Thousands of giant Pacific octopus eggs, laid more than a year ago, began hatching this spring at the Alaska SeaLife Center in Seward, facing a future with the odds overwhelmingly stacked against life. If a single hatchling survives to adulthood, it will be historic.
Aquarists at the center who've embraced the difficult task attempting to raise the young octopuses know the odds. Only once has a giant Pacific octopus been successfully reared from egg to maturity in an aquarium.
The diva at the center of the drama at the SeaLife Center’s "Denizens of the Deep" exhibit is named Lulu, a giant Pacific octopus. Lulu's kind can grow larger and live longer than any other species of octopus, averaging 16 feet across and weighing 110 pounds. According to National Geographic, the largest known giant Pacific octopus was a 30-foot-long specimen that weighed more than 600 pounds.
Lulu has guarded her clutch of eggs, numbering in the tens of thousands, since she began laying them in March 2012 after mating with Felix, a male giant Pacific octopus at the center. Tiny hatchlings known as paralarvae began emerging a year later, according to the center.
So far, about 400 eggs have hatched, said the center’s aquarium curator Richard Hocking. Some of the hatched octopuses from the group died, but a lot more have survived than not, he said. Hocking expects all the eggs to hatch by the end of May.
Babies are about a quarter-inch long, and already resemble their parents. They have eight tiny arms with accompanying suckers, and they swim by jet propulsion. Their eyes already are well developed. For now, they’re floating at the water surface eating. Once they grow to about a centimeter, they'll settle on the bottom of their marine environment. In the wild, upon settling, they would take refuge in crevices and under rocks and continue to feed and mature.
As the last of the eggs matures, Lulu will die. Both females and males die shortly after breeding. She’s proven to be an active mother. “Lulu is not feeding at this time but continues to groom and fan the eggs as attentive octopus mothers do in this final reproductive phase of their lives,” Hocking said in a press release.
Now 5 years old, Lulu is reaching the end of her life. Pacific octopuses don’t live much longer than half a decade, and Lulu has spent most of her life at the center. A researcher found Lulu in Prince William Sound in 2009 and donated her to the center. Back then, she was no larger than a tennis ball, Hocking said in an interview Friday.
While a female giant Pacific octopus only lays eggs once in her life, that effort can produce more than 30,000. On the other hand, males may mate with several females, but they also die several months after this reproductive period.
Other octopus species often are raised from eggs in aquariums across the globe -- but not giant Pacific octopuses. There’s a single documented case of the marine animal being successfully reared from an egg to maturity in an aquarium setting, which happened in the mid-1980s, according to the center.
The baby octopuses are difficult to raise because they’re very delicate after hatching and have specific nutritional demands. The center’s aquarists took several steps to increase their chances of survival, including harvesting wild and cultured zooplankton to feed the babies. “Rearing tanks” have also been constructed.
For many species in the wild, Hocking said, a 1-percent survival rate is the benchmark. The center estimates Lulu laid more than 30,000 eggs, so if 1 percent of her babies survive, they’re in great shape with 300 vital offspring, he said.
In 2004 and 2005, an attempt at raising octopus at the center failed, when all the Pacific octopus’s hatchlings all died after several months of care. The mother, Aurora, spent months attending to her eggs until they hatched. She stopped eating for weeks and her health deteriorated quickly. She was euthanized out of concern for her comfort. At the time of her death, two dozen baby octopuses were alive.
Hocking said he's not concerned with beating any record of raising octopuses in an aquarium, but rather is captivated by the wonder of raising the animals.
Besides LuLu and her offspring, the center houses six other octopuses, all the same species.
Visitors can see LuLu and her newly-hatched offspring swimming in the Denizens of the Deep tank -- and some of the hatchlings also can be viewed in a special display near the Discovery Touch Pool.
Jerzy Shedlock can be reached at jerzy(at)alaskadispatch.com