Harlingen South High School Biology
The world consist of animals
with a backbone and animals
that lack one. Vertebrate are
animals that contain a backbone
and make up about 2% of the
animal world. Invertebrates
animals that lack a backbone
make up 98% of the animal
world.
Phylum Porifera (Sponges)
1)No definite symmetry.
2)Body multicellular, few tissue, no organs.
3)Cells and tissues surround a water filled
space but there is no true body cavity.
4)All are sessile, (live attached to something
as an adult).
5)Reproduce sexually or asexually, sexual
reproduction can be either gonochoristic or
hermaphroditic.
6)Has no nervous system.
7)Has a distinct larval stage which is
planktonic.
8)Lives in aquatic environments, mostly
marine.
9)All are filter feeders.
10)Often have a skeleton of spicules.
The Phylum Echinodermata
1)Possess 5-rayed symmetry, mostly radial,
sometimes bilateral.
2)Body has more than two cell layers, tissues and
organs.
3)Body cavity a true coelom.
4)Most possesses a through gut with an anus.
5)Body shape highly variable, but with no head.
6)Nervous system includes a circum-oesophageal
ring.
7)Has a poorly defined open circulatory system.
8)Possesses a water vascular system, which
hydraulically operates the tube feet or feeding
tentacles.
9)Without excretory organs.
10)Reproduction normally sexual and gonochoristic.
11)Feeds on fine particles in the water, detritus or
other animals.
12)All live marine environments.
The Phylum Cnidaria
1)Radially Symmetrical.
2)Body multicellular, few tissues,
some organelles.
3)Body contains an internal cavity
and a mouth.
4)Two different forms exist, medusa
and polyp
5)Reproduction is asexual or sexual.
6)Has a simple net like nervous
system.
7)Has a distinct larval stage which is
planktonic.
8)Lives in aquatic environments,
mostly marine.
9)Mostly carnivorous otherwise filter
feeders.
10)May have a minimal skeleton of
chitin or calcium carbonate.
The Phylum Platyhelminthes
1)Bilaterally symmetrical.
2)Body having 3 layers of tissues
with organs and organelles.
3)Body contains no internal cavity.
4)Possesses a blind gut (i.e. it has a
mouth but no anus)
5)Has Protonephridial excretory
organs instead of an anus.
6)Has normally a nervous system of
longitudinal fibres rather than a net.
7)Generally dorsoventrally flattened.
8)Reproduction mostly sexual as
hermaphrodites.
9)Mostly they feed on animals and
other smaller life forms.
10)Some species occur in all major
habitats, including many as parasites
of other animals.
The Phylum Nematoda
1)Bilaterally symmetrical, and vermiform
(wormlike).
2)Body has more than two cell layers,
tissues and organs.
3)Body cavity is a pseudocoel, body fluid
under high pressure.
4)Body possesses a through gut with a
subterminal anus.
5)Body covered in a complex cuticle.
6)Has a nervous system with pharyngeal
nerve ring.
7)Has no circulatory system (no blood
system)
8)Reproduction normally sexual and
gonochoristic.
9)Feed on just about everything.
10)Live just about everywhere, many
species are endoparasites.
The Phylum Annelida
1)Bilaterally symmetrical and vermiform.
2)Body has more than two cell layers,
tissues and organs.
3)Body cavity is a true coelom, often
divided by internal septa.
4)Body possesses a through gut with
mouth and anus.
5)Body possesses 3 separate sections, a
prosomium, a trunk and a pygidium.
6)Has a nervous system with an anterior
nerve ring, ganglia and a ventral nerve
chord.
7)Has a true closed circulatory system.
8)Has no true respiratory organs.
9)Reproduction normally sexual and
gonochoristic or hermaphoditic.
10)Feed a wide range of material.
11)Live in most environments.
The Phylum Arthropoda
1)Bilaterally symmetrical (in most cases).
2)Body has more than two cell layers, tissues and
organs.
3)Body cavity a true coelom.
4)Most possesses a through straight gut with an
anus (in most cases).
5)Body possesses 3 to 400+ pairs of jointed legs.
6)Body possesses an external skeleton (in most
cases).
7)Body is divided in 2 or 3 sections.
8)Nervous system includes a brain and ganglia.
9)Possesses a respiratory system in the form of
tracheae and spiracles (in most cases).
10)Possesses a open or lacunnar circulatory
system with a simple heart, one or more arteries,
and no veins, (in most cases).
11)Reproduction normally sexual and
gonochoristic, but can be parthenogenetic.
12)Feed on everything.
13)Live everywhere.
The Phylum Mollusca
1)Bilaterally symmetrical.
2)Body has more than two cell layers, tissues and
organs.
3)Body without cavity.
4)Body possesses a through gut with mouth and
anus.
5)Body monomeric and highly variable in form, may
possess a dorsal or lateral shells of protein and
calcareous spicules.
6)Has a nervous system with a circum-oesophagal
ring, ganglia and paired nerve chords.
7)Has an open circulatory system with a heart and
an aorta.
8)Has gaseous exchange organs called ctenidial
gills.
9)Has a pair of kidneys.
10)Reproduction normally sexual and gonochoristic.
11)Feed a wide range of material.
12)Live in most environments.
The Phylum Chordata
1. They have bilateral symmetry.
2. Chordata have segmented bodies, which include
segmented muscles.
3. Chordata have a well-developed coelem.
4. They have a hollow never cord that usually ends
with a brain.
5. Chordata have a post anal tail at some point in
their life.
6. They have pharyngeal or gill slits at some points
in their life.
7. Chordata have a ventral heart, with blood
vessels and a closed circulatory system
8. They have complete digestive system, meaning
that they have a different anus and mouth.
9. They have an endoskeleton made out of either
bone or cartalige.