Two Psychopathic Fish

[Buzz1329]

In my 9-month old 180 reef, are 2 yellow tangs, a purple tang (PT), a scribbled Rabbitfish (SR), a six-line wrasse, and a yellow-bellied damsel.
They all seem to get along, or at least I have never noticed any sustained aggressive behavior. But the PT and especially the SR appear to be unhappy, bordering on psychotic. When I am viewing the tank, the SR rarely comes out from behind the rock wall. When I feed pellets, flake, or frozen food, the SR presses itself against the front of the rock wall and loses all color. It might eat a bite or two passing by, but that’s it. The PT on the other hand darts around the tank like he is being pursued by a shark. It snatches chunks of food, dashes back behind rocks, and repeats until the food is gone.

All the other fish, including the yellow tangs that are significantly smaller than the SR and PT, feed and generally behave normally. (The yellow tangs used to be somewhat reclusive, but they now appear to be behaving normally).

I also feed Nori 2x a day. Both the PT and the SR rush up to the Nori, take a bite or two, and then BOLT back behind the rocks, returning to the Nori from time to time and repeating the same behavior. The yellow tangs feed calmly and steadily on the Nori.

The only times I have seen the PT and SR swim fairly calmly in the water column is when they are apparently not aware I am watching the tank from a distance.

I’m thinking the two nutjobs are reacting to my presence near the tank, which by the way is in a room that rarely gets any passerby’s or observers besides me.

Assuming I am freaking them out, is there anything I can do to calm them? I have tried standing in plain view whenever I feed the tank hoping they would associate me with something positive – food! But it’s not working.

FWIW, tank parameters are fairly steady at 35 ppt salinity, 7.8 – 8.0 alk, 400-425 calc, 10-20 ppm NO3 (I’m working on it), undetectable phosphates, 78-79 degrees temp, and weekly 10% water changes.

I use 2 WP40s and 1 WP25 (on wave timers) for in-tank circulation, plus 2 x 300 gph return pumps. Filtration consists of a 3000INT SRO skimmer, and bags of GFO and GAC (rinsed weekly and changed monthly) in an old Zeolite reactor. My LED lights are on a 12 hour dawn to dusk schedule. All water used in the tank is filtered through a RO/DI unit.

Besides green, brown, and red nori, I also feed algae based pellets, Ocean Nutrition flakes, frozen food including spirulina brine and mysis shrimp, Rod’s food, and Prime Reef.

When I have been able to observe the SR and PT, behaving calmly, they appear to be in good health – fat with no signs of disease or infection. Plus both have grown an inch or two since entering the tank. All the other fish appear to be in perfect health.

What, besides psychotherapy and psychotropic drugs, can I do to calm the 2 lunatics down?

Thanks,

 

[snorvich]

You have four largish grazers in a 6 foot tank. Zebrasoma tangs tend to be progressively territorial as time passes, especially in shorter tanks. Just my opinion . . .

 

[desjardinii]

What about trying some reverse psychology by placing a mirror in front of them, it may bring out some aggression and help them to forget?

 

[Buzz1329]

You have four largish grazers in a 6 foot tank. Zebrasoma tangs tend to be progressively territorial as time passes, especially in shorter tanks. Just my opinion . . .

Interesting. I guess I never considered a 6' long tank to be "shorter," but live and learn. So which one(s) would you recommend I remove?

 

[Buzz1329]

What about trying some reverse psychology by placing a mirror in front of them, it may bring out some aggression and help them to forget?

Thanks. I'll definitely give this a try.

 

[snorvich]

the rabbit fish is least aggressive, more subject to intimidation. Zebrasoma tangs are the most aggressive and usually the one there longest will be the PITA. Which may or may not be the largest. For tangs, tank length trumps tank volume by a lot. The more tangs you wish to "mix" the more length will help in the process.

 

[woodnaquanut]

I have a one spot FF. I don't know if FF traits are shared but what you describe fits the one spot personality perfectly.

As I come up to the tank it hides. If I sit quietly it will begin normal behavior.

I have a theory they need dither fish to feel comfortable. Anthias, chromis, or some other free swimming, non-threatning fish to let them know it's OK to be out and about.

I think it's also hard in a room that doesn't get much traffic. They are used to quiet and no movement around the tank. When you come in the vibrations and movement freak them out. Perhaps visiting the tank many times per day will teach them it's OK and they don't need to hide. A little food treat each visit won't hurt. Eventually even the slow learners will, hopefully, catch on.

Of course you could always dose Qualudes! J/K!!