This data table contains embryo-larval development data from 24 h (24°C) and 48 (18°C) controlled laboratory toxicity experiments with oyster embryo (Crassostrea gigas) conducted at 18 °C and 24 °C. Embryos were exposed to nominal concentrations of copper (Cu), zinc (Zn), cadmium (Cd), and lead (Pb) in 24-well plates. Larval malformation was quantified as the number of normal and abnormal shell development per batch and replicate after 24 h (24°C) and 48 h (18°C).

The laboratory experiments were conducted at Plateforme expérimentale de Bouin IFREMER (Latitude: 46.9642, Longitude: -2.0444) from 2024-02-15T12:00:00Z to 2024-04-15T12:00:00Z. Broodstock of Crassostrea gigas originated from the IFREMER Argenton station (Brittany, France). The oysters were transferred to IFREMER Bouin, where they were held under controlled conditions in the facility prior to the experiments. Before the start of the experiments, broodstock were maintained at 8 °C from November 2023 until January/February 2024 to reset the reproductive cycle, followed by a gradual temperature increase and feeding (Skeletonema marinoi) to initiate conditioning.