MORPHOLOGICAL AND GENETIC CHARACTERIZATION OF PHAEOCYSTIS CORDATA AND P. JAHNII (PRYMNESIOPHYCEAE), TWO NEW SPECIES FROM THE MEDITERRANEAN SEA

作者：Adriana Zingone, Marie‐Josèphe Chrétiennot‐Dinet, Martin Lange, Linda Medlin · 发表于：Journal of Phycology · 年份：1999 · DOI：10.1046/j.1529-8817.1999.3561322.x · 被引用次数：87 · 研究领域：Protist diversity and phylogeny、Marine and coastal ecosystems、Microbial Community Ecology and Physiology

Two new Phaeocystis species recently discovered in the Mediterranean Sea are described using light and electron microscopy, and their systematic position is discussed on the basis of an analysis of their nuclear‐encoded small‐subunit ribosomal RNA gene (SSU rRNA) sequences. Phaeocystis cordata Zingone et Chrétiennot‐Dinet was observed only as flagellated unicells. Cells are heart shaped, with two flagella of slightly unequal length and a short haptonema. The cell body is covered with two layers of thin scales. The outermost layer scales are oval, with a faint radiating pattern, a raised rim, and a modest central knob. The inner‐layer scales are smaller and have a faint radiate pattern and an inflexed rim. Cells swim with their flagella close together, obscuring the haptonema, pushing the cell, and causing it to rotate about its longitudinal axis while moving forward. Phaeocystis jahnii Zingone was isolated as a nonmotile colony. It forms loose aggregates of cells embedded in a mucilaginous, presumably polysaccharide matrix without a definite shape or visible external envelope. The flagellated stage has the features typical of other Phaeocystis species. Cells are rounded in shape and slightly larger than P. cordata. The cell body is covered with extremely thin scales of two different sizes with a very faint radiating pattern toward their margin. Swimming behavior is similar to that of P. cordata, with the flagella in a posterior position as the cells swim. The SSU rRNA sequenc...