Hyper Corys 2

[TypicalNoah]

Hello,

New to this forum but not to f/w fish care. A friend of mine is harboring above average concern about her new cory cats. Whatever plain gray species would be sold without mention of a species name is what we've purchased. We bought all three from the LFS as they were a very cohesive and curious group. I've never seen LFS corys swimming so energetically and non-benthically...! So, here's the scoop. My friend has had them for a week now in a standard 29g high aquarium with some 4 lil otocinclus, two upside-down cats, a smaller gold gourami, and two swordtails. We've not noticed any aggressive behavior. But, the corys have settled down and dont swim in the water column anymore, they just hang out on the bottom. I wish I could give more details but the tank is far away and I'm writing for her sake. I can vouch that the parameters are all sane, slightly alkaline pH, temp between 75 and 77, inorganic nutrient levels not appreciably beyond zero...

Is this standard cory behavior? This is what I want to hear cory stories about.

The confounding variable is that about fifteen pounds of granite were just added a few days before this "settle down" observation, but they were thoroughly toothbrushed scrubbed without soap before being boiled for a few minutes each and added to the tank when cool. So... I ask more for the sake of curiosity if this settle down thing is natural. Thanks!!

 

[OldMan47]

Welcome to the forum Noah. Cories that settle on the bottom of my tank and don't move much cause me to worry. The temperature of the tank may be a bit high for many cories and without knowing which species it would be hard to say if that is a factor. If they are aeneus, they should be fine at your temperature but a plain color is a bit nondescript. Do you have any pictures so that we can identify the species and then get the right information for you?

 

[Johnlenham]

They sound like Bronze corys to me.
I spent about an hour looking at bronze,albino,panda and a few other types and the only grey ones are bronze's (aeneus).

 

[Inchworm]

Hi TypicalNoah

Welcome to the forum.

The most commonly sold gray corydoras is the C. aeneus (aka bronze cory.) Does your friend's fish look like this:

Are they a recent purchase? If so, they might have settled down to more normal behavior. That would mean that they are frequently active but not necessarily swimming upward. They can be expected to spend a fair amount of time searching the substrate for uneaten bits of food. You might also find that they are more active in the morning and/or in the evening, and especially after water changes.

Of course, if they're new to the tank, they might be coming down with a bacterial infection they picked up somewhere between the fish farm and the time they reached her, so it would be a good idea to keep an eye out for symptoms for a few weeks. Pay particular attention to their barbels, fins and tail. Corys like well oxygenated water, so be sure there is good movement at the surface.

A 29 gallon tank is a good size and doesn't appear to be overstocked, but adding rock to the bottom might have made them feel restrained since you took away some of their bottom space. I've noticed normally sedate corys become much more active when I removed rocks and plants for cleaning. The fish in this picture are the C. aeneus and some C. robinae, and they were swimming back and forth across the length of the 55 gallon tank they were in.

Please let us know how the fish are doing from time to time.

 

[TypicalNoah]

Hi!
This is Noah's Friend who has the Corys. Bear with me, I've never done this before, Noah is usually my guru for my fish tank. After looking at the pictures that y'all put up, I'm pretty sure that they are Bronze Corys. I've had them for a little longer than a week. The lady in charge of fish at the pet store commented about how active the three corys I bought had been. When we first put them in my tank they were just as active, but they have really changed their behavior since I put the large rocks in. Before, they were very active and usually together. Even when they were at the bottom of the tank, they were quickly looking through the gravel. Since I added in the big rocks, they have been just sitting at the bottom, not near each other. They really haven't been doing anything but 'breathing'. I did a partial water change last night and they perked up during that, but when I looked this morning they were just sitting on the bottom again. Is this normal?

 

[OldMan47]

You might follow Inchworm's roundabout suggestion and remove some or all of the rocks and see if that helps. Not many of us here would argue with inchworm about cories. When he makes an observation like that, it is well worth heeding.