green tiger barbs

Question
Hi,

So last night at about 1 am I checked our fish aquarium (have had it about 2 weeks).  We have 4 green tiger barbs.  I turned the light on (my brother turned it off but I had told him to leave it on because the temperature of the water will be too low by morning. Leaving it on keeps it at a comfortable temp for the fish 75-78 degrees).  When I turned it on the fish had lost their pigmentation.  They were white/transparent.  The color was gone from their fins as well.  After the light had been on for a bit they slowly regained their color.

I just wanted to make sure this was normal, since I had not read this about green tiger barbs.  Also what purpose would this serve?

Michelle

Answer
This is normal yeah...
lol, i was worried when i saw it too..
it happens to all fish...

do you have a heater in your tank? if so the water will stay the right temp. anyway the purpose is for predators...they loose there colour so they blend in with there surroundings better...(sand maybe?) and wont get found by predetors easily.