Roger T. Hanlon - Cephalopod Behaviour

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Second edition Roger T. Hanlon and John B. Messenger 2018

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RTH dedicates this book to Arlene, Erin and Grayson; and to many mentors and colleagues along the way, but especially to Patrick Bateson, Robert Hinde and Martin Wells who taught him the principles and values of studying the complex subject of behaviour.

JBM dedicates this second edition to the memory of his parents, Maggie and Frank, who encouraged his childhood fascination with animals.

As many readers will know, this new edition is long overdue, partly because of personal problems experienced by both authors, but also because we have had to examine a far larger number of new papers than we ever imagined when, many years ago, we cheerfully agreed to Cambridge University Presss invitation to write a second edition. It would be gratifying to think that our first edition helped stimulate new research into cephalopod behaviour, but there is no doubt that in the past 20 years, there has been a welcome surge of fascinating investigations into many aspects of the lives of these animals. As a result, we have come to realise, for example, that squid can detect infra-sound and that polarisation sensitivity is far more important in the lives of cephalopods than previously thought. Some of this new work has been done in the laboratory, but there have also been some beautiful field observations of, for example, the horizontal and vertical movements of the jumbo squid (revealed by special tagging); of the extraordinary reproductive behaviour of the giant Australian cuttlefish in shallow waters; and, in the depths, a glimpse of the complex flashing behaviour of the squid Taningia , as well as the first ever observations of living giant squid from submersibles.

In this edition, we have attempted to do justice to all this new work, with the inevitable result that the book has become very long, for which we apologise. The subject matter of the new edition is organised in the same way as in the first. The majority of the chapters reflect the combined inputs of RTH and JBM; but

Cephalopods are a very ancient and specialised group within the Mollusca. They are highly evolved, and in many features of their behaviour they have more in common with fish than with other invertebrates. In this book, we attempt to summarise what is known about the behaviour of modern coleoids the cuttlefish, squid and octopuses and their ancient relative, Nautilus . Curiously, given the great interest in cephalopod behaviour for more than half a century, it is the first book devoted exclusively to this theme. We have brought together field and laboratory data to present as complete a picture as we can of the life of cephalopods. In each chapter, we have drawn attention to those aspects of behaviour that will, we think, merit further study, not only to advance knowledge of cephalopods, but to add comparative data to behavioural biology. Where information is available, we have drawn on current theory in our analysis, but generally we have tried to avoid interpretations in terms of theory that may be out of date in a few years. We prefer to let the data speak for themselves. Our conceptual approach is primarily ethological, although we include functional morphology, physiology and neurobiology as needed. Where possible, we have considered questions of the function, causation, development and evolution of cephalopod behaviour. By the end, we hope to have shed some light on how and why these short-lived creatures with large brains behave the way they do.