Algae (79)

General descriptionAlgae were often assigned to the plant kingdom. Properties for including the algae into the plant kingdom were their ability to make their own food by photosynthesis, their structural similarity to land plants and the fact that the larger forms were observed to be sedentary. Eukaryotic unicellular organisms with chloroplasts were also called plants. Unicellular creatures that move and ingest food - protozoa - were called animals. Microbes such as Euglena that move but are photosynthetic were cla [Further read]imed by both botanists and zoologists, and showed up in the taxonomies of both the plant and animal kingdoms.

Green algae

Over 5,000 species of green algae are known, mostly unicells or simple filaments from fresh water, but there are diverse green algae in tropical marine habitats. Like land plants, the greens store starch (amylose or amylopectin) and have chlorophyll a and b as well as secondary pigments : carotenes, lutein, zeaxanthin. (Some Chlorophyta also have siphonoxanthin.) The chloroplast endoplasmic reticulum is absent in green algae, and t heir cell walls are often composed of cellulose, hydroxproline, glycosides, xylans, mannans or sometimes calcium carbonate.

Brown algae

The 1,500 species of brown algae are almost exclusively found in marine habitats. The browns include the largest of the seaweeds, Durvillea and the kelps, found in cold waters. The kelps present the most complex anatomy of all the algae with trumpet hyphae and sievelike cells that contribute to translocation. The brown algae have chlorophyll a and c, as well as carotenes and xanthophylls. Cell walls are composed of cellulose layered with polysaccharide (such as the valuable alginic acid.) Brown algal cells have a single nuclei and thylakoids in the chloroplast occur in bands of three. Most brown algae produce a motile cell (zoospores or gametes, or both).

Red algae

With over 4,000 species, most from marine habitats, the red algae range in morphology from simple unicells to unbranched and branched filaments to complex multiaxial uprights and crusts. Their pigments include chlorophyll a and the phycobiliproteins, red phycoerythrin (often the dominant pigment) and blue phycocyanin, as well as carotenes, lutein, zeaxanthin. Most reds have a complex life history with three phases: tetrasporophyte, gametophyte and carposporophyte. In fact, the post-fertilization development of the carposporophyte is the best part of each species' story. Red algae have no flagellated stages; their non-swimming sperm are called "spermatia." What are the odds of their success?

Phytoplankton

The term "phytoplankton" refers to a lifestyle, not a particular type of organism - many plant taxa have representatives that are phytoplankton. Within this set of pages I present basic information about phytoplankton, hoping to inspire you to look for yourself at these charismatic organisms. Phytoplankton display an amazing diversity of size, shape, color and motility which can only be appreciated by looking at them under a microscope. The rewards for a small amount of collecting effort are immense - so look on!

Seagrasses

Grasses are monocots--vascular plants (division Spermatophyta or Anthophyta) and a few, the seagrasses, have adapted to photosynthesis and reproduction in salt water. Seagrasses have well-developed rhizomes (horizontal stems) and air spaces (lacunae) that aid gas exchange and floatation of the flat leaves.

Acanthophora(1), Acetabularia(2), Actinotrichia(1), Amphiroa(1), Asparagopsis(1), Botryocladia(2), Bryopsis(1), Caulerpa(15), Chaetomorpha(1), Chlorodesmis(1), Cladophora(1), Codium(3), Colpomenia(1), Corallina(1), Corallinales(1), Dictyosphaeria(2), Dictyota(2), Falkenbergia(1), Fucus(2), Galaxaura(2), Gelidium(2), Gracilaria(3), Grüne(1), Halimeda(3), Halymenia(1), Hypnea(2), Kallymenia(1), Lomentaria(1), Mastophora(1), Mesophyllum(1), Neomeris(1), Padina(1), Penicillus(1), Peyssonnelia(3), Predaea(1), Rhodopeltis(1), Sargassum(1), Scinaia(1), Solieria(1), Turbinaria(1), Udotea(1), Ulva(2), unbekannte(1), Valonia(2), Ventricaria(1), Wrangelia(1), Zostera(1)