Yellow tail blue damsle fish HELP !!!

[zep]

Hey guys,

I have a pair yellow tail blue Damsel fish, have had them about 6-7 months from about 1 inch in size. They are feeding and active and in general seem happy and well.

About a week ago i noticed that there colour was changing slightly , a few dark patches on the body's etc. i haven't been at home for a few days, i got in late last night and didn't really pay much attention to the tank.

Today i have woken up to a full blown transformation in them. they are blue in colour still with yellow tails ( if anything even more vibrantly blue than before) however there fins have all changed colour to jet black!!! and the spaces in between there scales has also changed to jet black.

My wife has said that the damsels have been going nuts with the chromis constantly harassing them if they come to close etc and thinks they may of even killed two of them as shes found two dead on two separate days.

The tank is 800 liters and has 40 kg of live rock in along with a 7 inch Stars and Stripes puffer , a 12 inch Zebra moray and now 4 Chromis. Ive check the water parameters and all are well within the accept tolerances.

The only thing that i could think of is its some kind of spawning behavior. Any clues or ideas guys ?




The only thing i can think of is its stress or spawning behavior

 

[EmilyXLC]

I'm not sure why they are changing colours, but Damsels are known for their aggressive behaviour towards other fish. Chromis don't stand a chance. : (

 

[_Alex_]

soudns liek they could be reaching sexual maturity, a lot of fish change colors some once they start to.. sounds like they are a mated pair and fighting for territory. like mentioned above damsels are very aggressive and fish that are they same size, smaller, and even some times bigger they will torment to no end!

 

[zep]

i expected as much, i want to move them to a 100 ltr breeder but dunno if they have spawned yet.

I don't want to upset them to much to be honest but feel my chromis may have to go lol.

 

[TheSaint216]

I had three stripes that kind of did the same thing. Their tails didnt change color but the alpha developed a very pronounced white spot on what Id call his forehead. And when they were spooked it would disappear.

 

[EmilyXLC]

i expected as much, i want to move them to a 100 ltr breeder but dunno if they have spawned yet.

I don't want to upset them to much to be honest but feel my chromis may have to go lol.

I'd be careful with keeping the Damsels in the tank with the other fish, as they will probably become aggressive towards your other tankmates in time. I wouldn't move all of my livestock out of my display tank just to accommodate them. : /

 

[TheSaint216]

You should accommodate them they are under your care. I had three 3 stripes that were bullys. I took them out it a QT tank and rearranged rockwork, they like to be tough but will head for a cave right away if they feel threatened. Give them a space away from the other fish. After you keep them out for a week or two reintroduce them. They wont act as tough.