Are not manatees. Yet they have a similarity. Just as manatees do not appear on this blog, for about half the population, a gorilla does not appear in this video.
This just goes to show what Michael Oakeshott pointed out many years ago: when we enter into a practical endeavor, we define ends and means. When we do this, we filter what we experience. All that exists for us are basketball players and a bouncing ball of which we can count its passes.
Hence the power of philosophy: we see what we don't look for.