Animals
Animals are eukaryotic, multicellular, and food-ingestive. They use extracellular protein and carbohydrates to bind themselves together as opposed to cell walls of plants.
Muscle and nerve provide means for movement. Sexual reproduction involves cleavage of the fertilized egg into a ball of cells - the blastula, which gastrulates to form cell
layers that go on to undergo morphogenesis and become an embryo. Animals share hox genes which control the complex stages of development. All animals are a clade Metazoa. Bilateria includes the bilaterally symmetrical animals. Ecdyzoa includes nematodes and arthropods which secrete an exoskeleton. Trochophore larva are found in
annelids and mollusks.
Porifera
Cnidarians
Platyhelminthes
examples
symmetry /
coelom/ceph
sponges
none/radial,
no coelom or
cephaization
filter feeding
radial; no
coelom or
cephalization
jellyfish, sea anemone,
corals, hydras
flatworms: planarias,
flukes, monogeneans,
tapeworms
food chain
embryonic layers;
"stome"
digestive openings
other
n/a
choanocytes create
currents which draw
water and plankton
in, plankton are
trapped and digested
cnidocytes carry
venom that inject
"predator",
2; ecto- and
from tentacle to
"swimming" primitive nerve
endoderm; neither paralyze prey; prey
motion draws
net and
proto nor
are pulled to
prey to
muscle cells
deuterostome
gastrovascular cavity
tentacles
and digested
extracellularly
1; mouth = anus
some float, others
"swim" (medusas),
and yet others are
sessile (polyp);
cnidocytes with
venom are called
nematocysts
3; ecto-, meso-,
and endoderm;
neither proto nor
deuterostome
gastrovascular cavity
digests food in
planaria; flukes and
tapeworms absorb
food from host by
diffusion
1; mouth = anus
most members of this
group are parasites
all systems
3; ecto-, meso-,
exc.
and endoderm;
circulatory and neither proto nor
respiratory
deuterostome
tiny predators that
feed on other protists
2; full alimentary
canal
most are freshwater;
from 50um to 2mm
diameter
none
planarias are
nervous,
bilateral; no
scavengers;
muscular,
coelom,
flukes and
excretory,
primitive
tapeworms are digestive, and
cephalization
paraasitic
more
rotifers
bilateral; no
coelom,
limited
cephalization
free living
microscopic
predators
Lophophorates
Ectoprocta, Phoronida,
Brachiopoda
bilateral; no
coelom, very
limited
cephalization
most are free
living filter
feeders
Nemertea
proboscis worms and
ribbon worms
bilateral, no
coelom,
limited
cephalization
most are
predators
Rotifera
systems
all systems
except
skeletal,
respiratory,
circulatory
features
2; ecto- and
incurrent pores draw
endoderm; neither
in water/excurrent
proto nor
eject it
deuterostome
3; ecto-, meso-,
and endoderm;
neither proto nor
deuterostome
all systems
3; ecto-, meso-,
except skeletal and endoderm;
and
neither proto nor
respiratory
deuterostome
all have a lophophore horseshoe-shaped
none, or mouth and
crown of ciliated
anus
tentacles
most are marine
have a proboscis used
to shoot and paralyze
prey
most are marine
mouth and anus
Animals
examples
Molluscs
symmetry /
coelom
food chain
systems
embryo layers;
proto/deuterostome
features
digestive openings
other
chitons, gastropods
all ecological
(snails, slugs), bivalves
niches from
all systems,
2; mouth and anus; 2nd largest animal
bilateral,
have the head-foot,
(clams, mussels,
filter feeder to
circulatory
full alimentary
group; extremely
coelom
3 germ layers, are which has evolved into
scallops, oysters),
active
system is open
canal with
diverse; examples of
present, good
protostomes
the tentacles of
cephalopods (octopus,
predators,
except in
accessory digestive all niches, habitats,
cephalization
cephalopods
squid, nautilus,
some even are cephalopods
organs
and ways of life
cuttlefish)
parasites
Nematoda
roundworms: Ascaris,
heartworm, filaria
worms, hookworm,
pinworm, Trichinella
bilateral;
pseudocoeloo
m present,
limited
cephalization
scavengers,
parasites
all systems
except
skeletal,
respiratory,
circulatory
Annelids
oligochaetes
(earthworms),
polychaetes
(bristleworms), or
leeches
bilateral, full
coelom,
limited
cephalization
scavengers,
parasites
(leeches)
all systems
exc.
Respiratory;
circulation is
closed
3; ecto-, meso-,
and endoderm,
are protostomes
are segmented; most
live in moist
environments
full alimentary
canal with mouth
and anus
most are tunnelers,
important to recycling
dead organisms and
soil aeration
Arthropods
cheliceriformes
(horseshoe crabs),
myriapoda (millipedes
and centipedes),
hexapoda (insects),
crustacea (crabs,
lobsters, crayfish,
shrimp)
bilateral, full
coelom,
extreme
cephalization
all possible
niches
represented
all systems,
including open
circulation and
jointed legs
3; ecto-, meso-,
and endoderm,
are protostomes
are segmented;
insects have head,
thorax (legs), and
abdomen
full alimentary
canal with mouth,
anus, and
accessory glands
metamorphosis allows
offspring to exploit
different food and
habitat than parents;
largest animal group
Echinoderms
Chordates
(only the
vertebrates have
some
cephalization)
sea stars, brittle stars,
larvae bilateral
sea urchins, sand
while adults
dollars, sea lilies,
are radial, full
feather stars, sea
coelom
cucumbers
larvae
sea squirts (tunicates) bilateral, adult
radial
bilateral,
lancelets
coelom
vertebrates
bilateral,
coelom
3; ecto-, meso-, extremely common in
food enters in
most members of this
and endoderm;
soil and freshwater;
mouth and passes
group are free-living
neither proto- nor body is covered by a through alimentary
scavengers
deuterostomes
tough cuticle
canal to anus
predators,
filter feeders
all systems;
have a water
3; ecto-, meso-,
vascular
and endoderm,
system that
are deuterostomes
operate tube
feet
unsegmented body,
internal calcerous
skeleton
filter feeders
simple body
notochord in larvae
basket-body which
filter-feeds
marine only
filter feeders
simple body
notochord in adult
filter feeds with fishlike body
marine only
all niches
represented
all organ
systems
3; ecto-, meso-,
and endoderm,
are deuterostomes
mouth and anus are
most species are
one opening;
predatory on molluscs
parachute stomach
using tube feet to
used to eat
capture prey
molluscs
includes the largest
well-developed
embryonic notochord
land animals and the
head with brain and
becomes vertebrae
largest animals that
sensory equipment
ever lived