In 13 chapters with 60 clearly understandable, vivid, light-heartedly worded and separately enjoyable “wanted posters”, numerous astonishing phenomena of the marine fauna are described, without burdening the reader unnecessarily with technicalities.

More than 330 of the author’s underwater color photos illustrate the text. Inquiry into the wider relationships whets our curiosity and satisfies it wherever science has already found the answer. A fascinating macrocosm takes shape around the unique entwinements of marine fauna, evolution, and ecological systems.

This is no mere picture book, but a work in which text and illustrations are in proper balance. The reader is drawn to the pictures and the viewer to the text. Accounts of personal experiences enliven the narrative. Learning is seldom coupled with so much aesthetic pleasure.

Preface 7
Foreword 9
Prologue The sea – bridge to all life 11
1 The Dictates of Water The element demands adaptability 17
Classification Problems and Their Background Plant or animal? 18
The Sodium Balance of Aquatic Creatures Why do the cod and the lobster not taste salty? 22
Space Can Be Scarcer than Food Housing shortage on the seabed 25
A Practical Multipurpose Device with an Odd History The swim bladder of the fish 29
2 From Sensory Perceptions to Meaningful Signals Light, colors, and vision in the sea 33
No Motion – No Pictures From the animals’ point of view 35
The Evolution of Eyes The ancestors of our eyes are still alive 38
Compound Eyes Confer Privileges A thousand eyes for a single color picture 43
Colors Vain and Void Bright and beautiful – but futile and false 47
When Colors and Patterns Take on Missions Uniforms – flashy and discreet 51
3 Between Fear and Fascination Notorious predators, large and small 55
Nurse Sharks and Smooth Hounds Peace-loving cousins of the killers 57
Rays The flat-bodied relatives of the sharks 60
Obituary for a Murdered Friend When a tamed giant loses patience 65
Morays and Snake Eels Shrouded in tales of horror 67
Lizardfishes Miniature master predators 71
Lionfishes The poisonous peacocks of the sea 74
Lurking Dangers Cunningly Concealed Stonefishes and consorts 78
4 From the Endless Repartition of Immortality to the Invention of Pleasure and Death Forms of reproduction 85
The Sexual and the Asexual Reproduction in the sea 86
Farewell to Waste From purest chance to motivated mating 90
Nature’s Book of Sexy Stories Sex sharing and hermaphroditism 94
A Fascinating Chapter of Sociobiology Sex reversal among fishes 98
5 A 600-Million-Year-Old Enterprise Mammoth buildings and their tiny builders 103
Of Reefs and Corals The earth’s largest edifices 105
Skilled Hands, Unskilled Laborers, and Empty Sites Formative forces on the reef 110
Our Cup-Shaped Earliest Ancestors? A closer look at the stony corals 112
Wandering Coral Stocks The sea pens 116
6 Paradise with Strict House Rules The colorful communities of reef fishes 121
The Nimble Damselfish Family The lively rank and file of the reef 124
Butterflyfishes and Angelfishes Eye-catchers on the reef and in the home 126
Independent Evolutions in the Atlantic and the Indo-Pacific Two oceanic worlds separated by a cold curtain 129
Puffers and Porcupinefishes Deadly even after death 136
Soldierfishes Standing guard over the night shift on the reef 138
7 Early Triumphs of Evolution Everlasting veterans 143
Connecting Links between Chaos and Organization The sponges 145
Bristleworms Beauties miscalled by an ugly name 150
Living Fossils Using Ultramodern Technology The nautilus 155
Sea Squirts The unpretentious ancestors of the vertebrates 159
Microcosmic High-Tech Cnidarian cannons 162
8 Remarkable Achievements and Interrelations Oddities in ecological niches 165
Squatters in the Animal Kingdom Hermit crabs 167
Anemonefishes Subtenants in the robbers’ cave 170
Monsters and Midgets in a Lifelong Alliance Giant clams and their partners 174
Of Housing Construction and Textile Production Top rankers among the specialists 178
Giant Clam Bites Anchor Chain An unexpected mooring aid 179
Imaginative Good-Neighborly Arrangements Crabs in search of company 182
Hygienic Symbioses Services and swindles 183
9 Animal Systematics, as Exemplified by the Echinoderms A phylum worth meeting 191
Delicate Plumage with Predacious Habits The feather stars 193
Symmetry Treads Winding Paths The sea cucumbers 196
The Starfish with the Bad Reputation The crown-of-thorns 200
The Sea Urchin Public enemy number two in the sea 204
Reproduction by Self-Mutilation Emancipated starfishes 208
10 Odd Blossoms Forced by the Pressure of Selection Innovations from the experimental laboratories of evolution 211
Razorfishes A topsy-turvy life 212
Nature’s Rhinoplastic Experiments The ribbon eels 213
A Life Standing Erect in the Sand The garden eels 216
Fins for Walking and Gills as Jet Engines The anglers or frogfishes 218
11 Barely Credible, yet Related Of mollusks and magic 222
Something for Lovers of Little Gems Sea slugs 224
The Cuttlefishes Highly intelligent lower animals 228
Cowries and Congeners A page from the history of civilization 233
12 Subject to the Regional Laws of the High Seas The vagrants of the oceans 238
Witnesses of Change in Shapes and Behaviors The strange-looking hammerhead sharks 240
Scyphozoans and Sycophants Nomads of the high seas – aimless wanderers with attendants 243
The Horse Mackerels Cavalry troopers in metallic uniforms 248
Hitchhiking through Life The remoras 251
13 Water Alone Is Also Not Enough Commuters between sea and land 254
Dependent on Three Elements The (last?) marine turtles 256
The Mudskippers Fishes bound for life on land? 263
Fish-Shaped Mammals with Brains like Humans The dolphins 267
Epilogue The sea and the future 271
Authors cited 275
Index 276
Photographic credits 288

This book is a declaration of love for life. Constantly renewed amazement, admiration, and enthusiasm have made it, to my mind, the most fascinating of all subjects. The boundless diversity of forms in which life manifests itself is enthralling, and no less so are the perpetual transitions of coming into being and fading from existence on our planet.

Human consciousness paired with outstanding communicational capabilities have made man the first living being to be capable of reflecting on the developments that have led from the very beginning of the world to his own existence. Within modest limits, we can foresee, and even exercise increasing influence on, many a course of future development.

Since the dawn of culture, the focal point in much of our art, literature, and philosophy, to say nothing of our religions, has often been and still is death. The gift of life, death’s first prerequisite, on the other hand, is not infrequently treated as a self-evident right. But is it not in fact life itself that is the real wonder? How it originated, evolved, and spread in ever new varieties; how it appears at present; and what we can perhaps assume about its future. There is nowhere nearly so well suited as the sea to gain a closer acquaintance with the wonders of life, its perpetuity through successive generations, its history, and its exciting relationships. It was in the ocean that all things began, and for a very, very long time life was confined exclusively to the ocean. Life will also be totally extinguished when, in some future time just as remote, the seas evaporate, proving our astronomers’ prophesies. The future of the seas, and hence of all life, depends no less than its past on the sun, whose span of life is also not interminable.

For the last three decades, diving with underwater breathing apparatus has done me generous service as a source of visual instruction, on the spot, in the seas around the world. I am happy to share many of my experiences with the reader.

Only a small selection of the photographic documentation accumulated during that time could be accommodated between the covers of this volume. Quite apart from its illustrative value, it may help to convey a little of the aesthetic beauty with which nature has so richly blessed the seas. With very few exceptions, the photographs were all taken under water, in the natural habitats of the creatures portrayed. The chapters have been arranged so that each is self-contained and comprehensible even if read independently of the others; but they still follow in sequence as links in a larger chain: examples as stepping stones towards an understanding of the greater interrelationships in animate nature. For wherever our gaze rests, what we see always points beyond the boundaries of our visual field to the fundamentally indivisible wholeness of the living world. Only human endeavors to investigate and teach have made it necessary to classify and categorize, and in the doing created the false impression of independent entities. But for those prepared to recognize the signs of the times, it is a knowledge of the interrelations that is needed. We all of us will only be able to cast off our naïve irresponsibility towards nature when we have learned to grasp its essential features, but at the same time also to appreciate the value of the intermeshed components. Hardly anything can serve this purpose better than a more profound knowledge of the life beneath the waves.

This book makes no claim to stand comparison with the meritorious and essential textbooks and works of classification, and scientific terminology – though occasionally indispensable and also helpful to those who might care to probe further into the literature – has been used as sparingly as possible. First and foremost, my intention has been to promote or arouse astonishment and curiosity, and to amplify the basic general knowledge we all have of marine life. May it be thought of as an attempt to pass on to others all the pleasure and benefit I myself have derived from my preoccupation with life in the sea.

Dr. Werner GRÜTER is a university professor of neurology and psychiatry. Off the campus, he has, for some decades now, devoted his attention to marine biology, not least with a view to tracking down the wonders of evolution. Being an experienced scuba diver and underwater photographer, he was able to gain direct insights on the scene and collect the illustrative material for this book. His enthusiasm is contagious, thanks not least to his gift for explaining complex scientific contexts in readily understandable, amusing, and gripping terms. The author, who has established a foundation for the promotion of comprehensibly communicated science, himself sets an excellent example between these covers.