Sea Cucumbers-
Sea cucumbers have five rows of paired tentacles on the surface of the body. They are used for locomotion and for feeding.
Sea cucumbers do not have brain. Their nervous system consists of a ring and several nerves. Their senses are also poorly developed.
Sea cucumbers are able to modulate the shape of their body when needed. They can pass through tight spaces thanks to this feature.
Sea cucumbers are nocturnal creatures.
Fertilized eggs undergo several larval stages before they turn into adult sea cucumbers.
Sea cucumber are able for self-reproduction (they can produce offspring without partner). However, they prefer to reproduce by mating with other sea cucumbers.