Lec 8 Flashcards
- The shallow part of the ocean above the drop-off of the continental shelf, about 200m in depth.
- only a small part of the pelagic .
Neritic zone
The area where the ocean meets the land between high and low tides.
Intertidal zone
The area of the ocean lying beyond the continental shelf where water depths drop to below 200 meters.
Oceanic zone
is the water column itself, away from the bottom or the shore
Pelagic environment
shallowest, warmest, and the best light part similar to the photic zone.
Epipelagic (upper pelagic)
ecological realm that includes the entire ocean water column or defined as the part of the open sea or ocean that is not near the coast or sea floor
ocean’s pelagic zone / Pelagic realm
seaweeds and sea grasses are largely absent from the epipelagic because?
they have no place to attach.
Epipelagic lacks suspension feeders
T/F?
F, deposit feeders
Composed of viruses and called virioplankton.
Femtoplankton
Consists mostly of archaea and bacteria.
Picoplankton
they can be caught in nets, they are subdivided on the basis of size into (micro-, meso-, macro megaplankton).
Net plankton
Most important Phytoplankton
diatoms and dinoflagellates
They are common in temperate, polar regions, and other nutrient-rich waters . They are abundant both near the coast and in the open ocean
Diatoms
important in both Neritic and oceanic waters but tend to prefer warm areas. And they may be better-adapted to low-nutrient conditions than diatoms, or grow explosively into huge numbers sometimes causing red tides.
Dinoflagellates
grows in filamentous colonies. Sometimes forming red
tides, It is mainly abundant in nutrient-poor waters.
Cyanobacteria, Trichodesmium
are more abundant than the net phytoplankton
Picoplankton & Nanoplankton
are the most abundant picoplankton and account for at least 50% the ocean’s total primary production.
Cyanobacterium
not only regulates the phytoplankton productivity, but also fuels the benthic community via vertical particle flux.
Zooplankton
Are small crustaceans, they are so small that most large animals can’t catch them that dominate the net zooplankton about 70% or more of the community.
Copepods
- animals similar to small shrimps that live in the
oceans. - are efficient filter feeders
capturing phytoplankton, especially diatoms - eat small zooplankton.
Krill
Are a planktonic crustaceans that are small, like copepods.
Amphipods
Are large crustaceans, also occur in the net zooplankton, almost exclusively carnivorous.
Decapods crabs and Shrimps
group of molluscs known as phytoplankton grazers. They are small snails in which the foot has been modified to form a pair of “wings” that they flap to stay afloat.
Pteropods
Feed mostly on copepods. have a major role in epipelagic food webs.
Arrow worms or Chaetognaths
○ Can be quite large but are weak swimmers
○ drift with the currents as part of the plankton.
○ carnivorous
Jelly fishes
are temporary members of the plankton, they release
their eggs or young into the water column, and the planktonic larvae spend the early part of their lives in the plankton
Meroplankton
are organisms that spend their whole lives in the plankton.
Holoplankton
Almost all marine fishes have planktonic larvae.
T/F
T
total of …. diatom species and … dinoflagellate species for the complete area of the Arabian Gulf.
888 diatom, 211 dinoflagellate
…… numper of copepos species reported in Arabian Gulf
29
…… numper of copepos species reported in Arabian Gulf
29
is a free-swimming aquatic animals essentially independent of wave and current action. Animals that can swim against water currents.
Nekton
Organism spend their time either under, on or near the surface of the ocean floor.
Benthos
- Staying Afloat
- Predators and Their Prey
- Vertical Migration
- Trophic Levels and Energy Flow
adaptations of epipelagic organisms
Gas bubbles, or vacuoles, inside the cells of
Cyanobacteria
