The behaviour of Loligo opalescens as observed by a remotely operated vehicle (ROV) was analysed. Thirty-nine behavioural components were identified and classed into four categories: chromatic, postural, locomotory, and inking. The frequency with which components were expressed was correlated to whether or not an individual was schooling, shoaling, alone with the ROV, or in the presence of other species. Behaviours observed were compared to those reported for other Loligo species. Observations of schooling and feeding behaviour, and reactions to other species are included.