[p2ntuk]

Hi, Planted Tank's Member,

I've just done a ½ water change and remove some decorations for cleaning. Suddenly, my ember tetras seem like they are playing tag. However, I suggest that this big guy is asserting his dominance over the others. Any clue? Even now, one of the tetras (on the right side of the video) has come out to the front (it's like it has been found in the tag game). The small guy on the left is still "hiding" and sometimes dash to the front to pick the big guy.

Any clues? Is this aggressive behavior that I should be aware of?

Link to the video

 

[ZChalk]

I agree, the fish has claimed dominance over the front section of the tank and is actively patrolling it. Fortunately there is cover where the smaller fishes can hide and break line-of-sight. If there was no cover, you would see the dominant fish chase the other fish around the tank and eventually the smaller one would be so stressed it would succumb to disease. You can try resetting the territories by rearranging things but due to the size of the tank the fish will likely claim the majority of it. You often see it in smaller tanks when the fish mature, the bigger fish will literally bully to death the smaller ones.

 

[p2ntuk]

I agree, the fish has claimed dominance over the front section of the tank and is actively patrolling it. Fortunately there is cover where the smaller fishes can hide and break line-of-sight. If there was no cover, you would see the dominant fish chase the other fish around the tank and eventually the smaller one would be so stressed it would succumb to disease. You can try resetting the territories by rearranging things but due to the size of the tank the fish will likely claim the majority of it. You often see it in smaller tanks when the fish mature, the bigger fish will literally bully to death the smaller ones.

I see
However, I find it hard to understand. Several hours after the incident, slowly one fish and another come out to join the front fish. Then, they just shoal again as nothing has happened before. I'm trying to upsize my tank, but there is some major factor that is hampering it. I also plan to cut down some of the plants to reduce its size, should I postpone it?

By the way, thank you for the reply.

 

[Aaronious]

looks like front "big guy" is a female getting ready to spawn

Lots of little fish like this spawn first thing in the morning. I have Golden Danio in my 75 community. The fat females will come down and claim an area. (it's funny to watch them chase away a fish only to stop dead in it's tracks when they come face-to-face with a 9 inch pleco.)

Often in the mornings they will spawn I believe. I see the males "chasing" the females. Really they are following. If you watch and the male looses sight of the female he freaks out. Until he can find her and resume following her to fertilize the eggs.

as far as the plants I think that spawning will be more successful with more plant cover. so use that info however you want.

 

[NotThePainter]

And some fish spawn when there is a water change, killifish and cories are known to do this. I've even heard of breeders dropping the tank down to an inch of water just to get them to spawn.

 

[ZChalk]

Could be spawning, I'd just check to see if the belly from a top-down view looks larger (i.e. protruding - carrying eggs). Usually when they are spawning they do this flash dance and move side-by-side (check out some videos on tetra's spawning). It's also usually the smaller ones (males) pursuing the female. I'd probably leave the plants in and just monitor but it's good to hear that they are shoaling again.

I breeded sterbai cories (not intentionally) and it was obvious to tell the female as they looked pregnant (like their belly would burst). Started with 5 in the tank and ended up with somewhere around 35 (I called them my legion). The change in water temperature was definitely a key trigger.

 

[p2ntuk]

looks like front "big guy" is a female getting ready to spawn

Lots of little fish like this spawn first thing in the morning. I have Golden Danio in my 75 community. The fat females will come down and claim an area. (it's funny to watch them chase away a fish only to stop dead in it's tracks when they come face-to-face with a 9 inch pleco.)

Often in the mornings they will spawn I believe. I see the males "chasing" the females. Really they are following. If you watch and the male looses sight of the female he freaks out. Until he can find her and resume following her to fertilize the eggs.

as far as the plants I think that spawning will be more successful with more plant cover. so use that info however you want.

I see, will they be fine with the aquarium size? Actually I'm trying to delay their spawning because I don't want them to live in the small space. Thank you for the information, really appreciated it!

And some fish spawn when there is a water change, killifish and cories are known to do this. I've even heard of breeders dropping the tank down to an inch of water just to get them to spawn.

I see, thank you for the information!

Could be spawning, I'd just check to see if the belly from a top-down view looks larger (i.e. protruding - carrying eggs). Usually when they are spawning they do this flash dance and move side-by-side (check out some videos on tetra's spawning). It's also usually the smaller ones (males) pursuing the female. I'd probably leave the plants in and just monitor but it's good to hear that they are shoaling again.

I breeded sterbai cories (not intentionally) and it was obvious to tell the female as they looked pregnant (like their belly would burst). Started with 5 in the tank and ended up with somewhere around 35 (I called them my legion). The change in water temperature was definitely a key trigger.

I never knew that the "big guy" is female! Okay then, I'll keep the plant and keep checking their behavior. As long as it is not aggressive behaviour, I think it would be fine.

Actually, my average temperature is around 29-31°C. I don't think they will spawn in that temperature (?). I've tried using fan, but it's seems that my room temperature is just to high to keep the water temperature below 28°C. Will this be okay for tetras?

By the way, thank you for the replies, guys/gals! Really appreciated it!!

 

[Aaronious]

@p2ntuk
I doubt spawning will happen or be very successful in that set up. These fish will likely eat their own eggs or fry at some point. There are also 4? fish in there. So in that size it may or may not happen because they may not feel they get the privacy they need. or able to chase the others far enough. eventually they may be okay with it or with what space they do have and spawn, but then the initial thing I mentioned will likely happen.

to successfully do this, the main thing you need is another tank and have the end result being the eggs on their own to safely grow through the fry stages.