TY - JOUR

T1 - An inordinate fondness for inconspicuous brown frogs

T2 - integration of phylogenomics, archival DNA analysis, morphology, and bioacoustics yields 24 new taxa in the subgenus Brygoomantis (genus Mantidactylus) from Madagascar

AU - Scherz, Mark D.

AU - Crottini, Angelica

AU - Hutter, Carl R.

AU - Hildenbrand, Andrea

AU - Andreone, Franco

AU - Fulgence, Thio Rosin

AU - Köhler, Gunther

AU - Ndriantsoa, Serge Herilala

AU - Ohler, Annemarie

AU - Preick, Michaela

AU - Rakotoarison, Andolalao

AU - Rancilhac, Loïs

AU - Raselimanana, Achille P.

AU - Riemann, Jana C.

AU - Rödel, Mark-Oliver

AU - Rosa, Goncalo M.

AU - Streicher, Jeffrey W.

AU - Vieites, David R.

AU - Köhler, Jörn

AU - Hofreiter, Michael

AU - Glaw, Frank

AU - Vences, Miguel

PY - 2022

Y1 - 2022

N2 - Malagasy frogs of the subgenus Brygoomantis in themantellid frog genus Mantidactylus currently comprise 14described species of mostly brown, riparian frogs. Data fromDNA barcoding suggested that the diversity of this subgenusis dramatically underestimated by current taxonomy. Wehere provide a comprehensive revision of this subgenus. Weuse hybrid-enrichment based DNA barcode fishing to obtainmitochondrial DNA fragments from the name-bearing typematerial of 16 of the 20 available names for members of thissubgenus, and integrate these into a genetic dataset consistingof 1305 individuals sampled across Madagascar. By thusassigning the nomina to genetic lineages, we can confidentlyestablish synonyms, revalidate old names, and describe theremaining diversity. We take an integrative approach to ourdescriptions, drawing together genetics, morphometricsand morphology, and bioacoustics for assignment. We alsoprovide a robust phylogenomic hypothesis for the subgenus,based on 12,818 nuclear-encoded markers (almost 10 millionbase pairs) for 58 representative samples, sequenced using ahybrid-enrichment bait set for amphibians. Those data suggesta division of the subgenus into eight major clades and showthat morphological species complexes are often paraphyleticor polyphyletic. Lectotypes are designated for Ranabetsileana Boulenger, 1882; Rana biporus Boulenger, 1889;Rana curta Boulenger, 1882; Mantidactylus ambohimitombiBoulenger, 1918; Mantidactylus tripunctatus Angel, 1930;and Rana inaudax Peracca, 1893. For several other nomina,previous authors had considered a certain syntype as holotype;this has been seen as lectotype designation by implication,which, however, is ambiguous according to the provisions ofthe International Code of Zoological Nomenclature. Hence,we validate a previous lectotype designation by implicationfor Limnodytes ulcerosus Boettger, 1880 by explicitlydesignating the same individual as lectotype. In one othersuch case, that of Mantidactylus brauni Ahl, 1929, we deviatefrom previous authors and designate a different specimenas lectotype. We revalidate Rana inaudax Peracca, 1893 asMantidactylus inaudax (Peracca, 1893) bona species, andMantidactylus tripunctatus Angel, 1930 bona species. Theidentities of three further species (M. ambohimitombi, M.biporus, M. tricinctus) are largely redefined based on newgenetic data. By designating the lectotype of Rana aluta(MZUT An725.1) as the neotype of Mantidactylus laevisAngel, 1929 we also stabilize the latter nomen (as juniorsynonym of M. alutus) whose original type material is lost.Based on DNA sequences of its lectotype, we considerMantidactylus brauni Ahl, 1929 as junior synonym of M.ulcerosus (rather than M. biporus). We formally name 20new species and four new subspecies: M. ambohimitombimarefo ssp. nov., M. ambohimitombi miloko ssp. nov., M.mahery sp. nov., M. steinfartzi sp. nov., M. incognitus sp.nov., M. jonasi sp. nov., M. katae sp. nov., M. kortei sp.nov., M. riparius sp. nov., M. fergusoni sp. nov., M. georgeisp. nov., M. jahnarum sp. nov., M. marintsoai sp. nov., M.grubenmanni sp. nov., M. gudrunae sp. nov., M. augustinisp. nov., M. bletzae sp. nov., M. brevirostris sp. nov., M.eulenbergeri sp. nov., M. glosi sp. nov., M. stelliger sp. nov.,M. manerana sp. nov., M. manerana fotaka ssp. nov., andM. manerana antsanga ssp. nov. This leaves Mantidactylussubgenus Brygoomantis with 35 described species and sixsubspecies (including nominate subspecies). Based onour taxonomic revision, we discuss (i) the importance ofdefinitive assignment of historical names via archival DNAanalysis; (ii) the relevance of the subspecies category toname geographic variation within species; (iii) the valueof molecular characters in formal species diagnoses intaxa with substantial individual variation of morphology;(iv) the use of phylogenomic approaches for taxonomy, byconfirming that some morphologically similar taxa are noteach other’s closest relatives, and in several cases belong toentirely different major subclades within Brygoomantis, thusfacilitating lineage diagnosis; and (v) the need to interpretgenetic distances in a probabilistic framework rather thanusing fixed thresholds, where higher distances confer ahigher likelihood of genetic incompatibilities across thegenome and thus completion of speciation.

AB - Malagasy frogs of the subgenus Brygoomantis in themantellid frog genus Mantidactylus currently comprise 14described species of mostly brown, riparian frogs. Data fromDNA barcoding suggested that the diversity of this subgenusis dramatically underestimated by current taxonomy. Wehere provide a comprehensive revision of this subgenus. Weuse hybrid-enrichment based DNA barcode fishing to obtainmitochondrial DNA fragments from the name-bearing typematerial of 16 of the 20 available names for members of thissubgenus, and integrate these into a genetic dataset consistingof 1305 individuals sampled across Madagascar. By thusassigning the nomina to genetic lineages, we can confidentlyestablish synonyms, revalidate old names, and describe theremaining diversity. We take an integrative approach to ourdescriptions, drawing together genetics, morphometricsand morphology, and bioacoustics for assignment. We alsoprovide a robust phylogenomic hypothesis for the subgenus,based on 12,818 nuclear-encoded markers (almost 10 millionbase pairs) for 58 representative samples, sequenced using ahybrid-enrichment bait set for amphibians. Those data suggesta division of the subgenus into eight major clades and showthat morphological species complexes are often paraphyleticor polyphyletic. Lectotypes are designated for Ranabetsileana Boulenger, 1882; Rana biporus Boulenger, 1889;Rana curta Boulenger, 1882; Mantidactylus ambohimitombiBoulenger, 1918; Mantidactylus tripunctatus Angel, 1930;and Rana inaudax Peracca, 1893. For several other nomina,previous authors had considered a certain syntype as holotype;this has been seen as lectotype designation by implication,which, however, is ambiguous according to the provisions ofthe International Code of Zoological Nomenclature. Hence,we validate a previous lectotype designation by implicationfor Limnodytes ulcerosus Boettger, 1880 by explicitlydesignating the same individual as lectotype. In one othersuch case, that of Mantidactylus brauni Ahl, 1929, we deviatefrom previous authors and designate a different specimenas lectotype. We revalidate Rana inaudax Peracca, 1893 asMantidactylus inaudax (Peracca, 1893) bona species, andMantidactylus tripunctatus Angel, 1930 bona species. Theidentities of three further species (M. ambohimitombi, M.biporus, M. tricinctus) are largely redefined based on newgenetic data. By designating the lectotype of Rana aluta(MZUT An725.1) as the neotype of Mantidactylus laevisAngel, 1929 we also stabilize the latter nomen (as juniorsynonym of M. alutus) whose original type material is lost.Based on DNA sequences of its lectotype, we considerMantidactylus brauni Ahl, 1929 as junior synonym of M.ulcerosus (rather than M. biporus). We formally name 20new species and four new subspecies: M. ambohimitombimarefo ssp. nov., M. ambohimitombi miloko ssp. nov., M.mahery sp. nov., M. steinfartzi sp. nov., M. incognitus sp.nov., M. jonasi sp. nov., M. katae sp. nov., M. kortei sp.nov., M. riparius sp. nov., M. fergusoni sp. nov., M. georgeisp. nov., M. jahnarum sp. nov., M. marintsoai sp. nov., M.grubenmanni sp. nov., M. gudrunae sp. nov., M. augustinisp. nov., M. bletzae sp. nov., M. brevirostris sp. nov., M.eulenbergeri sp. nov., M. glosi sp. nov., M. stelliger sp. nov.,M. manerana sp. nov., M. manerana fotaka ssp. nov., andM. manerana antsanga ssp. nov. This leaves Mantidactylussubgenus Brygoomantis with 35 described species and sixsubspecies (including nominate subspecies). Based onour taxonomic revision, we discuss (i) the importance ofdefinitive assignment of historical names via archival DNAanalysis; (ii) the relevance of the subspecies category toname geographic variation within species; (iii) the valueof molecular characters in formal species diagnoses intaxa with substantial individual variation of morphology;(iv) the use of phylogenomic approaches for taxonomy, byconfirming that some morphologically similar taxa are noteach other’s closest relatives, and in several cases belong toentirely different major subclades within Brygoomantis, thusfacilitating lineage diagnosis; and (v) the need to interpretgenetic distances in a probabilistic framework rather thanusing fixed thresholds, where higher distances confer ahigher likelihood of genetic incompatibilities across thegenome and thus completion of speciation.

U2 - 10.11646/megataxa.7.2.1

DO - 10.11646/megataxa.7.2.1

M3 - Journal article

VL - 7

SP - 113

EP - 311

JO - Megataxa

JF - Megataxa

SN - 2703-3082

IS - 2

ER -