Signal Use by Octopuses in Agonistic Interactions

• Published in: Current biology Vol. 26; no. 3; pp. 377 - 382
• Main Authors: Scheel, David, Godfrey-Smith, Peter, Lawrence, Matthew
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 08.02.2016
• Subjects: Agonistic Behavior; Animal Communication; Animals; Female; Male; Octopodiformes - physiology
• ISSN: 0960-9822; 1879-0445
• DOI: 10.1016/j.cub.2015.12.033

Cephalopods show behavioral parallels to birds and mammals despite considerable evolutionary distance [1, 2]. Many cephalopods produce complex body patterns and visual signals, documented especially in cuttlefish and squid, where they are used both in camouflage and a range of interspecific interactions [1, 3–5]. Octopuses, in contrast, are usually seen as solitary and asocial [6, 7]; their body patterns and color changes have primarily been interpreted as camouflage and anti-predator tactics [8–12], though the familiar view of the solitary octopus faces a growing list of exceptions. Here, we show by field observation that in a shallow-water octopus, Octopus tetricus, a range of visible displays are produced during agonistic interactions, and these displays correlate with the outcome of those interactions. Interactions in which dark body color by an approaching octopus was matched by similar color in the reacting octopus were more likely to escalate to grappling. Darkness in an approaching octopus met by paler color in the reacting octopus accompanied retreat of the paler octopus. Octopuses also displayed on high ground and stood with spread web and elevated mantle, often producing these behaviors in combinations. This study is the first to document the systematic use of signals during agonistic interactions among octopuses. We show prima facie conformity of our results to an influential model of agonistic signaling [13]. These results suggest that interactions have a greater influence on octopus evolution than has been recognized and show the importance of convergent evolution in behavioral traits. [Display omitted] [Display omitted] •Octopus tetricus use a range of displays during agonistic interactions•Displays correlated with the outcomes of interactions•Closely matched displays were more likely to result in escalation Cephalopods show complex behaviors, including color changes. Scheel et al. assess the signaling role of body pattern displays by octopuses. Some displays are signals that mediate agonistic interactions. Comparisons of signal behavior among octopus species may provide a model for understanding the ecological factors shaping signal evolution.