INVERTEBRATES

WHAT ARE INVERTEBRATES?

Invertebrates are the animals which don’t have backbone. This simple definition hides the tremendous diversity found within this group which includes protozoa (single-celled animals), corals, sponges, sea urchins, starfish, sand dollars, worms, snails, clams, spiders, crabs, and insects.

CHARACTERSTICS

Invertebrates are eukaryotic because they contain complex structures enclosed within membranes.

Invertebrates are multicellular, which means that they are organisms that contain more than one cell.

Invertebrates don’t have cells walls because they are all animals and animals can not have cell walls.

Invertebrates don’t have cells walls because they are all animals and animals can not have cell walls.

97% of the animal kingdom is made up of

invertebrates.Some can be found in ponds, oceans, and other water environments.

Insects and some other invertebrates have exoskeletons.

An exoskeleton is a hard outer covering that

protects an animal’s body and gives it shape.

CLASSIFICATION OF INVERTEBRATESPoriferaCoelenterataPlatyhelmintthesNematodaAnnelidaArthropodaMolluscaEchinodermata

PORIFERAThey look like plants but they are animals.They have no mouth, stomachs, or other organs.Most live in oceans.The cannot move.Their bodies are full of holes, and their skeleton is made of spiky fibers Water flows through the pores of their body, aided by flagella, which enables them to catch food

COELENTERATAThey have tentaclesand mouth.They live on the ocean floor.They shoot poisonous darts.Some live in colonies and few in solitary. They feed by catching tiny animals in their tentacles.

PLATYHELMINTHES

Some are found in water or marshy soil and some are parasiticAcoelomates.Triploloblastic animals.Bilateral symmetry.

NEMATODALive in widest environments, some are found in water or marshy soil and some are parasitic.Commonly called round worms.Pseudocoel.Triploloblastic animals.Bilateral symmetry.

ANNELIDA

Live in widest environments, some are found in water or marshy soil and some are parasitic.Commonly called segmented worms.Truecoelom.Triploloblastic animals.Bilateral symmetry.

ARTHROPODA

Largest phylum in the animal kingdom.They have jointed legs.Haemocoel.Triploloblastic animals.Bilateral symmetry.Open circulatory system.

MOLLUSCA

These are soft bodied and aquatic animals.Soft body is covered with a protective shell.Triploblastic animals and exhibit bilateral symmetry.They have a modified muscular foot for locomotion.

ECHINODERMATAThese are exclusively marine animals.•Spines are present all over the body.•Triploblastic animals and exhibit radial symmetry.•The inner surface of the body bears number of appendages called tube feet which helps in locomotion and exchange of gases.

DONE BY: MAYA PALLAVI SINCHANA SUSHMA VIDYA