Mantidactylus gudrunae, Scherz & Crottini & Hutter & Hildenbrand & Andreone & Fulgence & Köhler & Ndriantsoa & Ohler & Preick & Rakotoarison & Rancilhac & Raselimanana & Riemann & Rödel & Rosa & Streicher & Vieites & Köhler & Hofreiter & Glaw & Vences, 2022

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 : 258-262

Mantidactylus gudrunae sp. nov.

Identity and justification.—This lineage has been considered as confirmed candidate species M. sp. 7 by Vieites et al. (2009) and M. sp. Ca7 by Perl et al. (2014). It is a member of the M. tricinctus clade, and strongly differs from the two other lineages in the clade ( M. tricinctus and M. grubenmanni ) by concordant strong divergence in 16S and Rag-1 sequences. Furthermore, it also differs in various morphological features (see Diagnosis below).

We are therefore confident that this lineage represents a distinct, evolutionarily isolated separate species.

Holotype.— ZSM 146/2004 (field number FGZC 274), adult male, collected by F. Glaw, M. Puente, R.D. Randrianiaina, and M. Teschke (née Thomas) on 7 February 2004 at Manantantely (24.983°S, 046.917°E, 20–150 m a.s.l.), Anosy Region, Madagascar. 16S and cox1 barcode sequences of the holotype are available from GenBank (accessions AY848141 and JN133257 ).

Paratypes.—A total of six paratypes : ZSM 136/2004 ( FGZC 250 ), ZSM 138/2004 ( FGZC 259 ), two adult males, and ZSM 154/2004 ( FGZC 286 ), adult female, with the same collection data as the holotype (7–8 February 2004); ZSM 68/2004 ( FGZC 115 ), adult female, collected by F. Glaw, M. Puente, M. Teschke (née Thomas), and R. Randrianiaina on 29–31 January 2004 at ‘Camp 1’, between Isaka and Eminiminy, Andohahela National Park (24.7586°S, 046.8542°E, 247 m a.s.l.); ZSM 95/2004 ( FGZC 167 ), adult male, and ZSM 96/2004 ( FGZC 168 ), adult female, collected by F. Glaw, M. Puente, M. Teschke (née Thomas), and R. Randrianiaina on 31 January 2004 above ‘Camp 1’, between Isaka and Eminiminy, Andohahela National Park (ca 24.750°S, ca 046.850°E, ca 350 m a.s.l.) .

Additional material.— The following specimens belong to genetically divergent populations and therefore are not included in the paratype series: ZSM 196/2005 ( FGZC 2594 ), adult female, collected by F. Glaw, and P. Bora on 4 February 2005 in the forest at the QMM Climate Station, Sainte Luce (24.7798°S, 047.1713°E, 23 m a.s.l.); ZSM 181/2021 ( ACZCV 375 , extraction ACP 3589, tissue ACZC 8514), ZSM 182/2021 ( ACZCV 376, ACP 3590, ACZC 8515), ZSM 183/2021 ( ACZCV 377, ACP 3591, ACZC 8516), collected by S. Hyde Roberts at Sainte Luce (S9) on 10 October 2016; MRSN A7044 ( FAZC 15282 , ACP 0997 , ACZC 4429 ), collected by F. Andreone and G.M. Rosa on 21 February 2012 at Sainte Luce ; MRSN A7045 ( FAZC 15419 , ACP 1053 , ACZC 4485 ) and MRSN A7046 ( FAZC 15427 , ACP 1057 , ACZC 4489 ), one male and one female, collected by F. Andreone and G.M. Rosa on 29 February 2012 at Tsitongambarika , Ivohibe .

Diagnosis.— Mantidactylus gudrunae sp. nov. is a member of the M. tricinctus clade as revealed by the phylogenomic analysis, and sister to a monophyletic group comprising M. tricinctus and M. grubenmanni . See Table 4 for a list of diagnostic morphological characters. The combination of small body size (male SVL 20–25 mm, female SVL 23–29 mm), presence of a whitish marking on snout tip and of a yellow inguinal marking, and absence of white spots on flanks, distinguishes M. gudrunae sp. nov. from members of other Brygoomantis clades ( Table 4 ).

Within the M. tricinctus clade, it differs from both M. tricinctus and M. grubenmanni by a slightly larger body size (male SVL 20–25 mm vs <20 mm), more strongly expressed webbing on foot, and lateral metatarsalia only partly connected or separated by webbing (vs connected). For detailed distinction from other new species described herein, see the respective species accounts. A full list of molecular diagnostic sites in the 16S gene of M. gudrunae sp. nov. in pairwise comparisons to all other Brygoomantis species is provided as Supplementary appendix.

Description of the holotype. —Adult male in good to moderate state of preservation ( Fig. 56 ). Tongue removed as tissue sample; femoral glands partly detached for examination in internal view. Body relatively slender.

Head as wide as body. Snout rounded in dorsal view, truncate in lateral view. Nostrils directed laterally, slightly protuberant, nearer to tip of snout than to eye.

Canthus rostralis weakly recognisable, slightly concave; loreal region slightly concave. Tympanum distinct and large, rounded, horizontal diameter of tympanum 88% of horizontal eye diameter. Supratympanic fold in its first part almost identical to tympanum edge, thereafter distinct, running rather straight from behind eye and bending about 70° close to posterior edge of tympanum towards forelimb insertion. Maxillary teeth present.

Vomerine teeth form two elongated aggregations, directed posteromedially from choanae. Choanae rounded.

Subarticular tubercles single. Inner and outer metacarpal tubercles present. Fingers without webbing. Relative length of fingers: I<II<IV<III. Finger discs slightly enlarged. Nuptial pads absent. Foot slightly shorter than tibia (97%). Lateral metatarsalia separated. Inner metatarsal tubercle present. Outer metatarsal tubercle indistinct but recognisable. Webbing formula: 1(no web), 2i(no web), 2e(traces), 3i(2), 3e(1), 4i(2.5), 4e(2.25), 5(1). Relative length of toes: I<II<V<III<IV. Skin on the upper surface smooth, some granules on flanks (in life, also tubercular on dorsum, without dorsolateral folds or longitudinal ridges). Ventral side smooth. Femoral glands with a large and distinct distal ulcerous macrogland; and a small proximal granular gland field apparently made up of only a few gland granules.

Colour in preservative: dorsally almost uniformly brown, with a dark band between the eyes bordering on a lighter colour on the anterior head surface. Some white spots and markings laterally on head. Limbs with dark crossbands. Ventrally, beige on limbs, brown with distinct white pattern on throat, chest and anterior belly. Larger white spots arranged to form a median intrreupted white line on throat. Lower lip ventrally with alternating white/ dark brown pattern. In life, colourarion was similar but more contrasted. A small yellowish marking was present in the inguinal region. The light ventral pattern was bright silvery white.

Variation.—Variation in measurements is given in Table 9. See Fig. 61 for colouration in life and its variation.

There is weak sexual size dimorphism (confirmed male SVL 20.2–24.4 mm [n = 7] vs confirmed female SVL 22.6–28.6 mm [n = 6]). Males have a larger tympanum than females (HTD/ED ratio is 62–79% in females, 75– 96% in males). Femoral glands of males in life distinct and coloured with a conspicuous yellowish shade; a large and distinct distal ulcerous macrogland is clearly visible, as is a smaller proximal granular gland field.

Natural history.—Specimens have been found along slow running water bodies in coastal rainforest. They are active during the night and call from water. Their call is rarely heard. The colouration of this species is quite variable, with some specimens showing an orangish colouration on the arms or on the dorsal stripe. Sometimes reminiscent of the colouration of species in the subgenus Ochthomantis (e.g. Fig. 61f ).

Calls.—The calls of this species have not yet been recorded.

Tadpoles.— The tadpole of this species has not been described.

Distribution.— Endemic to the South East of Madagascar ( Fig. 7 ). This species is known from Andohahela, Manantantely, Sainte Luce, and Tsitongambarika. Elevation range: 23–415 m a.s.l.

Etymology.—We dedicate this species to Gudrun Grubenmann from Z̧rich. Together with her husband Moritz, she has been travelling in Madagascar for many decades and has supported our research with important observations of Malagasy amphibians and reptiles.

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 56. Preserved holotype specimens of newly named species in the Mantidactylus tricinctus clade. Scale bars equal 5 mm.

FIGURE 61. Mantidactylus gudrunae sp. nov. in life, in dorsolateral and ventral view. (a,b) Adult male from Manantantely, photographed in 2004. (c,d) Adult male (holotype ZSM 146/2004 = FGZC 274) from Manantantely, photographed in 2004. (e) Unsexed specimen (ACZC 9918 = FAZC 15246) from Sainte Luce. (f) Unsexed specimen (ACZC 4418 = FAZC 15257) from Sainte Luce. (g) Unsexed specimen (ACZC 4447 = FAZC 15324) from Tsitongambarika. (h) Unsexed specimen (ACZC 4489 = FAZC 15427) from Tsitongambarika.