NGS data from historical museum collections help to clarify the conservation status of endangered or supposedly extinct species: the case of the Mascarene endemic freshwater shrimp

Macrobrachium hirtimanus (<ns0:xref ref-type="bibr" rid="R39">Olivier, 1811</ns0:xref>) is a species of freshwater shrimp endemic to the Mascarene Islands (Réunion, Mauritius and Rodrigues). The last documented occurrences of this species date from 1980 on Réunion Island and it is thought to be now extinct. In order to determine its taxonomic distinctiveness and conservation status, historical specimens preserved in the collections of the Muséum national d’Histoire naturelle of Paris have been sequenced using a shotgun Next Generation Sequencing (NGS) method, allowing to get mitochondrial DNA barcode sequences (16S, COI) from 4 specimens collected between 1818 and 1926 on Réunion and Mauritius Islands. These sequences will be useful to build reference libraries for future eDNA surveys in the rivers of the Mascarenes that will help ascertain the conservation status of the species by guiding environmental surveys and updating the IUCN assessment. A discussion is provided on reasons leading to the possible extinction of M. hirtimanus as well as a list of specimens extant in museum collections worldwide.