Phylum Chlorophyta

Phylum Chromophyta

Phylum Rhodophyta

Phylum Euglenophyta

Phylum Dinophyta

Phylum Cryptophyta

Phylum Prymnesiophyta

Phylum Charophyta

Phylum Myxomycota

Phylum Dictyosteliomycota

Phylum Oomycota

All members have eukaryotic cells.

Individual life cycles vary considerably, but reproduction is generally by cell division and sexual processes.

Most multicellular members produce some motile cells.

Phytoplankton...plankton..Greek for wanderer meaning that they are passively transported. Nekton are those that swim. Size categories of plankton:

ultraplankton: less than 2 um

nanoplankton: 2-20 um

microplankton: 20-200 um

macroplankton: 200-2000 nm

megaplankton: greater than 2 mm

Types:

Holoplankton...spend entire life in open waters

Meroplankton...spends part of life as plankton and part as a benthic or bottom dweller.

Tychopelagic...normally attached but break off and can then be found in the plankton.

Divisions

Cyanobacteria (Cyanophyta) Blue-green algae (Monera)

Chlorophyta green algae

Chrysophyta golden algae/silicoflagellates

Haptophyta- coccolithophores

Xanthophyta yellow-green algae

Bacillariophyta diatoms

Dinophyta (Pyrrophyta) dinoflagellates & zooxanthellae

Cryptophyta cryptomonads

Euglenophyta euglenas

Division Cyanophyta/Cyanobacteria Blue green Algae are prokaryotic cells specialized to carry on photosynthesis. Chlorophyll, phycobilins, phycocyanin, beta-carotene and xanthophylls are the pigments so color range is great..red, blue-green, black, olive, yellow, violet. The only other prokaryotes that carry out photosynthesis are some autotrophic bacteria.

There are hemosynthetic bacteria too that release stored energy in chemical compounds (H2S) . Blue-green algae contain a bluish pigment, PHYCOCYANIN. (Considered bacteria).

Photosynthesis occurs on folded membranes within the cell (rather than chloroplasts).

They do produce O2 etc. and probably played a role in the oxygen in the atmosphere.

The presence of this ultraplankton is only being discovered .

Responsibilities of blue greens include forming dark crusts along wave splashed zones , exploiting polluted sediments and even forming a few types of red tides (Trichodesmium erythraea).(skin rashes).

Blue-greens also carry out nitrogen fixation in the ocean, converting N into nitrates to be converted to proteins. Some blue-greens live on the surfaces of seaweeds and sea grasses (epiphites) and some are known to lose their ability to photosynthesize, becoming heterotrophs.

The Green Algae

Includes about 7,500 species that occur in a rich variety of forms and occur in diverse, widespread habitats.

Greatest variety found in freshwater lakes, ponds, and streams.

Most have a single nucleus.

Most reproduce both sexually and asexually.

Chlorophyta..few marine planktonic reps. but lots of macroscopic, benthic types

Chlamydomonas

Common inhabitant of freshwater pools.

Pair of whip-like flagella on one end pull the cell through the water.

Single, cup-shaped chloroplast with one or two pyrenoids inside.

Proteinaceous structures thought to contain starch synthesis enzymes.

Asexual Reproduction

Nucleus divides by mitosis, and cell contents become two daughter cells within the cellulose wall.

Develop flagella and swim away.

Ulothrix

Thread-like alga.

Single row of cylindrical cells forming a filament.

Basal cell functions as a holdfast.

Spirogyra (Watersilk)

Common freshwater algae consisting of unbranched filaments of cylindrical cells.

Frequently float in masses at the surface of quiet waters.

Asexual Reproduction

Fragmentation of existing filaments.

Sexual Reproduction

Papillae fuse and form conjugation tubes.

Oedogonium

Epiphytic filamentous green alga.

Each cell contains a large, netlike chloroplast that rolls and forms a tube around and toward the periphery of each protoplast.

Other Green Algae

Chorella - Widespread green alga composed of tiny spherical cells.

Reproduce by forming either daughter cells or autospores through mitosis.

Desmids - Mostly free-floating and unicellular.

Reproduce by conjugation.

Other Green Algae

Hydrodictyon (Water Nets) - Net-like, tubular colonies with hexagonal or polygonal meshes.

Asexual reproduction as well as isogamous sexual reproduction.

Volvox - Colonial green algae held together in a secretion of gelatinous material

Reproduction asexual or sexual.

Other Green Algae

Ulva (Sea Lettuce) - Multicellular seaweed with flattened green blades.

Isomorphic reproductive structures.

Cladophora - Branched, filamentous green alga with species represented in both fresh and marine waters.

Mostly multinucleate.

CHLOROPHYTA. The great majority of green algae are restricted to fresh water and terrestrial environments.

Only 10% are marine but they are dominant in environments with wide variations in salinity such as bays and estuaries, tide pools (sewage outfalls) .

These are the stock from which land plants derived and in full agreement in regards to pigment, starch, cellulose etc

May exist as single cells, simple or branched filaments, blades, organized into tubes that are intertwined and usually grass green in color.

Few green algae are as complex as the other groups but their pigments and food reserve are the same as in higher plants. (evolved from green algae.)

Chlorophyll b in green and land but not other algaes).

They are unicellular, filamentous multicellular, shapes can vary in the same species according to their environment.

Enteromorpha is a thin hollow tube, Ulva, sea lettuce is leafy-like, Valonia, forms huge spheres /clusters of them in tropical waters., some branch and Caulerpa and Cladophora have tubes with many nuclei, spongy, branching thallus Codium and segmented with deposits of calcium carbonate in their walls to ward off predators but

end up cementing the reef together in reef areas...Halimeda... a Coralline green algae!

Life Histories of seaweeds involve an alternation of gamete producing phase (gametophyte) and spore producing phase (sporophyte).

Green algae...Ulva (sea lettuce) have two identical phases. 1. Sporophyte (diploid) produces flagellated zoo spores (haploid) (meiosis) and these 2. swim briefly and settle on the bottom and 3. grow into a gametophyte phase (male or female) and produce motile gametes which 4. fuse to form zygotes (diploid).

Codium, another green algae is more like animals and produces gametes by meiosis which fuse and form a zygote and grows into the familiar plant.

The Yellow-Green Algae (Xanthophyceae)

Mostly freshwater organisms with a few marine and terrestrial representatives.

Two flagella of motile cells are oriented in opposite directions.

Aplanospores formed during asexual reproduction.

Sexual reproduction rare.

The Golden-Brown Algae (Chrysophyceae)

Most occur in the plankton of bodies of fresh water.

Motile cells have two flagella of unequal length inserted at right angles to each other.

Photoreceptor on short flagellum.

Chrysophyta...golden/yellow color because in addition to chlorophyll. a & c there is a dominant carotenoid, fucoxanthin and many members have a cell covering of small siliceous scales. The silicoflagellates have an internal glass skeleton. Rare today.Characterized by star shaped internal skeleton made of silica and a single flagellum.

Silicoflagellates are one of the lesser known types of photosynthetic protists found in the oceans. They are prominent because of their bizarre "skeleton" which consists of a rigid flattened basket of hollow tubes. Two to 8 spines project radially from the central basket. Because the construction of this skeleton is so robust, scientists can estimate abundances of this organism fairly easily.

Fossils of the skeleton indicate that the diversity of silicoflagellates was once greater than the few species we have today. The cell itself is a lumpy bag containing golden-brown bodies (chloroplasts) that sits around the central part of the skeleton.

Where do they live?

Silicoflagellates are found in sun-lit zones of the of the ocean and are generally more common in colder waters. During winter they can be found closer to the tropics, but they retreat to cooler waters again in the warmer months. The distribution of their fossilised skeletons is used to help determine sea-temperatures in earlier ages

The Haptophytes

Most are unicellular, with two smooth flagella of similar length inserted at the apex.

Flagella aid in food capture.

Haptophyta.. or Coccolithophorids, flagellated spheric cells covered with button like structures called coccoliths made of calcium carbonate. This was broken off the above class because of different types of flagella. Phaeocystis forms gelatinous clumps, visible and can effect migration patterns of fish.

Coccolithophorales

Emiliana huxleyi - global distribution, bloom former, major player in marine phytoplankton

Thought to be largest global producer of calcium carbonate, hence major sink for CO2.

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Also, blooms long ago followed by anaerobiosis, caused them to sediment and gave rise to oil deposits in the North Sea. The coccolithophores have small calcareous plates covering them and the patterns go way back in fossil records and are used by oil companies.

Xanthophyta...like Chrysophyceae but have no fucoxanthin pigment. The Xanthophyta include more than 600 species. Members of this group are photosynthetic organisms which live primarily in freshwater, though some are found in marine waters, in damp soil, or on tree trunks.

Euglenophyta...euglena..class contains only unicellular flagellates, chlorophyll. A and B and a flexible cell covering...no wall!

Euglenophyta...euglena..class contains only unicellular flagellates, chlorophyll. A and B and a flexible cell covering...no wall!

Bacillariophyta...diatoms...most important group in terms of primary productivity. The characteristic yellow-brown color is due to CAROTENOID pigments in addition to two types of chlorophyll (a and c). Half of the 12,000 species are marine. The brownish scum in a fish tank consists of millions of diatoms.

The Diatoms (Bacillariophyceae)

Among best known and economically most important members of this phylum.

Mostly unicellular

Occur in both fresh and salt water.

Particularly abundant in colder marine habitats.

Diatom Characteristics

1. Usually unicellular but chains do occur

2. Pigments chlorophyll. a & c and fucoxanthin (gold/brown)

3. Food reserve is chrysolaminarin and oils (buoyant)

4. Only flagellate cells in reproduction (uniflagellate.)

5. Walls made of glass called frustule.

6. Looks like petri dish

7. Two symmetries..radial and bilateral which divide diatoms into 2 sub-divisions..Centric & Pennates

Reproduction...valve to valve...one product of the division retains the parental epivalve (top) and the other the parental hypovalve (bottom) which results in the bottom being slightly smaller than the parent because a new inside always grows back.

Continued vegetative reproduction reduces the size until it gets to its smallest size and this diploid cell produces gametes which fuse to form a full size zygote. Only the small cells will undergo sexual reproduction and if they get too small, they can't even do that.

Dinophyta /Pyrrhophyta or the Dinoflagellates Mostly unicellular with 2 unequal flagella , one that wraps around a groove in the middle of the cell, and the other that trails free, and include the non-motile zooxanthellae (found in corals).

The are most abundant in warm waters and second to diatoms in cold water.

The Dinoflagellates

Unicellular

Contain two flagella.

One trails behind the cell.

Other encircles the cell at right angles.

Most have disc-shaped chloroplasts.

Contain xanthophyll pigments.

Many have tiny projectiles.

Many types of toxins produced. (Red Tides)

Characteristics of Dinoflagellates

1. Most are marine

2. Chlorophyll a, c, peridinin. Starch, oils , but can ingest food stuffs

3. Distinctive flagella pattern

4. Some without walls (naked) and others with walls (Armor) with cellulosic plates fitting together like armor which may have spines,

5. Half are colorless, some heterotrophic, sparophitic, phagocytic, parasitic and some photosynthetic. It is thought that through

evolution they have gained the ability to function as primary producers by "capturing" and using chloroplasts from other algae.

6. some bioluminescent

7. some responsible for red tides and 20 spp.. secrete toxins. They reproduce by simple cell division and form blooms that often color the water red, reddish-brown, yellow or unusual shades.

a. all toxic ones are photosynthetic

b. all are estuarine or neritic forms

c. all probably produce benthic, sexual resting stages

d. all capable of producing monospecific blooms (suggest competitive advantages through exclusion

e. all produce bioactive-watersoluable or lipid soluble toxins that are hemolytic, or neurotoxic in activity. (NSP, PSP, Dsp)

The Zooxanthellae are a variety of dinoflagellates which have developed a close association with an animal host. The hosts range from sponges to giant clams but the most important are the ones in the stony corals.

They help fix carbon through photosynthesis, release organic matter to be used by the coral, help in formation of the coral skeleton.

It was once believed that all zooxanthellae were the same species, Symbiodinium microadriaticum (Rowan and Powers, 1991). However, recently, zooxanthellae of various corals have been found to belong to at least 10 different algal taxa.

The Euglenoids

Spindle-shaped.

No cell wall, thus changes shape as it moves.

Sub-membrane strips and membrane form pellicle.

Contains gullet.

Contains red eyespot.

Reproduction by cell division.

The Cryptomonads

Asymmetrical, unicellular marine and freshwater algae with two flagella.

Single two-lobed chloroplast with starch granules surrounding a central pyrenoid.

Distinctive nucleomorph

Gullet

Ejectosomes

Reproduction by mitosis

The Stoneworts

Primarily aquatic organisms of shallow, freshwater lakes and ponds.

Often precipitate calcium salts on their surfaces.

Axil with short lateral branches in whorls.

Sexual reproduction is oogamous.

Diatoms

Oils are sources of vitamins.

Diatomaceous Earth

Filtration

Polishes

Reflectorized Paint

Other Algae

Chlorella

Potential human food source.

Algin

Produced by giant kelp.

Ice Cream, Salad Dressing

Latex Paint, Textiles, Ceramics

Regulates water behavior.

Agar

Produced by red alga Gelidium.

Solidifier of nutrient culture media for growth of bacteria.

The Plasmodial Slime Molds

Totally without chlorophyll and are incapable of producing their own food.

Distinctly animal-like during much of life cycle, but fungus-like during reproduction.

Plasmodium converts into separate small sporangia (each containing spores) during times of significant environmental changes.

The Cellular Slime Molds

About two dozen species of cellular slime molds are not closely related to the other slime molds.

Individual amoebalike cells feed independently, dividing and producing separate new cells periodically.

Human and Ecological Relevance

Break down organic particles to simpler substances.

The Water Molds

Often found on dead insects.

Range in form from single spherical cells to branching, threadlike, coenocytic hyphae.

Coenocytic hyphae may form large thread masses (mycelia).

Phylum Chlorophyta

Phylum Chromophyta

Phylum Rhodophyta

Phylum Euglenophyta

Phylum Dinophyta

Phylum Cryptophyta

Phylum Prymnesiophyta

Phylum Charophyta

Phylum Myxomycota

Phylum Dictyosteliomycota

Phylum Oomycota

Members include seaweeds, sea grasses, mangroves, marsh grass, microscopic algae.

they are eukaryotic

contain organelles enclosed by a membrane

photosynthesis takes place in chloroplasts--green,brown, or red organelles.

lack flowers, roots stems and leaves.

While most are referred to as plants, some have flagella and show animal characteristics...and some are actually claimed by both botanists and zoologists as theirs!

Taxonomically, a compromise has placed them in the Kingdom Protista…the unicellular forms.

Seaweeds...dominant marine plants containing chlorophyll and additional pigments from blue to red.

Seaweeds are all eukaryotic and most are multicellular.

But some that are unicellular or simple filaments are considered seaweed because the classifications of seaweeds is based not only on structure,

but also on other features such as types of pigments and food storage products.

Classification characteristics used to classify are;

1. form which starch is stored

2. composition of cell wall

3. presence of motile with flagella

4. level of complexity

5. sometimes, reproductive patterns (reds)

Red Algae is Rhodophyta

Green Algae is Chlorophyta

Brown Algae is Phaeophyta

Algae are Thallus, meaning they lack true roots, stems, and leaves, fruits, connecting tissue etc. and

photosynthesis occurs throughout the plant, not just the leaves.

Parts: Holdfast, stipe, blade, air bladders (pneumatophores).

(list functions)

The Brown Algae (Phaeophyceae)

Relatively Large

Most Marine

Non-Unicellular or Colonial

Many have a thallus differentiated into a holdfast, a stipe, and blades.

Blades may have gas-filled bladders.

Sargassum - Floating Brown Seaweed

Fucus - Common Rockweed

Phaeophyta..microscopic to 60' make up the largest and structurally most complex.

Colors range from olive green to dark brown, due to yellow pigments fucoxanthin dominance over chlorophyll.

Pigments are xanthophyll and carotene and chlorophyll.

The simplest brown algae have a finely filamentous thallus as in Ectocarpus.

There is the fan shaped Padina.

Many species of brown alga are found in the intertidal zone and known as rockweeds and in deeper areas of the cool coastal zones are the kelps, the largest and most complex of all brown algaes.

As mentioned before, kelp plays an important in the coastal production with many organisms finding homes around the kelp beds.

Some kelps consist of a single blade, Laminaria, which are harvested for food.

Kelps have been estimated to grow up to 50 cm (20 inches) per day.

Alginic Acid, a gummy, slimy layer in cell wall, is used as an emulsifying agent (algin)..(Know uses) (algae Readings)

Brown algae...Nereocystis (bull kelp). The kelp is the sporophyte or diploid phase and

1. certain areas of the fronds (sori) become darker

2. meiosis occurs and haploid zoo spores are formed.

3. They settle to the bottom and grow into microscopic gametophytes.

4. The female produces eggs but holds them and the male produces sperm which are released and

5. attracted to eggs, fertilize them and

6. zygotes are formed which germinate into the sporophyte plant.

Kelp (how are chances for fertilization increased?) ....Fucus, another brown algae or rockweed, is again, like animals where the

1. diploid plant forms gametes through meiosis

2. fertilization occurs

3.the zygote immediately germinates back to the sporophyte

Gametes are produced in cavities called CONCEPTACLES.

Rhodophyta has more species of these than green and brown combined.

It has the highest commercial value, and don't get as large as brown algae.

absence of flagellate stages

presence of other pigments mainly phycobilins

The Red Algae

Most species are seaweed.

Tend to occur in warmer and deeper waters than brown algae.

Most are filamentous.

Relatively complex life cycle involving three types of thallus structures.

Colors mostly due to phycobilins.

Numbers of species produce agar.

Floridean starch as food reserve (scattered throughout cells)

Existence of special female cells (carpogonia) and male gametes (called spermatia) for sexual reproduction.

Cell walls with inner rigid component and outer mucilage or slime layer. This is like the alginates and very valuable.

The structure of the thallus of red algae does not show the wide variation in complexity and size that is observed in brown algae.

Most reds are filamentous but thickness, width and arrangement of the filaments vary a great deal.

There are many variations in the shapes, sizes and colors of the reds.

One important in marine environments are the red alga Corallines.

These are characterized by deposits of calcium carbonate around their cell walls.

These can be encrusting on the rocks or articulated, branching plants, with colors from light to reddish pink-white when dead.

Warm water corallines are active in reef development.

1. Sporophyte produces tetrasporangia (site of meiosis) which produce 4 haploid tetraspores.

2. Gametophytes grow from the spores and their gametes (spermatia and carpogonia) fuse and

3. are retained and develop into a special mass of diploid cells (the carposporophyte)

4. which breaks up into many carpospores (diploid) and

5. these grow into a sporophyte generation which resembles the gametophyte (isomorphic) and..(go to 1)

Red algae Porphyra or Nori is a valuable food source but has an atypical life history with the gametophyte being the large leafy plant and the sporophyte being the tiny "conchocelis" found living in discarded shells. The Typical red cycle is that of Polysiphonia.

THE IMPORTANCE OF CORALLINE ALGAE

Corallines as carbon stores

Coralline algae take up carbon for use in the process of photosynthesis, as do most plants, but they have an additional mechanism of carbon uptake, the calcification process.

Calcium is deposited in the cell walls of coralline algae in the form of calcium carbonate.

Coralline algae may be one of the largest stores of carbon in the biosphere.

Non-geniculate corallines are of particular significance in the ecology of coral reefs, where they provide calcareous material to the structure of the reef, help cement the reef together, and are mportant sources of primary production. Coralline algae are especially important in reef construction, as they lay down calcium carbonate as calcite.

Although they contribute considerable bulk to the calcium carbonate structure of coral reefs, their more important role in most areas of the reef, is in acting as the cement which binds the reef materials together into a solid and sturdy structure.

An area where corallines are particularly important in constructing reef framework is in the algal ridge that characterizes surf-pounded reefs in both the Atlantic and Indo-Pacfic regions. Algal ridges are carbonate frameworks that are constructed mainly by nongeniculate coralline algae (after Adey 1978).

They require high and persistent wave action to form, so are best developed on the windward reefs in areas where there is little or no seasonal change in wind direction. Algal ridges are one of the main reef structures that prevent oceanic waves from striking adjacent coastlines, and they thus help to prevent coastal erosion.