I just added a bristlenose to my main 55 gallon tank (after quarantine, of course.) What an awesome fish! The other fish have been observing him/her, but he/she just goes about his business. (I don't know if it's a male or female yet - it's not 'bristled' yet.) As a welcoming gift, I went to the LFS and bought a really cool piece of driftwood that doubles as a cave. I now have one very content pleco! :girl: