Marine Science: The Great Plankton Race
The sun is the base of all food chains. Phytoplankton use the sun to
photosynthesize. As such, these organisms must remain in the "well-lit" or
photic zone of the water.
Zooplankton
(pronounced "Zoh-playnk-tin") feed off of phytoplankton, so
they must also have a way to stay in the photic zone. Being plankton, however,
they are not good swimmers; they are "drifters", by
name and virtue. To stay in the photic zone, plankton have special
adaptations to remain afloat.
Dinoflagellates, a type of phytoplankton, use
flagella, or long tails to help stay afloat; ciliates
use cilia, or hair-like extensions. Other plankton form
chains with each other to gain surface area to stay afloat.
Some plankton have vacuoles or other compartments in their bodies to
help provide buoyancy. These adaptations give each plankton species an
advantage.
Not all plankton float in the
water, some are benthic; that is, they are found on the
bottom of the lake on rocks and sediment. (An easy to remember the
definition of the word 'benthic' is the 'b' found in benthic and bottom.) These
plankton do not need to have adaptations to stay afloat as they are neither
solitary or have apparatus to move, albeit slowly. Other plankton attach
themselves to vegetation in the water. Planktonic, drifing, plankton
are the ones who have a vested interest in not sinking. Most zooplankton can
move; they undergo a diurnal migration where they migrate
to deeper water during the day and return to the top at night (They do this
because they escape predators by going to deeper water and return back to the
top later on.) It is thought that these zooplankton undertake this
energetically costly migration to avoid predation and
to conserve energy. However, when they are feeding in the
photic zone, they want to be able to stay suspended while expending as little
energy as possible, so they can still utilize flotation
adaptations.
Vocabulary
Photic zone: The depth of water in a lake or ocean that is exposed to
sufficient sunlight to photosynthesize.
Plankton: Small organisms that float or drift in great
numbers in bodies of salt or fresh water; a primary food source for many
animals, and consists of bacteria, protozoans, algae, cnidarians, tiny
crustaceans such as copepods, and many other organisms.
Benthic: Non-floating plankton; these plankton do not
float in the water - instead they live attached to or on top of a solid surface
like rocks, plants, sediment, even a single grain of sand; planktonic diatoms
are typically pennate, or not round - this is the most common type of diatom to
find in alake.
Planktonic: Floating in
the water column; planktonic diatoms are typically centric, or
round.
Phytoplankton: A type of plankton
(drifting marine organism that makes up the foundation of the marine food web)
that relies on photosynthesis. This group is comprised mostly of single-celled
algae, diatoms, and bacteria.
Zooplankton:
A type of plankton that feeds on phytoplankton.
Adaptations: Any
physical or behavioral trait that allows an organism to better survive in its
environment.
Cilia: Hair-like extensions found on
ciliates, a type of plankton, to help them move and catch
food.
Flagella: Tails found on
dianoflagellates, a type of plankton.
Surface area: The total area of all
of the faces and curved surface of a solid object.
Density: Mass per unit of volume; a
measure of the relative "heaviness" of objects.
Micron: A unit of
length equal to one millionth of a meter. This is the unit used to measure
plankton size. Conversion formulas: microns = 1000 x mm; millimeters = microns x
0.001.
The sun is the base of all food chains. Phytoplankton use the sun to
photosynthesize. As such, these organisms must remain in the "well-lit" or
photic zone of the water.
Zooplankton
(pronounced "Zoh-playnk-tin") feed off of phytoplankton, so
they must also have a way to stay in the photic zone. Being plankton, however,
they are not good swimmers; they are "drifters", by
name and virtue. To stay in the photic zone, plankton have special
adaptations to remain afloat.
Dinoflagellates, a type of phytoplankton, use
flagella, or long tails to help stay afloat; ciliates
use cilia, or hair-like extensions. Other plankton form
chains with each other to gain surface area to stay afloat.
Some plankton have vacuoles or other compartments in their bodies to
help provide buoyancy. These adaptations give each plankton species an
advantage.
Not all plankton float in the
water, some are benthic; that is, they are found on the
bottom of the lake on rocks and sediment. (An easy to remember the
definition of the word 'benthic' is the 'b' found in benthic and bottom.) These
plankton do not need to have adaptations to stay afloat as they are neither
solitary or have apparatus to move, albeit slowly. Other plankton attach
themselves to vegetation in the water. Planktonic, drifing, plankton
are the ones who have a vested interest in not sinking. Most zooplankton can
move; they undergo a diurnal migration where they migrate
to deeper water during the day and return to the top at night (They do this
because they escape predators by going to deeper water and return back to the
top later on.) It is thought that these zooplankton undertake this
energetically costly migration to avoid predation and
to conserve energy. However, when they are feeding in the
photic zone, they want to be able to stay suspended while expending as little
energy as possible, so they can still utilize flotation
adaptations.
Vocabulary
Photic zone: The depth of water in a lake or ocean that is exposed to
sufficient sunlight to photosynthesize.
Plankton: Small organisms that float or drift in great
numbers in bodies of salt or fresh water; a primary food source for many
animals, and consists of bacteria, protozoans, algae, cnidarians, tiny
crustaceans such as copepods, and many other organisms.
Benthic: Non-floating plankton; these plankton do not
float in the water - instead they live attached to or on top of a solid surface
like rocks, plants, sediment, even a single grain of sand; planktonic diatoms
are typically pennate, or not round - this is the most common type of diatom to
find in alake.
Planktonic: Floating in
the water column; planktonic diatoms are typically centric, or
round.
Phytoplankton: A type of plankton
(drifting marine organism that makes up the foundation of the marine food web)
that relies on photosynthesis. This group is comprised mostly of single-celled
algae, diatoms, and bacteria.
Zooplankton:
A type of plankton that feeds on phytoplankton.
Adaptations: Any
physical or behavioral trait that allows an organism to better survive in its
environment.
Cilia: Hair-like extensions found on
ciliates, a type of plankton, to help them move and catch
food.
Flagella: Tails found on
dianoflagellates, a type of plankton.
Surface area: The total area of all
of the faces and curved surface of a solid object.
Density: Mass per unit of volume; a
measure of the relative "heaviness" of objects.
Micron: A unit of
length equal to one millionth of a meter. This is the unit used to measure
plankton size. Conversion formulas: microns = 1000 x mm; millimeters = microns x
0.001.