I have tried feeding my octopus saltwater shrimp because they are cheaper than the hermit crabs I've been giving him, but he seems to have trouble catching them. I'm wondering if I should go back to hermit crabs or if it'll be ok to keep giving him these shrimp. I have put six shrimp in the tank since thursday and right now (it's Monday afternoon) I can still see four shrimp in the tank. He's probably about four inches in diameter from tenticle to tenticle and he's been eating roughly 2 blue leg hermit crabs a day for the past few weeks. The shrimp look like they are about as big as two or three hermit crabs, so I'd have expected him to eat 3-5 of those shrimp by now since it's been 5 days since I started putting them in there, but he's eaten at most two. Any advice on this would be most appreciated!