I'll keep pushing the thorny sea stars as I think they are the best thing since sliced bread for CUC in an octo tank. They are carnivores, are day active and not shy, do a good job finding all the scraps while adding interest and terrific color. I have read posts that recommend against them but I have had several for over two years. They are the healthiest of all my starfish/serpents (most do well but some lose arms or parts of arms) and have neither damaged the few softies I keep in with the octos nor eaten any coraline algae. They come in several colors but the bright orange is my favorite.
Now that Kalypso is big he doesn't touch the snails. Every once in a while he will yank one off the glass, but he doesn't eat them.
I tried a sea hare. It disappeared pretty quick. Darnit.
I wouldn't use a cucumber personally. But I'm one of those rare few who have experienced a cuke nuke first hand. Most people don't take it seriously, but once you lose about $2000 worth of livestock in one whack you'll be a believer.
I will gladly take your word for it Animal Mother, and look into those thorny stars Denise, Thanks. I figure I will start out with a healthy CUC of hermits and snails, and try and ween the Octo to fresh shrimp and silversides...some live fiddlers as I can afford them.
living in australia i hear about the crown of thorns a bit and wouldnt have picked one for an octopus tank mate. if i recall correctly they get fairly large and are covered in sharp venomous spines, which could either kill, or inflict a very painful injury in an octopus if they came into contact. wouldnt the octopus have to constantly moniter it and make sure not to venture too close, effectively putting it on edge almost constantly and stressing it?