Anyway to trap a crab?

[typhoonreef]

I have a green emerald and a sally lightfoot,need to get them out.Impossible to get by hand or net,any suggestions about how to make a trap or buy one.Thanks .

 

[Premiumaq]

Thoroughly clean a two liter bottle, and cut off the top where the neck begins to taper. Perforate the bottom of the bottle like a sieve. Punch two holes near the top, opposite each other, and tie strings to them, long enough to lay over the edge of the tank. Lay the trap on its side, with the mouth close to one wall of the tank. Bait it with something meaty. When a crab enters, pull the cords to raise the bottle upright, trapping them inside the smooth walls.

 

[typhoonreef]

I will give it a try ,thanks.