What shape do spirilla bacteria have?

Spirilla bacteria are characterized by their spiral shape, which resembles a corkscrew or twisted rod. This unique morphology allows them to move more effectively in liquid environments, as their shape aids in propulsion. The spiral form is a distinguishing feature that sets spirilla apart from other bacterial shapes, such as rods (bacilli) and spheres (cocci). Understanding bacterial shapes is essential in microbiology, as it helps in identification and diagnosis of bacterial species based on their structural characteristics. Therefore, spirilla distinctly refer to the spiral-shaped bacteria, making this choice the clear and accurate answer.