The top of the umbrella crab is called the carapace.
they feed on a coralline algae which is usually pink or red and encrusts stones.
If you are reffering to the trap in crab fishing it is called the "pot".
That is just the name they came up with. There is no specific reason. It comes from a Latin word 'Umbra' and its meaning is shade or shaded
A crab's shell is called a carapace.
The pole on an umbrella is called the shaft. It is usually made of metal or wood and extends from the handle to the canopy to provide support and stability.
Ferrule
Your hermies are communicating.
a ten legged crab is called a decacrab
There is an Umbrella Plant - Schefflera arboricola
The top part, the bell.
The first pair of legs containing the chelae (claws) are called chelipeds. All five pairs are called pereopods
केकड़ा is the word crab in Hindi.