Honolulu Star-Advertiser © Susan Scott
March 17, 2006
One of my favorite recent e-mails comes from Joe, a reader in Ireland who writes that he’s been reading my column for a long time.
“There should be more Web sites like this that appreciate the ocean just for its beauty, not what mankind can exploit from it,” he wrote.
It made my day to know people so far from Hawaii read my columns. Joe also asked a good question (I really like this guy).
“I have long been fascinated by moray eels and their intriguing behavior, especially knotting to take down large prey,” he wrote. “My question is, Have you or anyone you know ever seen a moray knotting in the wild? I am just curious to know how they do it. Are they quick? Slow? Bloody?”
I’ve not seen a moray eel tie itself in knots and don’t know how fast they do it. I do, however, have a reliable fish book in which the author describes it.
Moray eels sometimes catch fish that seem too big for them to swallow. But because most morays have wide jaw gapes and large mouth cavities, they manage large prey pretty well.
Usually, the eel snags a fish with its sharp, backward-leaning teeth. The eel then turns the prey in its mouth to aim it down the throat head first. This way, the prey’s fins lie flat and it goes down smoothly. Tail-first swallowing would cause the prey’s sharp fin spines to stick up and poke the moray’s mouth.
But sometimes even big-mouthed morays bite off more than they can chew. In these cases, some species resort to a behavior called knotting.
With its tail, the eel forms two loops around its body and then yanks its head backward through the tight knot. In this way, the eel can either tear a piece of flesh off its impaled prey, therefore killing it, or flatten the prey’s body enough to swallow.
When a moray eel rips a chunk of flesh from a live fish, I imagine blood would flow.
Occasionally, an eel will hold a prey caught in its teeth inside the body knot for some time, as if to squash it small.
The author uses the word “rapidly” to describe the eel’s backward head movement but doesn’t say anything about how fast the eel ties itself in knots. Since the moray has a too-large, struggling fish in its mouth at the time, I would guess it goes about forming the knot quickly.
Joe also wants to know if other fish families knot themselves, and the answer is yes. Hagfish draw themselves through self-made knots to rid themselves of slime, abundant among these scavengers.
I don’t know anyone who has seen a moray tie itself in knots, nor is this behavior mentioned in my local fish books. This makes me think knotting among moray eels is quite rare or at least rarely seen. If I do see it, however, believe me, you’ll read about it here.
It was a long time ago that I asked Star-Bulletin editors to let me try writing some upbeat stories about marine animals. Who would have known that 19 years later, people in Ireland would be reading and appreciating that positive approach?
Thanks, Joe, for letting us know.