Invertebrates Facts
- Invertebrates are multi-cellular and all the cells have different responsibilities to keep the animal alive.
- Invertebrates have no backbone or bony skeleton or cells wall like all other animals.
- Invertebrates like echinoderms do not have heads.
- There are millions of invertebrates living in our house in the name of dust mites which are hardly visible to human eyes.
- Invertebrates under a process called metamorphosis through which they change form as they grow.
Characteristics of Annelids
The common characteristics of annelids are as follows:
- Annelids have a long cylindrical body
- The body is segmented internally as well as externally
- Bilaterally symmetrical
- Vermiform
- They are cephalopods
- They have a true body cavity
- Annelids have a gut with mouth and anus
- The body is divided into three sections. They are prosomium, truck, and pygidium
- They posses a nervous system with a nerve chord
- Posses a closed circulatory system
- No true respiratory system organs are present
- Reproduces sexually
- Can adapt themselves to most of the environments
- Some species of annelids have a pair of legs like appendages that are attached to every segment
- They have concentric nerve cell
- The head posses the sensory structure
- Annelids have a hydrostatic skeleton structure
