Female octopuses will chuck seashells at males who irk them

Female octopuses will chuck seashells at males who irk them

Having eight arms can make it possible to have some exciting sporting events (just look at the bizarre history of octopus wrestling ).). But, if the idea of battling it out with a 100-pound, multi-armed sea beast wasn’t scary enough, imagine having eight arms throwing seashells at you. The study, published in the open-access journal PLOS , shows that octopuses intentionally throw debris like silt and shells at other octopuses for the first time.

In 2015 and 2016, the team of scientists from Australia and the United States used underwater cameras to record the behavior of the gloomy octopus (Octopus tetricus) in Jervis Bay in southeastern Australia. The bay is home the world’s whitest sand on it beaches , Australia’s smallest penguin species, fairy Penguins , marine mammals, and a lot more cephalopods.

“Our study was prompted by the unusually high number of octopuses in this area,” said David Scheel, a professor of marine biology at Alaska Pacific University. PopSci. “Interactions between octopuses are very common when there are many animals present. This location offers the rare opportunity to study behaviors other than mating.

The team looked at 24 hours of footage from several days and found 102 instances of debris throwing activity in a group of about 10 octopuses. It was not always possible to identify the individual assailants.

[Related: Slap another cephalopod on the vampire squid’s family tree. ]

After the octopuses had collected silt from the ocean floor or shells, they released the projectiles by using a tube-shaped structure that is above its legs and that can eject water. The siphon was used for propelling the material through the water between their eight arms.

The projectiles were often thrown a long distance from the body. To do this, the octopuses needed to move their siphon to an unusual position. This difficulty indicates that their throwing behavior was not consistent with what is required for their general movements in water.

” The throwing of objects that have been directed by the thrower, Scheel states, is a rare animal behaviour. “Doing this under water, even for a short distance, seems especially unusual and quite hard to do, making this an even more striking behavior.”

YouTube video

The octopus returned from a foraging trip 18 minutes earlier and assumed a characteristic feeding posture. As the throw is made, another octopus approaches her and they touch as the shells fall. Despite the reach, the context of this throw was scored as Eating. The pattern was described as mottled and the vigor was high. CREDIT: Godfrey-Smith et al., 2022, PLOS ONE, CC-BY 4.0.

While both males and females were observed throwing, 66 percent of throws were made by females. The throws were almost all made in or near interactions with other octopuses such as arm probes and mating attempts. About 17 percent of throws observed hit other octopuses, which isn’t too bad for an animal that lives under water and lacks opposable thumbs or rotator cuffs.

In addition to their cool tentacles, octopuses can change their skin coloration, with dark colors generally associated with aggression. The team discovered that octopuses with darker skin tones could throw more forcefully, and are more likely to strike another octopus.

[Related: Argonaut octopuses are enigmatic–down to their self-made ‘shells.’]

But octopuses that were hit by thrown material weren’t completely helpless. They would often alter their behavior to duck or raise their arms in the direction the thrower is sending.

” To our knowledge, throwing by octopuses was not reported before. Therefore, to discover them throwing at other species of octopuses, is new. Octopuses are usually solitary animals. Scheel says that this is another way they try to interact with one another.”

Although it is hard to know the exact purpose of the shell chucking, the observations suggest that some octopuses can target other individuals under certain circumstances. This is a complicated behavior that has only been observed previously in some non-human animals like chimpanzees, capuchin monkeys, elephants, and birds.

“Wild octopuses project various kinds of material through the water in jet-propelled ‘throws,’ and these throws sometimes hit other octopuses,” the authors said in a joint statement. “Some evidence suggests that some throws that hit others may be targeted and play a social function .”

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