OBSERVATION
The scientific method starts with careful observation. A scientist might observe any aspect of living organisms or investigate observations from the publications of other scientists. But always, the process of the scientific method begins with observation.

What observations can you make about this situation? Some possible observations include:

The shrimp is associated with the algae.
The shrimp seems to be eating the algae.
The algae are green.
The shrimp is green.
The shrimp and the algae are similar in color.

Many other valid and appropriate observations are not listed. For this example, we will use the observation:

The shrimp and algae are similar in color.