Classifying invertebrates

2. •I am a courageous, resourceful
explorer and problem solver,
demonstrating my creativity
and charism.

3. •Look for issues, situations, and
sources of related information for
further study and investigation.

4. •Identify sources of related information to
distinguish the characteristics of
invertebrates.
•Look for various issues and situations related
to the interconnectedness between human
actions and the well-being of animals

5. INVERTEBRATES
•Animals without backbone (vertebral
column)
•The body parts are very simple compared
to vertebrates
•Believed to be the first set of animals that
live on earth

6. CLASSIFICATION OF
INVERTEBRATE ANIMALS
Arthropods
Mollusks
Poriferans
Echinoderms Cnidarian
Platyhelminthes
Nematodes
Annelids

7. ARTHROPODS (JOINT-LEGGED ANIMALS)
•Have segmented bodies and tough skeleton with
jointed appendages
•Largest group in the animal kingdom
•Divided into five groups: insects, arachnids,
crustaceans, centipedes, and millipedes

8. CHARACTERISTICS AND FEATURES
• Segmentation: They have three main body regions: head, thorax,
and abdomen.
• Exoskeleton: An exoskeleton provides framework for support and
protects soft body tissue.
• Jointed appendages: Arthropods have jointed and paired
appendages adapted for feeding sensing, walking, swimming and
mating.
• Feeding habits and structure: The mouthparts of most
arthropods include a pair of appendages called mandible.

9. INSECTS
•Have three pairs of legs or are the six-legged
arthropods.
•They have antennae and have three main body
sections- head, thorax, and abdomen.
•The head contains a pair of antennae; mouth parts
that are adapted for sucking, biting and chewing;
and a pair of compound eyes.

11. •The thorax is the middle part. Wings and three
pairs of walking legs are connected to the
thorax.
•The abdomen is the rear part of an insect. The
abdomen consists of eleven segments.
•Insects undergo metamorphosis.

12. ARACHNIDS
•Have four pairs of walking legs
•Have two body segments and no antennae.
•Most live on land and few live on water
•Some possess spinnerets with which they spin
threads into webs, cocoons, and nests

14. CRUSTACEANS
•Have five pair of legs for swimming and
walking.
•Crustacean’s body is made up of 50 segments,
but most crustaceans have only 19.
•The body is divided into three regions-head,
thorax, and abdomen

16. •Characterized by the presence of two pairs of
antennae located on the head. The antennae are
organs that touch, taste, and smell food. They can
hunt food in total darkness using the antennae.
•Most are marine or drift near the ocean bottom,
but some live in fresh water and few live on land.

17. CENTIPEDES
• “Hundred feet”
• Most of these animals really have less than one hundred
feet. They have 15 to 173 pairs of legs
• Have flattened bodies divided into two segments: the
head and the trunk.
• The head has a pair of long antennae and a pair of poison
claws called maxillepedes. The antennae are long and
slender with 14 or more than one hundred segments.

19. • The trunk consists of about 15 to 173 segments. A pair of
legs can be found attached per segment.
• They live on land, especially in moist places under logs,
barks and stones and are commonly found in dark.
• The antennae are long and slender with 14 to more than
100 segments.

20. MILLIPEDES
• “Thousand feet”
• They have cylindrical bodies consisting of about 20 to
more than one hundred segments. The body is divided
into head, thorax and trunk. The head contains a single
pair of antennae with seven or eight segments.
• Have two pair of appendages or legs on each of their
abdominal segment and one pair on its thorax segment.

22. •The mouth parts are adapted for chewing
plants.
•Millipedes protect themselves by curling
up.

23. MOLLUSKS (SOFT-BODIED ANIMALS)
•Are coelomate animals with bilateral symmetry, a
soft internal body, a digestive tract with two
openings, and a muscular foot and a mantle.
•Are found in aquatic (ocean and fresh water) and
moist land environment.

25. •Most mollusks have an open circulatory system. In
an open circulatory system, the blood is pumped
out of vessels into open spaces, which fuse oxygen
and nutrients into tissues that are bathed in blood.
It also moves carbon dioxide from tissues into the
blood.
•Some like squid and octopuses have a closed
circulatory system. The blood confined to the
vessels as it moves through the body.

26. ECHINODERMS (SPINY-SKINNED
ANIMALS)
•Echinoderms are marine animals with spiny
endoskeleton. They have a water vascular system,
tube feet, and radial symmetry as adults.
•The water vascular system of echinoderms works
together and enables them to get food. The
strainer-like opening structure of an echinoderm is
called madreporite.

28. SPONGES (PORE-BEARING ANIMALS)
• They have no tissue, no organ and most have symmetry.
• All are aquatic. Most of them live in salt water but few live
in fresh water. Sponges differ in color, size and shape.
• They differ in size. The smallest sponges measure less
than 1 inch in diameter. The largest sponges grow to
more than 4 feet in diameter.

30. CNIDARIANS (STINGING-CELL ANIMALS)
• The former name of cnidarians is coelenterates (or
coelentera).
• Cnidocytes are used by these animals in paralyzing their
prey.
• Have one body opening and most have two layer cells.
• They are adapted to aquatic, floating or sessile
attachment to surfaces under the water.

32. REFLECTIVE QUESTION
•In what ways have the
interconnectedness between human
actions and the well-being of animals
become more apparent to you, and how
does this understanding influence your
future choices and behaviors?