Pleco behavior

[jgolden]

Hey all. 2 quick questions re: my common pleco.

1. I've had the 75G up and running for about 4 months now. Prior to that, the pleco (bought an a paltry 2 inches in length - he is now 9-11/16" in length!!) had lived in the 10G for almost 2 years. Ever since I placed him in the 75G, I've noticed he'll be sitting on the bottom; glued to the side of the glass; etc, and suddenly lunge to the surface, surrounded by bubbles. It's almost as if he's burping  :? and that's the bubbles following him to the surface. After he hits the surface, he dives back down to the bottom. He's never done this in the 10G (probably didn't have the room), but I've never seen any other pleco do anything like this. (I've noticed the white hi-fin is also starting this). He is quite lively...

2. Are plecos normally aggressive at feeding time? The big guy chases the smaller pleco away from where I drop the algae chips in, even if I drop some in on both sides of the tank.Any other time, the 2 swim around side by side, clean the glass side by side, etc... Thoughts? (The white hi-fin has only been in the tank for 6 weeks, and is only 4-1/2" in length).

Thanks.

J

[Julie]

Oxygen level must be low at the bottom of 75.
Do you have an airstone?  Does it happen at a particular time of day?
All your readings ok?
They are aggressive fish and will challenge a full grown oscar if they are hungry enough and big enough.

Julie

[oenology]

I don't know about the burping thing but my commons also streak up to the top of the tank from time to time. Once one of them ended up on the floor. He was covered in dust (hmm, seems I hadn't vaccumed for a while) and dry. I put him back in the tank and he came back to life. That was 2 years ago. There's a stronger lid on that tank now. As for aggression as Julie said they can be very aggressive. I found a great series of photos of 2 plecos fighting on one of the sites dedicated to plecos, maybe plecofanatics.com.

[Aiglos]

My pleco is about the size of yours and does the same thing;  he will actually swim along the top of the water and eat flake food from the surface;  I wouldnt worry about it.

[Julie]

hmmmm.....I don't think they eat dust bunnies  :wink:
Only time my goes to the top of the 90 is when there is something wrong - dirty filter.....

Julie

[Aiglos]

Mine does this constantly.  There is nothing wrong with oxygen or bad water quality.  

I Believe he does this looking for food; as he usally does this after a feeding.

[Julie]

I think he's got a problem with his muffler - seems to be a lot of backfiring.

That's not what they are referring too though.

Julie

[mseguin]

From what I understand, plecos and cories have the ability to ingest air and use via a modification of their stomach or intestine. This enables them to obtain air in conditions where the oxygen levels are low (i.e the bottom of the Amazon basin).

[Julie]

Interesting how the intestine and muffler got connected.
My experience with my pleco is he will go for the top when ie temp is too high, or I've neglected the tank.
He's not eating, he's getting air, my tank is very deep.

Julie

[jgolden]

Bizarre. Thanks all. I've had 3 airstones in the bottom of the tank for a couple of months now. How would I measure O2 levels at differing levels in the tank? Guess for the aggression thing, I'll just up the algae chips for now.

[aidensmomma2000]

Weird- I've never seen them do that! Ive seen them dart to the top and straight back down though.

[Julie]

J- I'm just down the road from you.
Are you on a well?

Julie

[jgolden]

No, on the municipal water...

[Julie]

Plant expert please....it's got something to do with your planted tank and the exchange of gases.

Julie

[BigDaddy]

The difference in oxygen saturation at the bottom of 24 inches of water compared to 2 inches below the surface will be minimal.

Don't forget, we are talking about diffusion here...  The gases are trying to reach an equilibrium WITH THE ENTIRE TANK... not just sections of it.

If there is no oxygen at the bottom of a tank, then there is little to no oxygen at the top either.  So any fish would be suffering, not just bottom dwellers.

[Julie]

He's a pretty big fish though.

Julie

[BigDaddy]

He's a pretty big fish though.

Julie

:lol:

And its a pretty big tank too.  The size of the fish is irrelevant.

[Aiglos]

Plecos are also notorious swim bladder users;  they take oxygen from the surface and use it to properly float and stay balanced.

I seriously wouldn't worry about it; Like I said my Pleco does the same thing and I have LOTS of oxygen in my tank I did an experiment this afternoon and pointed my spray bar to the top of the water to make more water movement at the surface and the pleco is still doing this;  and I do 2x large weekly water changes with 2 established biofilters so Ammonia/nitrite/nitrate are hardly an issue;

Is there a pleco expert or more experianced fish keeper that can verify this ?   Again I am speaking with my limited fish keeping experiance; and only from my experiance

[Julie]

http://tropicalfish.site5.com/tfc/archive/index.php/t-4126.html
http://www.aquariacentral.com/forums/printthread.php?t=38436

[jgolden]

Thanks Julie. I'll notch it off to normal behavior that I haven't previously observed due to the smaller tank he was originally housed in.