R.I.P ned

[Tener ds]

Well I just got in from work it was very quiet in the living room
where both of my tanks are.
Turned the lights on and found that my air pump for my big tank had packed up,
then to my horror I saw ned my (L081) on his back at the back of the tank.
All over fish ok so it's not co2 gassing, as I use the air stone to de-gas the co2.
He was ok yesterday, he had some food and went under the filter, where he lives. His belly was normal size, not fat or skinny.
I netted him out and he was very stiff and looked like he hadn't been picked at by the other fish. Could this be old age? He was just under 4" long.
He will be missed.:cry:

 

[Brengun]

Can't offer any explanation but condolences to you for your loss.

 

[Lornek8]

Sorry for your loss. Unfortunately probably not old age. Though age and size aren't necessarily the same, GNs can reach 12"+.

What other fish are in the tank?
GN's come from areas of high oxygentation and flow. They could be more susceptible to low oxygen levels than many other fish.

 

[bigbird]

wow sorry for your loss. dont know the reason but again sorry :cry:

 

[Tener ds]

Sorry for your loss. Unfortunately probably not old age. Though age and size aren't necessarily the same, GNs can reach 12"+.

What other fish are in the tank?
GN's come from areas of high oxygentation and flow. They could be more susceptible to low oxygen levels than many other fish.

Hi lornek, there is a L134 and 10 cardinal tetras 2 ottos and a Molly.
There is a lot of flow in the tank too. May be just one of those things
that happen...

 

[dw1305]

Hi all,

Unfortunately probably not old age. Though age and size aren't necessarily the same, GNs can reach 12"+. What other fish are in the tank? GN's come from areas of high oxygentation and flow. They could be more susceptible to low oxygen levels than many other fish.

Unlucky Dave, I lost a L333 in a similar manner, Lorne has the answer and it is oxygen.

Turned the lights on and found that my air pump for my big tank had packed up, then to my horror I saw ned my (L081) on his back at the back of the tank. All over fish ok so it's not co2 gassing, as I use the air stone to de-gas the co2.

If you add CO2 to the water the diffusion gradient between the CO2 in the blood in the fishes gills and the water is lessened. CO2 takes longer to diffuse out, and the haemoglobin molecules are unable to pick up O2 molecules from the water. This is the Bohr effect, described in "Aeration and dissolved oxygen... " <http://plecoplanet.com/?page_id=829>.

Somewhat more surprisingly fish breathing rapidly, or showing other symptoms of respiratory distress, are unlikely to be suffering directly from low oxygen levels, but are more likely to be stressed by high levels of carbon dioxide in the water.

Without a sharp gradient between CO2 levels in the blood and CO2 levels in the water, it becomes increasingly difficult for the CO2 in the fishes blood to diffuse out across their gill surfaces into the water.

As the water quality declines the BOD rises, and so does the CO2 content in the water. Consequently the fish often they rise and hang at the water surface gasping atmospheric oxygen.

For Salmon and Trout dissolved CO2 in excess of 20 mg/L, can begin to impair the transport of oxygen (O2) in the fish's blood due to the Bohr effect, and it is likely that rheophilic plecs are similarly sensitive.

Whenever fishes rise to the surface, an immediate partial water change is urgent, and additional water current at the surface is needed (to drive off CO2 into the atmosphere). Addition of an air stone might also help in such an emergency...........

As signs of respiratory distress are often related to high CO2 levels in the water, we should definitely not add CO2 to tanks containing plecs, in fact the 20ppm CO2 level suggested for improved plant growth is about 40 times the natural atmospheric content.

If we have efficient gas exchange, either by water movement or filter design, as well as oxygen dissolving into the water, CO2 will dissolve out until it equilibrates with atmospheric CO2 levels (about 0.03% of the atmosphere).

In contrast to what is often written, unless we are physically adding CO2 to the water, water movement, and trickle filters, will add CO2 to the water when plants are actively photosynthesising (utilising CO2 and producing oxygen), and out-gas CO2 when levels in the water exceed those in the atmosphere

Baryancistrus sp. (L081) is a large rheophilic plec, likes warm water and will have a high oxygen requirement. Any increase in CO2 or decrease in oxygen levels, or their relative ratio in favour of CO2, is likely to proof fatal.

This is one of the reasons why they are so difficult to keep long term, even if your oxygen levels are spot on 99.99% of the time, that 0.001% when they aren't kills them. Nothing else is anything like as critical.

To make it even more difficult we can't accurately measure oxygen levels in the tank, and "oxygenation and aeration" is a complicated subject that has a lot to do with subjects like water flow and biological filtration, which may not be initially immediately apparent.

cheers Darrel

 

[Tener ds]

cheers darrel.
just done a water change followed an hour later by a water test,all ok.
all fish are ok and theres no bad smells etc.
checked the air pump,works fine now..:dk:
i think it was knocked over whitch cut the air flow,not sure.as per know one here knows anything about it....:wb::wb:

 

[dw1305]

Hi all,

just done a water change followed an hour later by a water test,all ok.......

That is the problem, really we are dealing with parameters that we can't measure so we have to try and maximise it via high flow, efficient biological filtration, plants etc. We actually have a dissolved oxygen meter in the lab (~£1000), but it is a real s*d to calibrate.

A fish like Ned could die from low O2 whilst fish that come from still waters (some Tetra's etc) won't experience any discomfort.

Some of the plecs can breathe air via their stomach lining (like Gibbis etc) in the same way that a Cory catfish can. Because the Plecs and Cories both belong to the "superfamily" Loricarioidea (Loricariidae and Callichthyidae) and have this adaptation it is likely that rheophilic plecs like Baryancistrus, Hypancistrus etc (which live in constantly highly oxygenated water) have lost this ability. I haven't seen it, but apparently they still have this behaviour and often gulp air at the surface in conditions of sub-optimal oxygenation, although they can't actually absorb any of the oxygen from it.

cheers Darrel