Long finned zebra danio behavior

[Fishytales12345]

I tried posting this on an existing thread, but go no responses. So I am trying it as a new thread. My observation and question(s) are concerning the breeding or other cause of the change in behavior of 6 long finned zebra danios (Brachydanio rerio).

We made a major move and restarted everything from scratch beginning on January 1st of this year. A 10 gallon quarantine, a low-light 20 gallon planted hex, and most recently our 70 gallon planted tank.

The 70 gallon tank was planted in mid April. We had danios among many other species for three years before our move and these danios have been residing in our 20 gallon planted tank for 10 weeks now, always active. The 70 gallon tank has cycled. The ammonia has come and gone, the nitrIte has come and gone, the nitrAte is at 10ppm. After most of the plants were rooted or established, we introduced 6 danios to the tank three days ago. The first two days they acted like we have noticed all the time before. They would come right up to the front of the tank wriggling like puppy dogs welcoming home their owner. They constantly swam back and forth mid level in the tank, but always one or two would make excursions to the top or bottom or behind all the plants.

When I came home today, they were all huddled behind and under the large sword plant and would not come out. They were constantly moving behind there though. After three hours now, they have all returned to acting normal (to me).

The danios are the only animals in the tank except for a few inherited snails on the plants.

Two are most likely female based on their size and shape.

Could this change in behavior be stress from the transfer three days ago? Or is there possibly spawning going on here?

Water parameters are still all proper.

Any thoughts and comments would be appreciated.

Howard

[lauraleellbp]

Sounds like spawning to me.

Any moss back there?

Do the females look any skinnier?

[Fishytales12345]

The two larger ones do appear to look skinnier today. They still gather around the one place behind the large sword plant.

There is no moss in this tank. There is ground cover in the foreground (dwarf hair grass) but that is about 8 inches forward of the sword plant.

Current observations are that they spend most of their time now in the front of the tank, like they used to do, but still occasionally go back to the same point under the sword.

Thanks for the quick reply post, Laura.

Howard

[Tex Gal]

Lauralee is right. It's spawning. Unless your tank is HEAVILY planted you won't see any eggs or fry. They will eat them. Mine spawn all the time in my 125g. If I take them out and relocate them at dusk they will spawn overnight. Then I move them back to the 125g. A few days later I have fry! They will spawn everytime over night. So cool!

[Fishytales12345]

Thank you both for the replies!



Howard

[lauraleellbp]

You're quite welcome!

If you put some fine-leafed plants back there (like java moss or pellia or something along those lines) for the eggs and fry to hide in, don't be surprised if you see little fish swimming around at some point...

I actually had some cherry barb fry hatch out and survive under the plates of my undergravel filter and in my Emperor HOB filter - I found them at different times while I was doing tank maintenance and was VERY surprised!

[fishboy87]

Thats really weird as I have rummies acting similarly and I do have a couple of large ones straying off occasionally. Good luck with yours and I agree on what lauralee said about the fine leaved plants.

[Fishytales12345]

Thanks for the additional advice. I do have some Java Moss in my other tank and I will move some of it over.

Thanks again and best regards,

Howard