Peripheral injury alters schooling behavior in squid, Doryteuthis pealeii.
Animals with detectable injuries are at escalated threat of predation. The anti-predation tactic of schooling reduces individual predation risk overall, but it is not known how schooling behavior affects injured animals, or whether risks are reduced equally for injured animals versus other school members. In this laboratory study we examined the effects of minor fin injury on schooling decisions made by squid. Schooling behavior of groups of squid, in which one member was injured, was monitored over 24h. Injured squid were more likely to be members of a school shortly after injury (0.5-2h), but there were no differences compared with sham-injured squid at longer time points (6-24h). Overall, the presence of an injured conspecific increased the probability that a school would form, irrespective of whether the injured squid was a member of the school. When groups containing one injured squid were exposed to a predator cue, injured squid were more likely to join the school, but their position depended on whether the threat was a proximate visual cue or olfactory cue. We found no evidence that injured squid oriented themselves to conceal their injury from salient threats. Overall we conclude that nociceptive sensitization after injury changes grouping behaviors in ways that are likely to be adaptive.
Marine Science Department, Coastal Carolina University, 301 Allied Drive, Conway, SC 29526, United States.
Megumi
M
Oshima
Department of Bioengineering, Union College, 807 Union Street, Schenectady, NY 12308, United States.
Theodor
T
di Pauli von Treuheim
Biology Department, Williams College, 59 Lab Campus Drive, Williamstown, MA 01267, United States.
Julia
J
Carroll
Program in Sensory Physiology and Behavior, Marine Biological Laboratory, 7 MBL St Woods Hole, MA, United States.
Roger T
RT
Hanlon
Department of Integrative Biology and Pharmacology, McGovern Medical School at UTHealth, 6431 Fannin St, Houston, TX, 77030, United States.
Edgar T
ET
Walters
Department of Biology, San Francisco State University, 1600 Holloway Ave, San Francisco CA 94132, United States. Electronic address: rcrook@sfsu.edu.
Robyn J
RJ
Crook
D000818:Animals; D003463:Cues; D049832:Decapodiformes; D005260:Female; D008297:Male; D012919:Social Behavior; D013997:Time Factors; D014947:Wounds and Injuries / Q000523:psychology*
(3–6) Schooling; Cephalopod; Invertebrate; Nociceptive sensitization; Social behavior