Fish pigmentation. A key issue for the sustainable development of fish farming

Abstract

Pigment pattern defects are one of the leading causes of performance loss in aquaculture. Thus, despite the improved methodologies for farming of marine and fresh water fish species, there is still a high incidence of larvae with pigmentation abnormalities. The reason for the relatively high incidence of color abnormalities is unknown but is probably the result of complex interactions between genetic and environmental factors. Nevertheless, and in spite of the importance of the problem, there is scanty information about the pigmentation pattern development in aquaculture fish species, which makes the control of this problem difficult. In mammals, the pigment pattern is mainly dependent on the type of melanin that is synthesized and on the shape of melanocyte. However, in fish the pigment patterns result by the combination and patterned distribution of different pigment cell types, each expressing chemically distinct pigment. Thus showing that the cellular basis for pigment pattern formation is different in the two groups. Therefore, better understanding of the molecular regulation of pigment pattern development and pigment abnormalities in fish will lead to new approaches to increase the efficiency of fish farming by reducing pigment anomalies in aquaculture. This chapter will summarize the current state of knowledge of the processes through which fish coloration is produced and controlled. We will summarize the available data, guiding the reader through the cellular and molecular determinants of fish pigmentation. We will also explore the current research of pigment abnormalities observed in fish species and the possible reasons of their high prevalence in commercial fish farming.