INVERTEBRATES

Invertebrates Animals without backbones

97% of all animal species

Invertebrates

Phylum Molluska

Phylum Echinodermata

Phylum Platyhelminthes

Phylum Nematoda

Phylum Arthropoda

Phylum Cnidaria

Phylum Porifera

Phylum Annelida

PHYLUM PORIFERA (Sponges)

• “Porifera” means pore – bearing• lacks true tissues & organs; incomplete

digestive system • has skeleton that supports & protects the

body; made up of “spicules”

PHYLUM CNIDARIA

• Radially symmetric• digestive chambers with a single

opening, which serves as both mouth & anus

• Includes: hydras, jellyfish, corals and sea anemones

2 body forms: polyp form and medusa form 1. polyp form - cylindrical; mouth & tentacles at the upper end 2. medusa form – shaped like an upside-down bowl; mouth & tentacles facing downwardhas tentacles with stinging cells called “cnidocytes” that paralyzes their preys

PHYLUM CNIDARIA

Jellyfish -medusa

Coral - polyp

Hydra

JellyfishSea anemones

Coral

PHYLUM PLATYHELMINTHES (Flatworms)

• with flattened bodies; bilateral symmetry• lacks body cavity• most flatworms are parasites

• 3 major groups: flukes, planaria & tapeworms 1. Flukes – parasites that absorb the

nutrients from the body of a host harming it; causes a disease called schistosomiasis

2. Planarians – non-parasitic, lives in moist environments & free-living

3. Tapeworms – long ribbon-like flatworm; can infect humans through eating undercooked meat of an infected cow or pig

PHYLUM PLATYHELMINTHES (Flatworms)

Planaria

Fluke

Tapeworm

PHYLUM NEMATODA (Roundworms)

• has cylindrical bodies tapered at both ends & covered by a tough cuticle

• includes parasitic types: trichina, filaria, pinworms, & hookworms

• Many are introduced through poorly cooked pork or walking barefoot in contaminated areas.

• Some diseases caused by roundworms: elephantiasis, trichinosis.

Pinworm

TrichinaHookworms

Filaria

PHYLUM ANNELIDA (Segmented Worms)

• With segmented bodies which has a ringed appearance

• Includes: earthworms & leeches

PHYLUM MOLLUSKA (Mollusks)

• Second largest animal phylum• Includes: oyster, clams, snails, squids

and octopuses• Some are sources of food for

humans.

Oysters

Clams

Snail

Squid

Octopus

PHYLUM ECHINODERMATA (Spiny-skinned)

• Includes: starfish, sea urchin and sea cucumbers• Has internal skeleton for support &

protection

Starfishes

Sea cucumber

Sea urchins

PHYLUM ARTHROPODA (Arthropods)

• Largest group in the animal kingdom• Has exoskeleton; segmented body & joint

appendages• Divided into 4 groups: 1. Crustaceans – lobsters, shrimps, crabs & crayfish 2. Insects – ants, mosquitoes, bees, wasps, bugs & flies 3. Arachnids – spiders, mites & scorpions 4. Myriapods – centipedes & millipedes

LobsterShrimp

Crayfish

Hermit crab Crabs

Crustaceans

Name the insects!

Spiders

Scorpion

Ticks

Mites

Arachnids

Myriapods

The End