Why Are They Shoaling?

[SJ2K]

Ammonia, Nitrite and Nitrate are all fine, no new 'threats', why on earth are my tetras all shoaling?

Need any more details, just specify.

 

[mark7616]

cause tetras are shoaling fish.

 

[SJ2K]

Its a strategy only used when under threat, any other time they free swim.

 

[Thirdfloor]

cause tetras are shoaling fish.

There is a mixture of terminology that often happens with schooling/shoaling.

When a group of same-species fish swim together in a loose group, moving independently but staying in the same relative group, its called schooling
When a group of same-species fish swim together in a close knit group, mirroring each others movements precisely and moving as one body, its called shoaling.
The difference is very notable.
Fish school by design, they like to be near others of their kind.
Fish shoal as a response to a threat/predator or when in a strange environment, its a survival instinct.

It also seems that folks in the UK call it shoaling in general whereas in the US the term schooling is more common.

There was a great thread a while back on this topic, I'll see if I can find it and add a link here. What I posted is what it boiled down to.

As for your tetras, schooling is normal. Shoaling would indicate some kind of threat trigger. You say your water parameters are fine so thats out, did you recently get a cat or something? lol

 

[SJ2K]

No new threats and they are in a very tight group (where as before they'd be all seperate).

 

[Inchworm]

Hi SJ2K

What are your cory cats doing? Are they schooling, shoaling, or hiding out?

 

[SJ2K]

They always hide out together whenever somones around, seem fine though.

 

[Inchworm]

Hi SJ2K

Your corys shouldn't be nervous around you, unless you constantly do something to upset them. It is normal for them to swim and play together, something like this:

While they are often more active toward the evening, this is not always the case. If you don't often see this kind of behavior, I would consider it a possibility that they are afraid of the cichlid in your tank. I can't speak for the behavior of tetras, but it might be something for you to continue to inquire about.

 

[SJ2K]

They've been like this long before the introduction of any cichlids but it is a good idea I think its partly due to the small group.

 

[Luketendo]

They are probably friendly. I have fish who have formed big groups in both of my tanks.

Silver Tips + Cherry Barbs
Black Phantoms + Black Neons

They don't really shoal as such, but they do play together and form groups and eat together, it's because they are very active fish they like each other's company, whereas in the big tank the silver tips and cherrys stay away from the gourami and the angelfishes, but they always stay with each other.

 

[SJ2K]

Looks like theres no real defined reason, there just mad/dieing.

 

[CFC]

Have you recently put up the xmas decorations? Flashing lights and sparkly tinsel could be mildly stressing them.

Oh, and if i remember rightly a school of fish is a group of fishes all traveling in one direction where as a shoal of fish is a group of fish just hanging about with each other with no particular purpose.

Just some more mindless information from somewhere at the back of my brain

 

[Rosanna]

Yes we (SJ2K and myself) have recently put up christams decorations but on the other side of the room...And im not sure if they were together before then or not

 

[SJ2K]

Started before the xmas stuff (I believe), is probably somthing to do with the snail "killer" (which managed to kill a fish and leave all the snails?). No doubt ive poured some stupid copper based killer into the water, im working towards removing it atm though and no one else seems to be suffering

 

[brads]

My neons always shoal as do my copper harliquns oh and my tiger barbs always stick together.