- They generally inhabit 80m water depth from the southern sea of Jeju island to the northern sea of Taibei.
- They are delicious fishes.
- Vinctifer is the most famous fish fossil of Santana formation in Brazil(later Cretaceous period) and distinguished by denser scales of middle line at the abdomen.
- It feeds on small sized Crustaceas in the bed of shallow sea.
- A spawning season is the fall.
- The length of carapace is 0.8~1m.
- Because it grazes seaweeds primarily, it's much influenced by environmental pollution.
- The length of carapace is around 2.5 cm and width is 4.0 cm.
- During egg tide, they get out of the hole and eat a diatom on the surface of muddy bed.
- They are a big crustacean having a hard carapace like iron type and called a living fossil
- They live in a deep sea of over 10m in winter but when lay eggs, they approach the seashore.
- The exoskeleton of a carapace and an abdomen is very hard.
- There are many big and small thorns on the upper carapace and tentacles. The breast and legs don't have claws.
- A shell is yellowish red and has many thorns.
- It's very difficult to classify each species because many shape variations.
- Cellana nigrolineata is the largest species out of umbrella shells, a keel leans forward, height is high and circular oval shape.
- They are discovered in the southern coast and Jeju island of Korea.