Large gravel in Geophagus tanks ???

[neutrino]

Ime geos will try and sift whatever's there, whether sand or gravel. Before I switched all my tanks to sand years ago, I did have an incident or two of geos getting a bit of gravel stuck in its mouth. In the case I remember most clearly, he managed to get it spit out but only after a few hours, a relief that I didn't have to intervene. Afterward, he wasn't deterred and he and the other geos in the tank continued 'sifting' gravel. Already had a sand tank by then, the experience was another nail in the coffin of gravel tanks for me.

The other nail in the coffin was maintenance. I siphoned the gravel in my gravel tanks every water change. Sand tanks, every couple of months at most. Interval gets based on results, partly to do with how many fish and how much sifting they do (at present all my tanks have at least some fish that do sand sifting).

I don't do bare tanks, not for any species and not for fry. Always substrate and other features in the tank, even mostly open tanks. Always my policy based on my personal brand of common sense, but in more recent years several studies have been done on this, more than one species. Such studies typically find fry develop smaller brains in bare environments, and the advantage to fry raised in 'enriched' environments then placed in bare environments tended to disappear, interpreted by the studies I read as 'plastic' brain development in fish.

Come to your own conclusions, but I never did bare tanks and for me this only reinforced my preference on this.

 

[neutrino]

Ime geos will try and sift whatever's there, whether sand or gravel. Before I switched all my tanks to sand years ago, I did have an incident or two of geos getting gravel stuck in their mouths. In the incident I remember most clearly, he managed to get it spit out but only after a few hours, a relief that I didn't have to intervene. Afterward, he wasn't deterred, he and the other geos in the tank continued 'sifting' gravel. Already had at least one sand tank by then, the experience was another nail in the coffin of gravel tanks for me.

The other nail in the coffin was maintenance. I siphoned the gravel in my gravel tanks every water change. Sand tanks, every couple of months at most. Interval gets based on results, partly to do with how many fish and how much sifting they do (at present all my tanks have at least some fish that do sand sifting). I have lightly stocked tanks that I'm not needing to siphon in 6 months or longer, based on checking every so often and finding them clean, not simply ignoring them.

I don't do bare tanks, not for any species and not for fry. Always substrate and other features in the tank, even mostly open tanks. Was always my policy based on my personal brand of common sense, but in more recent years several studies have been done on this, more than one species. Such studies typically find fry develop smaller brains in bare environments, and the advantage to fry raised in 'enriched' environments then placed in bare environments tend to disappear, interpreted by the studies I've read as 'plastic' brain development in fish.

Come to your own conclusions, but I never did bare tanks and for me this only reinforced my preference on this.

 

[RD.]

I must have raised a lot of mentally challenged fry in the past. Come to think of it, most of the larger scale breeding operations that I have seen over the years also used bare tanks for fry. I'm curious as to what species were involved in these experiments? Not doubting the results, it makes sense, but I wonder if those same fish could reverse the brain stunting once placed in an enriched setting? I sold or gave my fry away at pretty small sizes.

 

[wfex4]

Before keeping Retroculus, I used sand only for my all my geo tanks. I added some Retroculus to my large display tank and mixed in a couple bags of gravel, and the other geos don't seem to have any problems sifting the sand/gravel mix. I would say its your preference on whether to use sand, gravel, or a mix of the two. Just be sure if you use gravel that it is on the smoother side to avoid cutting up their mouths.

 

[Toiletcar]

I love a sand/pebble mix. Looks good and keeps the fish busy.

 

[neutrino]

I must have raised a lot of mentally challenged fry in the past. Come to think of it, most of the larger scale breeding operations that I have seen over the years also used bare tanks for fry. I'm curious as to what species were involved in these experiments? Not doubting the results, it makes sense, but I wonder if those same fish could reverse the brain stunting once placed in an enriched setting? I sold or gave my fry away at pretty small sizes.

Trout, salmon and zebrafish are the ones I've seen articles/studies on. One of the more recent studies I saw concluded fry reared in bare environments could catch up later on when put in a more complex environment. Had some of this archived in a post on another forum, but the links are broken now. Here's one I do have.

Some of what I've seen was study of salmon hatchery fish survival upon release into the wild, seems like some of what I've read reported an advantage to wild survival after varying water levels, current, etc. and also fewer parasites in the enriched environment-- contradicts the theory of some that a bare environment equals fewer health issues. The (unproved) suggestion I read was lower chronic stress in an enriched environment as explaining the fewer parasites.

Don't know how critical this really is to life in a hobbyist's tank, but it suits my aesthetic and philosophical preferences...

I think it would be interesting to study if there's any relationship between closer to wild (bigger) brain development and aggression. Personal experience is aggression depends on the individual, even among equally dominant fish, and I haven't seen a correlation to cleverness of fish I've had, some of the more inventive fish have been relatively mellow, but that doesn't qualify as a scientific study.

 

[neutrino]

I love a sand/pebble mix. Looks good and keeps the fish busy.

Haven't seen any issues with geos on sandy bottom with a bit of gravel here and there. I like the look also. My experience has been when there's sand to sift they avoid the gravel, when it's gravel alone instinct makes them sift the gravel. My opinion is if the gravel is small enough it might be okay, but not 100% foolproof, since I had a couple of issues in the past, so I'd say sand is safer and easier on them.

 

[darth pike]

I had to remove many a gravel piece that got stuck in the mouth of various Geo's when I worked in a LFS. Not fun for me or the fish. Not all survived the experience (the same with leaving it in and hoping the fish was able to eventually spit it out). It didn't happen with every Geo, the percentage was probably rather small overall, but the experience did stick in my mind.

 

[RD.]

Hey Chris, that's interesting. In the wild, perhaps this would be mother natures way of thinning out the herd?

 

[darth pike]

Could be. It was mostly the younger to med ones, not the full sized adults. And it was rare, maybe 1-3 a year which given the sheer number that we had, would be a small percentage over all. I just wouldn't want to risk my own.

Reminds me of a George Carlin quote, "The kid who swallows too many marbles doesn't grow up to have kids of his own."