Guibemantis fotsitenda, Koppetsch & Pabijan & Hutter & Köhler & Gehring & Rakotoarison & Ratsoavina & Scherz & Vieites & Glaw & Vences, 2023

Koppetsch, Thore, Pabijan, Maciej, Hutter, Carl R., Koehler, Joern, Gehring, Philip-Sebastian, Rakotoarison, Andolalao, Ratsoavina, Fanomezana M., Scherz, Mark D., Vieites, David R., Glaw, Frank & Vences, Miguel, 2023, An initial molecular resolution of the mantellid frogs of the Guibemantis liber complex reveals three new species from northern Madagascar, Vertebrate Zoology 73, pp. 397-432 : 397

Guibemantis fotsitenda sp. nov.

Fig. 9

Holotype.

ZSM 292/2005 (field number FGZC 2781), adult male, collected at 'Camp Mantella ' in Marojejy National Park (14.43767°S, 49.77555°E, 481 m a.s.l.), Sava Region, northeastern Madagascar on 14 February 2005 by F. Glaw, M. Vences and R.D. Randrianiaina.

Paratypes.

Five specimens: ZSM 291/2005 (field number FGZC 2780), adult male with same collection data as holotype; ZSM 289/2005 and 290/2005 (field numbers FGZC 2721-2722), as well as UADBA uncatalogued (FGZC 2723 and FGZC 2724), two unsexed specimens, all collected at a site in between Andrakata and Andapa (geographical coordinates not taken) on 13 February 2005 by F. Glaw, M. Vences and R.D. Randrianiaina.

Diagnosis.

This species corresponds to the mitochondrial lineage NE2 as defined herein. It is assigned to the subgenus Guibemantis Pandanusicola of the genus Guibemantis based on presence of intercalary elements between ultimate and penultimate phalanges of fingers and toes (verified by external examination), small body size, moderate to weakly expressed webbing between toes, connected lateral metatarsalia, the presence of both inner and outer metatarsal tubercles, femoral glands in males, absence of nuptial pads, small body size (SVL 25.1-26.0 mm in males; female size unknown), and molecular phylogenetic relationships. Within Pandanusicola , the new species is distinguished from all species except G. liber , G. razandry , G. razoky , and G. tasifotsy by femoral glands type 1 (vs. type 2) as defined by Glaw et al. (2000), thus possessing a large number of small gland granules in a relatively diffuse field covering most of the thigh ventrally, and by its probable breeding in open swamps (vs. phytotelmic breeding in Pandanus leaf axils). It can be distinguished from G. tasifotsy by its different brownish color pattern lacking a green dorsal and lateral coloration with series of distinct white blotches along the lower flanks. The new species differs from all G. liber lineages occurring in the Northern Central East and Southern Central East of Madagascar by its high DNA divergence> 5% in the mitochondrial 16S gene, and probably by a somewhat smaller snoutvent length. Guibemantis razoky (see above) has a larger body size (26.5-33.9 mm in males, vs 25.1-26.0 mm in males of G. fotsitenda ). Guibemantis razandry (see above) is the closest relative of G. fotsitenda sp. nov., and no obvious morphological differences between these two species are known, despite their clear divergence in mitochondrial and nuclear-encoded DNA in near-sympatry. The new species differs from G. liber , G. razandry , and G. razoky by 23, 23, and 50 diagnostic positions in the analyzed fragment of the cytochrome b gene, respectively (see Appendix 2 for a list of diagnostic sites).

Description of holotype.

Adult male in good state of preservation (Fig. 9 ). Pieces of muscle tissue removed from both left and right thigh for molecular analysis. SVL 25.5 mm. For full morphometric measurements see Table 1 . Body relatively slender; head slightly longer than wide, wider than body; snout slightly pointed in dorsal and lateral views, rounded in ventral view; nostrils much nearer to tip of snout than to eye and pointed anterolaterally; canthus rostralis relatively distinct, slightly concave; loreal region concave; tympanum distinct, relatively small, its diameter 60% of eye diameter; distinct supratympanic fold; tongue ovoid, distinctly bifid posteriorly; vomerine teeth as one weakly expressed rounded aggregation posterolateral of each choana; choanae small, rounded. Forelimbs slender; subarticular tubercles distinct and single; central metacarpal tubercle large and rounded, outer metacarpal tubercle smaller and oval; a small but indistinct prepollex (which could also be considered as an inner metacarpal tubercle) at base of first finger. Fingers without webbing; relative finger length I<II<IV<III; finger discs distinctly enlarged; nuptial pads absent. Outer toe and finger discs darker than inner toe and finger discs. Hind limbs long and slender; when adpressed along body, tibiotarsal articulation reaches center of eye; lateral metatarsalia connected by tissue; inner metatarsal tubercle distinct, larger than outer; outer metatarsal tubercle distinct; webbing formula of the foot 1(traces), 2i(traces), 2e(1), 3i(2.25), 3e(1.25), 4i(2.5), 4e(2.75), 5(1); relative toe length I<II<V<III<IV. Skin dorsally smooth; ventral skin smooth on throat and chest, slightly granular on belly. Femoral glands not intact due to tissue excision.

After sixteen years in preservative (70% EtOH; Fig. 9 ), dorsal background coloration light brownish with irregular beige mottling, and several scattered dark brown spots. Area above eyes dark brown, a thin interocular band with a small beige medial interruption. A dark brown rostral stripe is present. Tympanic area dark brown. Several dark brown crossbands present on hindlimbs. Ventral side without dark color elements; belly of a faded beige, throat bright white. Coloration in life not recorded.

Variation.

The four available specimens (all males) are morphologically and morphometrically rather similar to each other (Table 1 ). ZSM 291/2005 has a thin light vertebral stripe while ZSM 289/2005 has a distinct and broad light middorsal band. Femoral glands are well visible in paratype ZSM 290/2005; here, in preservative, they are relatively distinct from external view, consisting of many small gland granules in a diffuse field covering most of the thigh ventrally, thus of type 1 as defined by Glaw et al. (2000).

Natural history.

No natural history observations on this species were made, but its habits and habitat are likely similar to those of other species of the G. liber complex. It occurs both in intact primary rainforest (Marojejy) and in degraded forest (Andrakata-Andapa). Vocalizations of this species have not been recorded.

Distribution.

The species is reliably known from two sites in northern Madagascar: (1) the type locality Marojejy (Camp Mantella , at low elevation), and (2) a site between Andrakata and Andapa also located at rather low elevation. Furthermore, individuals from (3) Ambodivoangy at the north-eastern edge of the Makira Reserve, at ca. 30 m a.s.l., are provisionally assigned to this species based on evidence from nuclear genes, despite their assignment to G. razandry based on mitochondrial DNA (see Discussion below). This seems to be a species specialized to habitat at low elevations (known from near sea level to ca. 480 m a.s.l.).

Etymology.

The name is derived from the Malagasy words fotsy meaning white, and tenda meaning throat, referring to the white throat (vocal sac) typical for this and other species of the G. liber complex. The name is used as a noun in apposition to the genus name.

Figures

Figure 9. Preserved name-bearing holotype specimens of Guibemantis razandry sp. nov. (ZSM 293 / 2005) (A, B), Guibemantis razoky sp. nov. (ZSM 1746 / 2010) (C, D), and Guibemantis fotsitenda sp. nov. (ZSM 292 / 2005) (E, F) in dorsal and ventral view.