As time passed, the researchers gathered samples from the same shark more than once, and the sharks seemed to remember the encounters fondly—they began slowing their swimming rate when the researchers approached, and in some cases, stopped swimming altogether, making it easier for the researchers to do their work. They suggest that removal of the parasites reduces irritation and makes swimming more efficient.
Whale sharks found to slow down to allow researchers to scrape off parasites
How cute is that!