The recently established diatom Coscinodiscus wailesii (Coscinodiscales, Bacillariophyta) in Brazilian waters. I: Remarks on morphology and distribution

Abstract

SUMMARY Coscinodiscus wailesii Gran et Angst is a large centric diatom (280‐500 µm diameter) from marine phytoplankton, characterized by a cylindrical frustule with flat valvar surface, two marginal rings of rimoportulae on the mantle, and two macrorimoportulae. Cells from cultured and natural populations collected in Paranagua Bay, Parana, southern Brazil were observed under light and scanning electron microscopes to verify the populations’ correct identity and morphology. In both populations, a typical central rosette or a hyaline area was found in the valvar center. The species’ distribution in Brazilian waters was revised, and a discussion on possible vectors of transport was made. Blooms of the species occur sporadically in the coast of Parana, seeming to affect the local trophic chain.