The case of the disappearing fish...

sh8wn9

Member
So, I have a biocube 29 thats been up for a little over a year now. The tank is pretty stable, I dont have any issues with water quality...my concern is for my fish. Ive lost 4 fish over the year, and only one has been accounted for. I started with two clowns and they got along great. Then I added a yellow watchman goby...he def took control of the bottom part of the tank. So these three always got along good. A few months after that I added a skinny mandarin dragonete. He loved it in there and became very fat and happy. Nobody ever bothered him...the other fish didnt even seem to know he existed. Anyways, somewhere along the line the bigger clown fish started harrasing the smaller clownfish and chasing him about. About 4 times I found him in either chamber 1,2,or 3 of the biocube. It was like he hated him for some reason. Until finally the bigger clownfish made him jump out the wrong side of the tank and ended up jumping onto the carpet. Dead fish...ok at least I know what happened. Before the clownfish died I added a 5th and final fish...a blue reef chromis. I know 5 is pushing it for 29g, but all the fish were small, and I had good filtration. Anyways, the bluw reef chromis disappeared overnight. Gone, without a trace. Ummm, I still have no idea what happened and figured it was hiding until I never saw it again.
OK, a few more months pass and I add a purple pseudochromis. Hes great, the big clownfish hates him for a week and chases him, but eventually learns to live with him. A few months later, hes gone! I have no idea what happened with him...one night hes there, and the next morning theres no trace, no remains, no nothin. Then a few weeks ago, my mandarin is gone! I dont understand it, he was loving it in there, and got along with everyone. I even added a hang on back refugium with chaeto to give him even more pods.
How could fish in a small tank like that, just disappear overnight with no trace of any remains, no amonia rise, no fish on the carpet, no floating fish???
Its like they just vanish. Im not sure if a clean up crew can eat a fish overnight????
So, a bit ago I added a purple firefish goby, who seems to be accepted by the other fish now. So now the tank contains, the bully clownfish, the new purple firefish goby, and the yellow watchman goby.
Anyone have any idea whats happening to my fish?
 

1Reefer

Active Member
Idk but I know my CUC can make short work of a shrimp so id imagine a small fish like a chromis or a pseudo wouldn't take long either.
 

woolfe

Active Member
Do you have a cat? Fluffy could be having a midnight snack of fresh sushi. :yummy: If the fish are being chased, the ones you listed as disappearing are known to jump except maybe the mandarin. He likely slowly starved to death in such a small system. Even if you had the entire tank full of rock, your tank is too small for a mandarin. (Unless you train him to eat frozen food.)
 

tnwillia

Well-Known Member
Anything under 4 inches in my tank that dies is gone in 24 hours or less by my CUC. Some times I see it but most of the time they just disapear as yours have. Good luck!
 

Izzy

Member
LOLS I just started experiencing the same issues. Its weird So far the diamond goby and now a firefish goby have vanished... I searched High Low nothing.
 

tnwillia

Well-Known Member
I just took pictues of my Sally Light foot taking a dead firefish apart. He'll be gone before I get up tomorrow. That's why they are called CUC!
 

AlaskaFish

New Member
I had a similar problem this morning. One of my clown fish disappeared from my 29 BioCube. I looked really good with a flashlight but could not find him. Finally I went online and looked it up here. After reading these posts, I tore my back-end system apart and checked all the chambers in hopes of finding him before it was too late...nope, he wasn't in any of the three chambers. Finally I started taking all the live rock out, and found him under one of them, unfortunately it was too late for him.

Any suggestions on how to keep fish from getting trapped under rocks?
 

Charra Hammett

New Member
I have had a biocube for about 5 years now and my fish disappear consistently. I have never found one even when I know it was there earlier in the day but isn't later in the day. It drives me crazy and I wish I knew where they were disappearing to. I only have a cleaner shrimp and 2 very small blue hermit crabs in there so I know it is not them that are eating the fish that fast. If anyone knows why this is happening please share!
 
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