You can keep them singly but their behavior is unprecictable. Not like they might snap like a trigger, but I couldn't tell you how any particular one might act.
One of my friends had 9 of them and they looked like a tumbleweed.
Lets see if we can solve these terrible problems. Oh, I know, CLOSE THE LID, and let's see, how 'bout we don't have ammonia in our tank. DUH Wow, he's not much of a problem solver eh?
They will help clean sand too.
No, best in groups over 3.
Coral Cats are fun to buy because they get stuck in the net and the LFS guy doesn't know they sting. Then when he gets nailed by one you say " they sting?! I don't want them anymore". Not that I would actually do that
IMO yes they do. Marine animals have complicated social structures. Several species mate for life when up here it's quite rare. It isnt much of a stretch of imagination that they may develop friendships as well. Especially in a alien environment as like communal captivity.
Dont have one now but have even kept 3, 1 male 2 female. I give a little when I get up, a little when I get home, a little an hour before lights out. No more than they can finish in 2-3 minutes.
I'm not a member of the Tang Police, Sailfins get huge. While on the subject why does this site list different tank sizes for different selling sizes of the same fish. A small hippo and a show Hippo Tang are the same fish. Why does one have a tank minimum of 40 and the other 140?
For Raccoon minimum tank some sources say 75, others 55. I know many people who have gotten them at under 4" and they have lived happilly in 55s for many years. He would have to be your biggest fish in the 55.
How the heck do you dress a ferret Man I'm losin it just thinking of somebody tryin to get a little sweater oever it's head. :hilarious
We had ferret hammocks too. They have a hard time getting their front end and back end to run in the same dirction, heck, I have trouble getting into a hammock.