Download Section 26.1 Summary – pages 693-697

1. Which of these animals are called fish, but really aren’t?
2. Which of these animals are not called fish, but really are?
3. How does the body plan of a fish differ from that of the other animals pictured?
INVERTEBRATES
• Invertebrates are animals without backbones.
• They range from sponges, cnidarians (like jellyfish),
worms, arthorpods (insects, shellfish, to echinoderms
(starfish)
• They have different types of
body symmetry
• Some are very simple and do not
have organs, some do not have
skeletal structures, and those that
do usually have exoskeletons
SPONGES
CNIDARIANS
Most successful
animal
INVERTEBRATES
ARTHROPODS
These are the
only
invertebrates that
have an
endoskeleton
MOLLUSKS
ECHINODERMS
WORMS
SPONGES
Habitat: All marine and freshwater
Under Phylum: Porifera, which
means
“poreup
bearer”
• Invertebrates
make
95
percent of all animals.
Movement: Sessile as adults
The simplest
animal
Body Shape: Asymmetrical
Size: Some are as small as a quarter
and some are as big as a door
SPONGES
Sponges can
reproduces both
asexually and sexually!
Asexual reproduction occurs
when a piece of the sponge
falls off, settles, and grows into
a new sponge.
SPONGES
Most sponges reproduce sexually.
• Some sponges have separate sexes, but most
sponges are hermaphrodites.
• A hermaphrodite is an animal that can produce
both eggs and sperm.
Hermaphrodites
do not fertilize their
own gametes, but
cross-fertilize with
other organisms of the
same species.
The animal kingdom as a whole is diverse like the sponges
themselves….
Some invertebrates are asexual:
This means the offspring comes from part of
the organism and is AN EXACT genetic copy of
the parent animal.
Examples of Asexual Animals:
Some Jellyfish
Some Starfish
Sponges
Some worms
Some insects
The animal kingdom as a whole is diverse like the sponges
themselves….
Many animals are sexual:
This means there are male and female
gametes produced and the sperm fertilize the
egg to create new offspring. The offspring are
not genetically identical to one parent.
Examples of Sexual Animals:
Almost all vertebrates
Most Insects
Some jellyfish
Ah ha!
Male coral releasing sperm into the
water, for EXTERNAL fertilization.
Hermaphrodites are a type of sexual reproducing animal:
These are animals that make both sperm and eggs, but they do not
fertilize themselves (there would be no point if they did because
their offspring would be identical to them), so they swap sperm and
eggs with other hermaphrodites to produce genetically different
offspring.
Disturbing
Examples of Naturally Sexual
Hermaphrodite Animals:
Snails
Most worms
Banana slugs
Hamlets (type of fish)
VERTEBRATES
A vertebrate is an animal with
an endoskeleton and a
backbone.
PHYLUM: CHORDATA
BODY PLAN: ALL HAVE BILATERAL SYMMETRY
VERTEBRATES
All vertebrates have:
COMPLEX SENSORY ORGANS
CLOSED CIRCULATORY SYSTEM
A NERVOUS SYSTEM WITH
COMPLEX BRAINS
EFFICIENT RESPIRATORY
SYSTEMS
REPTILES
FISH
MAMMALS
VERTEBRATES
AMPHIBIANS
BIRDS