• The crustaceans are an extensive sub edge of arthropods.
• There exist crustaceans of salty water, of sweet water and, even, terrestrial.
• The crustaceans are fundamentally aquatic and live in all depths, either in the marine
environment or sweet water.
• They eat plankton: set of organisms mainly microscopic, which float in salty or sweet waters.
1) They have a shell or hard crust that protects them.
2) Their legs are articulated.
3) They must change to grow.
4) Are aquatic and breathe through gills.
5) Some crustaceans are almost in extinction for example:
Carrucho, Juey, Lobster and prawn
• Fish are aquatic vertebrate animals that are typically ectodermic covered with
• Fish are abundant in the sea and in fresh water, with species being known
from mountain streams as well as in the deepest depths of the ocean.
• Fish eat many types of insects and other fish
Fish display a wide variety of colors and color patterns. Skin coloration can have many functions. Many
fish have color patterns that help them blend in with their environment.This may allow the fish to avoid
being seen by a predator. Some fish, such as the flat fishes, can change their skin coloration to match
the surrounding habit.
• Fish can also have disruptive markings to hide body parts. Species such as the jackknife fish high-hat
and some angelfishes have dark lines that run through the eyes.These lines may serve to hide the
eyes so that other animals cannot tell where the fish is looking or even if it is a fish.Also horizontal
lines may be a sight line for aiming attacks on prey. Some fishes, like butterfly fishes, have spots on
their body that resembles eyes.This may serve to confuse prey and predators alike. In addition to
coloration, some fish, like the sea dragon, have body shapes that can further mimic their habitat.
• Fish coloration can also be useful in catching prey. Many sharks exhibit coloration known as counter
shading. Sharks that have counter shading are dark on the dorsal (upper) side and light on the ventral
(lower) side.With this color scheme any prey looking down on the shark will see a dark shark against
a dark sea bottom, making it hard to detect the shark. Conversely, any prey looking up at the
shark, will see the light belly of the shark on the light background of the ocean surface water lit by the
sun or moon.
• Coloration can also be used to advertise. Fishes like the darters and sticklebacks, may use color to
attract and recognize potential mates.
They range from freshwater to marine ecosystems , even in habitats with high
• water pollution.
• the building of dam.
• removal of water use by humans.
• the introduction of exotic species.
• Steel-head trout: It is a rainbow trout that spends part of his cycle of life in the
• Giant cat fish : It is one of the bigger fish of sweet water of the
world, managing to measure up to 3 m.
• Chinook salmon: It is a fish of 46 kg and 3 metres long.
• They have a soft body and without forming rings.
• Can have shells with one or two valves produced by the mantle.
• Move themselves through a muscular foot of diverse forms.
• Breathe through gills.
• Are oviparous.
• It is a type of molluscs:
• They have not got external shell.
• Some of them, as the squid, take a bag of ink to muddy the water in case of danger.
• Have long tentacles in their heads.
• Are marine and breathe through gills.
• There is only one marine reptile: sea turtle.
• They are omnivorous.
• Sea turtles eat corals, which provide them calcium, aquatic
vegetation, algae, and when eating meat they choose between small
invertebrates such as octopus or jellyfish.
• Turtles migrate constantly through the areas of food and reproduction.
• Introduction :
The sea dolphins are one of the loveliest creatures made by God. They are
very intelligent creature. They live in water. but they are sea mammals, and
not a deep sea fish. These sea dolphins are warm-blooded and grow up to a
size of approx (1.2-9.5) meters. They can weigh up to 10 tonnes. They have
a life span of about 40 years. They produce very sweet and lovely sound
when they talk to each other. They are very peaceful sea animals and are
often found in groups playing with each other. They have a smooth and
• Habitat and Behaviour :
They have a smooth and streamlined skin, which allows them to swim smoothly in water.They take short
cat snaps while sleeping.They feed mostly at night and are very active during this time.They can dive to a
great depth of about 1640 feet inside water and can also leap up to a great height above water.
• Reproduction and Breeding :
They carry their young one inside their womb and the gestation period is about 12 months.The baby stays
with its mother for around (3-6) years. During this period they learn the techniques of social
interaction, feeding and how to live in groups. During mating time, males leap to show females that how
powerful they are. And they do this also to keep away the predato.
• Sea whales are among the largest Sea animal in the world.They are the most
mystifying and interesting of all creatures.They are large, aquatic mammals.
Studies have shown that these Sea mammals have actually originated from
small, primitive land creatures which have returned to the water for living some
70-90 million years ago.They breathe in through lungs instead of gills. Like all
mammals, they have hair but not as much as land mammals.They have a high
body temperature, i.e. they are warm-blooded.They have mammary glands to
nourish their young.Whales have a four-chambered heart.
I took information from the
following places :