To an orca, a sunfish is a bit like a watermelon: a nutritious, watery snack, but hard to swallow whole. Also like watermelons, sunfish (also called mola) don’t bite back. This makes them the ideal “training prey” for juvenile orcas, according to New Zealand orca scientist Ingrid Visser.
In the first-ever review of orca-sunfish interactions, Visser, along with sunfish researcher Marianne Nyegaard and orca researcher London Fletcher, found several instances of juvenile-parent orca pairs hunting sunfish.
About 40 per cent of the dozens of photos, videos and oral accounts they analysed didn’t appear to be about predation, but simply entertainment. Orcas flung sunfish like frisbees, pushed them around underwater, and balanced them on noses in what Visser calls a “mola moustache”.
The researchers also found records of orcas extracting a meal of intestinal spaghetti: “It’s like they’ve got a string of sausages in their mouth, pulling them out of the sunfish, which is often still alive and swimming around,” says Visser. “They split the sunfish up like a taco or a pita bread… stick their faces in, and eat the insides out.”
One underwater video filmed in New Zealand reveals that sunfish are quick on their fins despite their dinnerplate anatomy. “We thought the orca were pushing the sunfish upside down,” says Nyegaard, “but the mola was thrashing and spinning in crazy manoeuvres all by itself. I thought, ‘What the hell is it doing?!’”
The sunfish was attempting to evade the orca by using a suite of sneaky moves, including spinning rapidly, breaching, flipping upside down, or positioning itself with its rigid backside towards the orca’s mouth.
“People thought sunfish were just great big blobs and that mola design was cumbersome, but this adds further proof that they’re actually quite good at swimming,” says Visser. “They can breach, their cruise and boost speeds are impressive, and this is more recognition of their agility.”