Final answer:
The rod-shaped bacteria are called bacilli. They are one of the three main bacterial shapes, alongside cocci (spherical) and spirilli (spiral-shaped). The shape of bacteria is not dependent on their phylum.
Step-by-step explanation:
The type of bacteria that has a rod shape is called bacillus or bacilli in the plural form. Bacteria are broadly categorized based on their shapes into three main types: cocci (spherical), bacilli (rod-shaped), and spirilli (spiral-shaped). In a given field of view under a microscope, the proportion of bacterial cells that are bacilli can vary widely depending on the sample. Nevertheless, bacilli are a common shape for many bacterial species.
For example, Vibrio cholerae, the bacterium that causes cholera, is known for its characteristic curved rod shape, which is a variation of the bacillus form. When observing prokaryotic cells, it's important to note that the shape of the bacterium is not necessarily dependent on the phylum it belongs to; for instance, phyla like Chlamydia, Spirochetes, Cyanobacteria, and Gram-positive bacteria can contain species that are cocci, bacilli, or spirilli.