GENERAL HISTOLOGY

Detailed explanation-1: -invertebrate, any animal that lacks a vertebral column, or backbone, in contrast to the cartilaginous or bony vertebrates. More than 90 percent of all living animal species are invertebrates.

Detailed explanation-2: -An invertebrate is an animal without a backbone. In fact, invertebrates don’t have any any bones at all! Invertebrates that you may be familiar with include spiders, worms, snails, lobsters, crabs and insects like butterflies. However, humans and other animals with backbones are vertebrates.

Detailed explanation-3: -Invertebrates do not have backbones or internal skeletons, but some have hard coverings. Insects, spiders, worms, snails, and most ocean animals are invertebrates.

Detailed explanation-4: -Animals without backbones are called invertebrates. They range from well known animals such as jellyfish, corals, slugs, snails, mussels, octopuses, crabs, shrimps, spiders, butterflies and beetles to much less well known animals such as flatworms, tapeworms, siphunculids, sea-mats and ticks.

Detailed explanation-5: -The most familiar invertebrates include the Protozoa, Porifera, Coelenterata, Platyhelminthes, Nematoda, Annelida, Echinodermata, Mollusca and Arthropoda. Arthropoda include insects, crustaceans and arachnids.