Plankton Flashcards
What is plankton?
Small and microscopic organisms that drift or float in the water column
What are the two main categories of plankton?
- Phytoplankton (plant-like, photosynthetic)
- Zooplankton (animal-like, heterotrophic)
What is the difference between plankton and nekton?
Plankton drift with currents; nekton are actively swimming organisms
What are phytoplankton?
Photosynthetic plankton that produce oxygen
What are zooplankton?
Animal plankton that feed on phytoplankton or other zooplankton
Name the 2 types of zooplankton.
- Holoplankton (spend their whole life as plankton)
- Meroplankton (planktonic only during larval stages)
What is a plankton bloom?
A rapid increase in plankton population, usually in response to favorable light and nutrient conditions
What is a picoplankton?
A plankton that is 0.2 - 2 micrometers in diameter
What is a nanoplankton?
A plankton that is 2 - 20 micrometers in diameter
What is a microplankton?
A plankton that is 20 - 200 micrometers in diameter
What is a mesoplankton?
A plankton that is 200 - 1000 micrometers in diameter
What are diatoms?
Phytoplankton
Single-celled phytoplankton with silica cell walls (called frustules)
What are dinoflagellates?
Phytoplankton
Single-celled phytoplankton with two flagella for movement and often cellulose plates as armor
What makes some dinoflagellates dangerous?
Phytoplankton
Some produce toxins that cause harmful algal blooms (HABs), such as red tides
What are cyanobacteria (blue-green algae)?
Phytoplankton
Photosynthetic bacteria considered among the oldest life forms
Why are cyanobacteria important in the ocean?
They contribute to nitrogen fixation and primary production, especially in oligotrophic waters
Coccolithophores
Phytoplankton
Single-celled phytoplankton that produce calcium carbonate plates
What are copepods?
Zooplankton
Tiny crustaceans and some of the most abundant multicellular organisms on Earth
What is krill?
Zooplankton
Small, shrimp-like crustaceans that feed on phytoplankton and are a major part of the food web
What are foraminifera?
Zooplankton
Single-celled zooplankton with calcium carbonate shells, often used as climate proxies in ocean sediment cores
What are radiolarians?
Zooplankton
Single-celled zooplankton with intricate silica skeletons and pseudopodia for capturing food
What are salps?
Zooplankton
Transparent, barrel-shaped, gelatinous zooplankton that move by jet propulsion and feed on phytoplankton
What are chaetognaths (arrow worms)?
Zooplankton
Predatory zooplankton with transparent bodies and grasping spines used to catch prey like copepods
What are meroplankton?
Zooplankton
Temporary plankton, such as the larval stages of fish, mollusks, crustaceans, and echinoderms
What is bioluminescence?
The production and emission of light by living organisms through a chemical reaction
What are the key components of bioluminescence?
- Luciferin (light-producing molecule)
- Luciferase (enzyme)
- Oxygen
The reaction produces light and a byproduct called oxyluciferin.
What is the difference between bioluminescence and fluorescence?
Bioluminescence is a chemical light-producing reaction within the organism; fluorescence is the emission of light after absorbing external light.
