Which knife is specifically used for cutting a grapefruit?

The knife specifically used for cutting a grapefruit is the grapefruit knife. This specialized knife is designed with a serrated edge to easily slice through the tough skin and segments of the grapefruit without crushing the fruit itself. It often features a curved blade that helps to navigate the fruit's shape, making it easier to cut and serve.

Using a grapefruit knife makes the process efficient and reduces the risk of injury, as it is specifically designed for this task, unlike the other types of knives mentioned. A chef’s knife is versatile for many chopping and slicing tasks but lacks the specific design needed for a grapefruit. A paring knife is more suited for small tasks like peeling or creating decorative cuts, while a fillet knife is designed for fish and delicate filleting tasks. Therefore, the grapefruit knife stands out as the most appropriate choice for handling grapefruit.