Heteromorphic life histories in arctic coccolithophorids (Prymnesiophyceae)

During three visits to Disko Bay, West Greenland, we found four different types of prymnesiophyte flagellates with heterococcoliths from species of the genera Papposphaera Tangen and Pappomonas Manton and Oates in characteristic and consistent combinations with holococcoliths from species of the genera Turrisphaera Manton, Sutherland, and Oates and Trigonaspis Thomsen. We conclude that several taxa previously considered to be autonomous species are, in fact, part of life histories combining hetero- and holococcolithophorid forms in a manner somewhat similar to that known from studies of cultured strains of Coccolithus pelagicus (Wallich) Schiller and Crystallolithus hyalinus (Gaarder) Markali. Similarly, Calciarcus Manton, Sutherland and Oates and Wigwamma Manton, Sutherland and Oates also may be alternate phases of a coccolithophorid life history.