Valentine's Day octopus mating session canceled out of cannibalism concerns

The Seattle Aquarium cancelled its usual Valentine's Day spectacle – a public viewing of two giant Pacific octopuses mating – for fear that the encounter might take a dark turn.

The aquarium has held an Octopus Week in mid-February for the last decade, the highlight typically being a "blind date" featuring two cephalopods that have reached peak age and size for mating, Samantha Larson reported for Crosscut.

But this year, scientists at the aquarium are concerned that Kong, the male, who at 70 pounds is over twice the size of the largest female they could find from nearby Puget Sound, might be more interested in a snack than a lover.

“Even if we put a 30- or 45-pound female out there, there’s a chance he would see her as food,” Seattle Aquarium curator Tim Carpenter told the nonprofit Seattle news outlet Crosscut. “We were looking for an animal of at least 60, 65 pounds.”

The switch avoided the sort of public scene the aquarium experienced in 2006, when curators placed an octopus inside a tank with a shark. They expected the eight-armed bottom-dweller to stay hidden. Instead, it ate the shark.

The aquarium's octopus week will still feature octopus education through Feb. 21, although it kicked off with an alternate event, in which Kong swam with a human diver. Kong will be released back into Puget Sound later this week, KIRO TV reported.

Sexual cannibalism is common among most species of octopus, especially the large ones, although usually the danger goes the other way around, reported the BBC. Male octopuses are usually at greater risk of being strangled and eaten when they approach a female to mate.

"There's always the threat of cannibalism," Richard Ross of the California Academy of Science's Steinhart Aquarium told the BBC.

Regardless of whether the octopus had turned cannibal, had the event been held it would have likely been the last Valentine's Day for both animals. Octopuses, typically solitary creatures, are terminal breeders, meaning the male grows to peak size at age 3 or 4, then dies shortly after mating, while the female lives just long enough to see her eggs hatch.

Still, new research indicates the aquarium might have had some warning about the octopus's intentions. Octopuses in Australia changed color when they met, and scientists observed they turned dark before attacking and pale before fleeing, according to a study published in January in the journal Current Biology.

But even a color-coded alert system would not provide enough assurance for biologists, who noted that, for cephalopods and humans alike, love can be fickle. 

“A blind date is a blind date," Carpenter told Crosscut. "You never know how it’s going to go."