Abstract:
Attractive colouration of ornamental fishes is an important quality criterion in the
aquarium fish industry. Ornamental fish cannot synthesize colour-producing carotenoid
pigments and therefore must rely on dietary carotenoids in natural or synthetic forms to
achieve their colour pigmentations. The aim of this review is to compile and summarize
recent investigations into different carotenoid sources used in ornamental fish feed
formulations and to highlight the research gaps and investigation needs in the field of
aquaculture. The natural carotenoid sources which have been widely used for enhancing
colouration are non-photosynthetic organs of higher plants, microalgae, seaweeds, crus tacean by-products, and red yeast. Consumers mostly prefer to use natural sources rather
than synthetic sources. The problem faced by aquaculturists is stabilization of the gained
skin colour after terminating feeding of the fish. Advanced investigations are needed to
identify the stability of the colouration in the ornamental fish during their life cycle.
Further, this review encourages the use of other available natural carotenoid sources in the
ornamental fish industry in order to reduce the use of synthetic pigment products and
invites research to be done on a genetic level in order to fully understand colour
distribution patterns and sustainability of colouration gain.
