Multicellular primary producers (macro algae)

Parts of seaweed

Thallus: the seaweed body

Blade: the flattened part of the thallus

Holdfast: structure attaching the thallus to a surface

Stipe: stem-lie structure between Holdfast and blade

Air bladder: buoys the plant for maximum sunlight for photosynthesis.

Reproductive structure

Green Algae

scientific name: chlorophyta

• habitat: mostly freshwater, multicellular are typically marine

• cell structure: mostly uni-cellular

• ecological roles: food and shelter for some small species

• commercial uses: Nori, supplement in some aquaculture foods

Red algae

scientific name: Rhodophyta

habitat: 98% of 6000 species are marine, mostly benthic in distribution

cell structure: Almost all are multicellular

ecological roles: aid in the creation of coral reefs (red coralline algae precipitates calcium carbonate)

Commercial uses: phycocolloids from cell walls are valued for gelling and stiffening.

Brown Algae

scientific name - Paeophyta

• habitat: almost exclusively marine (99.7%), mostly benthic, more abundant in coastlines of higher latitudes

• cell structure: multicellular, has air bladder

• ecological roles: kelp forest house for diverse organisms

• commercial uses: thickening agents for food, cosmetic, dental, and tile industries. Food for some and cattle feed for some.