The document discusses the classification of algae based on their habitats, identifying three main categories: aquatic, terrestrial, and specialized algae. Aquatic algae are subdivided into freshwater and marine forms, while terrestrial algae can be saprophytic or cryptophytes. Specialized algae are found in extreme environments, such as thermophytic in hot springs and cryophytic on snow, and include various other types living in association with different organisms.

1. Algal identification in
the sent sample

2. many algae which are found inhabiting in a variety of habitats, like terrestrial, cryophytic, parasitic, endophytic, thermophytic,
halophytic etc. So, according to the habitat, we may classify algae as aquatic algae, terrestrial algae and algae of specialized
habitats.
A. Aquatic algae- Majority of algae are aquatic and found either completely submerged or free floating on the surface of
water. These algae occur on pools, ponds, ditches, river, streams, tanks, salt water, etc. Aquatic algae can be further divided into
fresh water forms and marine forms.
(i) Fresh water forms- Numerous types of algae are found in fresh water habitats like pool, ponds, lake, ditches or slow
running river. Chlamydomonas, Volvox and Hydrodictyon are found in stagnant water, whereas Cladophora, Oedogonium,
Ulothrix and few species of Vaucheria occur in slow running water bodies. The members of Xanthophyceae,
Euglenophyceae, Cyanophyceae, Chrysophyceae, Conjugales and Diatoms are common in fresh water.
(ii) (ii) Marine forms- Marine algae are found in salty water of sea and oceans. Generally, the members of phaeophyceae,
Rhodophyceae and some Chlorophyceae (Enteromorpha, Caulerpa. Ulva, Codium, etc.) are found in marine water. Marine
algae have macroscopic thalli and are generally considered as ‘sea weeds’. The free floating and free swimming microscopic
algal forms together with other similar organisms constitute the planktons of water bodies, plankton forming algae may
either be free floating from the beginning and never attached are called Euplantons (e.g., Microcystis, Chlamydomonas,
Scenedesmu, Cosmarium etc.) or attached in the beginning but later becomes free floating are called as Tychoplanktons such
as Cladophora, Cylindrospermum, Rivularia etc. Some unicellular and filamentous forms of algae grow luxuriantly on the
surface of water and make the place leathery called water blooms that give fishy smell and water is not considered for
drinking purpose. Water blooms are generally formed by solitary alga, rarely by few algae. The colour of the algae
determines the colour of the bloom. Water blooms are generally formed by the rapid growth and multiplication of algae.
They generally belong to class Cyanophyceae. However, some members of Chlorophyceae, Chrysophyceae, Pyrrophyceae
and Euglenophyceae are also known to cause water blooms. In the salt lake of Sambhar, Anabaenopsis forms bloom.

3. B. Terrestrial algae- Those algae which are found in soil are termed as terrestrial algae. These algae are either found on the
surface of the soil (saprophytes) or beneath the soil surface (cryptophytes). Vaucheria, Botrydium, Fritschiella and Oedocladium
are some examples of saprophytes while Nostoc, Ananbaena are cryptophytes.
C. Specialized algae- Such algae are found in habitats other than water or soil. There are several types of specialized
habitats:
i. Thermophytic algae- The algae occurring in hot water springs at a very high temperature (70 degree or above) are
thermophytic algae. Oscillatoria brevis, Synechococcus elongates, Mastigocladus, Haplosiphon lignosum, etc. are some
of the examples of thermophytes.
ii. Cryophytic algae- These algae are found on snow clad mountains and impart attractive colours to the snow.
Haematococcus nivalis imparts red colour to the snow, whereas Chlamydomonas yellowstonensis is responsible for the
green colour of the snow particularly in Arctic region. Certain species of Protoderma and Scotiella cause yellow or
yellow green colour, whereas Ancyclonema nordenskioldii imparts brown or purple tinge to the snow.
iii. Halophytic algae- These algae are found in saline water containing high percentage of salts e.g., Dunaliella,
Stephanoptera and Chlamydomonas ehrenbergii.
iv. Lithophytic algae- Some algae grow on moist rocks, wet walls and other rocky surfaces. e.g., Rivularia and
Gloeocapsa.
v. Epiphytic algae- These algae grow on other aquatic plants e.g., Oedogonium, Aphanochaete, Bulbochaete, etc.
vi. Endophytic algae- These algae are found inside the higher plants. Nostoc is found in the thallus of Anthoceros, and
Anabaena grows inside the coralloid roots of Cycas.
vii. Epizoic algae- Many algae grow on the shells of mollusks, turtles and fins of fishes and are known as epizoic algae.
Cladophora is found on snails and shells of bivalves, Protoderma and Basicladia are found growing on back of turtles.
viii. Endozoic algae- Endozoic algal cells are found inside the body of aquatic animals. E.g. Zoochlorella is found inside
the Hydra.

4. ix. Parasitic algae- The best example of parasitic algae is Cephaleuros virescens causing red rust of tea (Camelia sinensis).
Polysiphonia festigata is reported as semiparasite on Ascophyllum nodosum.
x. Symbiotic algae- Several members of Cyanophyceae (Cyanobacteria) grow in association with other plants. Lichen serves as
the best example of symbiosis in which fungi from Ascomycetes and Basidiomycetes grow together with members of
Cyanophyceae.
The algae which had been appear in the intake of the plant:

5. Bacillariophyceae (Diatoms)
Occurrence: In all kind of fresh water,
sea, soil and terrestrial habitats.
Pigments: Chromatophores are yellow or
golden brown. Nature of accessory
pigments is not very definite.
Surirella spp.
Dimensions: Cells are 16-120 μm long
and 12-45 μm wide.

6. Occurrence: Found in sea and
fresh water,
Myxophyceae
(Cyanophyceae or Blue green algae)
Dimensions: Cells
vary from 0.5-9 μm in
diameter.
Microcystis SPP
Ecology: Microcystis is usually part of the
phytoplankton, but may also form
granular clumps on bottom substrates.
Colonies are common in enriched
lakes, ponds and reservoirs or in slow-flowing
eutrophic rivers. Microcystis,
like many other cyanobacteria, prefers high
water temperatures and usually
form blooms during the summer periods under
conditions of adequate
nutrient supply.

7. Order Mysidacea:Holmesimysis,marine (10–20 mm)

8. Chlorophyta Green algae
Occurrence: Most forms are fresh
water and a few are marine.
Dimensions: Cells are 2-50 μm long
(mostly 5-20 μm) and 8-22 μm wide.
Chlamydomonas Spp.
Members of the genus are widely distributed,
being found in every kind of aquatic habitat.
Species of this genus are the most likely green
swimming algal cells to be encountered.
Chlamydomonas is a vast genus, with a very large
number of species described, but many are probably
not true species. Species are difficult to identify.

9. Chlorophyceae (Green Algae)
Occurrence: Most forms are fresh water and a few are
marine.
Coelastrum colonies are cosmopolitan and planktonic in
freshwater habitats (ponds, lakes and slow-flowing rivers) from
arctic to tropical environments. Coelastrum is often abundant in
mesotrophic to eutrophic conditions.
Coelastrum Spp.
Dimensions: Cells are 2-30 μm in diameter and
colonies are up to 100 μm across.
Species of Coelastrum are generally less widespread than those
of Scenedesmus Meyen.

10. Algal Bloom indicate a high rate of contamination and organic waste that help algal
growth