I was just wondering what the difference was between the common green algae and the brown algae.
Any info will help me and others.
Thanks,
Mudvayne
Any info will help me and others.
Thanks,
Mudvayne
What is the diffgerence between algae
- Thread starter mudvayne
- Start date
When the term Algae is used today, it refers to simple eukaryotic photosynthetic organisms, unicellular or multicellular, which have their pigments localized in membrane-bounded intracellular bodies and have no vascular system.
though they are extremely numerous, they do not exist as a taxonomic group. originally, they were placed mainly within the Plant Kingdom as a diverse group which included microscopic unicells at one end of the size scale, and giant ocean kelp with fronds extending a hundred metres at the other.
currently they are regarded as separate phyla within the Kingdom Protoctista -- a large group which includes all the microscopic unicells having a nucleus. within the new classification, there is enormous diversity. the grouping still includes microscopic unicells at one end of the scale and giant ocean kelp at the other.
the separation of the bacteria and the blue-green algae from the other micro organisms marks the most important shift in the last hundred years in terms of the way life on Earth is viewed. blue-green algae are now classified among the Bacteria. It is in effect the division of all living creatures into two major groups:
1. The Prokaryotes -- those having no nucleus (Kingdom Bacteria: the traditional bacteria and blue-green algae), and
2. the Eukaryotes, those which have a nucleus. The Eukaryotes are therefore all living creatures except the bacteria and blue-green algae. They comprise the remaining four Kingdoms: Protoctista, Fungi, Plants and Animals.
The algal phyla which most concern the freshwater biologist are:
Bacillariophyta
known as diatoms, they exist as both unicellular and colonial. they have a silica shell in two parts and no flagellae. they are enormously abundant in the oceans and freshwater. they comprise a sizeable fraction of all life on Earth. over ninety percent of the biosphere is plant life, of which diatoms make up about a quarter by weight. they are enormously abundant in the upper layers of the world's oceans, providing high-grade nutrition to creatures as diverse as protozoans and baleen whales, and supplying the atmosphere with around a quarter of its oxygen.
most diatoms are much less than half a millimetre in size, but their oil-rich, silica-shelled bodies, sinking to the ocean floor in vast numbers over long periods of time, have been transformed into the petroleum deposits of the world, and their skeletons have formed thick strata of diatomaceous earth which has found application in human products as varied as dynamite and toothpaste.
While most diatoms are to be found in the oceans, they are also abundant and important in freshwater habitats and in moist soil. the siliceous skeleton common to all varieties is frequently described as structured like a pill box or Petri dish, and offers two possible views -- the valve view (as in viewing a Petri dish from the top) and the side or girdle view. they present a great variety of shapes which are mostly symmetrical, and rectangular.
the photosynthetic pigment of diatoms is brown, and occurs in the pennate diatoms usually in the form of two identical plastids running the length of the cell, and in the centric diatoms in the form of numerous sometimes clumped granules.
http://www.indiana.edu/~diatom/cystelli.jpg
Chlorophyta.
A large and varied group of green pigmented algae which store energy in pyrenoids and as starch. Forms include unicellular, filamentous and colonial varieties. Includes Chlorella, Spirogyra, Scenedesmus, Oedogonium, Volvox.
Chrysophyta.
Golden-brown algae. Includes Synura, Uroglena.
Charophyta.
Stoneworts: occur in ponds attatched to the bottom by rhizoids. Includes Chara, Nitella.
Cryptophyta.
Unicellular, with two slightly unequal flagellae at the apical end. Includes Chilomonas, Cryptomonas.
Cyanophyta.
Blue-green algae; also called cyanobacteria. Have no nuclei. Includes Anabaena, Oscillatoria, Nostoc, Spirulina. these are now classified amongst the Bacteria -- their lack of a nucleus distinguishes them from all the other algae.
Dinophyta
Dinoflagellates. Unicellular, biflagellate with flagellae in two different planes. External cell wall often features sculptured plates. Frequently the main organism in toxic algal blooms.
Euglenophyta:
Unicellular with single obvious flagellum. Usually have a red eyespot, green plastids and paramylon granules, called pyrenoids.
Includes Euglena, Phacus, Trachelomonas.
Haptophyta.
Also called Haptomonada. A smaller group of unicells bearing calcareous plates (scales and coccoliths) and a haptonema, visible only with an electron microscope in most cases. Primarily marine; few freshwater genera.
Xanthophyta.
Yellow-green algae; colour due to chlorophyll and carotenoid pigments. May be unicellular, filamentous, colonial or siphonaceous in form. Includes Tribonema, Botrydium.
Phaeophyta: Overwhelmingly marine and macroscopic. Includes kelps.
Rhodophyta
Mainly marine. For much of the course of life on Earth, these microscopic algae have been, and are still, extremely important. More than 10,000 living diatom species are known, with about the same number of named fossil forms.
http://www.thetropicaltank.co.uk/algae.htm#brown
though they are extremely numerous, they do not exist as a taxonomic group. originally, they were placed mainly within the Plant Kingdom as a diverse group which included microscopic unicells at one end of the size scale, and giant ocean kelp with fronds extending a hundred metres at the other.
currently they are regarded as separate phyla within the Kingdom Protoctista -- a large group which includes all the microscopic unicells having a nucleus. within the new classification, there is enormous diversity. the grouping still includes microscopic unicells at one end of the scale and giant ocean kelp at the other.
the separation of the bacteria and the blue-green algae from the other micro organisms marks the most important shift in the last hundred years in terms of the way life on Earth is viewed. blue-green algae are now classified among the Bacteria. It is in effect the division of all living creatures into two major groups:
1. The Prokaryotes -- those having no nucleus (Kingdom Bacteria: the traditional bacteria and blue-green algae), and
2. the Eukaryotes, those which have a nucleus. The Eukaryotes are therefore all living creatures except the bacteria and blue-green algae. They comprise the remaining four Kingdoms: Protoctista, Fungi, Plants and Animals.
The algal phyla which most concern the freshwater biologist are:
Bacillariophyta
known as diatoms, they exist as both unicellular and colonial. they have a silica shell in two parts and no flagellae. they are enormously abundant in the oceans and freshwater. they comprise a sizeable fraction of all life on Earth. over ninety percent of the biosphere is plant life, of which diatoms make up about a quarter by weight. they are enormously abundant in the upper layers of the world's oceans, providing high-grade nutrition to creatures as diverse as protozoans and baleen whales, and supplying the atmosphere with around a quarter of its oxygen.
most diatoms are much less than half a millimetre in size, but their oil-rich, silica-shelled bodies, sinking to the ocean floor in vast numbers over long periods of time, have been transformed into the petroleum deposits of the world, and their skeletons have formed thick strata of diatomaceous earth which has found application in human products as varied as dynamite and toothpaste.
While most diatoms are to be found in the oceans, they are also abundant and important in freshwater habitats and in moist soil. the siliceous skeleton common to all varieties is frequently described as structured like a pill box or Petri dish, and offers two possible views -- the valve view (as in viewing a Petri dish from the top) and the side or girdle view. they present a great variety of shapes which are mostly symmetrical, and rectangular.
the photosynthetic pigment of diatoms is brown, and occurs in the pennate diatoms usually in the form of two identical plastids running the length of the cell, and in the centric diatoms in the form of numerous sometimes clumped granules.
http://www.indiana.edu/~diatom/cystelli.jpg
Chlorophyta.
A large and varied group of green pigmented algae which store energy in pyrenoids and as starch. Forms include unicellular, filamentous and colonial varieties. Includes Chlorella, Spirogyra, Scenedesmus, Oedogonium, Volvox.
Chrysophyta.
Golden-brown algae. Includes Synura, Uroglena.
Charophyta.
Stoneworts: occur in ponds attatched to the bottom by rhizoids. Includes Chara, Nitella.
Cryptophyta.
Unicellular, with two slightly unequal flagellae at the apical end. Includes Chilomonas, Cryptomonas.
Cyanophyta.
Blue-green algae; also called cyanobacteria. Have no nuclei. Includes Anabaena, Oscillatoria, Nostoc, Spirulina. these are now classified amongst the Bacteria -- their lack of a nucleus distinguishes them from all the other algae.
Dinophyta
Dinoflagellates. Unicellular, biflagellate with flagellae in two different planes. External cell wall often features sculptured plates. Frequently the main organism in toxic algal blooms.
Euglenophyta:
Unicellular with single obvious flagellum. Usually have a red eyespot, green plastids and paramylon granules, called pyrenoids.
Includes Euglena, Phacus, Trachelomonas.
Haptophyta.
Also called Haptomonada. A smaller group of unicells bearing calcareous plates (scales and coccoliths) and a haptonema, visible only with an electron microscope in most cases. Primarily marine; few freshwater genera.
Xanthophyta.
Yellow-green algae; colour due to chlorophyll and carotenoid pigments. May be unicellular, filamentous, colonial or siphonaceous in form. Includes Tribonema, Botrydium.
Phaeophyta: Overwhelmingly marine and macroscopic. Includes kelps.
Rhodophyta
Mainly marine. For much of the course of life on Earth, these microscopic algae have been, and are still, extremely important. More than 10,000 living diatom species are known, with about the same number of named fossil forms.
http://www.thetropicaltank.co.uk/algae.htm#brown
