Three Main Types Of Skeleton (Hydrostatic, Exoskeleton And Endoskeleton)

Biology
Topic: Types Of Skeleton
Types Of Skeleton
There are three main types of skeleton. These are hydrostatic skeleton, exoskeleton and endoskeleton.
1. Hydrostatic (Fluid) Skeleton
Hydrostatic Skeleton is the type of skeleton possessed by soft-bodied animals. They have fluid pressure to provide support. Fluid is secreted to fill the spaces in the body. The fluid presses against the muscular body wall, causing the muscles to contract, exerting pressure against the fluid. This helps to maintain the shape and form of the animal. Examples of organisms with this type of skeleton is the earthworm and anemones.
2. Exoskeleton
Exoskeleton is the type of skeleton which is found outside or external part of the body of some animal. Most invertebrates do possess cuticle which is composed of chitin. Chitin is a non-living substance commonly found covering the outer part of the body of some animals. Such external skeletal tissues encloses, supports, gives shape, protects and also enable the animals to move.
Examples of organisms with exoskeleton include invertebrates like Euglena, Paramecium, Hydra, tapeworms, snails, insects, prawns, crabs, spiders, millipedes, crayfish etc. Organisms with this type of skeleton can grow by a process called moulting or ecdysis. In this process, an organism sheds off its old skeleton, grow and later is covered with a new one.
3. Endoskeleton
Endoskeleton is the type of skeleton which is found inside the body of animals. Endoskeleton exists in bony or cartilagenous skeleton of fishes, toad, lizards, birds and mammals. Endoskeleton in vertebrates is made of cartilages and bones. Endoskeleton in mammals include the skull, vertebral column or back-bones, ribs and the bones of the fore and hind limbs.