Fig. 3

Fig. 3

Mineralogenic effect on the operculum of 6-dpf zebrafish larvae exposed to Skeletonema costatum (SKLT) and Tetraselmis striata CTP4 (CTP4) extracts. A Composite image of a 6 dpf zebrafish larva, where operculum area (OpA) and head area (HA) are highlighted with a continuous line and a dashed line, respectively, and where AR-S stained mineralized structures detected by fluorescence microscopy appear in red. B, C Effects of SKLT (B) and CTP4 (C) on the operculum area. Values are presented as mean ± standard error and as a percentage over the negative control (Ethanol) (n > 15). The picture panels on the right side of each graph present images of opercular bones from negative and positive (calcitriol) control fish and fish exposed to the higher concentration of each extract. Normality was tested though Anderson–Darling test (p < 0.05). Asterisks indicate values significantly different according to one-way ANOVA followed by post hoc Dunnett’s or Kruskal–Wallis test. Each experimental group was tested against the negative control group (Ethanol). p < 0.0002 (***) and p < 0.0001 (****)