Sea cucumber: characteristics
- Marine animals with leathery skin and an elongated body
- Contains only one gonad
- Reproduce by releasing sperm/ova into surrounding ocean water
- Can produce thousands of gametes
- Males and females are usually separate
- Eggs are fertilized internally, fertilized zygote is picked up with feeding tentacle by cucumber
- Egg remains in pouch in adult body until growth is complete and it emerges as young sea cucumber
- Some species known to brood young inside body cavity
- Egg develops into free-swimming larva after three days of development