T Mossambica Orange
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The color of orange in the Orange mossambica comes from two distinctly different sources. The orange is somatic and occurs as pigmentation througout the dermal layer and while breeding for it appears to bring out more and more orange, it is apparent that it is the reduction of black chromatophores that allows the orange to become more apparent. Those areas of the fish which respond to hormones such as the fronz of the head and the tip of the spines show the most darkening when the sexual stimulation or dominance is present and so pregnant females ready to lay eggs or who has already laid them or has fry that have left her mouth to feed on or near the bottom. This darkening of the chromatophores in response to the sexual chemicals gives her a fierce appearance as she defends the area of the pond or tank where her fry are swimming. A mother tilapia with these markings on her head will attack any fish or other creature that happens to swim near the area they occupy. It is pure speculation as to whether the darkening is presented as a way of making her more fierce when defending her territory
The chromatophores which darken by moving already made melanon into them are also very common in the Red Red and Red Butterball tilapia, but in the case of the Red tilapia which show a lot of red the chemical moved into the chromatophore is red instead of black and is most probably a precurser to melanin
The red tilapias like the black tilapias are able to move the dark colored chemicals into their chromatophores in response to darkening in the tank or landscape where they are kept so that if you want your fish to be very light or whiteish you can keep them in a white bucket, box or container for 30 to 40 minutes and they will lighten up considerabley. If you want them to try to match a dark color which means turning black if they have melanon in their skin or darker red if they have the red pigment in their skin.
Much of the selection that I have done over the years is to first select in the red fish for a lack of melanin in their skin and then to select from the remaining fish the darkest and best distributed red pigmentation showing. |
