Fish scales are calcified structures present in skin which have a protective function but which are also implicated in calcium homeostasis. Information about the molecular and cellular organisation of scales and the endocrine factors which regulate their turnover is scarce. In the present study as a first step to studying the influence of hormones on scale metabolism we aimed to characterize elasmoid scales from the sea bream (Sparus auratus), the dynamics of scale regeneration and the possible regulation of this process by calcium availability. Regenerating scales were evident 7 days after their removal in fish maintained in seawater (SW) and brackish water (BW). In BW, the activity of enzymes involved in scale turnover, tartrate resistant acid phosphatase (TRAP) and alkaline phosphatase (ALP), increased indicating active remodelling. The higher activity of TRAP compared to ALP suggests that the reduced calcium availability in BW led to calcium mobilization from the scales. The results suggest that the scales can be used as a regulated reservoir of calcium in this fish.info:eu-repo/semantics/publishedVersio
