Transcript 4.12 KingdomAnimalia

Animals in the Oceans
The
Kingdoms
Kingdom Animalia
Marine
Phylum Porifera
• These are sponges which live in clear,
shallow ocean waters around the world.
• The adults are sessile (fixed in place).
• They are filter-feeders of small
microorganisms and bits of organic matter.
• They are usually hermaphrodites :Each
individual produces sperm and eggs.
• Larvae live as meroplankton.
Phylum Cnidaria
• Class Hydrozoa live as dense colonies of
polyps. The adults are usually sessile and
the larvae are meroplankton.
• Portuguese Man-of-War looks like a
jellyfish but is actually a colony. Fish are
trapped by special stinging tentacles which
poison the prey and digested by the
feeding polyps.
Phylum Cnidaria
• Class Scyphozoa are called jellyfish.
• The sexes are separate. The larvae are
sessile polyps which undergo asexual
budding to produce medusae.
• These medusae mature into adult jellyfish
which are drifters (meroplankton). Their
mouths are located on the underside
surrounded by tentacles.
Phylum Cnidaria
• Class Anthozoa are the corals and anemones
which exist only as polyps.
• Anemones live in tide pools and shallow coastal
waters.
• Corals are colonial polyps which secrete
limestone walls made of calcium carbonate. All
can feed with tentacles but most live with
symbiotic algae.
• These form coral atolls (islands) and barrier
reefs in warm ocean waters.
Phylum Mollusca
• This taxon includes the squid, clams,
mussels, snails and slugs.
• There are about 100,000 species.
• They share a basic body plan: a fleshy
foot and mantle and a shell (or its
remnants).
• They range is size from minute to 18 m in
length (the giant North Atlantic squid).
Phylum Mollusca
• Class Polyplacophora are called chitons.
• Chitons have a shell composed of eight
simple plates.
• These are slow-moving organisms which
creep along over the bottom of tide pools
and graze on algae as they go.
Phylum Mollusca
• Class Gastropoda includes snails and their
relatives.
• The name means “stomach foot”.
• During its development, a snail’s body
undergoes torsion (twisting) caused by
uneven muscle growth.
• Some have beautiful shells and others are
shell-less such as the nudibranch and
slug.
Phylum Mollusca
• Class Bivalvia have two hinged shells
which is closed by powerful muscles.
• These are mostly filter-feeders using
mucus to trap small particles of food from
the water.
• Some bivalves are mussels, scallops,
oysters and clams.
Phylum Mollusca
• Class Cephalopoda include the squid, octopus,
cuttlefish and nautilus.
• The name means “head-foot”.
• The squid and cuttlefish have a reduced internal
shell. All have well developed eyes.
• They are active predators feeding on fastmoving invertebrates and vertebrates.
• Their foot is modified into tentacles with suckers
and the mouth has a beak for tearing and ripping
food. They are the most intelligent
invertebrates.
Phylum Annelida
• Class Polychaeta are segmented marine worms.
• Some are active swimmers while others live
inside burrows and tubes.
• Most are particle feeders trapping minute
plankton and loose material in cilia or mucuscovered tentacles.
• The sexes are separate releasing eggs and
sperm into the water to fertilise. The larvae
become part of the meroplankton.
Phylum Arthropoda
• There are over 900,000 species of
arthropods which have been described.
About a million more are left to identify.
• Arthropod means “jointed feet (legs)”.
• They have exoskeletons, jointed bodies
and to grow, they must molt.
• They are a very successful phylum filling a
large variety of niches, and large numbers
of offspring.
Subphylum Crustacea
• Subphylum Crustacea includes crab,
lobster, shrimp, copepods and barnacles.
• Their larvae may have an entirely different
diet than the adults. Marine forms are
benthos and plankton.
Phylum Arthropoda
• Trilobites were extinct marine arthropods.
• Many of the marine forms are very
important because microscopic
crustaceans compose most of the
plankton.
• Subphylum Chelicerata includes the
horseshoe crabs and sea spiders.
Phylum Echinodermata
• These are the ‘spiny-skinned” animals.
• The larvae have bilateral symmetry but the
adults have a five-part radial construction.
• They are exclusively marine and brackish
(estuarine) water animals.
• They have numerous tube feet which are
moved by hydraulic pressure.
Phylum Echinodermata
• Class Stelleroidea are seastars (starfish)
and brittle stars.
• They are slow-moving predators which
each bivalves such as oysters.
• The seastar can regenerate any of its
arms. An arm, as long as a bit of the
central disk is attached, can regenerate
the entire animal.
Phylum Echinodermata
• Class Echinoidea includes the sea urchins
and sand dollars.
• Sea urchins can overgraze areas of the
seafloor if not kept in check by their
predators. Now sea urchin roe is a sushi
delicacy.
• Other classes include the brittle stars and
sea cucumbers.
Phylum Chordata
• This group of animals is diverse and
includes humans.
• All chordates have gill slits (sometimes
only in the embryo), tubular nerve cords, a
notochord (in the embryo) and a postanal
tail.
• Members of the subphylum Vertebrata all
have backbones.
Phylum Chordata
• The Class Amphibia contains the frogs,
toads and salamanders.
• There are NO MARINE AMPHIBIANS!
Class Chondrichthyes
• Class Chondrichthyes includes the sharks
and rays whose skeletons are made of
cartilage.
• Fertilization is internal but embryo
development varies among species.
Class Osteichthyes
• Class Osteichthyes means “bony fish”.
• They are not closely related to sharks and
rays.
• In most bony fish, fertilization is external
and large numbers of eggs are released
into the environment.
Class Reptilia
• Class Reptilia includes sea snakes and
turtles, marine iquanas and saltwater
crocodiles. They are ectothermic.
• Some lay eggs on land such as the
crocodiles and turtles. Sea snakes give
birth to live young.
• They are all air breathing but spend most
of their lives in the salt water.
Class Aves
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These are birds all of which have feathers.
They are endothermic.
Fertilization is internal and all lay eggs on land.
There are a large number of shorebirds which
prey on fish and other marine creatures. These
include seagulls, ospreys, and the like.
• Some birds can dive such as cormorants, terns,
salt water ducks and penquins.
Class Mammalia
• These are animals which have hair and
produce milk.
• They are endotherms and are airbreathing.
• Fertilization is internal and they have live
young.
• Marine mammals include dolphins,
porpoises and whales. Seals, sea lions,
and walrus are called pinnepeds.