Genetic variability of New Caledonian Boeckella De Guerne & Richard, 1889 (Copepoda: Calanoida), with the description of a new species

Abstract

Thirteen new freshwater populations of the copepod genus BoeckellaDe Guerne & Richard, 1889 were found during three expeditions to New Caledonia (‘La Planète Revisitée,’ 2016-2018). The 12 populations from the Plaine des Lacs, which show remarkable genetic diversity among themselves, were identified as B. spinogibbaDefaye, 1998, the only species of its genus known from New Caledonia until now. The sole exception, the population from Mont-Dore 22 km further east, appeared genetically and morphologically distinct from the others and is described herein as a new species. The two species are distinguished from each other by the shapes of the male and female P5, female Th5, and body colour. A previously published key is amended to separate the species. Our concatenated COI+28S phylogeny places the two New Caledonia species as a new branch within Boeckella, distinct from the branches consisting of South American, Antarctic and Australasian species. All 13 Boeckella populations inhabit the extreme south of New Caledonia, an area known for endemism and high heavy metal concentrations in the soil. Extensive mining activity in this metal-rich area, begun in 1873, is now leading to conflict with conservation goals. By using aerial photographs to trace the fate of the pond that is the type locality of B. spinogibba, we confirmed that it disappeared between 2007 and 2014 as a result of the expansion of the Goro nickel mine.