Marine Plants All plants are multicellular have cell

Marine Plants • All plants are multicellular, have cell walls and chloroplasts (which contain the green pigment, chlorophyll) • All plants make their own food (glucose) by photosynthesis

PLANTS VASCULAR ROOTS - absorb nutrients/water - anchors plant STEMS - carry nutrients to the leaves - carry food to the roots NON-VASCULAR LEAVES - photosynthesis *includes flowering plants, pine-bearing plants and ferns *includes algae, moss and liverworts

Marine Plants are divided into: 1. Chlorophyta: includes green algae (ex. spongeweed, sea lettuce) 2. Rhodophyta: includes red algae (ex. Irish moss, Nori) 3. Phaeophyta: includes brown algae (ex. Rochweed, kelp) 4. Anthophyta: includes all flowering marine plants (including marine grasses)

Each group differs in: 1. Photosynthetic pigments (other than chlorophyll) 2. Morphology (structure) 3. Habitats 4. Reproductive strategies

Algae Blade: flattened, broad leaf-like part of plant; photosynthetic Stipe: flexible, stem-like part of plant that helps to absorb “shock” of wave action *While some species (particularly brown algae) have specialized conducting tissue, it lacks xylem and phloem. Holdfast: root-like structure whose only function is to hold the plant to substrate; the holdfast does not absorb water or nutrients (as the roots do)

Reproduction in Algae meiosis Diploid (2 n) Sporophyte Haploid (n) spores

Green Algae (Chlorophyta) • One of the largest groups of algae • Found in fresh and marine water, both benthic and planktonic • May be unicellular, colonial or multicellular, flagellated or not

Sea Lettuce (Ulva): large blade

Spongeweed (Codium): UNICELLULAR, but macroscopic and multinucleated

Enteromorpha: tubular, grows attached to substrates in intertidal zone

Caulerpa: grows by rhizome-like structure

Halimeda: flattened, calcified (calcium) blades (tropical)

Acetabularia: looks like small umbrellas (one celled, about 8 cm long)

Brown Algae (Phaeophyta) • Have brown to olive green color due to presence of both chlorophyll (green pigment) and xanthophyll (yellow pigment) • Brown algae form independent habitats for marine life (ex. Kelp forest, Sargassum mats) • Many have “air bladders” to help algae float toward surface (and light!) • Algin extracted from brown algae is useful in making various products such as toothpaste, paint, shaving cream, soaps.

Macrocystis: giant kelp (Pacific) large corrugated blade with serrated edges and a single elongated air bladder at the base of each blade. Found in low intertidal areas. Grows up to 20 meters in length and sometimes forms large underwater kelp forests.

Laminaria: Northeast kelp (grows to about 3 ft. )

Fucus: rockweed, grows attached to rocks

Sargassum: floats in large mats in tropical ocean

Sargassum – have gas-filled balls that keep the seaweed afloat

Postelsia: (sea palms)

Red Algae (Rhodophyta) • Most commercially valuable group of algae • Contain red pigment, phycoerythin, which “hides” chlorophyll color • Most abundant in shallow waters (due to low availability of red light at deeper depths) **some species, however can survive at depth • Some species have calcium carbonate in cell walls (makes them hard, brittle)

Porphyra (aka “nori): cultivated in Japan, China and Korea for food

Chondrus (aka “Irish Moss”): harvested in US for carageenan and agar (gelling agents) used in ice cream, pudding and jello

Corallina: branching red algae found on rocks (contains calcium carbonate)

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