{"id":33488,"date":"2020-12-30T00:05:11","date_gmt":"2020-12-30T08:05:11","guid":{"rendered":"https:\/\/hakaimagazine.com\/?post_type=custom_news&p=33488"},"modified":"2022-01-26T11:11:25","modified_gmt":"2022-01-26T19:11:25","slug":"octopuses-are-eight-armed-taskmasters","status":"publish","type":"custom_news","link":"https:\/\/hakaimagazine.com\/news\/octopuses-are-eight-armed-taskmasters\/","title":{"rendered":"Octopuses Are Eight-Armed Taskmasters"},"content":{"rendered":"

Even a crafty hunter like an octopus sometimes needs help. On tropical coral reefs around the world, the day octopus<\/a> scours the seafloor in search of tiny mollusks and crustaceans that hide within calcified crevices. But every so often, this prey eludes the octopus\u2019s many-armed grasp. Unfortunately for the fleeing prey, groups of fishes\u2014sometimes four or five different species\u2014might be lying in wait, ready to cut off its escape and leaving it within the octopus\u2019s reach.<\/p>\n

For the octopus and the fish, it may seem like harmonious cooperation. But on this team, everyone plays an important part and must invest effort in capturing prey. If a fish joins the group and doesn\u2019t pull its weight, the octopus can eject it from the group with a swift punch.<\/p>\n

According to Eduardo Sampaio, a doctoral candidate at the University of Lisbon in Portugal and lead author on a new study documenting the behavior<\/a>, there are a number of reasons an octopus might throw hands, from keeping its hunting partners in line to ejecting a parasitic group member.<\/p>\n

Goatfish, for example, are active hunters that create prey opportunities for the octopus and the rest of the group, while blacktip grouper are ambush predators that hide and wait for prey to pass by. Sampaio says the octopus might view the goatfish as a collaborator, while viewing the blacktip grouper as a competitor that needs to be ejected.<\/p>\n

\u201cThese hunting groups are complex. Every member has a different hunting strategy and a different level of investment,\u201d says Sampaio. \u201cIn a situation like this, we would expect partner control mechanisms to evolve to help ensure a more fair distribution of payoff.\u201d<\/p>\n

To record octopuses\u2019 outbursts, Sampaio and his collaborators followed hunting groups with underwater camera rigs capable of capturing a three-dimensional view of the reef and the positions of the animals within it.<\/p>\n