Underwater Adaptations

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Behavioral Adaptation in Water
A behavioral adaptation in the
oceans is the use of loud, lowfrequency calls by fin whales to
communicate with other whales
over great distances.
fin whale
Ray fish
One of the ways for sea creatures to
deception their selves is digging themselves
in the sand. Fully cover their physique with
silt as well as gravel and customarily their
eyes
Behavioral Adaptation in Water
pupfish
Some fish can enter a sleep-like state, but they
do not hibernate. During the coldest parts of
winter, pupfish burrow into the muddy bottom
and become dormant until the weather warms
up. Aquatic frogs and toads such as the
leopard frog and American bullfrog usually
hibernate underwater. They don’t, however,
dig into the mud like turtles. They lie just
above the mud, or only partially buried in the
mud.
tuna
Many types of fish , (like tuna,
sharks,
dolphins,
sailfish,
swordfish, etc.) migrate on a
regular basis, on time scales
ranging from daily to annually or
longer, and over distances ranging
from a few metres to thousands
of kilometres.
Behavioral Adaptation in Water
A group of fish that stay together for
social reasons are shoaling, and if the
group is swimming in the same
direction in a coordinated manner,
they are schooling. Fish derive many
benefits from shoaling behavior
including defense against predators
and
increased
hydrodynamic
efficiency.
Structural Adaptation in Water
Mimicry
Camouflage
Rock fish
pygmy seahorse
Protection from predator
Porcupine fish
Attracting prey
Scientists have discovered more than 180
species of biofluorescent fish that glow in
neon shades.
Some of the fish glow just around their eyes.
Others have intricate fluorescent patterns on
their bellies or backs. And some of the fish
glow all the way through their bodies.
Special features
starfish
If a starfish loses an arm, an organ or even most of
his body, he can re-grow whatever part he needs as
long as part of the central ring is intact. Thanks to
this ability, if a predator attacks and manages to take
a bite, a starfish won't bleed to death, get an
infection or be permanently crippled. In fact, one
starfish may become two if part of the central ring is
attached to the part separated from the main body
The cuttlefish, actually a
cephalopod relative of octopuses
and squid, can shift shape and
change its skin color to hide from
danger by impersonating its
surroundings—like a chunk of a
coral, a clump of algae, or simply
a patch of sand.
cuttlefish
Structural Adaptation in Water
Streamlined body shape
Most aquatic animals have a streamlined body shape that reduces water
resistance to enable the animal to move faster in water, e.g. dolphin.
Modified limbs
Many aquatic animals have modified
limbs to help them propel their bodies
forward and control their movement in
water, e.g. fish have fins,
frogs and ducks have webbed feet,
seals and turtles have flippers
water boatman has oar-like legs.
Modified limbs
Most jellyfish use a form of jet propulsion to move
through seawater. They squeeze their bodies in
order to push jets of water from the bottom of their
bodies to propel the jellyfish forward.
Blubber
Some aquatic animals have a layer of
blubber or fat which helps them to
stay buoyant in water.
manatee
Swim bladders
Most fish have swim bladders to
help them stay afloat or buoyant
in water.
Adaptations for moving in water
• Most aquatic animals have a streamlined body shape that
reduces water resistance to enable the animal to move faster in
water, e.g. dolphin.
• Some aquatic animals have a layer of blubber or fat which helps
them to stay buoyant in water.
• Many aquatic animals have modified limbs to help them propel
their bodies forward and control their movement in water, e.g.
fish have fins, seals and turtles have flippers, frogs and ducks have
webbed feet, water boatman has oar-like legs.
• Most fish have swim bladders to help them stay afloat or
buoyant in water.
Explain that:
• Adaptations are important for animals to survive, move and
protect themselves.
Throughout the oceans, marine
organisms must deal with
several things that are less of a
problem for life on land:
•Regulating salt intake
•Obtaining oxygen
•Adapting to water pressure
•Dealing with wind, waves and
changing temperatures
•Getting enough light
Salt Regulation
Fish can drink salt water, and eliminate the salt through their gills.
Salt Regulation
Seabirds also drink salt water, and the excess salt is eliminated via the
nasal, or “salt glands” into the nasal cavity, and then is shaken, or
sneezed out by the bird.
Salt Regulation
Whales don’t drink salt water, instead getting the water they need from the
organisms they eat.
Temperatures
Many ocean animals are cold-blooded and
their internal body temperature is the
same as their surrounding environment.
Marine mammals, however, have special
considerations because they are warmblooded, meaning they need to keep their
internal body temperature constant no
matter the water temperature.
Marine mammals have an insulating layer
of blubber (made up of fat and connective
tissue) under their skin. This blubber layer
allows them to keep their internal body
temperature about the same as ours,
even in the cold ocean. The bowhead
whale, an arctic species, has a blubber
layer that is 2 feet thick
Water Pressure
In the oceans, water pressure increases 15 pounds per square inch for every
33 feet of water. While some ocean animals do not change water depths very
often, far-ranging animals such as whales, sea turtles and seals sometimes
travel from shallow waters to great depths several times in a single day. How
can they do it?
Water Pressure
The sperm whale is thought to be able to
dive over 1 ½ miles below the ocean
surface. One adaptation is that lungs and
rib cages collapse when diving to deep
sperm whale depths.
The leatherback sea turtle
can dive to over 3,000 feet.
Its collapsible lungs and
flexible shell help it stand
the high water pressure.
leatherback sea turtle
Wind and Waves
Animals in the intertidal zone do not have to deal with high water pressure, but need to
withstand the high pressure of wind and waves. Many marine invertebrates and plants in this
habitat have the ability to cling on to rocks or other substrates so they are not washed away, and
have hard shells for protection.
One physical adaptation used in the intertidal zone
is a crab's hard shell, which protects it from
predators, drying out and being crushed by waves.
Light
Organisms that need light, such as
tropical coral reefs and their associated
algae, are found in shallow, clear waters
that can be easily penetrated by sunlight.
Since underwater visibility and light
levels can change, whales do not rely on
sight to find their food. Instead, they
locate prey using echolocation and their
hearing.
In the depths of the ocean abyss, some
fish have lost their eyes or pigmentation
because they are just not necessary.
Other organisms are bioluminescent,
using light-giving bacteria or their own
light-producing organs to attract prey or
mates.
Oxygen
Adaptations for breathing
atmospheric oxygen
Adaptations for breathing oxygen
dissolved in water
• Blowholes located on top of their heads
to help them breathe when they are
swimming near the water surface, e.g.
whale, dolphin
• Nostrils at the tip of their snouts; the
nostrils are shut when underwater and
breathing occurs only when the nostrils
are out of the water, e.g. seal, walrus
• Breathing tubes that stick out of the
water surface to take in atmospheric
oxygen, e.g. water scorpion, mosquito
larva, mosquito pupa
• Carry air bubbles in their adapted wings,
legs or hairy bodies, e.g. water spider,
water beetle
• Gills that help to extract oxygen from the
water and release carbon dioxide back into
the water, e.g. fish, prawn, tadpole
• Special thin layer of skin to help them
breathe in the water, e.g. frog, flatworm,
salamander
• Gill chambers to store water and keep
the gills wet all the time so the animal can
use oxygen from the water in the gill
chambers, e.g. mudskipper, hermit crab
Oxygen
All living things need oxygen. Land animals take in oxygen from the atmosphere, while
aquatic animals can either make use of oxygen from the atmosphere or oxygen
dissolved in the water.
Adaptations for breathing atmospheric oxygen
Marine mammals need to come to the water surface to breathe, which is why the
deep-diving whales have blowholes on top of their heads, so they can surface to
breathe while keeping most of their body underwater.
Adaptations for breathing atmospheric oxygen
Nostrils at the tip of their snouts; the nostrils are shut when underwater and breathing occurs
only when the nostrils are out of the water, e.g. seal, walrus
Adaptations for breathing atmospheric oxygen
Whales can stay underwater without breathing for an hour or more because they
make very efficient use of their lungs, exchanging up to 90% of their lung volume with
each breath, and also store unusually high amounts of oxygen in their blood and
muscles when diving
Adaptations for breathing atmospheric oxygen
mosquito larva
Breathing tubes that stick out
of the water surface to take
in atmospheric oxygen, e.g.
water scorpion, mosquito
larva, mosquito pupa
Adaptations for breathing atmospheric oxygen
Carry air bubbles in
their adapted
wings, legs or hairy
bodies, e.g. water
spider, water beetle
water beetle
Adaptations for breathing oxygen dissolved in water
Gills that help to extract oxygen from the water and release carbon dioxide back into
the water, e.g. fish, prawn, tadpole
Adaptations for breathing oxygen dissolved in water
flatworm
Salamander
frog
Special thin layer of skin to help them breathe in the water, e.g. frog,
flatworm, salamander
Adaptations for breathing oxygen dissolved in water
Gill chambers to store water and keep the gills wet all the time so the
animal can use oxygen from the water in the gill chambers, e.g.
mudskipper, hermit crab
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