of little importance; trivial.
"the petty divisions of party politics"
synonyms: trivial, trifling, minor, small, unimportant, insignificant, inconsequential, inconsiderable, negligible, paltry, footling, pettifogging; More
of secondary or lesser importance, rank, or scale; minor.
"a petty official"
Sharks have eyelids, but they do not blink because the surrounding water cleans their eyes. To protect their eyes some species have nictitating membranes. This membrane covers the eyes while hunting and when the shark is being attacked.