectotype MNHN 1953.246 from ‘ Andringitra: Cirque Boby (altitude: 2.520 métres)’, designated by Vences and Glaw (1999). The eight paralectotypes, all from the same locality, are numbered MNHN 1989.3590–3597 .

Identity.— Mantidactylus madecassus is a morphologically distinct and apparently microendemic species restricted to high elevations on the Andringitra Massif. Its identity has been unambiguously assessed by Vences and Glaw (1999) based on morphology, and is here confirmed by a 16S sequence obtained from the lectotype, MNHN 1953.246.

Diagnosis.—A member of the M. curtus clade and sister to M. ambohimitombi from which it strongly differs morphologically. See Table 4 for a list of diagnostic morphological characters. The combination of a body size of 27–34 mm ( Table 5 ), smooth dorsal skin without dorsolateral ridges, strongly expressed foot webbing with almost fully webbed fifth toe, small tympanum size in males (7–10% of SVL), vomerine teeth absent, and especially, the bilobed subarticular tubercles (unique in Mantidactylus madecassus and illustrated by Vences & Glaw 1999) distinguishes this species from species of the other clades in Brygoomantis . Within the M. curtus clade, this high-elevation endemic differs from all species by its double or rather bilobed subarticular tubercles, and from all species exept M. curtus , M. pauliani , and M. ambohimitombi marefo , by a conspicuously short snout in many specimens. The species is an endemic to high elevations on the Andringitra Massif, where at slightly lower elevations, also M.bourgati occurs;a distinction from that species can readily be achieved by the combination of bilobed subarticular tubercles, shorter snout, usually smaller size and smoother skin, as well as more uniform silvery-whitish ventral colour in M. madecassus . For detailed distinction from new species described herein, see the respective species accounts. A full list of molecular diagnostic sites in the 16S gene of M. madecassus in pairwise comparisons to all other Brygoomantis species is provided as Supplementary appendix.

Variation.—Variation in measurements is given in Table 5 . See Fig. 19 for colouration in life and its variation. There is weak sexual size dimorphism (confirmed male SVL 27.0– 29.8 mm [n = 2] vs confirmed female SVL 29.3–33.7 mm [n = 5]). For a more detailed discussion of this species’ morphology and a morphometric comparison to M. pauliani , see Vences and Glaw (1999). Relative tympanum size is larger in males than in females ( Vences & Glaw 1999). Femoral glands in males include a distal ulcerous macrogland only, and rudimentary glands are also present in females.

Natural history. —Specimens were found in small, cold, clear mountain streams at high elevations of the Andringitra Massif. They were sitting in the water, especially in shallow side puddles next to the canal-like streams, at night.

Calls.—The call of this species has not been recorded.

Tadpoles.— The tadpole of M. madecassus was described by Thomas et al. (2005).

Distribution.— Apparently microendemic to high elevations on the Andringitra Massif ( Fig. 7 ). Elevation range: ~ 2488 m a.s.l.

Etymology.—Latin adjective referring to the occurrence of the species in Madagascar.

Figures

FIGURE 7. Mantidactylus subgenus Brygoomantis species distribution based on verified records, divided by clade (Mantidactylus stelliger sp. nov. is presented alongside the inaudax clade for practicality). Colours for species correspond to those in Figs 2 and 4. Inset map shows the geographic regions of Madagascar identified by Boumans et al. (2007), referred to throughout the text.

FIGURE 19. Mantidactylus madecassus in life, in dorsolateral and ventral view, and their habitat. (a) Adult specimen (unsexed) from Cuvette Boby, Andringitra Massif, photographed in 1994. (b,c) Adult specimen (ZSM 755/2001 = FGMV 2001.538; unsexed) from Cuvette Boby, Andringitra Massif, photographed in 2001, and (d) closeup of ventral surface of its hand showing the bilobed subarticular tubercles (yellow arrows). (e) Pond at Cuvette Boby, habitat of M. madecassus. (f) Landscape at Cuvette Boby.