Download Invertebrates

Animals:
Invertebrates
Characteristics of Invertebrates
• What is the difference between a vertebrate
and an invertebrate?
– Vertebrates are animals with a backbone,
invertebrate are animals without a backbone
• Do you think there are more vertebrates or
invertebrate?
– Invertebrates make up 90% of all animal species
• All animals, including invertebrates are
multicellular, and most have specialized cells
• Grows attached to one
spot on the ocean floor
• Body of sponges have
many pores, or holes
• Moving ocean water
carries food and oxygen
through the pores into
the sponge
• At the same time it
releases waste products
into the water
• Sponges function on
their own
Sponges
Coelenterates
• All contain a central cavity with only one opening
• Have a cup-shaped body
• Most of their mouths are surrounded by tentacles with
stinging cells called nematocysts
• They use these stingers to kill or stun other animals
• Once food is stunned and eaten, waste product will exit
through the same opening
• Unlike sponges, coelenterates contain groups of cells
that perform specialized functions
• Examples: coral, sea anemones, jellyfish
Corals
• Corals, like all coelenterates, are soft-bodied
organisms
• They use minerals in the water to build a hard
protective covering of limestone
• Corals live together in colonies, grow into
wide variety of shapes and colors
• Algae live inside coral’s body and help make
them food
Sea Anemones
• Look like underwater
flowers
• Have stinging cells that
poison fish when they swim
over , then they eat the fish
• Clownfish, however, are not
harmed by the anemones
Jellyfish
• Can deliver a painful poison
through its stinging cells
• Also use their tentacles to
gather food
• Move by jet propulsion
• Overview video
Worms
• Worms take part in the
formation of some
pearls
• They act as an irritant
• Worms are classified
into 3 groups
– Flatworms
– Roundworms
– Segmented worms
Flatworms
• Have flat bodies and live in ponds
and streams
• Can regrow missing or cut off body
parts
• Examples: Planarians , and
tapeworm(attach themselves to a
host and takes food and water from
it)
Roundworms
• Resemble strands of
spaghetti
• Food passes from the
mouth end to the tail end
through a digestive tube
• Trichinosis is a disease
caused by eating pork
containing roundworms,
that is painful and harmful
to cure
Segmented Worms
• Example: Earthworm
• Have a digestive system
with a crop and gizzard
– Crop is a saclike organ that
stored food
– Gizzard grinds up food and
then passes it into the
worm’s intestine
•
•
•
•
Closed circulatory system
Moist skin for gas exchange
Sexual reproductive system
Simple nervous system
Mollusks
• “Mollusks” means soft in
Latin
• Examples are snails, clams,
octopus, and squids
• Mollusks have a soft fleshy
body
• Most have a strong
muscular foot
• Head region contains the
mouth and sense organs
such as the eyes
• A soft mantle covers much
of the body, this produces
the material that make up
the hard shell
• Grouped according to
characteristics such as a
shell presence, shell type,
and foot type
One-Shelled Mollusks
• Called univalves
• Only have 1 shell
• Have interesting features in
their mouths called radula
– It resembles a file and is used
to file off bits of plant matter
into smaller pieces to be
swallowed
Two-shelled Mollusks
• Called bivalves
• Have two shells
• Move through the water by
clapping their two shells
together, which force water
out between the shells
• Do not have radula
• Often called filter feeders
since they spend most of their
time straining the water for
food
Head-Footed Mollusks
• Most highly developed mollusks
• Include the octopus, squid, and the nautilus
• Most do not have an outer shell, but have
some type of shell somewhere on their bodies
• Move by water propulsion
• Watch video “Mollusks”
Spiny-Skinned Animals
• Spiny-skinned animals are invertebrates with
rough, spiny skin
– Starfish, sand dollar, sea cucumber, sea urchins
• Starfish are not really fish they are a type of
spiny-skinned animal
– Have 5 or more arms with tubes that resemble
suction cups on the bottom of them
– These tubes help the animal move and help open
clam shells to eat them
Arthropods
• Most successful invertebrates on the earth
• The name arthropod mean jointed legs
• Their jointed legs and exoskeleton are main
characteristics
• An exoskeleton is a ridge outer covering, it
does not grow as the animal grows
• Some types are crustaceans, centipedes,
millipedes, arachnids, and insects
•
•
•
•
Crustaceans
Examples: crabs, lobsters,
crayfish, and shrimp
All live in a watery
environment
Obtain oxygen from the
water through their gills
Bodies are divided into
segments
•
•
•
•
Centipedes/Millipedes
Described as worms with
legs
Centipedes have 1 pair of
legs on each segment, while
millipedes have 2
Centipedes eat animals,
millipedes eat plants
Centipedes can inject
poison, while millipedes
cannot
Arachnids
• Includes spiders, scorpions, ticks, and mites
• Bodies are divided into 2 main sections
– Head-chest section
– Abdominal section
• Very in shape and size, however, all have 8 legs
INSECTS
Section 10-8
• There are more kinds of
insects than all other
animal species combined.
• It is estimated that there
are over 300 MILLION
insects for every single
person alive on the earth!
INSECTS
A little about insects!
• Insects can fly
• They vary in
appearance
• Insects eat the plants
we use for food
• Others eat the clothes
we wear
• Some even eat your
house!
INSECTS
Insect Anatomy
• Divided into three main
sections
– Head
– Thorax
– Abdomen
• Insects have three pairs of legs
• Most have wings
• Have an open circulatory
system
– Their blood is not contained in
blood vessels
INSECTS
Simple vs Compound Eye
• Insects have compound eyes
– More than one lens
• We have simple eyes
– Only one lens
INSECTS
METAPHORSIS
• Insects go through several
stages of growth and
development
• Many change in appearance
• Different stages include
– Eggs
– Larva: stage that the insect
emerges from the egg
– Pupa: stage in an insects life
when it is wrapped in a
cocoon.
– Adult
INSECTS
• Most lead solitary lives
• Insects attract mates in
differ ways
– One way is by giving off
a scent called a
pheromones
INSECTS
• Other insects are known as
social insect, they cannot
survive alone, these insect
form colonies
– Example: ants, bees, termites,
wasp
INSECTS
• Insects have many
defense mechanisms to
aid their survival
– camouflage