Rhodophyta A long chain of glucose sugars with lots of side branches. Store sugars as glycogen or Floridean starch A long chain of glucose sugars with lots of side branches. They are also known as red algae or rhodophytes. They are multicellular organisms. Characterized by photosynthetic pigments such as phycoerythrin, phycocyanin and allophycocyanins, and the absence of flagella and centrioles. They don’t have chloroplast endoplasmic reticulum. Characterized by their branching. They are able to thrive at deeper depths of the ocean compared to other algae. They are mostly found along the coastal and continental shelf areas of tropical, temperate and cold- water regions. It consists of approximately 5000 genera and 5000 species. It is one of the most ancient eukaryotes, with fossils that date back to the mid-proterozoic.

Structures Open protoplasmic connection connects daughter cells. Pitplug closes the connection between 2 daughter cells. Red, algal cell wall An inner layer with cellulose. Gelatinous outer layer. Contain amorphous mucilages (shapeless mucuses). Nuclei Chloroplasts Contain phycobilins, chlorophyll a, carotenes, xanthophylls. Phycobilisomes Involved in photosynthesis Spermatangia Male reproductive organ, filled with spermatia (male reproductive cell). Carpogonium Female reproductive organ.  Trichogyne Hair like receptor of the carpogonium. Cytoplasm Forms floridean starch

Reproduction Reproduce both sexually and asexually. The spermatium relies on water to reach the carpogonium. It makes contact with trichogyne and its nucleus merges with that of the carpogonium. The carpogonium forms a large bulb, which separates and becomes young red algae.

Nutrition They obtain energy through photosynthesis. Some rhodophytes were found to be parasitic in nature.

Ecology Some transport nutrients from their host through a haustoria. Some transfer their nuclei into the host plant and hijack the host. Most are found in marine ecosystems, while a few are found in freshwater. They live attached to surfaces. They harness light efficiently, which enables them to live at great depths. Coralline red alga is essential in marine ecosystems because they are reef-building organisms. They produce calcium carbonate in their cell walls. Some red algae have been found to be parasitic

Examples Corallina officinalis Porphyra tenera Galaxaura spp. Tubular thicket algae. Heavily calcified and forms hemispherical domes, up to 15 cm, attached by a single holdfast or root. Its segments branch out dichotomously. Its segments are tubular in shape, smooth, and hard with flexible joints The tips of its branches have a central hole. They are redish to orange and off-white in color. They are most commonly found attached to rocks or rocky surfaces. Corallina officinalis Marine species, also known as coral weed. Whitish-pink to lilac in color. Its calcified, branching and segmented fronds reach up to 12 cm in length from a crustose, disk shaped root. Urn-shaped reproductive organs. 60-70 mm high They are often found attached to rocks or mollusk shells. It is abundant especially on exposed coasts. The calcium carbonate within its cell walls strengthens its structure and causes it to appear pink. This substance also protects them from being eaten by shore grazers. Serve as a home for small organisms which eat the microorganisms living on it. Porphyra tenera It is also known as nori. Small, red alga. They have crinkled edges and are able to reach a width of 20 cm. They are irregularly shaped, leaf-like and membranous. Appear green in their early stages. Appear brownish-purple or purple-red in maturity. They live on exposed coasts and are attached to rocks or mollusks. They can also be found in the midtidal to splash zone. They are most abundant in temperatures between 4-9 °C

Sources http://www.ehow.com/how-does_4574307_algae-reproduce.html http://lifeofplant.blogspot.com/2011/01/red-algae.html http://marinelife.about.com/od/plants/p/redalgae.htm http://www.microscopy-uk.org.uk/mag/indexmag.html?http://www.microscopy-uk.org.uk/mag/artmar99/red.html http://university.uog.edu/botany/Plant_Di/rhodophyta.htm http://www.algaebase.org/search/species/detail/?species_id=107 http://www.marlin.ac.uk/speciesinformation.php?speciesID=3039 http://porphyra.wetpaint.com/ http://www.fao.org/fishery/species/2790/en