Bell Ringer

Name the 3 classes of seaweed and their corresponding colors.(hint: vocab words)

Seaweed Classification

Chlorophyta

• Green algae• No accessory pigments• Live at or near the surface• Land plants evolved from chlorophytes

Chlorophyta

• Only ~10% of 7,000 species are marine• Genus Ulva is a familiar, delicate, lettucelike

edible seaweed– Can tolerate impure waters of urban coasts

Chlorophyta

• Ulva makes use of highly concentrated nutrients near sewage outlets to grow and multiply

• Most other species prefer clean waters

Ulva

• Live in marine & brackish waters• Edible • Sea lettuce

Ulva

• Thallus is flat & blade-like• 2 layers of cells, no differentiation of tissues

Phaeophyta

• Brown algae• Almost all 1500 species are marine• Largest of all algae– Can reach up to 132 ft (record is over 200 ft)– Can grow up to 20 in per day

• Includes kelp

Phaeophyta

• Some are annuals, some live up to 7 years• Tan/brown color comes from the accessory

pigment: fucoxanthin– Can allow photosynthesis to occur at greater

depth– Some grown in water up to 115 ft deep

Phaeophyta

• Live in temperate & polar habitats• Few live in tropics

Macrocystis

• Live in Pacific Ocean kelp forests• Economic & ecological importance– Harvested to feed abalone– Organisms that thrive in kelp forests support

commercial fishing & recreational activities

Macrocystis

• Wide variety of environmental conditions– Perennial nature– Growth habits– Wide distribution

Rhodophyta

• Most of world’s seaweeds are red algae• 4000 species• Smaller & more anatomically complex

Rhodophyta

• Accessory pigment, phycobilins, allows rhodophytes to excel in dim light

• Record depth for photosynthesizer: 879 ft– Tropical caribbean

Rhodophyta

• Grow slowly and may be 10s or even 100s of years old

• May also live on rocks at the surface– Most common surface dwellers grow as purple or

pink film on rocks, shells, other seaweeds, glass, or plastic

Coralline algae

• Calcareous• Remove large quantities of dissolved calcium

carbonate from seawater & deposit within tissues

• Accumulate to form large beds of stone-like algae

• Grow in sub-tidal quiet bays with clear water, mainly in Europe