Eutreptia

Eutreptia consists of single, free-swimming cells that are spindle-shaped with pronounced euglenoid movement (metaboly). Two heterodynamic flagella are present, both highly active while swimming, with a reddish eyespot near the base. Eutreptia is photosynthetic with green chloroplasts; there may be numerous discoid or ribbon-shaped chloroplasts, often radiating from central pyrenoids surrounded by grains of paramylon. While swimming, it rotates along the longitudinal axis; sometimes the cells creep along a substrate (in mucus). It sometimes forms a palmelloid stage in which cells divide repeatedly. ==Taxonomy==

Eutreptia is distinguished from the related genus Eutreptiella in that the two flagella are of nearly equal length, while Eutreptia has flagella of markedly unequal lengths. Species are distinguished based on the size and shape of cells, length of flagella, and presence of pyrenoids. Species: • Eutreptia globulifera Goor • Eutreptia lanowii Steuer • Eutreptia papillifera Péterfi • Eutreptia pascheri Skvortsov • Eutreptia pertyi Pringsheim • Eutreptia pyrenoidifera Matvienko • Eutreptia scotica Butcher • Eutreptia thiophila Skuja • Eutreptia viridis Perty ==References==