New Tetras exhibiting odd behaviour?

Question

Have just introduced my first fish t my freshwater community tank, 10 glowlight tetras. water quality is being monitored and is fine, and the fish have been in about 24 hrs. At first they grouped together ie for the first 18 hr or so, which is what i would expect from a 'schooling fish'. Now they have grouped into a 2 or three groups ad have started chsing each other, difficult to tell but i think its the same fish being chased all the time...
my question is this, is this mating type behavior ( these fish are fairly young as they are recent purchases) or have i bought too many for one 'school', or would you say they are in distress?

Answer 1

They are probably fine.
The chasing is territorial behavior. Nothing to worry about. Tetras, like many animals, develop a pecking order.

Introducing 10 fish at one time to a brand new aquarium is probably not a great idea. You may experience a nitrogen spike in the tanks bio load, as it is not acclimated to the level of fish waste (uneaten food and fish feces) that you have put in it. It's usually better to phase fish into a new tank slower (2 or 3 per week). My recommendation would be to underfeed the fish at first - make sure they eat as much of the food that you put in as possible, with very little or no extra - and do frequent water changes. 20% change after the first week, 15% after the second week, and 10% each week thereafter until your tank 'cycles'. This will prevent initial fish die-off that you could experience from initial overstocking.

Answer 2

The other tetras that are being chased may actually be sick or weak and the other fish sense it. I don't how big your tank is, but another option could be that the sex of the other tetras are female and the males are harassing them.

Believe it or not the best remedy to this is give it a few more days. If the fish being chased show signs of illness, i.e. white on the fins or gills, remove them immediately. If they remain healthy, get more tetras so the neons have more fish to harass and they don't stress the others out so badly they never get to rest or eat. This will make them sick too. I would also add a little more stress coat if you have it. This will help the stressed fish.

Make sure the chased school of neons are eating. If they aren't this could be a potential sign of illness. I would immediately take them back to the pet shop with a sample of my water and get some more tetras. Usually, pet stores will give new fish or a refund if everything is fine with your tank and they sold you bad fish.

Good Luck and Take Care

Answer 3

The female is larger and stronger than the male and has a round ventral section. The male is slenderer and has more color. It can be considered breeding behavior, but it can be that they are still adjusting to the new tank and can't decide where to school as a group since they ten to be active fish.
A

Answer 4

You might try contacting the pet store where you purchased the fish and talk with them about what's happening. Hopefully they'll have some insight into the situation. If they're no help, Google it & see what you come up with. Good Luck!

Answer 5

Google it!