Transcript Intro. to the 10 Major Animal Phyla

Phylum Porifera
Composed of sponges
About 10,000 species.
Considered to be the
1st group of animals on
Earth.
 Sponge body even
contains cells that
resemble protists.
Choanocytes
Phylum Porifera
Found in either fresh or marine water.
Lack organs and symmetry
Shapes may be like cups, fans, crusts, or tubes
Haliclona oculata
Red barrel sponge (also known as
Xestospongia)
Phylum Porifera
Some species are large as barrels.
Sponge body pierced by pores (Porifera), through
which they feed by circulating water. (filter feeding)
Phylum Porifera
Reproduction is both
asexual and sexual.
Larval stage freeswimming, adults are
sessile.
Bath sponges were once
living sponges.
Phylum Cnidaria (stinging-celled
animals)
 Includes jellyfish, sea
anemones, corals, and
Portuguese man-of-war.
 Considered to be the 2nd
big group of animals to
have evolved.
Elkhorn Coral
Phylum Cnidaria (stinging-celled
animals)
First animal group with organs level of organization.
Saclike bodies include mouth surrounded by tentacles
that sting and paralyze prey.
Almost all are marine.
Phylum Cnidaria (stinging-celled
animals)
About 10,000 species.
Have radial symmetry
Certain species
alternate between a
polyp and medusa
form; others may
spend lives as either
polyps or medusas.
Phylum Cnidaria (stinging-celled
animals)
 A man-of-war is a
floating colony of
many cnidarian
animals in the polyp
form, which live and
work together.
Phylum Ctenophora
Composed of tiny,
jelly-fish animals called
comb jellies.
About 50 or so species.
Do not sting.
Comb jellies
Sea gooseberry
Phylum Ctenophora
Colorless, transparent;
although many employ
bioluminescence.
Have 8 rows of cilia
along their bodies,
which they use for
locomotion.
Principal food for sea
turtles.
Phylum Platyhelminthes
Includes all flat (platy)
worms.
About 15,000 species.
Were the first bilaterally
symmetrical animals on
Earth.
Phylum Platyhelminthes
Some species are free-living (e.g. Planaria), but most
are parasitic (tapeworms and flukes).
Phylum Nematoda
Composed of worms that have round bodies.
Have complete digestive systems with mouth(s) and
separate anus(es).
About 80,000 species.
Phylum Nematoda
Some are parasites,
including Ascaris and
heartworms.
Majority live in soil and
are not parasites.
Phylum Annelida
Composed of worms whose bodies are divided into
segments.
Examples: Earthworms, leeches, and many beautiful
marine worms.
Phylum Annelida
About 12,000 species.
Have what is called a closed circulatory system –
comparable to that found in advanced animals.
Phylum Mollusca
Includes soft-bodied animals such as clams, oysters,
snails, octopuses, and squids.
About 110,000 species.
Phylum Mollusca
Phylum is divided into 3
main classes:
Bivalvia (rigid shell of 2
parts) – clams, oysters,
mussels, and scallops
2. Gastropod (large, muscular
foot attached to their
stomach) – snails, slugs,
and whelks
3. Cephalopods (large head) –
conches, octopuses, squids,
and nautiluses.
1.
Phylum Arthropoda
Largest phylum in Animal Kingdom.
About 100,000 species known at present.
Composed of animals that have a segmented body
with a hard outer covering (exoskeleton) and
appendages that are jointed.
Phylum Arthropoda
5 main classes:
1. Crustacea – lobsters,
crabs, crayfish,
barnacles, and shrimp.
2. Arachnida – spiders,
ticks, mites and
scorpions.
3. Insecta – flies, ants,
beetles, fleas, lice,
bees, and roaches.
Phylum Arthropoda
4. Chilopoda – centipedes (have 1 pair of legs per body
segment).
5. Diplopoda – millipedes (have 2 pairs of legs per body
segment).
Phylum Echinodermata
Composed of animals whose skin is covered with
spines.
Includes sea stars (starfish), sea urchins, sea
cucumbers, and sand dollars.
About 6,000 species. All are marine.
Phylum Echinodermata
Larvae display bilateral symmetry; adults radial
symmetry.
Have an internal skeleton.
Many can regenerate lost parts.
Phylum Chordata
Best known of all the phyla.
Just under 45,000 known species.
At some stage of development, all chordates have: a
notochord (a flexible rod of cartilage in the back), a
nerve cord, and paired gill slits in the throat cavity.
Phylum Chordata
The phylum is divided into 3 subphyla:
1. Subphylum Urochordata – soft, saclike, marine
animals called tunicates or sea squirts.
2. Subphylum Cephalochordata – small, fishlike, marine
animals called lancelets.
3. Subphylum Vertebrata – all the different vertebrate
animals (7 classes). Vertebrate animals replace the
notochord with a backbone during embryonic
development.
Phylum Chordata
 The 7 classes of vertebrate animals:
1. Class Agnatha – the jawless fishes such as lampreys and
hagfish.
2. Class Chondrichthyes – the cartilaginous fishes such as
sharks.
3. Class Osteichthyes – the bony fishes such as perches and
trouts.
4. Class Amphibia – frogs, toads and salamanders
5. Class Reptilia – turtles, crocodiles, alligators, snakes and
lizards.
6. Class Aves – the birds.
7. Class Mammalia – the mammals.