Fearful Schooling Fish

[Spottedpleco]

I have a 55 gallon aquarium stocked with Harlequin Rasboras, Rummynose Tetras, Brilliant Rasboras, an Anglefish, a Rafael catfish, a Killifish, a Ancistrus and an L104 . There is a through ground covering of Java ferns. Whenever I bring a guest over, the schooling fish in that particular aquarium spook and huddle together in a corner. This has not been without injuries too, about a year ago, (as it happens they spooked when they saw me) two juvenile Harequin Rasboras sped into the glass, one died and the other has permanent soft tissue damage. I got the Angelfish in the hopes that having a calm fish in the middle of the aquarium would placate them. Now Teslan (Angelfish) can't be everywhere at once, sometimes he's off to the other side of the tank and they still spook. Is there a small confident species that can reassure these guys? I don't want to stock the aquarium too much more. Or should I get another Angelfish? I have Candy-cane Tetras, Neon & Cardinal Tetras, and Harlequin Rasboras in a 55 gallon alongside their aquarium and those guys aren't nearly as skittish.

[C. Andrew Nelson]

I love a mystery. Let me put on my detective hat (believe it or not I actually do own a Sherlock Holmes style deerstalker hat) and ask you a few questions.

1. What kind of stand is your tank on? Wood? Metal? How solid is that stand?

2. Where in your home is this tank? Ground floor? Upstairs? Garage?

3. What is the lighting like in the room where the tank is?

4. What is the flooring like in the room? Carpeted? Hardwood? Tile? And creaky floor boards?

5. Finally, do all the fish react this way or just the Tetras and Barbs?

I'm forming a theory, but I'll wait for your response before I say anything.

[Crazygar]

Your Cat will be spooking them at night. You do realize as it gets older, some of those smaller fish will become meals. Is the tank in a high traffic area? If so, the noise level might be bugging them. Remember that sound is amplified in water.

Gary

[Spottedpleco]

Your Cat will be spooking them at night...Gary

Lol and I was about to say.. "How did you know that I've got cats?" By the way, the "furry" cats are locked out of the fishroom during the night. I adopted my Rafael catfish in 2005 and he was already grown by then. I can't rule him out as spooking them during the night, the other 55 gallon doesn't have a Rafael catfish. I never see "Driftwood" - his name, at all. Unless I move a log. No fish have been "disappearing" though either. The aquarium isn't in a high traffic area except when I bring guests down.

[Crazygar]

Most "cats" are nocturnal which I am figuring since you've owned them for so long that part has been established.

How large are the schools and what type of fish?

Gary

[Spottedpleco]

1. What kind of stand is your tank on? Wood? Metal? How solid is that stand?

Metal, it is pretty solid unless I physically grab it and try to shake it.

2. Where in your home is this tank? Ground floor? Upstairs? Garage?

Basement.

3. What is the lighting like in the room where the tank is?

Florescent lighting from the dropdown ceiling.

4. What is the flooring like in the room? Carpeted? Hardwood? Tile? And creaky floor boards?

Tile

5. Finally, do all the fish react this way or just the Tetras and Barbs?

Just the Tetras & Barbs. They form a big spooked school.

I'm pondering if they are just feeding on each-others' nervous energy like when I bring 3 dogs to the vet at once and the new dog of the three picks up on the fearfulness of the other two and becomes fearful himself.

[Spottedpleco]

...How large are the schools and what type of fish? Gary

5 Harlequin Rasboras,

6 Rummynose Tetras,

5 Brilliant Rasboras

And in a while I may move the 5 Harlequin Rasboras to the tank next door that also has 5 Harlequin Rasboras to make a larger school of their species. And move in 10 Black Tetras that I bought the other day to take their place in the aquarium.

[Crazygar]

Try increasing your school size for your fish. While you have the minimum the adding more to make larger schools will help with less fear. Try that if your tank size permits.

Gary

[C. Andrew Nelson]

The reason I was asking all those questions is that Tetras can "hear" sounds. The are sensitive to vibrations from movement & noise in a room. I've known several people who have their tanks in rooms with creaky wooden floors that pick up and transmit all sorts of vibration and sound to the tank, spooking the fish and keeping them on edge. That's where I was going with my questioning. Doesn't look like that's the case for your set-up.

Interesting. Quite a mystery. I'll keep thinking on this.

[Crazygar]

I'm thinking the school sizes. Increasing them might ease this a bit or there is something else bothering them.

Gary

[Spottedpleco]

Thanks for the advice. When the local pet store gets some Rummynose Tetras etc in I'll buy some to add to the tank. I moved the Harlequin Tetras to combine them in the parallel aquarium that already had five individuals. Along the thoughts that C. Andrew Nelson mentioned about vibrations... It got me thinking about metal stands carrying vibrations more than wood stands. I was putting a bucket under the tank and it tapped the metal stand and made the fish spook. The metal supports carry vibrations pretty well. Wood vs metal stands are a consideration that I hadn't put much thought into before. I decided to eliminate some other suspects. I had moved some juvenile Black Neon Tetras into the aquarium and the Angelfish killed half of the school of ten by grabbing their caudal-fins and causing severe injury; very upsetting. So he got moved to the Rainbowfish Aquarium. And the Rafael catfish, apparently I had moved him to another aquarium at least a year ago. The other day, when I got nervous about the idea of him terrorizing the tetras I scoured the tank and turned up empty. Then I started to remember moving him to a another tank with bigger fish as well - but I forgot to update my records in excel. I also moved the killifish, he was bumping into the tetras for some reason.

[Crazygar]

Sounds like it was quite the task moving all those fish! I would be curious to see if it indeed was the stand they were one. What kind of floor do you have? Carpet? Hardwood?

Gary

[C. Andrew Nelson]

One day I hope to have enough tanks and fish that it will require me to use an Excel spreadsheet to keep track of them all.

[Crazygar]

Use it to keep track of Aquarium Maintenance. I religiously keep a log for Phoenix. I can go back years to find out what happened or what I did.

Gary