Overview of the main algal groups

Phylum Cyanophyta (blue-green algae/cyanobacteria) - Search Algaevision

  • blue-green, grey-green, violet, brown, purplish or red dependent on relative proportions of chlorophyll, phycocyanin and phycoerythrin
  • sometimes a brown sheath pigment (scytonemin) present
  • unicellular, colonial or filamentous (simple or branched)
  • internal membranes absent and so no organelles

Phylum Rhodophyta (red algae) - Search Algaevision

  • commonly red due to predominance of phycocyanin and phycoerythrin in chloroplasts
  • unicellular, filamentous or pseudoparenchymatous (flagellated stages absent)
  • food storage material - various, including floridean starch
  • unique features associated with reproduction

Phylum Euglenophyta (euglenoids) - Search Algaevision

  • green
  • commonly unicellular
  • often exhibit squirming movements, sometimes surrounded by an envelope or lorica
  • chloroplasts variously shaped
  • one or two flagella arising in a flask-shaped invagination
  • eyespot red, usually evident
  • walls with longitudinal or spiral striations
  • food storage material - paramylon

Phylum Cryptophyta (cryptomonads) - Search Algaevision

  • brown, blue, blue-green, red, red-brown, olive green, or yellow-brown due to accessory
  • pigments in one or two chloroplasts
  • unicellular (rarely colonial), often bean-shaped, frequently dorsiventrally flattened
  • two or more unequal subapical flagella arising in an anterior invagination
  • food storage material - starch or starch-like

Phylum Dinophyta (dinoflagellates) - Search Algaevision

  • usually brown due to presence of accessory pigments
  • unicellular, rarely coccoid or filamentous
  • walls firm or of regularly arranged polygonal plates
  • biflagellate - one flagellum transverse and encircling the cell, other directed posteriorly directed
  • food storage materials - starch and oil

Phylum Raphidophyta - Search Algaevision

  • yellow-green due to predominance of accessory pigment diatoxanthin in two or more chloroplasts
  • unicellular, dorsiventrally organised, with no outer wall (naked)
  • two flagella arising in an apical, funnel-shaped invagination, one flagellum directed forwards and other backwards
  • food storage material - oil

Phylum Haptophyta - Search Algaevision

  • cells are golden or yellow-brown due to presence of accessory pigments (principally fucoxanthin)
  • unicellular
  • flagellates have amoeboid, coccoid, palmelloid or filamentous stages
  • walls often possess calcified scales
  • two flagella, and between them an appendage known as a haptonema
  • food storage material - principally chrysolaminarin

Phylum Chrysophyta (golden-brown algae) - Search Algaevision

  • cells are golden to yellow-brown due to presence of accessory pigments
  • single coccoidal cells or palmelloid, filamentous or parenchymatous
  • mostly uniflagellate or with two flagella, one long and the other short
  • outer wall absent or cell(s) within an often urn-shaped envelope (lorica)
  • silica scales sometimes present
  • food storage material - oil or leucosin

Phylum Xanthophyta (yellow-green algae) - Search Algaevision

  • cells are typically yellow-green due to present of the accessory pigment diatoxanthin in two or more chloroplasts
  • unicellular, filamentous, colonial or coenocytic
  • motile forms have two subapical flagella
  • walls frequently of overlapping parts
  • food storage material - oil, fat or leucosin

Phylum Chlorophyta (green algae) - Search Algaevision

  • cells with one to several green chloroplasts
  • unicellular, colonial, filamentous, coenocytic or macrophytes with robust axes bearing
  • worls of branches and branchlets
  • motile or non-motile - if motile then normally have one, two or four usually apical flagella
  • food storage material - principally starch surrounding in one to several pyrenoids
  • sexual reproduction oogamous in some orders

Phylum Eustigmatophyta - Search Algaevision

  • cells are yellow-green, with main accessory pigment usually violaxanthin in one or more chloroplasts
  • unicellular and coccoidal
  • motile forms have one flagellum or two unequal flagella inserted near apex
  • eyespot unique, independent of chloroplast
  • pyrenoid unique
  • food storage material unknown

Phylum Phaeophyta (brown algae) - Search Algaevision

  • cells are brownish due to presence of carotenoids pigments (principally fucoxanthin) in one to several chloroplasts
  • freshwater species of microscopic branched filaments (often closely packed)
  • motile stages pear-shaped with two laterally inserted flagella
  • walls frequently contain alginic acid and fucinic acid
  • food storage materials - laminarin and mannitol

Phylum Prasinophyta (primitive green algae) - No images currently available on Algaevision

  • cells have green, rarely yellow-green, chloroplasts
  • unicellular flagellates, rarely non-motile, with one to eight lateral or apical flagella,
  • uually arising at base of a depression
  • walls and flagella mostly covered with organic scales
  • food storage material - starch or mannitol

Phylum Glaucophyta - Search Algaevision

  • cells are bright blue-green due to presence of phycocyanin and other pigments in
  • cyanelles (not equivalent to chloroplasts)
  • unicellular or colonial
  • food storage material – starch, produced outside the cyanelles

Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith