Plankton-Plankton are almost always at the bottom of the food chain in any marine environment, making them possibly the most important group.

-The word “plankton” isn’t necessarily a technical science term, it is a general word to describe small organisms with no control over their long-term movements.

-There are several groups and types of planktonic organisms.

http://science.discovery.com/videos/brink-package-algae-to-oil.html

PhytoplanktonDiatoms – phylum bacillariophyta

-Anywhere from 5,000 – 50,000 species estimated.

-More than 1 million diatoms can be created from 1 diatom in just 2 weeks.

-Make up 25% of photosynthetic biomass on Earth.

*Bilateral or Radial symmetry*Frustule - two-part silica skeleton. One layer sits outside of the other,

sort of like the lid of a petri dish

*Secretes a “mucous” through the raphe, long slit down the center of a diatom

raphe

PhytoplanktonDinoflagellates - Dinophyta

*2nd largest group of photosynthetic algae, behind

diatoms.

*Very few of them are heterotrophic parasites in fish.

-Small movements by means of flagella, protein appendages

that flip back and forth

-Red tide phenomenon is caused by dinoflagellates. Its an

overgrowth caused by excessive nutrients, water is reddish

brown due to tons of dinoflagellates in water. (up to 20 million

per liter) pictures on next slide.

-Many species are bioluminescent when disturbed.“……it is not the property of fire alone to give light;…small

drops of the water, struck off by the motion of the oars in

rowing, seem sparkling and luminous.”

Francis Bacon, 1605

Plankton - Red Tides-Large amounts of dinoflagellates turn the water reddish-brown, and make it

poisonous to humans and other organisms who live in the water.

Red tide off coast of Washington State

Off the coast of California

-These produce high amounts of potentially deadly neurotoxins.

Phytoplankton

*Mutualism between coral and

dinoflagellates

PhytoplanktonGreen Algae – Phylum Chlorophyta

*When you typically think of seaweed,

this is what you are actually thinking of.

*Photosynthetic, mainly multicellular in

marine ecosystems.

*Scientists believe that land plants may

have evolved from green algae due to

having similar types of cholorphyll.

*Produce cellulose (makes cells rigid

and hard).

*Different in that green algae lack roots

and transport structures (xylem and

phloem).

-Some species also have mutualistic relationships with coral and other cnidarians

(jellies).

PhytoplanktonRed Algae – Phylum Rhodophyta

*Similar to green algae, except they have no

cellulose, but some do secrete calcium

carbonate.

*Do NOT produce the same types of

chlorophyll as land plants and green algae.

*Some secrete calcium carbonate (act like

cement in a brick wall).

*Phycoerythrins – red pigments produced by red algae. NO OTHER

EUKARYOTE contains these pigments.

***They can live in deeper water because they absorb blue light,

which travels further than any other color on the spectrum.

PhytoplanktonBrown Algae – Phylum Phaeophyta

*Most complex structure of all types of

marine algae.

*Can have holdfasts (roots), blades

(leaves), stipes (stalks), pneumatocysts

(air-filled chambers to keep near light).

*Kelp can reach the surface from nearly

80 feet deep (grow almost a foot a day).

Sargasso Sea (Center of North Atlantic) –

named because of so much floating brown

algae (sargassum is a genus of brown

algae).

Amoeba/Paramecium

Amoeba – eukaryotes, engulf their

food using phagocytosis

Paramecium – eukaryotes, move

using cilia, tiny hairs. Hairs also

push food into mouth-like opening.

ZooplanktonPhylum Arthropoda

Copepod - plankton from

Spongebob

Daphnia – water fleas

(look like pregnant

birds)

Krill – closely related to

shrimp, one of the most

abundant animals in the

sea. Ostracod – swim in circles

with long appendages

Phylum cnidaria – hydra,

smaller sea anemone

Planaria – flat

worms, 2 eyespots.

Nematodes – Phylum Nematoda-These are extremophiles, meaning they can

survive in extreme environments.

-They can live in incredibly hot or cold habitats and

can survive on almost no food for weeks at a time.

-Tens of thousands of species have been identified,

most of which are parasitic.

Nematode digestive infection

Why are these all

so IMPORTANT?BOTTOM OF THE FOOD CHAIN!!!!!!!!!!!!!