2. Algae - Definition
The term "algae" covers many different organisms capable of producing oxygen through
photosynthesis (the process of harvesting light energy from the sun to generate carbohydrates). These
organisms are not necessarily closely related. However, certain features unite them, while distinguishing
them from the other major group of photosynthetic organisms: the land plants.
History of phycology
The history of phycology is the history of the scientific study of algae. The classification of plants
suffered many changes since Theophrastus (372–287 B.C.) and Aristotle (384–322 B.C.) grouped them
as "trees", "shrubs" and "herbs".
Little is known of botany during the middle ages — it was the Dark Ages of botany.
The development of the study of phycology runs in a pattern comparable with, and parallel to, other
biological fields but at a different rate. After the invention of the printing-press in the 15th century
(with the publication of the first printed book: Gutenberg's Bible of 1488) education enabled people to
read and knowledge to spread.
3. General characteristics
Habitat
The majority of algae live in aquatic habitats . Yet, the word "aquatic" is almost limited in its ability to
encompass the diversity of these habitats. These organisms can thrive in freshwater lakes or in saltwater
oceans. They can also endure a range of temperatures, oxygen or carbon dioxide concentrations, acidity and
turbidity.
For example, giant kelp are found more than 200 meters below the polar ice sheets, according to "Algae,"
while the unicellular green algal species Dunaliella salina is found in very salty, or hypersaline, environments
such as the Dead Sea. Free-floating, mostly unicellular algae that live within illuminated regions of water are
known as planktonic. Those that adhere to surfaces are known as benthic algae. Such algae grow on mud, stones,
other algae and plants, or animals, according to "Algae.“
Algae are also able to survive on land. Some unexpected places where they grow are tree trunks, animal fur,
snow banks, hot springs (according to "Algae") and in soil, including desert crusts
4. Mostly, algae live independently in their various growth forms (single cells, colonies, etc.), but they can also form
symbiotic relationships with a variety of non-photosynthetic organisms including ciliates, sponges, mollusks and
fungi (as lichens). One of the benefits of such relationships is that they enable algae to broaden the horizons of their
habitats.
Nutrition
As a general rule, algae are capable of photosynthesis and produce their own nourishment by using light energy
from the sun and carbon dioxide in order to generate carbohydrates and oxygen. In other words, most algae are
autotrophs or more specifically, photoautotrophs (reflecting their use of light energy to generate nutrients).
However, there exist certain algal species that need to obtain their nutrition solely from outside sources; that is, they
are heterotrophic. Such species apply a variety of heterotrophic strategies to acquire nutrients from organic
materials (carbon containing compounds such as carbohydrates, proteins and fats). Osmotrophy is the absorption of
dissolved substances, and phagotrophy involves engulfing bacteria or other such prey. Other algae, known as
auxotrophs, need to only acquire essential vitamins such as the B12complex or fatty acids (according to "Algae").
5. According to the authors of "Algae," it is widely accepted that the nutritional strategies of algae exist on a spectrum
combining photoautotrophy and heterotrophy. This ability is known as mixotrophy.
Reproduction
Algae are capable of reproducing through asexual or vegetative methods and via sexual reproduction.
According to the authors of "Algae," asexual reproduction involves the production of a motile spore, while vegetative
methods include simple cell division (mitosis) to produce identical offspring and the fragmentation of a colony. Sexual
reproduction involves the union of gametes (produced individually in each parent through (meiosis).
Classification of Algae
Classification Proposed by F. E. Fritsch (1935)
F. E. Fritsch (1935), also known as Father of Phycology, proposed the most acceptable and comprehensive algal classification.
Fritsch published two volumes of “Structure and Reproduction of the Algae”. His classification is based on different
characteristics as pigmentation, chemical nature of reserve food material, flagellar arrangement (kind, number and point of
insertion), presence or absence of organized nucleus in cell and mode of reproduction. He emphasized the account of living
forms of algae as compared to fossil forms, all of which have been grouped in one class. He classified algae into 11 classes.
6. Classification of Algae
The characteristics features of different classes as proposed by Fritsch are:
Class I: Chlorophyceae (Green Algae)
(a) Occurrence: Aquatic (mostly freshwater and few are marine) as well as
terrestrial.
(b) Pigments: Chlorophyll a and b; Carotenoids and Xanthophylls.
(c) Pyrenoids: Present.
(d) Reserve food material: Starch.
(e) Cell wall: Cellulosic.
(f) Structure: Unicellular motile to multicellular, heterotrichous filamentous.
(g) Flagella: Present, equal length (isokont), situated anteriorly, one whiplash and
another one is tinsel.
(h) Reproduction: Vegetative, Asexual and Sexual reproduction (isogamous,
anisogamous and oogamous).
Orders (9): 1. Volvocales 2. Chlorococcales 3. Ulotrichales
4. Cladophorales 5. Chaetophorales 6. Oedogoniales 7. Conjugales
8. Sipohonales 9. Charales
7. Class II: Xanthophyceae (Yellow: Green)
(a) Occurrence: Mostly freshwater and a few are marine.
(b) Pigments: Chlorophyll a, e, β carotene and xanthophylls.
(c) Pyrenoids: Absent.
(d) Reserve food material: Oil.
(e) Cell wall: Rich in pectic compounds and composed of two equal pieces overlapping
at the edges. Flagella unequal.
(f) Structure: Unicellular motile to simple fi lamentous.
(g) Flagella: Present, two unequal, situated anteriorly. Longer one tinsel and shorter
one whiplash.
(h) Reproduction: Vegetative, Asexual and Sexual (Mainly Isogamous, Anisogamy
is rare, Oogamous in Vaucheria).
Orders (4): 1. Heterochloridales 2. Heterococcales 3. Heterotrichales
4. Heterosiphonales
8. Class III: Chrysophyceae (Orange Algae)
(a) Occurrence: Mostly fresh water a few are marine.
(b) Pigments: Chlorophyll a, Dominant pigment is Phycocrysin.
(c) Reserve food material: Leucosin, fats, Chrysolaminarin.
(d) Cell wall: Silicifi ed or Calcifi ed, Cellulose absent.
(e) Structure: Unicellular motile to branched fi lamentous.
(f) Flagella: Present, Two in number, equal or may be unequal, inserted
anteriorly.
(g) Reproduction: Vegetative and Sexual (normally absent, but if present
isogamous).
Orders (3): 1. Chrysomonadales 2. Chrysophaerales 3. Chrysotrichales
9. Class IV: Bacillariophyceae (Diatoms/Yellow or Golden
Brown Algae)
(a) Occurrence: Cosmopolitan in nature, found everywhere in fresh water, marine
water, soil and terrestrial habitats.
(b) Pigments: Chlorophyll c, β carotene, Fucoxanthin, Diatoxanthin, Didinoxanthin.
(c) Pyrenoids: Present.
(d) Reserve food material: Fats, Volutin.
(e) Cell wall: Composed of silica as well as pectic substances. Divided in two
halves outer half is hydrated silica and inner half is composed of pectic
substances.
(f) Structure: Unicellular or Colonial.
(g) Flagella: Single, pantonematic in motile stages.
(h) Reproduction: Cell division and auxospore formation.
Orders (2): 1. Centrales 2. Pennales
10. Class V: Cryptophyceae (Nearly Brown)
(a) Occurrence: Found in both freshwater and marine waters.
(b) Pigments: Chlorophyll a, c, Xanthophylls – diatoxanthin, phycocyanin and
phycoerythrin.
(c) Pyrenoids: Pyrenoid like bodies present but independent of chromatophores.
(d) Reserve food material: Starch and/or oil.
(e) Cell wall: Absent
(f) Structure: Unicellular with anterior groove or pocket.
(g) Flagella: Biflagellate, both flagella apical or lateral, hairy, may be equal or
unequal.
(h) Reproduction: Mostly binary fission, Sexual reproduction is rare but only of
isogamous type.
Orders (2): 1. Cryptomonadales 2. Cryptococcales
11. Class VI: Dinophyceae (Dark Yellow or Brown)
(a) Occurrence: Mostly marine and a few are freshwater forms.
(b) Pigments: Chlorophyll a, c 2, β carotene, peridinin, neoperidinin, dominant pigments
are xanthophylls.
(c) Chromatophores: Present, Discoid.
(d) Reserve food material: Starch and Fat.
(e) Cell wall: Cellulosic.
(f) Structure: Mostly unicellular, branched fi lamentous and motile.
(g) Flagella: Present, two, equal.
(h) Reproduction: Sexual reproduction isogamous type (rare).
Orders (6): 1. Desmomonadales 2. Thecatales 3. Dinophysiales
4. Dinofl agellata 5. Dinococcales 6. Dinotrichales
Class VII: Chloromonadinae (Bright Green)
(a) Occurrence: Fresh water forms.
(b) Pigments: Xanthophylls in excess.
(c) Pyrenoids: Absent
(d) Reserve food material: Fat and Oil
(e) Cell wall: Absent.
(f) Structure: Motile unicells.
(g) Flagella: Two, Equal.
(h) Reproduction: By cell division, Sexual reproduction absent.
Orders (1): 1. Chloromonadales
12. Class VIII: Euglenophyceae
(a) Occurrence: Freshwater forms are known only.
(b) Pigments: Chlorophyll a, b, β carotene, astaxanthin,
antheraxanthin, diadinoxanthin,
neoxanthin.
(c) Pyrenoids: Pyrenoid like bodies are present in some.
(d) Reserve food material: Paramylon and some
polysaccharides.
(e) Cell wall: Proteinaceous.
(f) Structure: Unicellular.
(g) Flagella: Present (one or two).
(h) Reproduction: By cell division, Sexual reproduction if
present is of isogamous
type.
P. Baweja and D. Sahoo
The class has been divided into three families:
1. Euglenaceae 2. Astasiaceae 3. Peranemaceae
Class IX: Phaeophyceae (Brown Algae)
(a) Occurrence: Mostly marine.
(b) Pigments: Fucoxanthin is dominant, Chlorophyll a, c and
carotene.
(c) Pyrenoids: Stalked pyrenoids present outside the chloroplast
envelope.
(d) Reserve food material: Laminarin, mannitol and fats.
(e) Cell wall: Cellulose, alginic acid and fucinic acid.
(f) Structure: Microscopic to branched, fi lamentous
macroscopic parenchymatous
plants.
(g) Flagella: Zoospores fl agellated, fl agella unequal, one is
tinsel type.
(h) Reproduction: Sexual reproduction (isogamous,
anisogamous and oogamous).
Orders (9):
1. Ectocarpales 2. Tilopteridales 3. Cutariales 4. Sporochnales
5. Desmarestiales 6. Laminariales 7. Sphacelariales
8. Dictyotales 9. Fucales
13. Class X: Rhodophyceae (Red Algae)
(a) Occurrence: Mostly marine.
(b) Pigments: r- phycoerythrin and r – phycocyanin, chlorophyll
a, d, carotene and
xanthophylls.
(c) Pyrenoids: Chromatophores present and pyrenoid like bodies
are present in
lower forms.
(d) Reserve food material: Floridean starch.
(e) Cell wall: Outer pectic and inner cellulosic.
(f) Structure: Multicellular (uniaxial or multiaxial).
(g) Flagella: Absent (cell non – motile).
(h) Reproduction: Sexual and oogamous type.
Orders (7):
1. Bangiales 2. Nemalionales 3. Gelidiales 4. Cryptonemiales
5. Gigartinales 6. Rhodymeniales 7. Ceramiales
14. Class XI: Myxophyceae (Cyanophyceae, Blue Green Algae)
(a) Occurrence: Mostly fresh water.
(b) Pigments: c – phycocyanin, chlorophyll a, β carotene and c- phycoerythrin.
(c) Pyrenoids: Absent.
(d) Reserve food material: Myxophycean starch and cyanophycean granules
(proteins).
(e) Cell wall: Mucopeptides, amino acids, fatty acids and carbohydrates.
(f) Structure: Unicellular or Multicellular. Cells are prokaryotic in nature.
(g) Flagella: Absent (cell non – motile).
(h) Reproduction: Vegetative and asexual, sexual reproduction absent (genetic
recombination is reported in some members)
Orders (5):
1. Chroococcales 2. Chamaesiphonales 3. Pleurocapsales
4. Nostocales 5. Stigonemales
Some important suggestions proposed by Fritsch in his classifi cation can be
summarized as below :
15. 1. According to Fritsch, algae as a group must be considered as Division, therefore
it cannot be further divided into “phyta” and he thus classifi ed algae in 11 classes.
2. Class Conjugatae of Pascher’s classifi cation should be treated as an order (=
conjugates) of class Chlorophyceae.
3. Division Charophyta should be treated only as an order Charales
in class Chlorophyceae.
4. Euglenophyta was further separated into two separate classes i.e. Euglenineae
and Chlromonadineae.
5. Inclusion of Xanthophyceae, Bacillariophyceae and Chrysophyceae were separated
because of dissimilarities between them.
16. Classification Proposed by G. M. Smith ( 1955 )
G.M. Smith supported the classification proposed by Pascher (1914 , 1931 ) and proposed
a new classification with certain modifications. He divided algae into divisions and further into classes.
The seven divisions of algae as proposed are:
1. Chlorophyta Chlorophyceae e.g. Volvox Charophyceae e.g. Chara
2. Euglenophyta Euglenophyceae e.g. Euglena
3. Pyrrophyta Desmophyceae e.g. Desmarestia Dinophyceae e.g. Dinophysis P. Baweja and D. Sahoo
4. Chrysophyta Chrysophyceae e.g. Chromolina Xanthophyceae e.g. Botrydium Bacillariophyceae e.g.
Pinnularia
5. Phaeophyta Isogenerateae e.g. Ectocarpus Heterogenerateae e.g. Mynomena Cyclosporeae e.g.
Sargassum
6. Cyanophyta Myxophyceae e.g. Nostoc, Anabaena
7. Rhodophyta Rhodophyceae e.g. Polysiphonia, Gracilaria , Batrachospermum
Smith also recognized algae of uncertain systematic position and placed them
under chloromonadales and cryptophyceae.
17. Salient features of prochlorophyta
Prochlorophyta are a photosynthetic prokaryote members of the phytoplankton group Picoplankton. These
oligotrophic organisms are abundant in nutrient-poor tropical waters and use a unique photosynthetic
pigment, divinyl-chlorophyll, to absorb light and acquire energy.
These organisms lack red and blue Phycobilin pigments and have staked thylakoids, both of which make
them different from Cyanophyta. Prochlorophyta were initially discovered in 1975 near the Great Barrier
Reef and off the coast of Mexico. The following year, Ralph A. Lewin, of the Scripps Institution of
Oceanography, assigned them as a new algal sub-class. Prochlorophytes are very small microbes generally
between 0.2 and 2 µm (Photosynthetic picoplankton).
They morphologically resemble Cyanobacteria, Members of Prochlorophyta have been found as coccoid
(spherical) shapes, like Prochlorococcus, and as filaments, like Prochlorothrix.
In addition to Prochlorophyta, other phytoplankton that lack Phycobilin pigments were later found in
freshwater lakes in the Netherlands, by Tineke Burger-Wiersma. These organisms were termed
Prochlorothrix.
18. Prochloron (a marine symbiont) and Prochlorothrix (from freshwater plankton) contain
chlorophylls a and b; Prochlorococcus (common in marine picoplankton) contains
divinyl-chlorophylls a and b. In 1986, Prochlorococcus was discovered by Sallie W.
Chisholm and his colleagues.
These organisms might be responsible for a significant portion of the global primary
production. Like cyanophytes they are all clearly photosynthetic prokaryotes, but since
they contain no blue or red bilin pigment they were assigned to a new algal subclass, the
Prochlorophyta.
However, since their possible phylogenetic relationships to ancestral green-plant
chloroplasts have not received support from molecular biology, it now seems expedient to
consider them as aberrant cyanophytes.
19. Morphology
Prochlorophytes are very small microbes generally between 0.2 and 2 µm (photosynthetic
picoplankton). They morphologically resemble Cyanobacteria.
Members of Prochlorophyta have been found as coccoid (spherical) (Coccus) shaped, as in
Prochlorococcus, and as filaments, as in Prochlorothrix. Their association with ascidians from
tropical Pacific shores have been reported by various biologists. Such cells found associated with
surfaces of Didemnum colonies on the Pacific coast of Mexico, have been shown by electron
microscopy to be prokaryotic, which suggests that they are cyanophytes, that is, blue-green algae.
Although all known blue-green algae (other than a few apochlorotic types) contain phycoerythrin,
phycocyanin, or both, however, these ascidian symbionts are apple green and contain no
detectable bilin pigments. Furthermore, like the eukaryotic algae in the divisions Chlorophyta and
Euglenophyta, they contain two chlorophyll components, separable by chromatography and
provisionally identifiable as chlorophylls a and b, whereas no cyanophytes are known to contain
chlorophyll b.
20. The prochlorophytes are a diverse group of photosynthetic prokaryotes that fall within the
cyanobacterial lineage, yet lack phycobilisomes as light harvesting structures.
Instead, the prochlorophytes have a light-harvesting apparatus composed of the higher plant pigments
chlorophylls a and b. This review discusses the evolutionary relationships among these bacteria, with
focus on the structure and function of the photosynthetic apparatus.
This analysis yields a consensus from studies both on Prochloron sp. and Prochlorothrix hollandica as to
how the thylakoid membrane is organized.
The algal internal structure, resembling that of blue-green algae, consists of two definite zones bounded
by a thin (30–50 nm), multilayered cell wall. The outer zone is occupied by the photosynthetic lamellae
and the cytoplasm.
The central zone is electron-transparent and sometimes contains lamellae of unknown nature. However,
unlike single non-appressed thylakoids of the Cyanophyta, the algal photosynthetic lamellae are
composed of two-appressed thylakoids. The central zone undergoes binary division before cytokinesis.
21. Salient features of Chlorophyta
The class Chlorophyceae is commonly called as green algae. Chlorophyceae is very large group of algae and is
represented by about 429 genera and 6500 species. Chlorophyceae are mainly fresh water algae (about 90
percent species are fresh water and 10 percent marine). Fresh water forms are common in ponds, pools, lakes,
ditches, water tanks, and in river and canals.
Majority of Volvocales, Chlorococcales are planktonic forms.
Many Chaetophorales e.g., Coleochaete, Protococcus. Trentepohlia are epiphytic algae.
Many species of Cladophora and Characium are epizoic algae.
Some green algae like Trebouxia, Chlorella form symbiotic association ship with animals like Zoo chlorella and
Hydra.
Some green algae form symbiotic association with fungi to form lichens.
Cephaleuros is parasitic algae on leaves of tea, coffee, piper and magnolia plants. Cephaleuros causes red rust of
tea.
Chlamydomonas nivalis causes red snow and Chlamydomanas yellowstonensis causes green snow. Some
Chlamydomonas species are thermophilic.
22. Important Features:
(i) The cells are eukaryotic and contain mitochondria, Golgi bodies, plastids, endoplasmic reticulum and
ribosomes.
(ii) The cell wall is made of two layers, the inner layer mainly consisting of cellulose and the outer layer
consisting of pectic substances.
(iii) The chloroplasts are well organized, the main pigments are chlorophyll a and b, the other pigments are
α and β carotene and xanthophyll’s.
(iv) The shape of the chloroplast is variable. It may be cup shaped eg. Chlamydomonas, grodle shaped e.g.,
Ulothrix, reticulate e.g., chladophora, stella e.g., zygonema, spiral e.g., spirogyra, Discoid e.g., chara or
parietal e.g., Drapalnaldiopsis
(v) The reserved food is in the form of starch and its formation is associated with pyrenoids
(vi) The motile reproductive structures i.e., zoospores and gametes have 2,4 flagella which can be apical,
subapical, equal in size and acronemotic type.
(vii) The sexual reporoduction can be isogamous, anisogamous or oogamous
23. Salient features of Cyanophyta
Cyanobacteria or blue-green algae is a phylum of bacteria that gets energy through photosynthesis. Cyanobacteria are
now one of the largest and most important group of bacteria on earth.
Cyanobacteria are found in almost all habitats of ocean to fresh water, stone of deep purple, sea marsh, and to the
ground. They can be single-celled or colonize. Colonies can form filaments or sheets. Cyanobacteria include
unicellular, colony and colony filament. beberapa form filaments can differentiate into three different cells.
Vegetative cells are normal, photosynthetic cells in a good environment, and the type of thick-walled heteroksit
containing enzyme nitroginase.
Most Cyanobacteria are found diair bargaining, while others stay dilautan, there is ground moisture, moisturize even
the rocks in the desert.
Characteristics General of Cyanophyta:
1. Type of prokaryotic cells (similar to the bacteria)
2. There is a form of unicellular (single-celled), there are colonies and there is also a form of filaments.
3. Has the pigment chlorophyll, the pigment fikobilin karotinoid and consisting of phycocyanin (blue), and fikoeritin
(red). Combined these pigments create a bluish green color.
24. 4. Chlorophyll is not contained within the chloroplasts, but scattered throughout the protoplasm.
5. Characteristically autotroph because of chlorophyll.
6. The body structure is simple, the cell walls contain pectin, hemicellulose and cellulose are sometimes
in the form of mucus.
7. At the edge of the plasma contained chlorophyll dye, Carotene and two kinds of water-soluble
kromoprotein namely: phycocyanin fikoeritrin blue and red.
8. In the middle of the cell there is a section which is colorless containing DNA and RNA.
9. There is a reserve of glycogen as a food substance and there beside the granules sianofisin (lipo-
protein) that is located at the periphery and Volutin whose function remains unclear.
10. Green algae blue shaped filaments can also form a thick-walled spores that are resistant to hot and dry
and can menfiksasi or bind N (nitrogen) is heteroksit.
25. Salient features of Charophyta
Charophyta is a taxonomic group (a phylum) comprised of green algae that live predominantly
in freshwater habitats. Members of this phylum (called charophytes) used to be included in the phylum
Chlorophyta (chlorophytes). Both charophytes and chlorophytes are greenish in colour, photosynthetic,
and eukaryotic.
These basic features are due to the chlorophyll (green pigments) that are abundant in their thylakoids.
Similar to chlorophytes, the charophytes have chlorophyll a and chlorophyll b. Carotenoids are also
present but they are relatively few. Both chlorophytes and charophytes store their carbohydrates as
starch. One of the main differences between charophytes and chlorophytes is the use of a
phragmoplast that serves as a scaffold for cell plate assembly and later on during the formation of a
new cell wall during cell devision. Charophytes also have enzymes (e.g. class I aldolase, Cu/Zn
superoxide dismutase, glycolate oxidase, and flagellar peroxidase) not found in chlorophytes.
Charophytes are postulated to be the early ancestors of embryophytes (land plants). Embryophytes are
more closely related to the charophytes since their structures are more comparable than those of the
chlorophytes.
26. General characteristics
The charophytes, together with the chlorophytes, make up the green algae. As part of this algal group, the
charophytes are greenish in colour. This is due to the abundant chlorophyll (green pigment) inside their cell. Their
cell wall is chiefly made up of cellulose. They store their food reserves as starch.
Sub-groups
The phylum Charophyta includes the following classes:
Klebsormidiophyceae
Phragmoplastophyta
Charophyceae
Coleochaetophyceae
Mesotaeniaceae
Zygnematophyceae
The Embryophyta is also included though cladistically.
27. Salient features of Xanthophyta
1. Members of Xanthophyceae are commonly fresh water (Tribonema) and most of them are free floating. [Few
members are found to grow on mud (Botrydium) and also on walls or tree trunks (Characiopsis, Ophiocytium etc.). A
few members like Halosphaera are marine.
2. Plant body is unicellular (Heterochloris) or multicellular. [The multicellular bodies also exhibit various forms like
palmelloid (Chlorogloea), dendroid (Mischococcus), coccoid (Chlorobotrys), rhizopodial (Stipitococcus), filamentous
(Heterococcus) and siphona- ceous (Botrydium).
3. The cellwall is often absent but when its present it contains more pectic compounds than the members of
chlorophyceae. Occasionally cellulose is also present
4. Usually two flagella present but rarely one. They are unequal and inserted at the anterior end.
5. Chromotophores are discoid in shape and numerous in each cell
6. The pyrenoids are absent or rarely present. The pyrenoids are yellow green in colour. The photosynthetic pigments are
chlorophyll a, chlorophyll e (very little), P-Carotene, xanthophyll. The chief xanthophyll is diadinoxanthin.
7. The reserve food is oil, lipid and lucosin. Starch is not formed.
28. Salient features of Phaeophyta
The salient features of Phaeophyceae members:
1. Phaeophyceae commonly called as Brown algae.
2. Majority are marine habitats. Pleurocladia is a fresh water form.
3. Thallus may be filamentous, frond – like or giant kelps.
4. Thallus is differentiated into photosynthetic part-frond, stalk – like structure – stipe and a holdfast for attachment.
5. Chlorophyll ‘a’ and ‘c’ , carotenoids and Xanthophylls are photosynthetic pigments. 6. A golden brown fucoxanthin
pigment gives olive green to brown colour.
7. Mannitol and Laminarin starch is the storage material.
8. Motile spores with unequal flagella (one whiplash and one tinsel) are present.
9. Oogamous is the major type of sexual reproduction. Isogamy is also seen.
10. Alternation of generation is seen.
Example: Sargassum, Fucus, Laminaria and Dictyota.
29. Salient features of Rhodophyta
1. Rhodophyceae commonly called as red algae.
2. Mostly marine habitats.
3. The thallus is multicellular, macroscopic, and may be filamentous, ribbon – like etc.
4. Chlorophyll ‘a’ , r-phycoerythrin and rphycocyanin are photosynthetic pigments.
5. Asexual reproduction is by means of monospores, neutral spores and tetraspores.
6. Floridean starch is the storage material
7. Sexual reproduction in oogamous.
8. Male sex organ is spermatangium producing spermatium.
9. Female sex organ is carpogonium.
10. Spermatium is carried by water and fuses with egg forming zygote.
11. Zygote undergoes meiosis forming carpospores.
12. Alternation of generation is seen. Example: Ceramium, Gelidium and Gigartina.
30. Reference
The Algae World, Editors: Dinabandhu Sahoo,Joseph Seckbatch, Springer
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20Prochlorophytes.pdf
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Syamsuri, Istamar. 2007. Biologi. Jakarta : Erlangga
Indah, N. 2007, Taksonomi Tumbuhan Tingkat Rendah, Jember: IKIP PGRI Jember.
Hoek, C. van den, Mann, D.G. and Jahns, H.M. (1995). Algae An Introduction to Phycology. Cambridge: Cambridge
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