Figure 3

Figure 3

Mineralisation levels of median fin structures after two months of dietary treatment. Pterygiophores or radials, endoskeletal structures supporting the dorsal (a) and anal (b) fins (black arrows), present reduced mineralisation levels in low P diet (LP) treated zebrafish, in comparison with controls (RP) and high P diet (HP) fed animals. Likewise, Alizarin red S staining shows impaired mineralisation of dorsal and anal fin rays in LP animals. Scale bar: 500 µm. (c) Analysis of pterygiophores and quantitative analysis of fin rays mineralisation levels. Pterygiophores mineralisation levels were qualitatively evaluated as low, intermediate or high depending on Alizarin red S distribution in the bone. Fin rays mineralisation levels were quantitatively analysed: low, more than two non-mineralised segments; intermediate, one or two non-mineralised segments; high: all segments mineralised. Chi squared or Fisher’s exact test, pairwise comparison, *: p < 0.05. (d) Caudal fin rays stained with Alizarin red S display reduced mineralisation in LP animals compared to RP and HP zebrafish. Scale bar: 500 µm.