Asteroidea:
Examples:
- In most cases have a star-shaped body
- Largest species consisting of 1600 different species
- Aquatic organisms
- Most distinguishable class in the Echinodermata phylum
- They move by using their tube feet
- Predators
- In order to eat, many apart of this class have the ability to let their stomach come out, snatch their prey, then such it back inside of them
- Can grow anywhere from 2 centimeters to 1 meter
- Commonly damage coral reefs
- Complex nervous system with nerve ring
- Lack a brain
- Have the ability to regrow an arm if lost
Examples:
- Spinulosida
- Valvatida
- Solasteridae
- Brisingida
- Choriaster granulatus
- Paxillosida
- Forcipulatida
- Notomyotida
Holothuroidea:
Examples:
- Can also be known as “Sea cucumbers”
- Worm-like
- Soft-bodied
- Tubular-like body
- Are normally located on shallow-water coral reefs
- Oral tentacles
- Calcareous ring
- Lack arms
- Posses tentacles
- Lack a brain
- Sedimentary feeders
- Mouth and anus are separate
- Sessile and inactive
- Unique respiratory system
- Have a life expectancy of 5-10 years
- Can be found in large numbers
Examples:
- Aspidochirotida
- Cucumaria
- Sea apple (Pseudocolochirus)
- Stichopodidae
- Psolidae
Echinoidea:
Examples:
- Lack arms
- Globe-shaped
- About 940 species
- 6-12 meters in diameter
- Mouth is made up jaws
- Upper half of body is aboral surface
- Lower half of body is the oral surface
- Spiny
- Spines are used as defense against predators and to capture its prey
- Most live on rocks or coral reefs where waves tend to come
- Some of these organisms live under sediment
- Posses rigid tests
- Stinging structures
- Females can release millions of eggs into the water
- Specific organisms can live over 200 years
Examples:
- Sand dollar (Clypeasteroida)
- Echinoida
- Paracentrotus
- Echinocorys
- Spatangoida
- Psammechinus miliaris