Metapolystoma ohlerianum n. sp. (Monogenea: Polystomatidae) from Aglyptodactylus madagascariensis (Anura: Mantellidae)
Date
2023Author
Landman, Willem
Verneau, Olivier
Vences, Miguel
du Preez, Louis
Metadata
Show full item recordAbstract
Purpose Despite Madagascar’s high amphibian diversity of more than 400 species, only a few polystome species are known
from the island. The dissection of frogs from museum collections, together with amphibian and parasite surveys conducted
in Madagascar led to the discovery of an undescribed polystome infecting Aglyptodactylus madagascariensis. The purpose
of this study is to formally describe this species.
Methods Polystomes recovered from A. madagascariensis were stained (Acetocarmine) and mounted (Canada balsam) to
facilitate morphometrics and taxonomic drawings. Some specimens were fxed in absolute alcohol, a Bayesian tree inferred
from the analysis of concatenated 18S, 28S and COI gene sequences was constructed and pairwise distances were calculated.
Parasites collected from archived hosts in museums were used for histology and scanning electron microscopy (SEM).
Results Polystomes recovered from A. madagascariensis display characteristics of the genus Metapolystoma and morpho logically difered from all other known metapolystomes. The Bayesian phylogeny shows that Metapolystoma n. sp. ex. A.
madagascariensis and M. falcatum are sister species with high Bayesian posterior probability. Histological and SEM inves tigations contributed to morphological descriptions.
Conclusions Morphological examination supported by phylogenetic analysis and genetic divergences revealed distinct
differences from all known metapolystome species, supporting the description of a new species. Differences between
the life cycles of Metapolystoma and Polystoma provided additional evidence for the validity of that genus as taxon.
Whereas Polystoma may display ovoviviparity on rare occasions after incomplete egg expulsion towards the end of
the breeding season, Metapolystoma displays true ovoviviparity. We emphasize the need for parasite surveys in Mada gascar and recommended for museum material to be examined for polystomes to provide supplementary material and
localities for further field investigation.
Collections
- NWU Official [165]