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