For me, it’s my Whitetale Bristletooth Tang. I’ve only been in the hobby for about a year and an half and have a 70g display. Wanted one good sized fish and after doing research found that this was probably about as big as I could go, plus I loved their colors - he’d be the centerpiece of the tank. Well, I’ve had him for about a year now and he can be a bully.
I’ve gone through 4 Diamond Gobies - he chases them and caused 3 to jump (2 while cleaning and lid was off and I didn’t notice and one when I forgot to replace the little 3” x 5” cover for the feeding hole). The last one, was a good sized Diamond Goby, thought being bigger he could defend himself better - I drip acclimated and put him in at lights out time - was dead the next morning. I‘m convinced it was the Tang.
He also used to bully my Lubbock’s Wrasse. I added a small One Spot Foxface to help with bubble algae and he started to go after him until he flashed his spikes. Now, they are buddies and hang together - and he no longer bothers the Lubbock’s.
My LFS said they didn’t expect any issues from the tang as long as I didn’t add another Bristletooth. I’ve since done a lot of reading and have found that these Tangs don’t like Diamond Gobies. I’m now wondering if I’d rather have a Diamond Goby instead of the Tang as they are actually a pretty fun fish.