The communication methods of cephalopods like octopuses and squids

Cuttlefish adjust skin texture, like raising papillae, to enhance signals, per a 2009 Philosophical Transactions study.

Octopuses, especially solitary species, show less complex communication than social squids, per CMAS records.

A strong red color in octopuses often signals anger or agitation, per a 2018 Agalil study, though context varies.

Squids use chromatophores, iridophores, and leucophores for 300+ pattern combinations, per a 2022 Frontiers study.

Some male octopuses use enlarged suckers in a 'sucker display' to signal their sex, per a 2017 Journal of Molluscan Studies.

The blue-ringed octopus (Hapalochlaena lunulata) shows iridescent blue rings as a warning when provoked, per Smithsonian Ocean.

Cuttlefish use arm gestures, like raising arms, with color patterns to signal mating or aggression, per a 2024 Nature study.

Cephalopods produce and detect polarized light reflections for intraspecific signaling, per a 2006 Biology Letters study.

Caribbean reef squid (Sepioteuthis sepioidea) flash red to attract females and white to repel males, per a 2016 Mather study.

Chromatophores, pigment-filled cells, enable rapid color changes for signaling, like courtship displays, per a 2009 Nature study.