Diversity in Micromineral Distribution Within the Body of Ornamental Fish Species

This study was conducted to compare micromineral homeostasis across ornamental fish species. Ten different species (n = 3, total = 30) of live ornamental fish were randomly sampled from one big aquarium in a pet store in Belgium. All fish samples were dissected manually for the collection of targeted tissues. The tissue samples were ashed by microwave oven, and the extract was analyzed for copper (Cu), iron (Fe), and Zinc (Zn) by inductively coupled plasma mass spectrometry. Fe was associated with Cu in muscle tissue (p < 0.05), but neither of them were associated with Zn in the muscle. However, the three micromineral concentrations were correlated in the heart (p < 0.05). Similarly, all of them were correlated in the liver (p < 0.05), but none of them showed a significant association in the tail fin. Excess deposition of minerals in heart tissue is a new observation, and it is not known if this is meant as storage or rather the fish heart has a high requirement for microminerals. Storage in the tail fin should be interpreted as a sign of permanent deposition as a tool to dispose off toxic excess. The lack of correlation between the muscular concentrations of Zn on the one hand, and those of Fe and Cu on the other hand, further suggests that fish species distinctly differ in their micromineral metabolism. Although this exploratory study still leaves many questions unanswered, it points to the large diversity in micromineral metabolism among fish species.