classification of invertebrates
Those animals which have no backbone or vertebral column are called invertebrates. They are classified into nine phyla. Characteristics of the animals of these phyla are given below: 1. Phylum: Protozoa i. They are unicellular organisms. ii. They are mostly found in water. iii. These animals have pseudopodia, flagella or cilia for locomotion. iv. They can be free living or parasitic. Some examples: amoeba,paramecium etc 2. Phylum: Porifera i. Porifera means pore bearer animals, commonly called sponges. ii. Most of them are marine organisms except spongilla. iii. They are diploblastic animals. iv. They respire through general body surface. V. They do not move from place to place, so they are called sessile. vi. The presence of calcium and silicon makes their body rigid and strong. vii. Sponges have two types of openings on their body surface i.e. ostia(mouthlets) and osculums(anus). Some examples: sycon, spongilla,euspongia etc. 3. Phylum: Coelenterata i. The body of ...