A wondrous spectacle of nature began unfolding on March 6 at the Alaska SeaLife Center: LuLu, a Giant Pacific Octopus, has been tenderly guarding her brood of eggs, which she began laying in March 2012. Now, over a year later, tiny hatchlings known as paralarvae have begun to emerge, and the baby Octopuses are captivating visitors and staff.
LuLu laid eggs throughout the spring of 2012 after an encounter the previous fall with Felix, a male Giant Pacific Octopus. A female will lay up to 30,000 eggs only once in her lifetime, and she will brood and guard the eggs until they hatch. A male may mate with several females but will expire following this reproductive period. Lulu's lifespan will end when the last of her eggs hatch.
"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," said Richard Hocking, the Center’s aquarium curator.
While other Octopus species are frequently raised from eggs in aquariums, that is not the case with the Giant Pacific Octopus. Only once, in the mid-1980s, has a Giant Pacific Octopus been successfully reared from egg to maturity in an aquarium. Giant Pacific Octopuses are difficult to rear due to the delicate nature of the newly-emerged paralarvae and their unique nutritional needs. To increase the odds of raising the hatchlings to adulthood, aquarium staff are harvesting both wild and cultured zooplankton to feed the paralarval Octopuses and have also constructed special rearing tanks.
In the wild, the tiny hatchlings, which are about the size of a grain of rice, swim toward the ocean surface and can spend several weeks or even months drifting in the plankton-rich water until they are large enough to hunt in the depths. Once they settle to the bottom, juveniles take refuge in crevices and under rocks, where they are protected from predators while they feed and mature. Octopuses eat crustaceans and mollusks along with other bivalves, snails, fish and smaller Octopuses.
As adults, Giant Pacific Octopuses live in the cold waters of the northern Pacific Ocean off the coasts of Canada, Alaska, Japan, and Siberia at depths of over 200 feet (65 m). Adults attain an arm span of up to 14 feet (4.3 m) and weigh about 33 pounds (15 kg). They are considered the largest of all Octopus species. Little is known about these animals in the wild, so they are not protected by international treaties.