Is the deep ocean fish look ugly because due to darkness there is no visual sexual selection? If so, is there a common notion of beauty between humans and animals?
closed as primarily opinion-based by De Novo supports GoFundMonica, theforestecologist♦, WYSIWYG Mar 4 at 9:23
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I suspect the deep ocean fish look ugly to you because they are unfamiliar. The iconic fish species with which humans have coexisted forever are all surface fish, with common adaptations for surface living in the light. When one thinks of a fish the salmon or cod is what we think of.
The deep fish have different selection pressures. They do not need to be streamlined or svelte. A deep fish might think a surface fish is ugly because it cannot make its own light - how plain and dull. How can the surface worlders find a good mate if everyone is dark?