I have a love-hate relationship with damsels. Here are some of them:
Neon Velvet Damsel:
It's about 3.5", or maybe even close to 4" and it's white bar is beginning to fade. I've seen a 6" specimen at an LFS once and they're definately more colorful when small. I purchased this neon velvet along with a few other species and he was the smallest of them all, I thought it would get bullied or killed within a week. But it was good at dodging the more aggressive one's and eventually developed this 'technique' where when chased it would stop evading its pursuers and would dip its head either up or down (I forget which), but the vertical white bar would be in a horizontal position and it would the pursuers (other damsels) would stop their pursuits. It was kind of funny because in that position the line looked like the horizontal line in the "Do Not Enter" road signs (though in this application it meant "do not chase" in damsel body language and was obeyed).
Despite being the smallest (less than half the size of the others and the others were barely 2") it had an astounding rate of growth (at least compared to the others). I remember looking at the tank and noticing, almost overnight, it was the largest fish in the tank (well the others were still 2" but it was 2.5", up from 1"). It also grew in aggression and was no longer chased.
I eventually had to evict it from my reef tank because it would throw destructive 'hunger tantrums' (it would vandalize, but not consume, my xenia, when ever it was hungry, it always seemed to do it 20min before feeding time). Evicting it was easier said than done and involved me taking all my corals out, most of the rocks and all but an inch or two depth of water (and it
still was hard to catch! It's now in a fish only tank and doing fine.
Azure Damsel
I started out with a trio of these. A day or two later one almost killed the other (it would tolerate the 3rd just fine). I netted it out (fairly easily which shows just how close to death it was, they're usually impossible to catch) and placed him with my green spotted puffers. I half expected them to finish him off. But a day or two later (and still in tatters) it was terrorizing my puffers and wouldn't let them eat. It eventually got relocated into the tank containing the neon velvet. The other two seem to have paired up and are still in my reef tank, playing by the rules and doing fine. The above pic is the exhiled one in the fish only tank.
Female Blue Damsel
This damsel proved to be a pain in my reef tank as it would dig and fan sand all over my corals, and knock over or knock down any new corals that I added to the tank. I didn't want to tear my tank apart again to extract it so I figured maybe some distractions would help curb its undesired behavior. "Distractions" came in the form of adding:
Male Blue Devil
and
Two Stripe Damsel
The blue devil proved to be an effective distraction in curbing digging and sand fanning but introduced other problems. The blue devil lived up to its name and would tenaciously nip and bite me whenever I did tank maintenance or added new corals or whatever. It couldn't draw blood but it was definately annoying (going for the outside skin on my finger just below the knuckle, where rings are typically bound around). It also drove my pair of azure's and my royal gramma into hiding to the point I forgot they were in the tank.
The 2-stripe damsel, was perhaps the smallest fish in the tank but the most aggressive damsel of them all. I had no problem with it other than it would aggressively pick the food out of my suncorals the day after I fed them, it was getting to the point where he had to go because the polyps were no longer extending due to his abuse.
Using a trap, I extracted the blues and the two stripe. Sadly, the 2 stripe jumped out of his new home last week (it was giving the blue damsels hell in their new environment). I eventually had to move the blues to the larger fish only tank to make room for this:
http://www.aquariacentral.com/forums/showthread.php?t=136054
