Figure 3. Upper - Inverted microscope images of the different egg-developmental stages.

Stage 1 (morula, cleavage), Stage 2 (blastula, cleavage), Stage 3 (late gastrulation), Stage 4 (organogenesis); Lower - Embryonic development after 72 h, expressed as the percentage of the different stages at ambient conditions (amb., pH 8.), low pH (OA₁, pH 7.8), and extremely low pH (OA₂, pH 7.6). The eggs were incubated from females exposed to 0, 2 and 5 days of OA treatment (d0, d2 and d5 respectively).