First of all let me say I love the Niger/Redtooth Trigger, thus far it is the only fish I had in my first big (Aggressive) tank and have put one in my second as well. The are hardy, inexpensive, loaded with personality and beautiful..However this is not a good long term community/reef tank fish IMO. It is an aggressive fish. Will a Niger eat your coral? I doubt it. Will it eat your clean up crew? Maybe not. But when he grows up will he be aggressive toward your blenny/clown/fill in the blank smaller fish? Most likely yes. I see posts all the time here that say "I've had my Niger 6 months/ 1 year/ 1 and half years and he is great in my reef tank!" Still waiting for someone to say "Had my Niger 5 years, he is 10 inches long and he doesn't bother anyone" Nigers are known to be mild as juvi's and highly nasty as adults this is often the case with many other triggers. On the Trigger aggression scale (which runs 1-5, 1 being the least) the Niger gets a 3. Don't take my word for it, look at Fenner's book, he devides triggers into "more peaceful" and "troublemakers", Niger is in the later with Queen, Undy, Clown, Bursa and so on.
Oh, and as to my personal experience, I got my first at 2 inches, he was great for 2+ years, then he decided he didn't like my 5+ inch monster Maroon Clown anymore, destroyed him to the point I had to remove the Maroon before he was dead. He regularly squabbled with my large Lunare Wrasse and came out on top. Had I not had a huge Achilles Tang that had been in the tank forever the Niger would have ruled the tank.
If your looking for a trigger in a reef/community tank, start with Blue Throat or Sargassum (even those are risky), leave the Niger for the big aggressive tanks.
