New zebraifsh color morph?

[BillT]

I think I may have found a new zebrafish (Danio rerio) colormorph. For now I am calling it emerald green.
It has an iridescent greenish-blue color, lightly scattered mostly on the top quarter of the fish. It is the same color as the dorsal midline iridescent blue-green stripe down the back of the animal that some people may have noticed.
I found this in the genetics of a group of leopard zebrafish I got from a local fish store, that have a shiny white background. Some fish bred from this group show this greenish tinge to varying degrees.



This shows more of the variability of the color depending on viewing/illumination angle.



Being iridescent, makes it difficult to get a good picture. The color changes depending on the angle of illumination and angle of viewing. I had to mess around with the angle of the lights and flash to get it to show up at all.
This is probably due to a structural color instead of a pigment. You can grind something up and extract the pigment from it and it will have that color that it had before getting ground up. Structural colors can not be extracted in the same manner.

The perceived color is due to the constructive and destructive interference of the various wavelengths of light that are reflected off of numerous small structural sheets (like microscopic crystals) that are separated on the scale of a wavelength (or half a wavelength) of the light. As the angle of light changes, the length of the light path can be increased or decreased. This is similar to the colors produced on a film of oil of water. The light reflects off of both the top and bottom of the oil film. Different colors will be produced where the thickness of the oil film is different. Oil films can get down to one molecule thick.

[b125killer]

Congratulation them are some neat fish.

[Jo]

What a gorgeous find! They are lovely! Great pics!

[Mugwump]

Definately different....I wonder if a wild cross was done to get them??

[BillT]

Definately different....I wonder if a wild cross was done to get them??

I was incrossing the leopard zebrafish I had and a bunch of different phenotypes showed up in the offspring, including the greenish-blue haze.
There is also a embryonic lethal in the background. It deforms the body axis and causes edema of the pericardial sac (a bag that contains the heart) and results in death at or before larval stages. This can be seen if you look at the eggs in a weak microscope.

I also do crosses to "wild type" fish and did not find this color in there. The simplest explanation is that it involves a recessive only in the leopards.

[Mugwump]

Definately different....I wonder if a wild cross was done to get them??

I was incrossing the leopard zebrafish I had and a bunch of different phenotypes showed up in the offspring, including the greenish-blue haze.
There is also a embryonic lethal in the background. It deforms the body axis and causes edema of the pericardial sac (a bag that contains the heart) and results in death at or before larval stages. This can be seen if you look at the eggs in a weak microscope.

I also do crosses to "wild type" fish and did not find this color in there. The simplest explanation is that it involves a recessive only in the leopards.

I think you're right. I mentioned a wild cross because the lines are so 'clean'....great looking little critters.....sweeeeet

[BallAquatics]

That's cool Bill!  You can see a muted leopard pattern on the fish that are turning in the photos.  Very nice.  Do you by chance know David Parichy?

Dennis

[BillT]

You can see a muted leopard pattern on the fish that are turning in the photos.

Based on the small number of fish I have looked at, I think that the blue-green may show up better when the fish are less dark. Less melanin, maybe fewer melanocytes (melanin containing cells) making smaller or weaker spots. The most greenish ones look like a silvery fish if the light is not hitting the blue right to light it up.

Do you by chance know David Parichy?

Yes I do.
I was thinking about contacting him (or Steve Johnson, his former boss) about this. It is not a phenotype I have seen before. I have asked some other people who have seen a lot of pigmentation mutants and they have not seen it either.