A new species of Tortanus (Atortus) (Copepoda: Calanoida) from the Seychelles, Mauritius and Madagascar

A new species of the planktonic copepod Tortanus (Atortus) (Calanoida: Tortanidae), T. (A.) magnonyx is described from Seychelles, Mauritius and Madagascar. This is the sixth species of the Indian Ocean recticauda species group, of the Indo-West Pacific recticauda species complex, that has been described from the western Indian Ocean. The inshore areas where these copepods are found have been poorly surveyed, so the number of species found implies a high diversity.