Fanomezana Mihaja Ratsoavina

Dr. Fanomezana Mihaja Ratsoavina

orcid

Research Focus & Metrics

Academic Career Length

15Years (2012-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 September 2022 in Zootaxa
Verified
Journal Article
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MVMiguel Vences
Miguel Vences
MMMalte Multzsch
Malte Multzsch
SGSven Gippner
Sven Gippner
AMAurélien Miralles
Aurélien Miralles
Angelica CrottiniAngelica Crottini
Angelica Crottini
MSMark D. Scherz
Mark D. Scherz
The Lygodactylus madagascariensis species group, constituting the subgenus Domerguella, currently contains five valid species of inconspicuous dwarf geckos from Madagascar’s humid forests, but at least 18 deep genetic lineages have been revealed by recent molecular studies. Given the high morphological similarity of these lineages, taxonomic resolution of this astonishing diversity requires efforts to correctly delimit species, as well as assigning the available nomina to the species-level lineages identified. We here combine DNA sequences of one mitochondrial and two nuclear-encoded gene fragments with morphometric measurements and scale counts, and report evidence for a species status of most of the previously identified lineages. In particular, we rely on sympatric and often even syntopic occurrence of several of these lineages without evidence for genetic admixture, and consistent with subtle morphological differences. Furthermore, the very high divergences of 7.4–23.8% pairwise distances in the relatively conserved mitochondrial 16S rRNA gene, combined with a lack of haplotype sharing in the nuclear-encoded genes and differences in scale counts convinced us that most of the other, allopatrically distributed lineages also represent distinct species. We elevate L. madagascariensis petteri to species level and formally name eight new species: L. salvi sp. nov., a species from the Sambirano region in northern Madagascar, previously called L. sp. 8; L. tantsaha sp. nov. (L. sp. 10), a species occurring sympatrically with L. madagascariensis and L. petteri on Montagne d’Ambre in far northern Madagascar; L. roellae sp. nov. (L. sp. 17), a species characterized by a striped coloration in all known specimens, from northern Madagascar; L. winki sp. nov. (L. sp. 18), an unstriped species from northern Madagascar but belonging to a subclade mostly distributed in the eastern rainforests of the island; L. ulli sp. nov. (L. sp. 21), a species from the same subclade as L. winki but known only from the Marojejy Massif in the North East; L. fritzi sp. nov. (L. sp. 11), a further species of this subclade from coastal lowlands in the Northern Central East; L. hodikazo sp. nov. (L. sp. 23) known from a single specimen collected at the Tsingy de Bemaraha and therefore the only Domerguella species known from the West region of Madagascar; and L. hapei sp. nov. (L. sp. 26), an enigmatic species from the Sambirano region characterized by a striped pattern on the throat that is otherwise unknown in the subgenus. Three additional deep mitochondrial lineages of Domerguella were identified in our analysis, but could not be further analyzed due to the lack or scarcity of voucher specimens. More field work and collection of voucher specimens is needed to understand their status. Furthermore, the taxonomy of the Domerguella subclade occurring in eastern Madagascar, with three described species (L. guibei, L. miops, L. fritzi), two synonyms (L. septemtuberculatus, Microscalabotes spinulifer) and at least two further deep genetic lineages co-occurring in a relatively small area, requires further revisionary work, possibly aided by target-enrichment sequencing of the respective name-bearing types.

26 December 2021 in Ecology Letters
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Journal Article
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AMAddisu Mekonnen
Addisu Mekonnen
CDColleen Downs
Colleen Downs
EEEdu O Effiom
Edu O Effiom
MKMohamed Kibaja
Mohamed Kibaja
MLMike J Lawes
Mike J Lawes
CCColin A Chapman
Colin A Chapman
With open‐access publishing authors often pay an article processing charge and subsequently their article is freely available online. These charges are beyond the reach of most African academics. Thus, the trend towards open‐access publishing will shift the business model from a pay‐wall model, where access to literature is limited, to a pay‐to‐publish one, where African scholars cannot afford to publish. We explore the costs of publishing and the ability of African scholars to afford to publish via open access in top journals. Three‐quarters of the 40 top ecology journals required payment for open‐access publishing (average cost $3150). Paying such fees is a hardship for African scholars as grant funding is not available and it is not feasible to pay the fees themselves as salaries are low. We encourage funders and publishers to facilitate an equitable publishing model that allows African scholars to make their research available through open‐access publishing.

14 October 2024 in Vertebrate Zoology
Verified
Journal Article
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MVMiguel Vences
Miguel Vences
JKJörn Köhler
Jörn Köhler
CHCarl R. Hutter
Carl R. Hutter
MPMichaela Preick
Michaela Preick
APAlice Petzold
Alice Petzold
MSMark D. Scherz
Mark D. Scherz
The Malagasy stream-breeding treefrog species Boophis marojezensis contains bioacoustically and genetically highly divergent populations. Some of these populations have been defined as candidate species and emit somewhat bizarre advertisement calls consisting of multiple whistle-notes. We here enable a long-overdue taxonomic revision of this species complex by applying a museomics approach to sequence DNA from the holotype of B. marojezensis. Based on an integrative approach that combines divergence levels in mitochondrial DNA and in three nuclear-encoded genes, morphological data, and bioacoustic comparisons, we conclude that eight different species exist in this complex, seven of which are formally described herein as new. Although morphological differences between species are small and mainly separate small-sized from larger-sized species, conclusive evidence for the new species comes from their sympatric and sometimes syntopic occurrence without haplotype sharing in three nuclear genes and under maintenance of bioacoustic differences. Uncorrected genetic divergences in the mitochondrial 16S rRNA gene are >3% in almost all cases, and in some cases up to 8%. In reference to the otherworldly sounds by which these frogs fill Malagasy rainforests, some of them reminiscent of sounds of technical equipment in the fictional “Star Trek” universe, we here name and describe the seven new species in honor of fictional captains of starships, namely B. kirkisp. nov., B. picardisp. nov., B. siskoisp. nov., B. janewayaesp. nov., B. archerisp. nov., B. pikeisp. nov., and B. burnhamaesp. nov. The majority of these species occur in northern Madagascar, where up to three species can occur in immediate geographical proximity, e.g., B. marojezensis, B. burnhamaesp. nov. and B. pikeisp. nov. at different elevations in the Marojejy Massif. South of 16°S latitude, only B. janewayaesp. nov., B. picardisp. nov., and B. kirkisp. nov. are found, with the latter extending southwards to Ranomafana National Park. Our study confirms the existence of numerous morphologically cryptic and microendemic species among Madagascar’s amphibians, some of which are known only from unprotected sites and require adequate conservation management.

13 December 2021 in Animal Conservation
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TFT. R. Fulgence
T. R. Fulgence
DMD. A. Martin
D. A. Martin
RRR. Randriamanantena
R. Randriamanantena
RBR. Botra
R. Botra
EBE. Befidimanana
E. Befidimanana
FRFanomezana Mihaja Ratsoavina
Fanomezana Mihaja Ratsoavina
Large expanses of tropical rainforest have been converted into agricultural landscapes cultivated by smallholder farmers. This is also the case in north‐eastern Madagascar; a region that retains significant proportions of forest cover despite slash‐and‐burn shifting hill rice cultivation and vanilla agroforestry expansion. The region is also a global hotspot for herpetofauna diversity, but how amphibians and reptiles are affected by land‐use change remains largely unknown. Using a space‐for‐time study design, we compared species diversity and community composition across seven prevalent land uses: unburned (old‐growth forest, forest fragment, and forest‐derived vanilla agroforest) and burned (fallow‐derived vanilla agroforest, woody fallow, and herbaceous fallow) land‐use types, and rice paddy. We conducted six comprehensive, time‐standardized searches across at least 10 replicates per land‐use type and applied genetic barcoding to confirm species identification. We documented an exceptional diversity of herpetofauna (119 species; 91% endemic). Observed plot‐level amphibian species richness was significantly higher in old‐growth forest than in all other land‐use types. Plot‐level reptile species richness was significantly higher in unburned land‐use types compared with burned land‐use types. For both amphibians and reptiles, the less‐disturbed land‐use types showed more uneven communities and the species composition in old‐growth forest differed significantly from all other land‐use types. Amphibians had higher forest dependency (38% of species occurred exclusively in old‐growth forest) than reptiles (26%). Our analyses thus revealed that the two groups respond differently to land‐use change: we found less pronounced losses of reptile species richness especially in unburned agricultural habitats, suggesting that reptiles are less susceptible to land‐use change than amphibians, possibly due to their ability to cope with hotter and drier microclimates. In conclusion, our findings emphasize existing conservation opportunities – especially for reptiles – in extensive agricultural landscapes while highlighting the precarious situation of amphibians in disappearing old‐growth forests.

16 March 2023 in Ecology and Evolution
Verified
Journal Article
Open access
MSMark D. Scherz
Mark D. Scherz
RSRobin Schmidt
Robin Schmidt
JBJason L. Brown
Jason L. Brown
JGJulian Glos
Julian Glos
ELElla Z. Lattenkamp
Ella Z. Lattenkamp
MVMiguel Vences
Miguel Vences
How environmental factors shape patterns of biotic diversity in tropical ecosystems is an active field of research, but studies examining the possibility of ecological speciation in terrestrial tropical ecosystems are scarce. We use the isolated rainforest herpetofauna on the Montagne d'Ambre (Amber Mountain) massif in northern Madagascar as a model to explore elevational divergence at the level of populations and communities. Based on intensive sampling and DNA barcoding of amphibians and reptiles along a transect ranging from ca. 470–1470 m above sea level (a.s.l.), we assessed a main peak in species richness at an elevation of ca. 1000 m a.s.l. with 41 species. The proportion of local endemics was highest (about 1/3) at elevations >1100 m a.s.l. Two species of chameleons (Brookesia tuberculata, Calumma linotum) and two species of frogs (Mantidactylus bellyi, M. ambony) studied in depth by newly developed microsatellite markers showed genetic divergence up the slope of the mountain, some quite strong, others very weak, but in each case with genetic breaks between 1100 and 1270 m a.s.l. Genetic clusters were found in transect sections significantly differing in bioclimate and herpetological community composition. A decrease in body size was detected in several species with increasing elevation. The studied rainforest amphibians and reptiles show concordant population genetic differentiation across elevation along with morphological and niche differentiation. Whether this parapatric or microallopatric differentiation will suffice for the completion of speciation is, however, unclear, and available phylogeographic evidence rather suggests that a complex interplay between ecological and allopatric divergence processes is involved in generating the extraordinary species diversity of Madagascar's biota. Our study reveals concordant patterns of diversification among main elevational bands, but suggests that these adaptational processes are only part of the complex of processes leading to species formation, among which geographical isolation is probably also important.

21 January 2019 in Zootaxa
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Journal Article
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FRFanomezana Mihaja Ratsoavina
Fanomezana Mihaja Ratsoavina
ARAchille P. Raselimanana
Achille P. Raselimanana
MSMark D. Scherz
Mark D. Scherz
ARAndolalao Rakotoarison
Andolalao Rakotoarison
JRJary H. Razafindraibe
Jary H. Razafindraibe
MVMiguel Vences
Miguel Vences
Finaritra! A splendid new leaf-tailed gecko ( Uroplatus ) species from Marojejy National Park in north-eastern Madagascar