It's common knowledge that sea lions provide sustenance for large sharks, notably great white sharks and mako sharks.
The blubbery pinnipeds, so beloved by marine life observers, fall prey to sharks during ambush attacks that are violent and bloody.
But not so well known is that sea lions also are savage predators, and not shy about turning their aggression toward fairly large sharks.
On Monday off Newport Beach, Calif., passengers aboard a whale-watching boat watched in awe as a sea lion methodically devoured a 4-foot horn shark.
Capt. Ryan Lawler, of Newport Coastal Adventure, described the encounter to GrindTV:
"We were on a trip and looking for a gray whale that was supposed to be in the area. I saw some splashing which I knew wasn’t a whale or dolphin, but was big enough to catch my attention.
"Getting closer we saw a sea lion violently thrashing around some freshly caught prey. This is not too uncommon but we are always interested in what exactly it might be, as the sea lion’s diet varies widely.
"After I got a picture of predator and prey I realized it was a horn shark that was being eaten. While I have seen sea lions eat thresher sharks, angel sharks, and a variety of skates and rays this was the first horn shark, and a bit of a surprise because of the deeper water we were in (180 feet).
"And also keep in mind the horn shark has two defensive dorsal 'horns' to dissuade predators, so this sea lion was being pretty methodical about how it was eating this shark."
The scene was reminiscent of a prey event in the same general area in October 2015, when sea lions launched a frenzied and visible assault on thresher sharks.
That also was witnessed by whale watchers, who left with a greater understanding of critters known mostly for their docile demeanor and inquisitive nature around boaters.