Except when they have recently molted and have still-soft shells, Blue Crabs are very aggressive when threatened, although they will also burrow into sand to hide (Gosner 1978; Pollock 1998).
Baldwin and Johnsen (2009) investigated mate choice in Blue Crabs, carrying out mate choice experiments using males and manipulated photographs of females. Their results indicated that courtship and mate choice behavior in Blue Crabs can be stimulated by visual cues alone. Males showed a preference for females with red claw dactyls ("pincers"). In binary choice experiments, males displayed more often to photographs of females with red claws than to those with white claws or black claws, strongly suggesting that these male crabs made their choices based on the hue of the red claws and, more broadly, that Blue Crabs are capable of color vision and use color in mate choice.
No one has provided updates yet.