Octopuses are among the smartest marine animals. These intelligent cephalopods are known for using coconut shells as mobile homes and armor and changing colors on demand to evade predators. A new study by researchers at Germany's Max Planck Institute of Animal Behavior found that octopuses can also be strong leaders. They take charge of hunting packs and even discipline those who try to cheat.
The team, led by Dr. Eduardo Sampaio, collected over 120 hours of underwater footage of 13 hunting groups in the Red Sea. Each group comprised a big blue octopus (Octopus cyanea) and a group of fish. They observed that as the hunting group moved, the fish swarmed around the octopus, seemingly suggesting different directions. The octopus would then choose where to go.
“The octopus was the one stopping them from moving," Dr. Sampaio said.
The fish explored coral crevices and led the octopus to potential prey by hovering over the area or moving between the crevice and the octopus. The octopus would then cover the crevice with its body to trap the prey and grab it with one of its arms. Any prey that managed to escape would be instantly devoured by the waiting fish. The cephalopods teamed up with various fish species. However, they appeared to favor the blue goatfish, likely due to its strong team hunting skills.
On some occasions, the researchers noticed blacktip groupers hovering around the group, hoping to catch easy prey without doing any work. In these cases, the octopus would deliver a "punch," sending the fish scurrying away.
“The ones that get more punched are the main exploiters of the group. These are the ambush predators, the ones that don’t move, don’t look for prey,” Dr. Sampaio said.
The team published their findings in the journal Nature on September 23, 2024. They believe the hunting arrangement benefits both parties. The fish gain access to prey hidden in crevices that only the octopus can reach. The octopus can follow the fish to food, saving the effort of searching on its own.
However, the scientists still have some unanswered questions they hope to explore in future studies. For instance, they are unsure if the octopuses team up with the same individual fish each time or if they partner with any blue goatfish they encounter.
“Does this octopus like to hunt with blue goatfish generally, or does it really want to hunt with Martha, who is a good hunter, and not Steve, who is lazy?” Dr. Sampaio said.
Resources: Smithsonianmag.com, NBCnews.com, Livescience.com
