Great work. You’ve done a precise job of narrowing down your color pallet and taking advantage of the compositional simplicity of the shot. The 4 edges of the photograph are clean and clear of any distractions. The ripples in the water also add an interesting element because they create color gradients and shading in the water. This helps the image from appearing flat and lifeless. The positioning of the alligator is also very well done.
This assignment asked you to simplify the colors of a photograph and you’ve done a great job of that. The only issue I want to draw your attention to is the fact that your focus is slightly off. With portraits as well as animal photography the focus should always be on the subjects eyes. This really helps add a dramatic feel to the photograph. It gives the audience the feeling of looking at the person or animal in real life. Focusing on the eyes really brings the image to life.
However, in your photograph the eyes are slightly out of focus. It’s a small detail that isn’t noticeable until the image is enlarged, but it’s noticeable nonetheless. I bring this up because it is these small details that prohibit photographs from being great rather than good.
For example look at the following photograph of the eyes of a crocodile