ADAPTATIONS
Table of Contents
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Desert Adaptations
Tropical Rainforest Adaptations
Grassland Adaptations
Temperate Rainforest Adaptations
Temperate Deciduous Forest Adaptations
Taiga Adaptations
Tundra Adaptations
Ocean Adaptations
Adaptations
What Does Adaptation Mean?
• The special characteristics that enable plants
and animals to be successful in a particular
environment.
What are some reasons animals
adapt?
• Make a list on your paper and be prepared to
share with the class.
Adaptations are the result of evolution
• Adaptations occur because of natural genetic
variations in a species or because of genetic
mutations or changes!
• All species have a natural variety within them.
• Some of the variations and mutations can help
an animal or plant to survive better than
others in the species.
What are some adaptations that you
know about already?
• Make a list on your paper and be prepared to
share with the class.
Some
examples
• Fish have gills. These gills allow fish to breathe
underwater. Without gills fish would not be able
to survive in their habitat.
• Why can’t we breath under water?
• Why do whales and dolphins have to come to the
surface of the water?
Examples continued
• Birds have strong, hollow bones. These hollow
bones make birds very light. This is why they
are able to fly. Respiratory air sacs also form
air pockets in the birds hollow bones.
• If they had bones like humans, would they be
able to fly?
• What are some birds you know of that can’t
fly? Why can’t they fly?
Examples continued
• Plants have xylem so that they can transport
water and other nutrients from the root
system to the rest of the organism.
• What would happen if they didn’t have
xylem?
Structural
Adaptations
• Structural adaptations are physical features of
an organism like the bill on a bird or the fur on
a bear.
Behavioral Adaptations
• Behavioral adaptations are the things
organisms do to survive. For example, bird
calls and migration are behavioral
adaptations.
YOU WILL BE SHOWN SEVERAL
PICTURES OF ADAPTATIONS.
PLEASE INDICATE ON YOUR PAPER IF
THESE ARE STRUCTURAL OR
BEHAVIORAL ADAPTATIONS.
ZZZZZZZZZZZZZZ
ZZZZZZZZZZZZZZ
ZZZZZZZZZZZZZZ
Animal Adaptations
• Animals will adapt to their surroundings.
Animals of similar species can adapt to survive
in many different environments.
• You will now be shown several different
biomes and how the plants and animals in
those biomes have adapted to survive.
DESERT ADAPTATIONS
PLANTS
• Plants have many adaptations to cope with
the lack of water in the desert.
• The barrel cactus has an expandable stem
for storing water.
• Some other plants have adaptations that
reduce water loss from their leaves (this is
where most water is lost)
– Some have a waxy coating on their leaves
– Some have small leaves or no leaves at all
• All plants lose water through transpiration
(the process of water evaporation through
specialized openings in the leaves called
stomata, seen in this picture).
• The stomata of some desert plants like
bitterroot are smaller and there are less of
them.
• Many desert plants open their stomata only at
night, since there is less water loss when it is
cooler.
• Annual Plants- annual plants on the desert
survive periods where water is in short supply
because their seeds germinate only after heavy
rain, grow rapidly, and live their whole life-cycle
in just a few days.
• Perennial Plants- they endure the dry periods and
make the most of the scarce water supplies.
– Grasses have large and complex root systems that
allow them to collect water over a wide area.
– Bunchgrasses grow in isolated tufts. This reduces
competition between plants and assures each tuft of
grass its own territory from which to draw water. They
also grow tightly together which also conserves water
that would be evaporated by the wind.
• Suffrutescent Shrubs- are perennial plants
that use the strategies of both annuals and
perennial plants. They maintain a woody base
throughout the year, but grow leafy shoots in
the spring to allow them to utilize water.
These shoots die back when water is not
available.
– Example: Nuttall Saltbush
• Some plants, like sagebrush, look dull gray. This is
because they are covered in tiny hairs . Leaf hairs
reflect the rays of the sun and protect it from
being dried by the wind.
• Big Sagebrush grows two sets of leaves. Large
leaves in the spring that allow the plant to take in
water and grow rapidly. These fall off in the
summer. The smaller leaves that grow allow for
less evaporation and conserve water.
• Sagebrush also survives due to its three level root
system. These allow the plant to obtain all
available water.
• Some plants, like Rabbitbrush, have very small
leaves. This helps them conserve water.
• Whenever there is plenty of water, the Prickly
Pear Cactus collects moisture in the spongy
tissue of its enlarged stems, called pads. The
cactus can then draw on this stored supply
when the weather turns dry.
ANIMALS
• Conserving water is important for desert mammals. Some small mammals:
– Have no sweat glands
– Pass no urine or very concentrated urine like the kangaroo rat.
– Acquire all or most of the moisture they need from the food they eat.
• Almost all animals in the desert stay out of the
sun during the hottest part of the day. They
stay deep underground in burrows where it is
much cooler.
• Most animals get their water from the food
they eat. Green leaves contain a lot of water.
Carnivores get water from the bodies of their
prey, which contain liquid in the blood and
tissues.
• There are a few animals that can be seen
during the day. These animals protect
themselves from the heat by staying in the
shade.
• The ability to fly allows birds to cover great
distances in search of food and water. Because
flight generates a lot of heat, birds are
naturally adapted to high body temperatures.
• Flight also enables a bird to leave areas of
extreme hot or cold and to move to a more
temperate climate.
• Feathers also help insulate birds from the heat
of the sun.
• Owls and nighthawks gape open-mouthed
while rapidly fluttering their throat region to
evaporate water from their mouth cavities.
• Many birds are active primarily at dawn and
within a few hours after sunset, retiring to a
cool, shady spot for the remainder of the day.
• Bats, most rodents and some
larger mammals, like coyotes and
skunks, are nocturnal. This means
that they are active at night when
it is cooler and sleeping during
the hot daylight hours.
• The mule deer and the elk
are crepuscular during times
of extreme temperatures,
which means they are active
for a few hours at dusk and
dawn.
• Migration is another behavioral adaptation
some large mammals like elk and pronghorn
rely on to survive harsh temperatures.
• Several animals have evolved long
appendages to dissipate body heat into
their environment.
– The enormous ears of the jackrabbit and
mule deer release body heat when the
animal is resting in a cool, shady location.
• To survive extreme temperature, marmots and
other small mammals may enter a state of
suspended animation called estivation. During
estivation the animals breathing, heartbeat,
and other body processes slow down.
• Large animals like elk have thick coats. This
helps insulate their bodies against the heat.
• Some animals have lighter colored coats
which reflect more light than a dark coat.
• Reptiles have thick skin that minimizes water loss.
• Reptiles are “cold-blooded” (their body
temperature stays about the same as the
temperature of their surroundings). These
animals survive by avoiding extremely high or low
temperatures.
• Many reptiles are only active at night. Those that
are active during the day keep moving from
sunny places to shady spots.
• Some lizards have longer legs, so they absorb
less surface heat while running.
• Reptiles can also enter estivation.
• When the desert cools down the reptiles lose
their body heat. During the day, they will
sunbathe on rocks in order to raise their body
temperature.
• If the desert has harsh winters, the reptiles
will hibernate.
TROPICAL
RAINFOREST
ADAPTATIONS
PLANTS
• Plants in the rainforest have adaptations that
enable them to shed water efficiently.
• The leaves of many rainforest plants have drip
tips for this purpose.
• Tropical rainforest plants also have
adaptations to take in what little sunlight is
available on the dark forest floor.
• Large leaves are common; they increase the
amount of sunlight a plant can capture.
• Other plants, like orchids, bromeliads and
ferns, grow as epiphytes (a plant that grows
on another plant upon which it depends for
mechanical support but not for nutrients) high
up in the canopy where there is more sunlight.
• The strangler fig needs sunlight to grow and reproduce.
Seeds falling to the ground quickly die in the deep shade
and infertile soil of the tropical rainforest.
• Its seeds are deposited on branches of host trees by birds
and small animals that have eaten the fruit of the strangler
fig. The seeds sprout and send a long root to the ground.
• This root rapidly increases in diameter and successfully
competes for the water and nutrients in the soil.
• As the strangler fig matures, branches and leaves grow
upwards creating a canopy that blocks sunlight from the
host tree.
• Additional roots are sent out and wrap around the host
tree, forming a massive network of roots that strangle and
eventually kill the host.
• Because the weather is hot and wet, trees do
not need thick bark to slow down moisture
loss and have instead thin, smooth bark.
• They layers of rainforest are connected by
vines and ferns, and mosses grow on the
trees. Liana is a climbing vine that grows on
rainforest trees, climbing into the canopy so
its leaves get more sunlight.
• Many large trees have huge ridges called
buttresses near the base. They may be 1-12
meters high where they join into the trunk.
They increase the surface area of a tree so
that it can ‘breathe out’ more oxygen.
Nutrients in the soil are near the surface, so
the big rainforest trees have quite shallow
roots. The buttresses support the trees.
• Some trees have above-ground roots called
prop or stilt roots which give extra support to
the trees. These roots can grow about 85 cm
in a month.
• Some tropical rainforest plants are carnivorous,
or meat-eating.
• They have a cavity filled with either sweet or
terrible smelling nectar that attracts insects,
especially ants and flies.
• Inside the sides are steep and lined with
downward pointing hairs. Insects enter and lose
their footing or are prevented from leaving
because of the hairs.
• Rafflesia, in Indonesian rainforests, produces the
biggest flower in the world.
ANIMALS
• Because there are so many animals competing
for food, many animals have adapted by
learning to eat a particular food eaten by no
other animal.
• Toucans have adapted by developing a long,
large bill. This adaptation allows this bird to
reach fruit on branches that are too small to
support the bird’s weight. The bill is also used
to cut the fruit from the tree.
• The sloth uses a behavioral adaptation and
camouflage to survive in the rainforest.
• It moves very, very slowly and spends most of
its time hanging upside down from trees.
• Blue-green algae grows on its fur giving the
sloth a greenish color and making it more
difficult for predators to spot.
• Leafcutter ants climb tall trees and cut small
pieces of leaves which they carry back to their
nest. The leaf pieces they carry are about 50
times their weight. The ants bury the leaf
pieces, and the combination of the leaves and
the ants’ saliva encourages the growth of a
fungus, which is the only food these ants eat.
• Many rainforest animals use camouflage to
‘disappear’ in the rainforest. Stick insects are
perfect examples of this.
• There are also some butterflies whose wings
look like leaves.
• Camouflage is of course useful for predators
too, so that they can catch prey that hasn’t
seen them. The boa constrictor is an example
of a camouflaged predator.
• Some animals are poisonous, and use bright
colors to warn predators to leave them alone.
There are several species of brightly colored
poison arrow frogs.
• Monkeys and apes have adapted cleverly to tropical
rainforests. All have long arms to use the canopy to
swing through the trees, avoiding ground predators.
• The little aye-aye, a small Madagascan primate, has
evolved to be a nocturnal feeder in order to escape the
clutches of predators in the daylight.
• Its large eyes allow more light in at night, and it uses
echolocation to find its prey in the dark.
• The aye-aye take advantage of tall rainforest trees to
build his daytime nest for concealment out of sight of
rainforest predators.
• The aye-aye’s oddly elongated middle finger is evolved
to scoop insects for small holes in tree bark where
shorter fingers could not reach them.
• The South American jaguar, with its rich rosette
camouflage, has developed the ability to swim
well in its wet rainforest home.
• Adaptations of this sort allow the jaguar to find
food not only on the ground but in the plentiful
rivers and streams of the amazon, in the form of
fish, turtles and caiman.
• The jaguar has the ability to climb trees to
ambush unsuspecting prey walking on the
rainforest floor.
• A much smaller predator, the Amazon Horned
Frog has developed a body that convincingly
mimics “leaf litter.”
• The frog uses its brown-green, leafy-looking
body to lie amongst piles of dry leaves and
ambush its prey for a lazy dinner.
GRASSLAND ANIMAL ADAPTATIONS
PLANTS
• In order for grasses to survive the dry season and the
periodic fires, they have developed an adaptation that
allows them to grow quickly when there is adequate
water.
• Then when water becomes scarce, the grasses turn
brown to limit water loss. They store necessary
moisture and nutrients in their roots while they await
the return of the rainy season.
• With food and water reserves stored below ground, the
grasses are able to survive the effects of fire as well. In
fact, fire stimulates new growth and replenishes the soil
with nutrients.
• The baobab tree has adapted to the savannah
biome by only producing leaves during the
wet season.
• When leaves do grow, they are in tiny fingerlike clusters. The small size of the leaves helps
limit water loss.
• Another adaptation that enables the baobab
tree to survive the long months of drought is
its ability to store water in its large trunk.
• The acacia tree can survive drought conditions
because it has developed long tap roots that
can reach deep, ground water sources. It is
also fire resistant.
• Some varieties re-sprout from the root crown
when the above ground portion of the tree is
damaged by fire. Fire is not the only hazard
faced by the acacia tree.
• The acacia tree has developed very useful
physical and behavioral adaptations to discourage
animals from eating its leaves.
• It developed long, sharp thorns and a symbiotic
relationship with stinging ants. The ants live in
acacia thorns they have hollowed out, and they
feed on the nectar produced by the tree.
• When an animal takes a bite of the leaves (and
thorns), it also gets a mouthful of angry, stinging
ants.
• The ants defend their homes from other insects
as well, thus protecting the acacia tree.
• Giraffes feed on the tops of the acacia, which results in
the dome-shaped top characteristic of acacia trees.
• A behavioral adaptation aimed at preventing giraffe
feeding is a chemical defense system that is triggered
when the giraffe begins to much on the leaves.
• First, a poisonous alkaloid that tastes nasty is pumped
into the leaves. The giraffe only gets a couple of
mouthfuls of leaves before the remaining leaves
become inedible.
• Then, the tree warns other acacia trees in the area by
emitting a chemical into the air. The other acacia trees
respond by pumping alkaloid into their leaves.
ANIMALS
• During the rainy season, birds, insects, and
both large and small mammals thrive in the
savannah but the rainy season lasts 6-8
months.
• During the dry season, surface water from the
rain is quickly absorbed into the ground
because the soil is extremely porous.
• Competition for water during the dry season is intense.
Consequently, most birds and many large animals
migrate during the dry season in search of water.
• Because drought conditions are sometimes localized,
the migration may be just to another area within the
savannah.
• When drought conditions exist for a long time and over
a wide area, the animals may migrate to another
biome until the rainy season begins again.
• Although elephants do migrate, they have
physical adaptations that allow them to access
water that is not available to other animals.
• Baobab trees store water in their large trunks.
The elephant's physical strength and anatomy
allow it to tear open the trunk of the baobab
tree and to suck the water from it.
• An adaption used by small burrowing animals is to
remain dormant during times of drought.
• During the dry season, lightning frequently ignites the
brown, dry grasses that cover the savannah.
• Many of the animals have adapted to living with the
fires. The ability to fly or to run fast enables most birds
and large mammals to escape the flames.
• Some birds, such as the Fork-tailed Drongos actually
are attracted to the active fires. These birds feast on
fleeing or flame-roasted insects.
• Although small burrowing animals may not be able to
outrun the flames, they frequently survive the fire by
digging beneath the soil and remaining there until the
flames pass by them.
TEMPERATE
RAINFOREST
ADAPTATIONS
PLANTS
• Plants must adapt to a moist environment.
The trees grow bark that protects the inner
core from cold temperature, while protecting
the tree from parasitic fungi.
• Rain forests grow a startling variety of fungi on
trees, rocks and the earth. These take the
form of mushrooms, shelf fungi and ball fungi.
ANIMALS
• Most of the animals in temperate rainforests
live on or near the ground.
• Hibernation and migration are the most
prominent rainforest animal adaptations that
are seen in temperate rainforests. Black bears
spend the entire winter hibernating, thus
ensuring they don’t exert too much energy.
• Deer are smaller and have shorter antlers than
deer in other biomes. This adaptation gives
them the ability to move freely in the
underbrush.
• Larger carnivores, such as wolves and
wildcats, grow thicker pelts to protect them
during the cold winter months.
TEMPERATE DECIDUOUS FOREST
ADAPTATIONS
PLANTS
• In the spring, deciduous trees begin producing thin,
broad, light-weight leaves. This type of leaf structure
easily captures the sunlight needed for food production
(photosynthesis).
• The broad leaves are great when temperatures are warm
and there is plenty of sunlight. However, when
temperatures are cold, the broad leaves expose too much
surface area to water loss and tissue damage. To help
prevent this damage from occurring, deciduous trees
make internal and physical adaptation that are triggered
by changes in the climate.
• Cooler temperatures and limited sunlight are two
climatic conditions that tell the tree to begin adapting.
In the fall, when these conditions occur, the tree cuts
off the supply of water to the leaves and seals off the
area between the leaf stem and the tree trunk.
• With limited sunlight and water, the leaf is unable to
continue producing chlorophyll, the “green” stuff in the
leaves, and as the chlorophyll decreases the leaves
change color.
• The beautiful display of brilliant red, yellow, and gold
leaves, associated with deciduous forests in the fall, is a
result of this process. Most deciduous trees shed their
leaves, once the leaves are brown and dry.
ANIMALS
• Migration and hibernation are two adaptations
used by the animals in this biome.
• While a wide variety of birds migrate, many of the
mammals hibernate during the cold winter months
when food is in short supply.
• Another behavioral adaptation some animals
have adopted is food storage.
• The nuts and seeds that are plentiful during
the summer are gathered by squirrels,
chipmunks, and some jays, and are stored in
the hollows of trees for use during the winter
months.
• Cold temperatures help prevent the
decomposition of the nuts and seeds.
TAIGA ADAPTATIONS
PLANTS
• Evergreens use a wide variety of physical
adaptations. Some of these adaptations
include their shape, leaf type, root system,
and color.
• Their name, evergreen, describes an
important adaption. They are always—or ever
green. Because they don’t drop their leaves
when the temperatures cool, they don’t have
to regrow them in the spring.
• The taiga soil doesn’t contain many nutrients, and the sun
usually remains low in the sky. These two factors limit the
amount of energy available to the tree.
• By keeping their leaves, the evergreens are able to use that
limited energy for structural growth rather than producing
leaves.
• Although the taiga has moderately high
precipitation, the ground freezes during the
winter months and plant roots are unable to
get water.
• The adaptation from broadleaf to narrow
needle-like structures limits water loss
through transpiration.
• Evergreen needles do not contain very much
sap. This limits the risk of needle damage from
freezing temperatures.
• They do, however, contain a chemical that
repels animals who would eat the needles.
• The dark green color of the needles absorbs
the sunlight, and since the needles are always
present, once temperatures start to get
warms, photosynthesis quickly begins.
• The conical shape of the evergreens allows the
snow to slide off the branches rather then pile
up.
• If the snow can’t pile up on the branches,
there is less risk of broken branches due to the
weight of the snow.
ANIMALS
• Most animals migrate to warmer climates
once the cold weather begins. Some animals
have adapted to life in the taiga by hibernating
when temperatures drop.
• Other animals have adapted to the extreme
cold temperatures by producing a layer of
insulating feathers or fur to protect them
from the cold.
• In some instances, the adaptation of a
seasonal change in color of feathers or fur
protects the animal from its predators.
• The ermine, a small mammal, is a good
example of this adaptation. Its dark brown
summer coat changes to white in the winter.
• This adaptation helps the ermine blend into its
surroundings and makes it more difficult for
the ermine’s predators to spot them.
• The residents of the taiga prepare themselves for the
winters by accumulating layers of fat on their body to
withstand the chilling winters to keep themselves
warm and cozy.
• This characteristic can be seen in the cow moose, who
consumes plant shoots and water plants in summers
for a thinner layer that helps it to keep itself cooler
during the high temperature during daytime.
• In the beginning of spring and approaching winters
they switch over to conifer branches, berries and twigs
for thicker coats to protect themselves from the harsh
wind.
• Some taiga animals like the snowshoe hare
and lynx adapt themselves to the frigid
weather of taiga by growing more hair on the
foot pad or the bottoms of their feet to make
it easier to walk on the snow.
• The heavy weight animals like bison and
caribou throw snow instead of walking on it
and thus make a way for the other follower
animals like wolves and foxes.
• During winters, some animals like voles, mice, lemmings
and shrews live in snow tunnels under the snow.
• Though it seems like a contradiction, 20 inches of packed
snow can act like a fluffy down comforter and keep animals
warm--much warmer than the air above. Snow cover can
keep the ground at a steady temperature, even while the
air temperatures above the snow rise and fall.
• Warmth under this cover comes from deep within the
earth. Trapped under the snow, this heat melts a space
where animals can move about.
• Snow also reflects sunlight, keeping the sun's warmth from
reaching deep into the snowpack and melting it. Thus the
snowy world endures.
TUNDRA ADAPTATIONS
PLANTS
• Growing close together and low to the ground
are some of the adaptations that plants use to
survive.
• This growing pattern helps the plant resist the
effects of cold temperatures and reduce the
damage caused by the impact of tiny ice
particles of ice and snow that are driven by
the dry winds.
• Plants also have adapted to the arctic tundra by
developing the ability to grow under a layer of
snow, to carry out photosynthesis in extremely
cold temperatures, and for flowering plants, to
produce flowers quickly once summer begins.
• A small leaf structure is another physical
adaptation that helps plants survive. Plants lose
water through their leaf surface.
• By producing small leaves the plant is more able
to retain the moisture it has stored.
ANIMALS
• Migration and hibernation are examples of
behavioral adaptations used by animals in the
artic tundra.
• The fact that many animals do not live yearround in the tundra means they leave or
migrate for a length of time to warmer
climates.
• Hibernation is a combination of behavioral
and physical adaptations.
• For example, during the summer the brown
bear’s physical adaptation allows the food
eaten during the summer to be stored as a
layer of fat underneath its skin.
• The layer of fat insulates the bear from the
cold. While in hibernation the fat is slowly
converted into energy that maintains life.
• A physical adaption used by the musk ox is the growth
of two layers of fur—one short and the other long.
• Air is trapped in the short layer of fur and is warmed by
body heat. The warmed air, trapped close to the body,
acts as insulation from the cold.
• The layer of long fur protects the musk ox from the
wind and water. In addition to thick layers of fur, the
musk ox relies on another physical adaptation to help it
survive.
• The hooves of the musk ox are large and hard. During
the winter months, this adaption allows the musk ox to
break the ice and drink the water underneath.
OCEAN ADAPTATIONS
PLANTS
• Most ocean going plants have adapted to their
environment by developing gas sacs and air sacs
to lift their photosynthetic surfaces towards the
surface of the water, to collect sunlight.
Particularly in the deep ocean, these sorts of
adaptations are critical.
• Examples of this type of adaptation include
Sargasso sea weed, which are sometimes called
‘sea grapes’ because of the visibility of the gas
sacs.
• On oceanic plants, the root structure is called
a keepfast, and is an adaptation meant to
anchor the plants against the currents, and
there is no need for internal water
transportation within the plant.
• Most oceanic plants are more properly typed
as macroscopic algae than vascular plants.
• Ocean plants have to be able to handle the
dissolved salt in the water; the adaptation
mechanisms range from living in (comparatively)
low salinity regains of the ocean to complex
mechanisms that break down salt slowly into
chlorine and sodium ions, or storing it and
passing it along with the respiratory products of
the plants.
• This can cause beds of oceanic plants that directly
regulate the salinity of the water in their region
for their optimum environment.
ANIMALS
• Fish can drink salt water, and eliminate the
salt through their gills.
• 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.
• Whales don’t drink salt water, instead getting
the water they need from the organisms they
eat.
• Fish and other organisms that live underwater
can take their oxygen from the water, either
through their gills or their skin.
• Marine mammals need to come to the water
surface to breathe, which is why the deepdiving whales have blowholes on top of their
heads, so they can surface to breathe while
keeping most of their body underwater.
• 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.
• 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.
• The sperm whale is thought to be able to dive
over 1.5 miles below the ocean surface. One
adaptation is that lungs and rib cages collapse
when diving to deep 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.
• 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 substances so they are not washed way,
and have hard shells for protection.
• 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 lightproducing organs to attract prey or mates.