During an expedition off the coast of Costa Rica, some explorers captured beautiful images of a female squid floating in the water column using an ROV. her hands were wrapped around many eggswearing what looked like a huge black cloak.
The octopus in question belonged to a species Gonatus onyx, also known to experts as the black-eyed octopus due to the intense color of its irises. In connection with the squid, the female of this species never separates from the eggs after spawning and they can fast for monthsin order to guarantee their children a better chance of survival, away from predators.
This observation was made by oceanographers from Schmidt Ocean Institute, a private research organization dedicated to spreading the hidden beauty and ecological value of the deep sea. The scientists were still busy calibrating their instruments when they were lucky enough to record a few minutes of this encounter with G. onyx, explains the organization during a recent mission OctoOdyssey.
The scientists had to observe the octopus for some time before they understood what they had in front of them, namely that the huge shell actually hides up to 3000 eggswhich the animal protected and transported, in the cold waters of the ocean depths.
It is one of the two species of octopus present in the world that does not leave its eggs after the mating season and that ends a great sacrificetrying to protect them at all costs. In fact, the developmental period of embryos of this species is estimated to be between 6 and 9 months. Woman from G. onyx therefore, theoretically, they have to spend half a year accumulating resources to produce this huge amount of eggs, but also to survive during a long fast.
The “shell” to which the female attaches herself and in which the eggs are attached is actually a tube-shaped gelatinous box produced by the squid itself. It has holes at both ends and has a viscous consistency so that the eggs do not escape the mother’s control. from his side, a female swimming backwards gently extends and retracts her arms, in such a way that the water, already poor in oxygen at certain depths, flows through the gelatinous mass of the eggs.
Second Brad Seibelmarine biologistUniversity of South Florida, this species also has another peculiarity: since it is impossible for the octopus to maintain its strength, after months spent protecting the eggs, when they are about to hatch, the female is slower and subject to risks, becoming the target of many other species. In order to free itself from the threat, the octopus will therefore have to make more violent arm movements, which on the one hand contribute to the hatching of the eggs, on the other destroy the gelatinous box that helped protect them.
«This means that after months of development, only the most developed embryos can survive the birth and the stimuli coming from the mother», explains the scientist who in 2005 collaborated on the creation of a scientific article published in Naturewhich dealt with the topic.
The researchers also observed how the months of fasting and effort spent protecting the eggs lead to a gradual decline in the muscle condition and digestive glands of these octopuses, suggesting that they actually rely entirely on their energy reserves during hatching. But what are the consequences of this extreme sacrifice?
In general, octopuses breed only once in their lifetime, and both sexes die shortly after breeding, before the young are born. However, females of this species live longer and are able to see the birth of their babies. However, we should not imagine that they live long. A few days after all the eggs hatch, after the stress reported in previous months, they also die or are prey.
Black-eyed octopuses are one of the most common cephalopods living in the Pacific, from the coast of Japan to California, from the height of the Bering Sea to the warm waters of the equator. Adults have a mantle of 18 centimeters and prefer deeper waters, up to 1,000 m deep.