Preface

A firefly is a bioluminescent organism that produces light via a chemical reaction inside its body. But what makes a firefly glow, exactly? To answer this question, one must consider both proximate and ultimate analyses of animal behavior. A proximate analysis looks at mechanistic and ontogenic explanations, while an ultimate analysis examines evolutionary explanations for adaptation and phylogenetic history. These aspects (mechanism, ontogeny, adaption, and phylogeny) are known as Tinbergen's Four Questions. Developed by Nikolaas Tinbergen, this method was originally designed to explain animal behavior. However, this categorization is also useful for other biological traits. Hence, it is used in this book to examine the trait of bioluminescence, which is increasingly being used in biomedical applications such as cellular assays and imaging.

Section 1 on "Bioluminescence and Its Applications" contains three chapters. The first chapter examines bioengineering advances that have been applied to firefly luciferase, *Gaussia* luciferase, *Renilla* luciferase, *Ophophorus* luciferase, and bacterial luciferase. The second chapter describes a bioluminescent system called NanoLuc, which uses luciferase from the sea shrimp *Oplophorus gracilirostris*. The final chapter in this section presents a biomonitoring system of toxins in an environment using photobacteria cells.

Section 2 on "Bioluminescent Organisms" also contains three chapters. The first chapter in this section reports on the ecology and histology of the light organ of a luminous springtail discovered in Japan. The second chapter examines the effect of artificial light produced by camera illumination on the flashing behavior of synchronous fireflies in Thailand. The final chapter reviews the biofluorescence of terrestrial organisms, planarians, snails, earthworms, nematodes, velvet worms, arthropods, and vertebrates. It also describes the phenomenon of both fluorescence and luminescence in fireflies using original field observations.

I would like to express my appreciation to the chapter authors for their outstanding work, and also to Ms. Ivana Barać, Author Service Manager at IntechOpen, for effective communication and assistance during the preparation of this book.

> **Hirobumi Suzuki** Olympus Corporation, Tokyo, Japan

**1**

Section 1

Bioluminescence and

Applications

Section 1
