Coloration in fish

Hi Prof
I would like to know what factors contribute to good fish coloration or variation (food,water or gentics ect) ?
For example rift valley cichlids vary on location in the lake and have distinct diffrences in coloration
I have also seen tank bred with better coloration than wild caught and
visa versa

 

Which species are you referring to as there are distinct differences?

Kind regards,

Dirk

 

coloration

Sorry
Tropheus species , Cyprichromis leptasoma and Mbuna varieties

 

OK,

I am not a boffin on Rift Valley Cichlids but I do know something about their colouration.

As far as I know, the only one of these cichlids that has been selected for better colour and in this instance I mean red colour is the peacock, called Aulanocara baenschii. So in this cichlid the colour enhancement is genetic.

Any red and yellow colours can additionally be anhanced by feeding natural colorants such as astaxanthin and cathaxanthin. This will be deposited in their tissues where they would show their colour. This is a temporary process and if you would stop feeding foods containing these substances then their colour would slowly but surely become less. These colourants are not detrimental and do not damage the fish and most fish foods contain them.

Bright brilliant blue colouration on Rift Valley Cichlids, but also on many other cichlids such as discus is brought about by testosterone. In nature, the dominant male fish will produce the most testosterone and have the most brilliant colours which in turn will attract females. Not all fishes will therefore always show these brilliant blues. This blue colour also only starts forming when the fishes start reaching sexual maturity, so young fishes should have less bright blue colours in general. Man is of course always greedy and wants to sell his products as a result of which fishes are often treated with testosterone, which is a steroid, in order to induce the brilliant colours. Particularly fishes coming from the East are often treated in this way. This treatment is however negative and can cause permanent damage to the reproductive system of the fish, and males can become sterile as a result. I would therefore be very careful with small brilliantly blue coloured Rift Valley Cichlids.

Kind regards,

Dirk

 

colouration

Thank's for the info :top: