Tetras losing color at night???

**ddavis1979** · 10-21-2012, 01:16 PM

I have 5 black neon tetras that I like very much. However, i have been struggling lately with tank water quality.

Two mornings in a row I have woken up and turned the lights on, and the tetras looked terrible. I thought they were near death due to water quality. the black stripe was all but gone and they were sluggish hanging out the bottom. I walked by 15 min later and full color was back and they seemed fine.

Is this normal for overnights with no lights for tetra.....anyone have any thoughts on this?

**Goes to 11!** · 10-21-2012, 01:29 PM

Originally Posted by ddavis1979

Is this normal for overnights with no lights for tetra.....anyone have any thoughts on this?

It's perfectly normal for their color to fade when 'sleeping'.

**pjaldave** · 10-21-2012, 01:30 PM

+1 to 850R. The colors fade when the fish rests.

**Azurescriber** · 10-21-2012, 02:18 PM

Yup, I agree. My neons look pretty dim in the am. :)

**AllenIsbell** · 10-21-2012, 02:33 PM

This seems to happen with my Platy, too.

**ddavis1979** · 10-21-2012, 02:46 PM

What a sense of relief, thanks!

**~firefly~** · 10-21-2012, 05:15 PM

Yep, happens to my cherry barbs every night. To the point that I cannot tell the difference between the bright red males and the orange females.

**Lady Hobbs** · 10-21-2012, 05:29 PM

Because they are sleeping.

**AllenIsbell** · 10-21-2012, 05:42 PM

I was interested in a technical answer.

I Googled, "why do fish lose color while sleeping."

Came up with this:

"When fish lose their color, the chromatophores, which are the cells that control pigmentation, space out pigment granules farther apart, and their colors appear more dull. Drawn closer together, the colors appear more bright.

As for why their colors dull at night---my answer is that with any cell, it will conserve energy if at all possible. In the absence of light, maintaining color is useless, so fish can control their When fish lose their color, the chromatophores, which are the cells that control pigmentation, space out pigment granules farther apart, and their colors appear more dull. Drawn closer together, the colors appear more bright.

As for why their colors dull at night---my answer is that with any cell, it will conserve energy if at all possible. In the absence of light, maintaining color is useless, so fish can control their chromatophores when there is an environmental change, and thus control their color to some degree.

The same happens when a fish is stressed out. The fish has less energy, or energy is expended elsewhere in keeping the fish alive, so color becomes secondary and dulls out. I have heard that keeping a goldfish in complete darkness will turn them white as well, although I've never tried it. when there is an environmental change, and thus control their color to some degree.

The same happens when a fish is stressed out. The fish has less energy, or energy is expended elsewhere in keeping the fish alive, so color becomes secondary and dulls out. I have heard that keeping a goldfish in complete darkness will turn them white as well, although I've never tried it."

Now we all just got a little smarter.