My Public Aquarium: exhibit blues - how to make them?

[Viktor Jarikov]

Very much appreciated. Thank you.

*****

[Viktor Jarikov]

[Viktor Jarikov]

[Viktor Jarikov]

[Viktor Jarikov]

[Viktor Jarikov]

[Viktor Jarikov]

[Viktor Jarikov]

[Viktor Jarikov]

[Viktor Jarikov]

The Phoenix barbs shoal together with golden dorado and the latter nip their tails until almost none left. I doubt this is predatory nipping because everyone is fed generously. I think this is a hierarchical dominance by the dorado over the barbs.

[Viktor Jarikov]

All of a sudden, two of the 4 males each lost an eye a month or two apart. Their eyes appear unnaturally strongly bulging. IIRC the bulging started after that unknown infection that swept through all of our tanks in the summer 2018 and the bulging never subsided since then. Also, we used to have 12 of these catfish and over two years after the outbreak lost half of them one by one. I have a feeling the infection and the losses and the bulging eyes are connected... Anyhow here is an update on the five catfish.

[Viktor Jarikov]

[Viktor Jarikov]

The arapaima runt that was growing 3x slower than the other 4 has suddenly died. It had fed the day before passing at night at some point. It always fed in moderation, which makes the overfeeding as the cause unlikely at first approximation. Grew only 4.5 inches in 4.5 months. The cause of death is unknown. No foul play. I did cut it open but I'm not trained to know much about what I am looking at.

[Viktor Jarikov]

The ten dorado doubled in size from 1.5-2" to 3"-3.5" in 10 days with us:

[Viktor Jarikov]

[Viktor Jarikov]

Thug goes back to the jumbo 4500 gal. He was more or less ready anyway. Second try.

[Viktor Jarikov]

Even though I didn't witness it, I am pretty sure the dorado killed one of their own. It is of bigger size, looks bigger than average but a little smaller than the biggest in the group; the smaller and the smallest dorado look ok. First loss. Down to 9 from 10. No warning sign did I see, this was sudden - most of the tail was torn off and the anal fin was badly damaged and the body area around the anal fish was damaged; one pectoral fin was tattered. I thought the injured dorado could have survived but the next morning it was dead floating around on the surface upside down. In retrospect, maybe, if I separated it, it'd live, IDK.

The rest of the 9 look good, only one has a small portion of tail fish nipped off.

This raises species ID questions. As you know the vendor - Rod of Predatory Fins says brasiliensis. MFKers say unlikely, franciscanus is more likely, more common. Does this violence support the tentative frankie ID hypothesis?

[Viktor Jarikov]

I rehomed and hopefully will have saved a second victim. This time the smallest. They kept biting it across the dorsal side in the middle:

[Viktor Jarikov]

I thought I caught it in time but the attacked dorado from yesterday has not made it.

[Viktor Jarikov]

[Viktor Jarikov]

[Viktor Jarikov]

[Viktor Jarikov]

[Viktor Jarikov]

[Viktor Jarikov]

At 1.5ft and 6 months old, the 3 remaining pima little by little started to throw tantrums / freak out more often and more violently in the 8x2x2ft 240 gal, thrashing, jumping, hitting lids and the euro-bracing, especially the alpha female, the biggest. It looks like they wanted out of the tank, so off to 1800 gal they went.

[Viktor Jarikov]

I transferred the 3 pima from 240 gal to 1800 gal late at night, usually a bad idea but pima left me no choice, I thought they'd kill themselves. Right after the transfer, the 1.5ft Sorubim lima catfish were trying to take the equal size pimas in the mouth tail first, unsuccessfully of course. So I thought the lima wouldn't try again and went to bed. But the next morning there was visible tatter especially on the top of the caudal fins on all 3 arapaima. Looks like lima kept trying more than once.I transferred the 3 pima from 240 gal to 1800 gal late at night, usually a bad idea but pima left me no choice, I thought they'd kill themselves. Right after the transfer, the 1.5ft Sorubim lima catfish were trying to take the equal size pimas in the mouth tail first, unsuccessfully of course. So I thought the lima wouldn't try again and went to bed. But the next morning there was visible tatter especially on the top of the caudal fins on all 3 arapaima. Looks like lima kept trying more than once. Spawning season, I guess. Gotta bulk up.

[Viktor Jarikov]

Dissected 4 of the smaller dead red devil cichlids. Learned next to nothing.

[Viktor Jarikov]

[Viktor Jarikov]

[Viktor Jarikov]