There are over 25 species.

The major species are as follows:

A. aequalis
A. affinis
A.angstumalis marchita
A. aphanizomendoides
A. azollae
A. bornetiana
A. catenula
A. cedrorum
A. circinalis
A. confervoides
A. constricta
A. cyanobacterium
A. cycadeae
A. cylindrica
A. echinispora
A. felisii
A.flos-aquae flos-aquae
A. helicoidea
A. inaequalis
A. laxa
A. lemmermannii
A.macrospora macrospora
A. macrospora robusta
A. monticulosa
A. nostoc
A. oscillarioides
A. planctonica
A. scheremetievi
A. sphaerica
A. spiroides crassa
A. subcylindrica
A. torulosa
A. unispora
A. verrucosa
A. viguieri
A. wisconsinense
A. zierlingii

Anabaena is used as a model organism to study simple vision. The process in which light changes the shape of molecules in the retina, thereby driving the cellular reactions and signals that cause vision in vertebrates, is studied in Anabaena. Anabaena Sensory Rhodopsin, a specific light sensitive membrane protein, is central to this research.

The symbiotic relationship between A. azollae and Azolla has benefited farmers across the world. Because of the “in house” nitrogen source provided by A. Azollae, Azolla has been used as "green manure" in India, China and other south east asian countries to fertilize rice paddies and increase rice production.Azolla is either incorporated as green manure at the beginning of the cropping season or grown as a dual crop along with rice, in the standing water of flooded fields.

In addition to fertilizer, Azolla is also used in fish food and garden mulch and is a natural food for various types of insects. Azolla can be used and as a water purifier and for the control of weeds, mosquitoes, and the reduction of ammonia volatilization that accompanies the application of chemical nitrogen fertilizers.

List of major species are as follows:

Aphanothece atro-crustacea

Aphanothece bacilloidea 

Aphanothece bacteriosa  

Aphanothece bachmannii 

Aphanothece biceps

Aphanothece botryosa

Aphanothece bullosa 

Aphanothece caldariorum

Aphanothece castagnei 

Aphanothece clathrata 

Aphanothece cohenii 

Aphanothece comasii

Aphanothece conglomerata

Aphanothece curvata 

Aphanothece cylindracea 

Aphanothece desikacharyi

Aphanothece elabens

Aphanothece endophytica

Aphanothece floccosa

Aphanothece gardneri 

Aphanothece goetzei

Aphanothece granulosa

Aphanothece hardersii 

Aphanothece hegewaldii

Aphanothece karukerae 

Aphanothece krumbeinii

Aphanothece lemnae

Aphanothece marina 

Aphanothece maritima

This algae can produce glutamic acid, methionin, and phenylalanine, though its commercial production is yet to start.

Currently, seven major species are known:

Artemia tunisiana 
 Artemia species  
 Artemia franciscana
 Artemia parthenogenetica  
 Artemia sinica
 Artemia persimilis  
 Artemia urmiana

Artemia presently is exclusively used as fish fodder and
is one of the most popular fodders in industrial fishery.
Artemia is a superb, highly nourishing fodder for
industrial fish and shrimp bred at fish farms.
Due to its chemical composition, Artemia turned out to be
one of the best fodders for sturgeon fingerlings.

It is known in some cases that Artemia served as human food
as well. For example, American Indians living near Utah’s
Salt Lake found these crayfish to be quite delicious. Arabs
migrating westward from the Nil riverbed collected Artemia in salt lakes and prepared paste that, according to well-known
German geographer August Peterman (1822–78), reminded them of salted herring and ate Artemia instead of meat.

The major species are as follows:

B. argillaceum

B. becherianum

B. corniforme

B. cystosum

B. divisum

B. granulatum

B. milleri

B. pachydermum

B. stoloniferum

B. tuberosum

B. wallrothii

It is produces algae biodisel.

The major species are as follows:

C. moniligera
C. antennina
C. crassa
C. linum
C. okamurae
C. aerea
C. brachygona
C. spiralis

Chaetomorpha is cultivated for Chanos culture in brackishwater ponds and Consumed as food. It is also used for manufacture of a sweet meat.
Chaetomorpha is especially common in saltwater aquariums because it can be used for removal of nutrients, especially nitrates. Aquarists will commonly house this alga, perhaps with others, in a refugium. Once it has grown to a significant mass, a chunk of the algae is removed to be thrown out or donated to another aquarist, taking the nutrients it has absorbed out of the system. 
In addition to nutrient export, Chaetomorpha is known to host beneficial amphipods which can subsequently be used as a food source for corals and animals that may reside within the aquarium. 

The dominant species are as follows:

Chlorella vulgaris

Chlorella ellipsoidea

Chlorella pyrenoidosa

Chlorella autotrophica
Chlorella minutissima
Chlorella sorokiniana
Chlorella variabilis

 

The algae is used as production of other carotenoids such as lutein and canthaxanthin
In 1965, the Russian CELSS experiment BIOS-3 determined that 8 m2 of exposed Chlorella could remove carbon dioxide and replace oxygen within the sealed environment for a single human. The algae were grown in vats underneath artificial light.

Chlorella is consumed as a health supplement primarily in the United States and Canada and as a food supplement in Japan.

It is a Oxidative stress tolerant algae.It has limited cultivation in brackishwater fish ponds in Philippines by application of commercial fertilizers.
Cladophora is accused of damaging the fishing industry and shoreline property values along the Great Lakes in the United States. Quagga mussel populations have also increased tremendously in the same time frame.

Crypthecodinium cohnii is unicellular microorganisms,
,grown in a culture  medium including propionic acid.
The propionic acid increases the production of one
or more of dry cell weight, total lipid and docosahexaenoic

acid. 

This algae produces of PUFA, &

Polysaccharide, It also acts as a supplement for infant dietary intake, It also produces docosahexaenoic acids.

U.S. Pat. no. 5,407,957 discloses a method for culture of Crypthecodinium cohnii in a medium comprising glucose, as a carbon source, and yeast extract, dissolved in seawater.

Dunaliella is a motile, unicellular, rod  to ovoid shaped
(9−11 µm) green algae (Chlorophyceae), which are
 common in marine waters. The organisms are relatively
simple to cultivate and do not clump or form chains.

The dominant species are as follows:

D. acidophila

D. bardawil

D. bioculata

D. lateralis

D. maritima

D. minuta

D. parva

D. peircei

D. polymorpha

D. primolecta

D. pseudosalina

D. quartolecta

The major species are as follows:

Gelidium sesquipedale
Gelidium abbottiorum
Gelidium anansii

This algae used for production of human food,medicines, industrial products,and food ingredients etc.It is also used for production of agar agar. Medicines, Industrial applications,

Food ingredients, Personal care and Food Process.

Gelidium corneum contains hydrocolloid gel that is stronger than that found in most algae. Because of this, Gelidium corneum is a very important raw material for high quality (bacteriological grade) agar and agarose. It is also used in the confectionery food industry as Kanten (gelatine vegetale, isinglass) which can be made into edible paper (kanten-gami) or used in a variety of other applications as a vegetarian gelatin.

Gracilaria is a genus of red algae (Rhodophyta) notable for
its economic importance as an agarophyte, as well as its use
as a food for humans and various species of shellfish.
Various species within the genus are cultivated among Asia,
South America, Africa and Oceania.

The dominant species are as follows:

Gracilaria verrucosa
Gracilaria lemaneiformis
Gracilaria asiatica
Gracilaria tenuistipitata
Gracilaria verrucosa

The algae produces polysaccharides.
Gracilaria commonly appears as a macroalgae for sale in the aquarium trade. Its nutrient uptake ability makes it a suitable choice for a refugium, and it is a highly palatable algae to many herbivorous fish, such as tangs.
 Gracilaria is used as a food in Japanese, Hawaiian, and Filipino cuisine.
In the Philippines, it is called gulaman and used to make gelatin, also called gulaman.

The dominant species are as follows:

H. bikinensis
H. borneensis
H. cereidesmis
H. copiosa
H. cryptica
H. cuneata
H. cylindracea
H. discoidea
H. distorta
H. favulosa
H. fragilis
H. gigas
H. goreauii
H. gracilis
H. heteromorpha
H. howensis
H. hummii
H. incrassata
H. kanaloana
H. lacrimosa
H. lacunalis
H. macroloba
H. macrophysa
H. magnidisca
H. melanesica
H. micronesica
H. minima
H. pumila
H. pygmaea
H. simulans
H. stuposa
H. tuna
H. velasquezii

This algae is a Source of high carbohydrate.

Halimeda is responsible for distinctive circular deposits in various parts of the Great Barrier Reef on the north-east coast of Queensland,Australia. Halimeda beds form in the western or lee side of outer shield reefs where flow of nutrient-rich water from the open sea allows them to flourish, and are the most extensive, actively accumulating Halimeda beds in the world.

 

The dominant species are as follows:

Lyngbya aestuarii
Lyngbya bouillonii
Lyngbya confervoides
Lyngbya kuetzingii
Lyngbya polychroa
Lyngbya semiplena
Lyngbya hieronymusii

This algae is used as assay of antibacterial activity.
 Some Lyngbya cause the human skin irritation called seaweed dermatitis.

These are the four currently accepted species:

Macrocystis angustifolia
Macrocystis integrifolia
Macrocystis laevis
Macrocystis pyrifera  

The dominant species are as follows:

Microcystis aeruginosa
Microcystis argentea
Microcystis elongata
Microcystis holsatica
Microcystis lutescens
Microcystis marina
Microcystis pallida
Microcystis salina
Microcystis thermalis
Microcystis viridis

Human beings are likely to experience serious illness from drinking water containing large concentrations of microcystin.  In 1988 in Brazil, massive contamination of a drinking water reservoir with microcsytin caused over 2,000 cases of severe gastroenteritis with 88 deaths.  Fatalities have also been reported where microcsytin accidentally contaminated water used for kidney dialysis.  However, as noted above, there are no reports of fatalities or even serious illness resulting from recreational water activities related to Microycstis aeruginosa.  Nor is it clear what role, if any, microcsytin might play in causing the minor gastrointestinal or respiratory symptoms that sometimes occur following recreational water use where microcsytin is present in the water.

 

The dominant species are as follows:

N. azollae
N. caeruleum
N. carneum
N. comminutum
N. commune
N. ellipsosporum
N. flagelliforme
N. linckia
N. longstaffi
N. microscopicum
N. muscorum
N. paludosum
N. pruniforme
N. punctiforme
N. sphaericum
N. sphaeroides
N. spongiaeforme
N. verrucosum

The algae fixes carbon dioxide and nitrogen; produces hydrogen; survives acidic, anaerobic, and low-temperature
conditions.
Nostoc is a genus of cyanobacteria found in a variety of environmental
niches that forms colonies composed of filaments of moniliform cells in a gelatinous sheath. The name Nostoc was coined by Paracelsus.
Containing protein and vitamin C, [citation needed] Nostoc species are cultivated and consumed as a foodstuff, primarily in Asia. The N. flagelliforme and N. commune varieties are consumed in China, Japan and Java, N. commune is also consumed in the Andes. The preferred variety in Central Asia is N. ellipsosporum.

A research team from the biochemistry
department of the Chinese University of
Hong Kong said that international research
has shown that fat choy (Nostoc flagelliforme),
besides having no nutritional value, has also
been found to contain Beta-methylamino
L-alanine(BMAA), a toxic amino acid that
could affect the normal functions of nerve
cells. Professor Chan King-ming of the team
told the media that eating fat choy could
lead to degenerative diseases such as Alzheimer's, Parkinson's, and dementia.

The dominant species are as follows:

Oscillatoria limnetica
Oscillatoria salina
Oscillatoria laete-virens
Oscillatoria boryana
Oscillatoria acula
Oscillatoria acuminata sensu
Oscillatoria acuminata
Oscillatoria acuminata var. longe-attenuata
Oscillatoria animalis
Oscillatoria animalis
Oscillatoria apiculata
Oscillatoria rostrata
Oscillatoria sonorensis
Oscillatoria variabilis
Oscillatoria amethystina
Oscillatoria difficilis
Oscillatoria ibusukiensis
Oscillatoria schultzii
Oscillatoria uncinata
Oscillatoria granulata
Oscillatoria hummelii
Oscillatoria subformosa
Oscillatoria subsalsa
Oscillatoria tuwaensis
Oscillatoria biswasii
Oscillatoria gerdae
Oscillatoria luteola
Oscillatoria minnesotensis
Oscillatoria subpristleyi

Used in Pharmaceuticals,
Used as biofertilizers
Used as biofertilizers
Degradation and metabolisation of melaoidin pigment of distillery effluents .

Palmaria palmate
Palmaria stenogona

It is used as protein source.

Palmaria palmata also known as Dulse is a good source of minerals and vitamins compared with other vegetables, contains all trace elements needed by humans, and has a high protein content.
It is used in cooking: dulse's properties are similar to those of a flavour-enhancer. It is commonly referred to as dillisk on the west coast of Ireland. Dillisk is usually dried and sold as a snack food from stalls in seaside towns by periwinkle-sellers.

The dominant species are as follows:

Phormidium valderianum
Phormidium lucidum
Phormidium fragile
Phormidium tenue
Phormidium acuminatum
Phormidium janthiphorum
Phormidium lloydianum
Phormidium anabaenoides
Phormidium karakalpakense
Phormidium paulsenianum
Phormidium richardsii
Phormidium tortuosum  
Phormidium animale
Phormidium californicum
Phormidium ceylanicum
Phormidium cortianum
Phormidium dimorphum
Phormidium gardnerianum
Phormidium hennigsii
Phormidium insigne
Phormidium kolkwitzii
Phormidium okenii
Phormidium paucigranatum
Phormidium pavlovskoense
Phormidium pseudocortianum
Phormidium pseudopristleyi
Phormidium regelii
Phormidium roseum
Phormidium salinarum

The algae used as a aquaculture feed source,

The algae also used as a source of phycocyanin,

It is used in Production of phytobilin

pigments ,

this is used as pharmaceutiacals industry.

The dominant species are as follows:

Porphyra dioica

Porphyra linearis Grev.
Porphyra lucasii

Porphyra mumfordii

Porphyra purpurea (Roth)

Porphyra umbilicalis 

Used as food  or food supplements, protein source, minerals and trace elements
Most human cultures with access to Porphyra use it as a food or somehow in the diet, making it perhaps the most domesticated of the marine algae, known as laver, nori(Japanese), amanori (Japanese), zakai, gim (Korean), zicai (Chinese), karengo, sloke or slukos.The marine red alga Porphyra has been cultivated extensively in many Asian countries as an edible seaweed used to wrap the rice and fish that compose the Japanese food sushi, and the Korean food gimbap. In Japan, the annual production ofPorphyra spp. is valued at 100 billion yen (US$1 billion).
Nori has always been a staple in the diet of most Asian countries, such as China and Japan. Once collected, nori is washed in freshwater to get rid of the sediments, finely chopped, and spread on frames to dry. Often, nori is toasted and flavored for use in cooking. It is often sprinkled over rice as a flavoring, or used in sushi!
Besides Asian cultures, others have also utilized Porphyra as a food. In Ireland and the Wales, Porphyra is called laver and can be prepared by frying it in fat or as a pinkish jelly, which can be prepared by heating the fronds in a saucepan with minimal water and beating with a fork.
 
Porphyra does have a few medicinal benefits. It contains a sulfated polysaccharide called porphyran, which is a complex galactan. The physiological activity of porphyran in the animal body isn't clear right now, but studies have indicated some excellent health benefits from it. It may inhibit the growth of certain tumors. Also, when nori powder was mixed with a basic diet at 2% concentration and fed to rats, it preventd a purposely induced carcinogenesis. These results may be have been caused by the sulfation of the polysaccharide, which can enhance the effectiveness of it.
Another substance called porphyosin has been isolated from Porphyra. It appears to exhibit anti-ulcer activity in shay ulcers. However, porphyosin was found to be ineffective against stress ulcers.
In China and Japan, there are 7 main species used in commercial cultivation.
Porphyra yezoensis
Porphyra tenera
Porphyra haitanensis
Porphyra pseudolinearis
Prophyra kunideai
Porphyra arasaki

Porphyra seriata

The dominant species are as follows:
Porphyridium cruentum
porphyridium marinum
porphyridium purpureum
porphyridium sordidum
porphyridium violaceum 

The algae is used for production of polysaccharides,lipids,

PUFAs

The impotrtant species is:
sargassum natans
sargassum pallidum

The algae is a Unique source of PUFA

The major species are as follows:
Spirulina plantesis
Spirulina subsalsa
sprirulina fusiformis

It is used as protein source, rich source of beta-carotene, thiamine, riboflavin,
It is also used in pharmaceuticals
It is used as food supplement, rich source of beta-carotene, thiamine, riboflovin

The dominant species are as follows:
Tetraselmis suecica
Tetraselmis alacris
Tetraselmis apiculata 
Tetraselmis ascus 
Tetraselmis astigmatica
Tetraselmis chuii 
Tetraselmis convolutae
Tetraselmis cordiformis
Tetraselmis desikacharyi
Tetraselmis gracilis
Tetraselmis hazeni
Tetraselmis impellucida 

It is used as mass-oil producing-crop.

The dominant species are as follows:
Ulva lactuca

Source of protein, minerals and trace elements
U. lactuca is locally used in Scotland in soups and salads.Ulva lactuca is available in different forms
from companies in countries which include the UK, Ireland, France, Germany, Vietnam, China, Canada,
and the United States. It is sold both in fresh and dried form, in flakes, powders, and salad mixes. It is
a delicate seaweed with a mild flavor. Ulva lactuca is sometimes eaten as "green laver", but it is
considered inferior to purple laver. It is used as a seasoning by itself and in blends, and can be found in
soups and salads. It is a key ingredient in many cosmetic and personal care items such as soap, lotion,
toner, lifting cream, eye cream, lip cream, makeup remover, body polish, bath soaks, anti-aging products,
shaving lotion, shampoo, conditioner, and serums. It is also a component in gardening and fertilizer
products. Leading cosmetic brands which use Ulva lactuca as an ingredient in anti-aging products cite
that it contains a high concentration of amino acids (proline, glycine, lysine) which are the basic
components of proteins, and that it has an ability to stimulate the cells in the connective tissues to
synthesize collagen. This in turn can improve the skin’s elasticity and reduces lines and wrinkles.
Harvesting 

Ulva lactuca can be picked from spring into the summer depending upon weather and amount of sun.

The dominant species are as follows:

Undaria crenata
Undaria peterseniana
Undaria pinnatifida
Undaria undarioides

It is used in sea food products and also used as human food.
Undaria pinnatifida has a high nutritional value, containing high levels of calcium, iodine, thiamine, niacin, iron, vitamin B12, and protein. It is also a rich source of eicosapentaenoic acid, an omega-3 fatty acid, and also of polysaccharides.
A compound in Undaria pinnatifida known as fucoxanthin can help burn fatty tissue, even around internal organs. In Oriental medicine, Undaria pinnatifida has been used for blood purification, intestinal strength, skin, hair, reproductive organs and menstrual regularity.
Undaria pinnatifida can be considered a a sea vegetable, or edible seaweed. 
Health and personal care products including Undaria pinnatifida as an ingredient include:
Shampoo, hair treatments, and bath treatments
hand and foot care products
soaps, body polishes and oils
skin cleanser and toner products, detoxifying facial products
day creams and night creams
tooth cleaning products
There are many forms of edible Undaria pinnatifida, or wakame, including:
dried, chips, flakes, and strips
as an ingredient in sea vegetable salads, in condiments and chutneys
with soup and salad and pasta and oatmeal mixes
capsule form as a diet supplement
beer

Undaria pinnatifida is also included in some fertilizers and agricultural treatments.