Traditionally, octopuses (Order Octopoda) have been greatly feared among seafaring peoples. They have given rise to lots of mythological beings, such as the Akkorokamui of the Ainu people and the Kraken of Norse mythology. It is not for less, since these eight-armed animals have an extraterrestrial appearance, they are great predators and change color to camouflage themselves on the seabed.
However, these mollusks are admirable animals. They have a huge brain, great intelligence and a privileged memory. Their visual acuity is superior to ours and they can detect a large number of chemical substances through their skin. But have you ever wondered where these animals come from? How are octopuses born? We tell you everything in this article on our site.
Octopus reproduction
Before I tell you how octopuses are born, you should know very well how they reproduce. Most species reproduce only once in their lifetime[ 1] Therefore, they dedicate all their efforts to prepare for this moment. This strategy is known as semelparity and appears in many animals, such as salmon. The males die after copulation and the females when their young are born.
As for their type of reproduction, these molluscs only have sexual reproduction, that is, a new individual is only formed by union of two sex cells: an egg and a sperm. These come from a female octopus and a male octopus, respectively. Therefore, they are dioecious animals, that is, with the sexes separated (not hermaphrodites).
When the breeding season arrives, both sexes start looking for individuals of the opposite sex. They do this by following trails of chemicals or pheromones[2] Normally, several males find a lonely female, so they must compete with each other and show her who is the better: courtship begins.
Octopus courtship and copulation
The story of how octopuses are born begins with a fight. The male octopuses have a lot of competition and must fight with the other suitors. To do this, they stand on a high place, expand their body and change color, showing a series of drawings that are different in each species.
The males of the common Sydney octopus (Octopus tetricus) show the darkest color possible. The one with the lighter color loses and folds[3] For their part, the males of the algae octopus (Abdopus aculeatus) show black and white lines on their backs. This is a warning signal and if it doesn't work they can get hurt[4]
Therefore, the most competitive and fit male approaches the female, courting her. She can either accept it or reject it and wait for the next one. In the first case, she remains still and copulation begins. However, when the female is not receptive, fights between the sexes often break out. In Abdopus aculeatus, sexual cannibalism has even been documented[4], as female octopuses are usually larger than males.
Octopus copulation usually lasts one or several hours, although it is not a very elaborate process. One of the 8 arms of the octopus is actually a copulatory organ known as the hectocotyl. When the moment of copulation arrives, it introduces it into its internal cavity and takes a spermatophore (a structure that contains sperm). Subsequently, inserts his arm into the female, introducing the spermatophore.
In other types of mollusks, reproduction can be very different. If you want to know more, we recommend this other article on How mollusks reproduce.
Birth of the octopuses
After copulation, the female stores the sperm until the end of the reproductive season. This is because both sexes mate with multiple partners (polyandrygyny). Therefore, the female stores the sperm of several males, so that, when fertilization occurs, eggs from different fathers are formed [5]
Now that our female is full of eggs, she must find a good place to lay them. Normally, she does it in the holes or cavities that exist between rocks and corals. There, she places them one by one, hidden and attached to a surface. A clutch may contain between ten and several hundred eggs[ 5, 6]
Octopus eggs are usually elongated and soft, covered by a fine capsule. They measure only a few millimeters and are very fragile. For this reason, females usually guard and care for her eggsNormally, parental care lasts between 1 and 3 months, although there are exceptions. This is the case of the deep sea octopus (Graneledone boreopacifica), which lives in places so dark and cold that it must spend 53 months incubating its offspring[6]
A special case is that of the genus Argonauta, whose females make a shell in which they lay their eggs. They also hide under the shell, protecting them and giving them warmth until they hatch.
What are baby octopuses like?
When octopus eggs hatch, they hatch very small juveniles This is how octopuses hatch: they look very similar to adults, but with minuscule size. Like their parents, they are carnivorous animals and feed on other organisms even smaller than themselves.
Unlike what happens in other types of molluscs, baby octopuses are not larvae, since they do not undergo metamorphosis. However, they are known as paralarvae because they have a planktonic life They drift in seawater until they reach a suitable size to return to the bottom. In very few species, juveniles are benthic, that is, they live on the ocean floor like adults.
Now that you know how octopuses are born, you may be interested in knowing these 20 curiosities about octopuses based on scientific studies.
