animals without backbone

1. THE INVERTEBRATES

3. CLASSIFICATION OF
INVERTEBRATES
1. Arthropods
2. Mollusks
3. Echinoderms
4. Cnidarian
5. Annelids
6. Poriferans

4. 1. ARTHROPODS
• Arthropods have segmented bodies
and tough skeleton with jointed
appendages.
• They make up the largest group in the
Animal Kingdom
• Arthropods are divided into five groups:
Insects, Arachnids, Crustaceans,
Centipedes and Millipedes.

5. ARTHROPODS

6. CHARACTERISTICS OF
ARTHROPODS
• SEGMENTATION
- they have three
main body
regions;
HEAD,
THORAX
ABDOMEN.

7. CHARACTERISTICS OF
ARTHROPODS
• EXOSKELETON
- Arthropods
have hard
exoskeleton
outside their
body.

8. CHARACTERISTICS OF
ARTHROPODS
• JOINTED
APPENDAGES-
these are adapted
for feeding,
sensing, walking
and swimming.

9. CHARACTERISTICS OF
ARTHROPODS
• The mouthparts
include a pair of
appendages
called
MANDIBLE

10. CLASSIFICATION OF
ARTHROPODS

11. 1. INSECTS
• Insects have three pairs of legs or
are six-legged arthropods. Their
legs are adapted for crawling,
collecting pollen and jumping.
• Insects are the largest group of
invertebrates.

12. INSECTS
• Insects have
three main
body
sections –
HEAD,
THORAX
and
ABDOMEN

13. INSECTS
• Insects undergo
metamorphosis
or stages of
growth and
development.

14. EXAMPLES OF ARTHROPODS
(INSECTS)

15. ARACHNIDS
• Arachnids have
two body
segments and
have no
antennae.
• Arachnids
have four
pairs of
walking legs.

16. EXAMPLES OF ARACHNIDS

17. 3. CRUSTACEANS
• Crustaceans have five pairs
of legs for swimming or
walking.
• A Crustacean’s body has
three segments – HEAD,
THORAX and ABDOMEN.

18. CRUSTACEANS

19. CRUSTACEANS

20. 4. Centipedes
• Centipede means “ hundred feet” .
They have 15- 173 pairs of legs.
• Centipedes have flattened bodies
divided into segments – HEAD and
TRUNK.

21. CENTIPEDES
• Centipedes move
quickly to catch
and eat insects
and worms.
• Centipedes live on
land especially in
moist places.

22. 4. MILLIPEDES
• Millipedes means “thousand feet”.
They have bodies made up of about
20 or more that 100 segments.
• The body is divided into HEAD,
THORAX and TRUNK.

23. MILLIPEDES
• The mouth parts of Millipedes are
adapted for chewing plants.

24. MOLLUSKS

26. Mollusks (Soft-bodied Animals)
• Mollusks are coleomate
animals with bilateral
symmetry, a soft internal
body, a digestive tact with two
openings and muscular foot
and mantle.

27. MOLLUSKS
• Mollusks are found in aquatic
(ocean and freshwater) and
moist land environment.
• Mollusks use radula to scrape
food into their mouth.

28. EXAMPLES OF MOLLUSKS
• Snail
• Octopus
• Oysters (talaba)
• Clams
• Squid

29. ECHINODERMS

30. ECHINODERMS (Spiny-skinned
Animals)
• Echinoderms are marine animals
with spiny endoskeleton.
• Echinoderms use madreporite to
strain food from water.
• Almost all echinoderms have
internal skeleton made of hard
calcified plates.

31. EXAMPLES OF ECHINODERMS
• Starfish
• Brittle stars
• Sand dollars
• Sea Urchins
• Sea Cucumbers

32. SPONGES

33. SPONGES (Pore-bearing Animals)
• Sponges are pore-bearing
animals.
• They have no organs and lack
symmetry.
• All sponges are aquatic and
comes in different shapes.

34. SPONGES
• Sponges have many types of
skeleton made up of tiny
needle-like structure called
spicules that protects them
from animals who try to eat
them.

35. SPONGES

36. CNIDARIANS

37. CNIDARIANS
• Cnidarians are also called
stinging-cell animals.
• Its former name is
Coelenterates.
• It has stinging cells called
Cnidocytes

38. CNIDARIAN

39. CNIDARIANS
JELLYFISH SEA ANEMONE

40. WORMS

41. PLATYHELMINTHES
• Platyhelminthes are flatworms.
• Flatworms are thin, acoelomate that can
be free living or parasitic.
• Flatworms have no digestive system.
• Flatworms are hermaphrodites, they
produce both eggs and sperm cells.

42. PLATYHELMINTHES

43. NEMATODES
• Nematodes are roundworms that
have long, thin and round bodies.
• Roundworms have round bodies,
pointed at both ends and are
covered by tough cuticle.

44. NEMATODES
ASCARIS AND HOOKWORM

45. ANNELIDS
• Annelids are segmented worms.
• They have body segments to help them
move.
• Their bodies are divided into segments
with a ringed appearance.
• Annelids have bilateral symmetry and
have two openings- the mouth and
anus.

46. ANNELIDS
EARTHWORMS AND LEAF WORMS