I asked because having some idea of a shark’s visual system would be useful in deciding what does and doesn’t look like a seal to them, aside from silhouettes, motion, and brightness patterns.
I hope these Biologists realize there are other considerations besides shape and color involved in a fish attacking and eating prey.
For example our well known striped bass senses that if it is in the ocean, and moving, it is edible, regardless of its shape or color.
Therefore the striper eats herring, lobsters, crabs, eels, etc. which have radically different shapes and colors and behavior. They will also grab just about any fishing lure moving through the water, depending on its SIZE.
Figuring out what motivates an ocean species can be complicated for us land based animals. -Tom