CLASSIFICATION OF ALGAE

CLASSIFICATION OF ALGAE 

INTRODUCTION

ALGAE are thalloid structure, containing chlorophyll, performing photosynthesis.

They are mainly of aquatic habitat may be freshwater or marine, some are also terrestrial and are grown over moist soil, stone or wood. We may say that algae found in nearly every type of habitat.

The main reason behind this huge habitat are their carriers, for e.g  By Milliger et al.  on 23 species of beetles, 101 algal different genera have been reported.

 Yet the definite definition of algae is not clear.

Study of Algae	Phycology or Algology
Term algae were given by	Linnaeus
Father of algae	F.E Fritsch
Father of Indian algae	M. Osuri Parthasarathy Iyengar

ORGANISM CLASSIFICATION

In the Whittaker system of classification for all organisms' FIVE kingdoms were kept forth.

These are:-

1.       MONERA

2.       PROTISTA

3.       FUNGI

4.       PLANTAE

5.       ANIMALIA

The kingdom Plantae is further classified into:-

·         Cryptogams

·         Phanerogams

Cryptogams (crypto=concealed; gamos=marriage) are seed less plant.

Includes:-

·         ALGAE

·         BRYOPHYTE

·         PTERIDOPHYTE

Phanerogams(phanero= visible; gams=marriage) are seeded plants

Includes:-

·         GYMNOSPERM

·         ANGIOSPERMS

This classification system  is mostly considered for the classification of organisms, but the recent is of carlwoese in 1977 who further made  the two kingdoms from kingdom MONERA these are:-

·         ARCHEBACTERIA (ancient origin bacteria)

·         EUBACTERIA (recent origin bacteria)

ALGAL CLASSIFICATION

The quest to classify algae begins in the sixteenth century by the most brilliant biologist LINNAEUS in 1753 of whom, four genera are considered in these days  ULVA, CHARA, FUCUS, CONFERVA.

Later  W.H Harvey in1836 describes algae by observing them from different part of the world, on the basis of their pigments:-

·         CHLOROSPERMAE (green algae)

·         MELANOSPERMAE (brown algae)

·         RHODOSPERMAE (red algae)

Harvey recognized the importance of pigments.

This story of classification reached to A.W Eichler, in 1886 he classified algae into five groups

1.       CHLOROPHYCEAE

2.       PHAEOPHYCEAE

3.       RHODOPHYCEAE

4.       CYNOPHYCEAE

5.       DIATOMEAE

Further  A. Pascher in 1914 classified algae on the basis of phylogenetic or evolution, by considering algae as a kingdom and he revised it in 1931. He classified algae into 8 divisions and provided each division  certain classes.

  Given classification is:-

1.       CHRYSOPHYTA ·         CHRYSOPHYCEAE ·         HETEROKONTAE ·         DIATOMEAE 2.       PHAEOPHYTA ·         PHAEOPHYCEAE 3.       PYRROPHYTA ·         CRYPTOPHYCEAE ·         DESMOKONTAE ·         DINOPHYCEAE 4.       EUGLENOPHYTA ·         EUGLENINEAE 5.       CHLOROPHYTA ·         CHLOROPHYCEAE ·         CONJUGATAE 6.       CHAROPHYTA ·         CHAROPHYCEAE 7.       RHODOPHYTA ·         BANGINEAE ·         FLORODINEAE 8.       CYANOPHYTA ·         MYXOPHYCEAE

A well known U.S  Botanist  GILBERT MORGAN SMITH is best known for his books FRESH WATER ALGAE OF THE UNITED STATES  and MARINE ALGAE OF MONTEREY PENINSULA accepted algae should be divided into  certain division, but suggested following modification

1.       Modification within division Chlorophyta:-

              Smith suggested that the division charophyta should be placed as a class within division Chlorophyta. Hence division Chlorophyta have 7 divisions.

              Smith suggested class conjugatae as an order Zygnematales within class Chlorophyceae

2.       Smith suggested name XANTHOPHYCEAE to HETEROKONTAE

3.       Smith suggested name BACILLARIOPHYCEAE to DIATOMEAE

4.       Smith replaces class Phaeophyceae by three another class:- Isogeneratae; Heterogeneratae; Cyclosporae.

5.       In RHODOPHYTA smith placed Rhodophyceae only a class.

Hence the classification proposed by Gilbert Morgan Smith appear as:-

       

1.       CHLOROPHYTA	CHLOROPHHYCEAE CHAROPHYCEAE
2.       EUGLENOPHYTA	EUGLENINEAE
3.       PYROPHYTA	CRYPTOPHYCEAE DESMOKONTAE DINOPHYCEAE
4.       CHRYSOPHYTA	CHRYSOPHYCEAE XANTHOPHYCEAE BACILLARIOPHYCEAE
5.       PHAEOPHYTA	ISOGENERATAE HETEROGENRATAE CYCLOSPERMAE
6.       CYANOPHYTA	MYXOPHYCEAE
7.       RHODOPHYTA	RHODOPHYCEAE

The final classification of algae reached to the father of algology, Botanist F.E Fritsch.

In the years of 1935 and 1945 F.E Fritsch, he believes about the algae is different from Whittaker and woese , he does not consider algae as a kingdom he considers it equivalent to the division and on this basis classified different categories based on observation into 11 classes.

Hence there is no suffix phyta the only phyceae is found in his classification.

Some major points of his classification are:-

1.       MODIFICATIONS MADE IN CHLOROPHYTA OF PASCHER BY FRITSCH

a.       Conjugatae division of Pascher and order Zygnematales of Smith, in the classification of Fritsch considered as an order conjugales in class Chlorophyceae

b.      Division charophyta of Pascher and class Charophyceae of smith considered only as an order Charales of class Chlorophyceae.

2.       Desmokontae are not recognized by Fritsch

3.       Fritsch criticized the inclusion of Bacillariophyceae with the two Xanthophyceae and Chrysophyceae because of the variation in ploidy level, cell wall, pigments, the product of assimilation and reproduction.

4.       Euglenophyta of A.Pascher and G.M Smith were placed by F.E Fritsch in two classes:-

a.       Euglenineae

b.      Chloromonadineae

After applying all these modifications to the Pascher and smith classification Fritsch classification appeared as follows:-

1.       Chlorophyceae

2.       Phaeophyceae

3.       Rhodophyceae

4.       Chrysophyceae

5.       Dinophyceae

6.       Euglenineae

7.       Chloromonadineae

8.       Xanthophyceae

9.       Pyrrophyceae

10.   Mysophyceae

11.   Rhodophyceae