The entire article at Science Daily is well worth a read, so I encourage you to click this link and give it a go before proceeding. What follows is a short blurb, and the video they linked to.
The first video of tool use by a fish has been published in the journal Coral Reefs by Giacomo Bernardi, professor of ecology and evolutionary biology at the University of California, Santa Cruz.
In the video, an orange-dotted tuskfish digs a clam out of the sand, carries it over to a rock, and repeatedly throws the clam against the rock to crush it. Bernardi shot the video in Palau in 2009.
“What the movie shows is very interesting. The animal excavates sand to get the shell out, then swims for a long time to find an appropriate area where it can crack the shell,” Bernardi said. “It requires a lot of forward thinking, because there are a number of steps involved. For a fish, it’s a pretty big deal.”