Abstract
The carotenoids in the integuments, eggs and diet of three species of Tilapia (Tilapia nilotica, Tilapia mossambica and red Tilapia) were investigated.
The carotenoid patterns in the integuments of three species were quite similar and the following carotenoids were found; β-carotelle, cryptoxanthin, tunaxanthin A, lutein, calthax-anthin (3'-epilutein), zeaxanthin, diatoxanthin, cynthiaxanthin, triol, astacene, doradecin and rhodoxanthin.
Isolation of an unusual retro carotenoid, rhodoxanthin, C40H50O2, mp. 211-212°C, from Tilapia is the first example from animal kingdom.
In spite of being a fresh-water fish, Tilapia belonging to the division percichthyes contained tunaxanthin which is very common and dominant carotenoid in marine fishes. The fact described above supports the assumption proposed by the authors that tunaxanthin might be a chemical indicator in the division percichthyes.
The caroteoid patterns in the integuments of three spccics of Tilapia were very similar, but it was found that percentage compositions of individual carotenoids depend upon the stage of growth of fishes.
Lutein (35-45%) and zeaxanthin (34-44%) were found from eggs of Tilapia nilotica in free forms as major carotenoids.
β-carotene (23.4%), 1utein (615%) and zeaxanthin (5.4%) were fbund from their diet.
