Oyster shell hardness from study of eastern oysters (Crassostrea virginica) grown in a nursery with or without exposure to chemical cues from blue crabs

This dataset is associated with the study "Eastern oysters alter inducible defense mechanism of shell strengthening with age". This study tested which mechanism, hardness or thickness, juvenile eastern oysters use to strengthen their shells in response to chemical cues from predators. Data was collected from eastern oysters, Crassostrea virginica, grown in a nursery in Dauphin Island, Alabama, USA with or without exposure to chemical cues from blue crabs, Callinectes sapidus. Two age groups (four-week and eight-week-old post-settlement) of juveniles were included in this study. Oyster shells were tested for shell hardness within both shell layers. Measurements include the Vickers hardness values of foliated and prismatic oyster shell layers, as well as the number and length of cracks resulting from hardness tests.