Algae

 

Thallophytes

Thallus

 

No true roots, stems or leaves

No conductive (vascular) tissue

No lignin

 

High moisture levels

 

Morphological Variation

I. Unicellular

            A. solitary

            B. colonial

II. Multicellular

            A. filamentous

            B. non-filamentous

 

18,000 – 30,000 species

 

Classification based on:

1. Pigments

2. Motility

3. Reproductive Structures

4. Anabolite

 

Cyanophyta

Blue-green algae

 

Pigments:

chlorophyll a

phycocyanin

phycoerythrin

carotene

xanthophyll

 

Motility:

no active motility;

may show gliding

 

Reproduction:

asexual only:

binary fission,

fragmentation,

aplanospores

 

Anabolite:

cyanophycean

starch

 

slimy layer made of pectin

 

heterocysts

 

akinites

 

 

Representative Genera:

 

Gloeocapsa

 

Anabaena

 

Oscillatoria

 

 

Optimum Temperature

 

Lichens

 

Plankton

 

 

Eukaryotic Algae

Shape of the chloroplast

SOME are coenocytic

SOME have holdfasts

 

Chlorophyta

Green algae

 

Pigments:

chlorophyll a

chlorophyll b

small amounts of

carotene and

xanthophyll in some

 

Motility:

most non-motile; up

to 8 anterior, equal

flagella in some gametes

and unicellular forms

 

Reproduction:

asexual:

binary fission,

fragmentation, aplanospores,

zoospores

sexual: isogamy, anisogamy,

oogamy, conjugation, cell fusion

 

Anabolite:

starch

 

Representative Genera:

 

Chlamydomonas

 

Gonium

Pandorina

Eudorina

Volvox

 

Pamelloid state

Chlorella

 

Spirogyra

 

Scalariform conjugation

 

Most algae are haploid in the

conspicuous part of their

life cycle.

 

Ulothrix

 

Heterothallism

Homothallism

 

Ulva

 

Desmids

 

Euglenophyta

Animal-like algae

 

Pigments:

chlorophyll a

chlorophyll b

carotene

 

Motility:

all actively motile,

1 to 3 anterior flagella

 

Reproduction:

asexual only:

longitudinal fission

 

Anabolite:

paramylum; some fats

in some species

 

Representative genus:

Euglena

 

Astasia

Paranema

 

 

Chrysophyta

Golden-brown algae

Glass algae

 

Pigments:

chlorophyll a

chlorophyll c

xanthophylls

carotene

fucoxanthin

blue, red and

brown pigments

 

Motility:

some non-motile;

2 unequal, anterior

flagella on some;

a few have pseudopodia

 

Reproduction:

asexual:

fission,

auxospores

sexual (rare):

isogamy,

oogamy

 

Anabolite:

leucosin (oil)

mannitol (alcohol)

chrysolaminarin (carbohydrate)

 

Representative Genera:

 

Vaucheria

 

Family Bacillariophyceae

Diatoms

            Frustule

            Valves

            Aereola

 

            Pennate

            Centric

 

            Raphe

 

            Diatomaceous Earth

            Kieselguhr

 

Pyrrophyta

Fire algae

 

Pigments:

chlorophyll a

chlorophyll c

(others same as Chrysophyta)

 

Motility:

2 unequal, lateral

flagella

 

Reproduction;

asexual:

fission

sexual (rare):

isogamy, anisogamy,

oogamy

Anabolite:

leucosin

 

Dinoflagellates

 

Posterior flagellum

Transverse flagellum

 

Red tide

 

Phosphorescent

Sea glow

 

Representative genera:

Peridinium

Gymnodinium

Pfiesteria piscicida

 

 

Phaeophyta

Brown algae

 

Pigments:

chlorophyll a

chlorophyll c

fucoxanthin

 

Motility:

only in zoospores

and gametes; 2 unequal,

lateral flagella

 

Reproduction:

asexual:

zoospores,

fragmentation

sexual: isogamy, oogamy

 

Anabolite:

laminarin

 

all are multicellular

 

Representative genera:

 

Laminaria

Fucus

Sperm with 2 unequal,

lateral flagella, the shorter

one directed forward and

the longer one directed

backward

 

Ectocarpus

 

Reproductive cycles

 

Sargassum

 

Sargasso Sea

 

Kelps

 

 

Rhodophyta

Red algae

 

Pigments:

chlorophyll a

chlorophyll d

phycoerythrin

phycocyanin

 

Motility:

none

 

Reproduction:

asexual:

carpospore

sexual:

“oogamy”

 

Anabolite:

floridean

starch

 

stellate chloroplast

 

trichogyne

 

spermatia

(singular: spermatium)

Representative Genera:

 

Nemalion

 

Gelidium

 

Chondrus

Carrageenan