Harlequin Rasboras: Color changing?
 

Hello,

I have had my Harlequin Rasboras in my tank for a little more than a week now. They are coming along quite well, but I had a curiousity about the black stripe on their bodies.

Before I put them into my tank, they had to go through a rainy, slippery and bumpy ride home in the car. When I took a look at them all in the bag to make sure they were all okay, just about all of their black stripes VANISHED. There was just a small hint of black there!

As I put them in warming cups and let them float in the aquarium, the color started to come back, and since they've been in the aquarium, they have had extremely vivid contrast in their color.

Do they normally exhibit this behaviour when they are startled?

They are a wonderfully welcome addition to my tank, and I completely understand why Takashi Amano uses them in so many of his aquascapes.

__ Some additional questions for anyone who has the time to answer them

* There is one rasbora in the school that seems far more clever than the others, and will separate itself from the school independently, more often than any of the others. Do rasboras, being a schooling fish exhibit "alphas" in their group?
* My rasboras never stay at the top of the tank for more than a quick dart to grab a piece of food. They stay at the middle to bottom of the tank at all times, and sometimes they do not notice the food at the top of the tank. Is there a good "mid level" food that they could have delievered to them more efficiently than the tropical flakes that are quickly being consumed by the top level fish?

Thank you!

Yes, many fish will "color out" when stressed. Very common and it sounds like yours are now doing very well. :-)

Yes, they have a pecking order.

Mine also stay mostly mid level but will dart to the top for food. If I feed flake I usually will put a pinch in below the water near the filter outflow so the flakes start to sink immediately rather than float. I also feed NLS pellets in the micro size which are small enough for them to eat. These will float for just a second or two and then sink. So look for a sinking pellet for community fish that will be small enough for them to eat. Also, frozen foods such as brine shrimp or bloodworms will sink and can be fed as a treat a couple times a week.

Yes any stress can cause the loosing of color, may that be transportation stress, stress of aggressive other fish in the tank set up, stress from high NO's in your water - Kinda like us humans turning pale when something really shocking happens to us you know what I mean?