A new species of sea anemone (Saccactis coliumensis n. sp.) living under hypoxic conditions on the central Chilean shelf

The new speciesSaccactis coliumensis is described with an emendation of genusSaccactis lager, 1911 (family Actiniidae). The taxonomic relations of the genus are discussed giving additional information onIsoulactis chilensis Carlgren, 1959 andIsocradactis magna sensu Carlgren, 1924. The terms “verrucae”, “vesicles” and “acrorhagi” are discussed and taxonomically valuated. The anemoneS. coliumensis lives in eutrophicated sediments on the central Chilean shelf that is at least temporarily under the impact of deoxygenated waters from the Peru-Chile-Subsurface-Current. The most conspicuous features of the new species (the ruff of delicate, gill-like vesicles beneath the tentacles and its thick pedal disc ectoderm with small, fragile spirocysts and cilia-like structures) may be considered adaptive in this peculiar habitat.