Is It Significant That my Fish Prefer Swimming Near the Surface?

EtherealGirl · 03-25-2009, 04:53 PM

After reading some random threads, I found some things that made me wonder if my dwarf platys and male guppy are trying to tell me something by the fact that they seem to prefer swimming near the surface. They feed only at the surface on the floating food (rarely if ever swimming mid-tank to catch falling food) and they spend most of their leisure swim-time in the top fifth of the tank. They'll do quite a bit of "side-shimmy" too (what I call it when they swim rapidly up and down the side of the tank from top to bottom, as if they're trying to attract or reach the fish they think they see doing the same thing (their reflection

).

I got thinking that maybe they need more oxygen or something?? If this behavior is anything other than normal, please advise as to how to remedy. Thanks!

gregpape23 · 03-25-2009, 10:58 PM

If they are strictly swimming on the surface, than you probably have an oxygen exchange problem. A simple fix is just to add an air stone. Which isn't a bad idea even if you don't have a problem. I think it looks nice.

-Greg

Jay · 03-26-2009, 07:06 AM

Quote:

If they are strictly swimming on the surface, than you probably have an oxygen exchange problem

IMO I think that is a hasty and incorrect diagnosis

If they were gasping as the surface, then there may be a problem.

Guppies, mollies, live-bearers in general are surface feeders by nature. Wild guppies feed on mosquito larvae, small insects, etc. That they are at the surface in normal. If you added some plants, I think you would see the guppies picking around on the lower leaves.

The other behavior is probably just a repetitive "loop" I see lots of different fish do it more than occasionally. My loaches in particular.

Jay

louistheloach · 03-27-2009, 11:27 PM

I agree with Jay....I have guppies and other fish like danios that prefer the top of the water column, going below less often, but my guppies do go lower to nibble at what ever it is on the plants.

I have had fish do that fast swim thing against the glass too. I always thought it had something to do with the reflection in the glass.....like they could see another part of the tank they were trying to get to......

ltl

EtherealGirl · 03-28-2009, 09:38 PM

I actually have come to agree with Jay & LTL after further onservation. Of course as soon as I posted this, I noticed that they all actually spend a fair bit of time swimming through the middle space, only eat at the surface and prefer the top third for hanging out.

Like you, I have long figured (yeah, right, real long...I've had the tank for a whole 11 weeks

) that the Side Shimmy is either about trying to get to the reflected tank they see but can't enter, or about trying to reach the reflected fish which they see but can't approach.

Thanks to all for your feedback. (It's so nice to hear from so many different folks!)

And greg, thanks for the suggestion about the airstone. I had a 4" one in the beginning which was buried by gravel and made bubbles so big my tiny fish were afraid of them

. Then I tried raising it above the gravel which made smaller bubbles and I kinda liked it, but the fish still didn't care for it. Then I tried a 1" stone but it was still just not the right look. Then I found out that the airstone doesn't add that much in the way of oxygen, since (I think I have this right) the majority of the oxygen exchange takes place on the surface, mostly from the filtered water being reintroduced to the tank. So now there's no airstone. I think if (actually, we all know that I really mean WHEN I move up to a bigger tank

, I may try the airstone thing again. I think it may look better in a bigger tank with more plants, etc.)

gregpape23 · 03-29-2009, 01:12 AM

Quote:

Originally Posted by EtherealGirl

Then I found out that the airstone doesn't add that much in the way of oxygen, since (I think I have this right) the majority of the oxygen exchange takes place on the surface, mostly from the filtered water being reintroduced to the tank.

That is correct, the air from the airstone itself is not what is adding the oxygen, it's the agitation @ the surface where the exchange happens. So yeah, if the filter is agitating the water, then that would work.
So basically, you are absolutely correct.

-Greg