Classification of Marine Organisms Unit 2 Flashcards
What are the three types of marine organisms?
nekton, plakton, and bethos
Plankton nickname, definition, 3 examples
“drifters”
Small microscopic organisms that drift or float in the water.
Jellyfish, diatoms and protozoans
Nekton nickname, definition, 3 examples
“swimmers”
Aquatic animals that swim and move independently in water currents
Fish, squid, octopus
Benthos nickname, definition, 3 examples
“Bottom-dwellers”
Flora and fauna found at the bottom of oceans, lakes or seas. They can also be found in sediments
Sea anemones, sponges, coral
Phytoplankton (D & E)
autotrophs (undergo photosynthesis) diatoms and cyanobacteria
Zooplankton (D and E)
heterotrophs. Krill and isopods
Bacterioplankton (including picoplankton) (D and E)
Free living bacteria. Purple and green bacteria.
Virioplankton (D and E)
Even smaller than bacterioplankton. Bacteriophages and algal viruses
Holoplankton (D and E)
Organisms that spend their entire lives as plankton. Krill, diatoms
Meroplankton (D and E)
spend their adult life as nekton or benthos but as a juvenile are plankton. Crabs, octopus.
Macroplankton (D and E)
Large floating animals/algae. Jellies and sargassum
Why aren’t nekton able to move throughout the entire ocean?
Gradual changes in temperature, viscosity and availability of nutrients limit their lateral range. Changes in water pressure limit their vertical range.
3 types of benthos
epifauna, infauna, nekton benthos
Epifauna (D and E)
Live on the surface of the sea floor, either attached to rocks or moving along the bottom. Crustaceans.
Infauna (D and E)
live buried in the sand, in discarded shells, or within the mud that exists on the sea bottom. Clams
Nekton Benthos (D and E)
Live on the bottom of the ocean yet have the ability to swim/crawl through the water above the ocean floor. Octopi, crabs.
What percent of marine organisms are terrestrial? What percent are marine?
87% of species are terrestrial, 13% are marine.
How many marine and terrestrial species inhabit Earth?
The total number of species cataloged in both marine and terrestrial biomes is 1.8 million.
How many species are discovered each year?
2,000 species are discovered each year.
Why don’t we know more about the ocean?!
Because of the ocean’s immense size and its inaccessibility
If the ocean is such a prime habitat for life and if life originated there, why do so few of the world’s organisms live in the oceans? (3 reasons)
The marine environment is more stable than the terrestrial, especially in temperature, meaning that it lacks variability so less species evolve from the environment.
What are the 2 major divisions in the oceans?
Pelagic and benthic
Name the 2 zones that the pelagic environment is divided into
Neritic province and oceanic province
Pelagic definition
Where drifters and swimmers live
Benthic definition
Where marine algae and animals that do not float or swim live
Neritic province
Extends from the shore seaward and includes all water less than 660 ft deep, typically the continental shelf.
Oceanic province
seaward of the neritic province, depth beyond 660 ft, continental slope.
The oceanic province is subdivided into four zones. Name each and give a brief description of each. Know depth (in meters) of each zone.
Epipelagic: Surface -> 200 m. Oxygen levels decrease, nutrients increase
Mesopelagic: 200 -> 1000 m. Bioluminescence is common. Shrimp, squid, deep sea fish
Bathypelagic: 1000 -> 4000 m.
Abyssopelagic: deepest parts of the ocean below 4000 m.