Marine Phytoplankton Species

Taxonomy

• Classification of phytoplankton is based on their surface ornamentation, color, cell morphology and their food reserves. A compound or inverted light microscope with a magnification of between 250x and 400x is most commonly used to identify them. Some species can be difficult to differentiate, and in such cases an electron microscope is used to pick up minute details that identify the species.

Diatoms

• Diatoms are a major group of algae and also one of the most common types of phytoplankton. Diatoms are analogous to grass in the oceans: they rest at the base of the trophic pyramid as primary producers and carry out a large amount of the ocean's photosynthesis. Species of marine diatoms include: Bacillariophyceae, which are unicellular alga with siliceous frustules; Centric diatoms, which include common marine genera such as Skeletonema, Chaetoceros, Thalassiosira; and Pennate Diatoms, whose body plan is arranged along a longitudinal axis.

Dinoflagellates

• Dinoflagellates are a class of marine phytoplankton that possess a longitudinal furrow and a transverse girdle. They produce oil and starch as food reserves and including the following orders: Prorocentrales, which lack furrows; Dinophysiales, which are often highly compressed; Gymnodiniales, which has no hard parts and thus isn't preserved in fossil records; Peridiniales, which are identified by plate arrangement; Noctilucales, whose main phase is a large, naked cell, commonly with a tentacle; and Pyrocystales, whose most common marine genera is Pyrocystis. Recognized species of dinoflagellates include: B. apsteini, B. chattoni, B. contortum, B. crassum, B. elongatum; B. hyalinum and B. inornatum.

Other Species of Marine Phytoplankton

• Chloromonads have chloroplasts, from yellow to brown in color. Twenty described species of Chloromonads exist. Prymnesiophytes, also called Haptophytes, include more than 500 species. One prominent member is the coccolithophore, composed of calcium carbonate. Sillicoflagellates are a class of phytoplankton that have numerous golden-brown chloroplasts and a single anterior flagellum. There are only three species of Sillicoflagellates. Other marine phytoplankton include Euglenoids, Prasinophytes, Cryptomonads, Chrysophytes and Chlorophytes.