u dunno, but if you wanna cath a crab real fast do what i did, get a clear glass or clear jar, i used meaty cichlid pellets because they sink, put the food in the jar and lean it at a 45* angle with the lip of the jar on a rock so he can get in really easy,, but wont get back out over the slippry glass. it took less than a minute for mine to get there.