Is it normal for some fish to not acclimate to captivity, and some just disappear?

[JLAudio]

Ive had a salt water tank for about 4 years and a reef for a little over a year. Ive had my ups and downs, but I currently have a beautiful 110 gallon reef with great paramaters (ammonia n nitrite 0, nitrate under 10, calcium 400, phosphates, alk, all the usual suspects perfect) All my corals are the hardy shrooms, polyps, brains, colt, leathers (spaghetti, toadstool, etc.) Thriving and growing like crazy, However...

Here is the question, I have a few loyal fish that have been with me for a while (pair of maroons, yellow hippo tang, cpl damsels) but Ive been unsuccessful at acclimating a few new fish. Some just seem to hide behind the rocks and never even attempt tp eat or anything (this happened recently with a yellow tang (I know I already had one but I added another 2, so there would be 3 LFS advice, rrather than just 2) A copperband butterfly (I fed him mysis shrimp but wasnt interested), and a niger triger (controversial but I wanted to believe)

The other dilemma is that over time certain fish just go missing? (could it be my carpet anemones, or a natural life process and some just die?
Is this just part of the game, because all likely suspects are not the factor (parameters, aggressive tankmates, temp, oh etc)

 

[fritz]

your trouble is adding fish to an already stocked tank of mean fish. Hippos are not nice even for tang standards. Your two tangs likely have very set boundaries and agreements. Your new tang is taking space away from one if not both and that will cause problems.

Damsels are like gangs and they too have their "turf" any new fish will likely get very very bullied.

Maroons are VERY nasty fish that attack humans without a second thought. They certainly are not afraid of fish. Again territory issues.

A niger trigger.....well a niger could hold it's own in this tank but I would expect some casualties.

Copperband butterflies aren't the best fish for captivity. I'd say that you have a very aggressive reef with long time territories already staked out. Adding fish at this point without rearranging your rockwork would lead to death of new comers. That likelihood would skyrocket if you pick new fish with histories of not eating well / adapting to captivity well or just being shy fish.

 

[JLAudio]

You make great points fritz, thanks!