Studies on woloszynskioid dinoflagellates I: Woloszynskia coronata re-examined using light and electron microscopy and partial LSU rDNA sequences, with description of Tovellia gen. nov. and Jadwigia gen. nov. (Tovelliaceae fam. nov.)

Abstract

K. Lindberg, Ø. Moestrup and N. Daugbjerg. 2005. Studies on woloszynskioid dinoflagellates I: Woloszynskia coronata re-examined using light and electron microscopy and partial LSU rDNA sequences, with description of Tovellia gen. nov. and Jadwigia gen. nov. (Tovelliaceae fam. nov.). Phycologia 44: 416–440.Sediment samples were collected from a small pond in southern Sweden. Several cysts from the samples germinated into clonal cultures, identified as Woloszynskia coronata (Wolosz.) R.H. Thompson 1951. They were compared with other species of Woloszynskia established in culture, using scanning electron microscopy, transmission electron microscopy, partial large subunit ribosomal DNA (LSU rDNA) and morphology of the resting cysts. Significant differences were found, and we conclude that the genus Woloszynskia as presently circumscribed is artificial, and comprises at least four genera. In this first paper we transfer W. coronata to a new genus; Tovellia gen. nov., type species: Tovellia coronata (Wolosz.) comb. nov. Previous studies on ultrastructure and DNA sequencing referring to Woloszynskia coronata are based on W. coronata var. glabra, which is raised to species level as Tovellia glabra sp. nov. Other species included in the new genus are Tovellia apiculata (basionym Woloszynskia apiculata Stosch) and Tovellia stoschii (basionym Woloszynskia stoschii R. Shyam & Sarma). Two identical cultures presently identified as Woloszynskia limnetica Bursa (from University of Washington Culture Collection, Seattle) and W. pseudopalustris (J. Schiller) Kiselev [from Culture Collection of Algae at the University of Cologne, Cologne] differ from Tovellia in LSU rDNA sequences and in cyst type and are transferred to Jadwigia gen. nov., as J. applanata sp. nov. The most striking feature of Tovellia and Jadwigia is the anatomy of the eyespot, which is extraplastidial, and composed of nonmembrane bound lipid globules. This type of eyespot is also present in Katodinium campylops (T.M. Harris) A.R. Loebl., a species undoubtedly related to Tovellia, and in ‘Glenodinium sp.’ sensu Kreimer 1999, and together they form a distinct family, Tovelliaceae fam. nov.