**Preface**

The rapid development of aquaculture worldwide has been driven by the emergence of new techniques. In this book, we aim to provide an update on current research and technological advancements in various aspects of aquaculture, including biotechnology, ecotechnology, feeding technology, and environmental technology.

One of the key areas covered in this book is biotechnology. Recently, researchers have been focusing on isolating and characterizing genes that provide resistance to bacterial infection and environmental stress. By understanding the genetic makeup of aquatic organisms, we can develop strategies to enhance their resistance to common diseases and stressors. This not only improves the overall health and well-being of the organisms but also ensures sustainable aquaculture practices.

Feeding technology is another important aspect addressed in this book. In recent years, scientists have been working on developing advanced feeding techniques that improve the immunity and stress resistance of aquatic organisms. By optimizing the nutritional content of their feed and incorporating additives that enhance immune response, we can ensure the proper growth and development of aquaculture species.

Additionally, this book also explores the detection of the impact of thermal stress on marine fish immunity. With increasing global temperatures and climate change, it is crucial to understand the impact of thermal stress on aquatic organisms. By studying the immune response of marine fish to thermal stress, we can develop effective mitigation strategies to protect these species and maintain the sustainability of aquaculture.

Moreover, light color manipulation to improve algal growth is another area of interest covered in this Special Issue. Algae are an essential component of aquatic ecosystems, and their growth is crucial for maintaining a healthy environment for aquaculture species. By manipulating the color and intensity of light, we can optimize algal growth, which in turn supports the growth and development of other organisms in the ecosystem.

Lastly, this book highlights the use of integrated multi-trophic systems to improve production. By combining different species in aquaculture systems, we can create a symbiotic relationship where the waste products of one species serve as nutrients for another. This integrated approach not only improves the overall efficiency of aquaculture but also reduces the environmental impact.

The research presented in this book focuses on marine fish, shrimp, sea cucumbers, sea urchins, and algae to showcase the new technological developments in aquaculture. However, the findings and techniques discussed in these papers have the potential to be extended to other species in aquaculture. They serve as a foundation for further research and innovation in the field, leading to the continued growth and improvement of aquaculture practices.

We would like to express our sincere gratitude to all of the authors whose valuable contributions have made the publication of this book possible. Their dedication and hard work have significantly enriched and enhanced the coverage of this publication. It is our hope that this book will inspire further research and collaboration, ultimately contributing to the sustainable development of aquaculture worldwide.

> **Zhenhua Ma and Jianguang Qin** *Editors*
