Young wild octopuses may form a 'fight club' and slap territorial fish if they get too close

New research reveals that young octopuses form "fight clubs" of sorts with certain territorial fish, slapping them as they defend their territory. The aggressive behavior is more complex than previously thought, according to the study published in the journal Behavioural Processes. Scientists observed 101 interactions between juvenile Brazilian reef octopuses and 10 species of reef fish along the northeastern coast of Brazil and on oceanic islands.

The octopuses reacted differently to territorial and nonterritorial fish. They slaps and flinched in response to territorial fish, while nonterritorial fish elicited longer, less confrontational encounters as the octopuses continued foraging. The researchers noted that octopuses displayed a "half-blotch" pattern on their skin when interacting with territorial fish, which seemed to deter the fish from attacking. This adaptive behavior highlights the complexities of octopus-fish interactions.