Abstract

The increase in CO2 emissions produces heating and reduced pH in the oceans, which can have negatives effects on many marine organisms, in particular those with calcified structures (i.e. mollusk), affecting mainly their larval stages. We studded Strombus gigas, an important gastropod in the Caribbean sea, to known the influence of near-future predictions (ocean warming and acidification) over larval growth, their survival and calcification ratios. Larval culture was realized maintain constant temperature and pH (supplying CO2 continuously). We employing three treatments (Control = 28°C-pH 8.1, T1 = 28°C-pH 7.6, T2 = 31°C-pH 7.6) in triplicate. Growth (n = 30 larvae per age/treatment) and survival were evaluated in larvae of 0, 10, 20 and 30 days old. Calcification was evaluated in S. gigas larval shell from 0, 3, 10, 20 and 30* days old (*settlement) by EDX and RAMAN analysis. One-Way ANOVA (p(α0.05)) was realized to larval growth, survival and shell calcification. Treatment 2 showed higher values in growth rate over time (from 31.55 ± 18.84 to 23.73 ± 16.18μm; p (α0.05) < 0.0001). We observed a difference of 14.17% in survival rate between control and treatment 2 (p (α0.05) = 0.0148). Average calcium proportion was major in the control 35.10 ± 9.48% wt, without differences among treatments (p (α0.05) = 0.0875), moreover, the shell composition (aragonite and calcite) showed differences among treatments, where aragonite intensity (206 cm) was greater 858.07 ± 610.59a.u. at the control, and calcite (282 cm) was recorded only in the T2 with an average intensity of 457.63 ± 298.32a.u. Our results suggest that this specie could be adapted to warmer conditions, but the combination with an acidified environment could produce several issues in his composition and larval availability in future scenarios.

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