While “nature” encompasses the entirety of the natural environment, the term “biodiversity” means the variety of living organisms inhabiting Earth, in all its forms and its interactions. Biodiversity includes various levels of biological organization, spanning from individual genes and organisms to entire ecosystems. It plays a crucial role in providing the benefits we derive from nature, often referred to as ecosystem services or nature's contribution to people. These services include provisioning, such as food and wood; supporting, such as soil formation and nutrient cycling; regulating, such as air and water purification; and cultural, including recreation and eco-tourism.
Freshwater fish represent more than 18,000 species of biodiversity worldwide, with a wide range of shapes, sizes, behaviors, distributions and origins. These different species in turn reflect a functional diversity that fulfills important ecosystem functions for the benefit of humans.
The diversity of freshwater fish provides humans with both direct and indirect benefits, including fishing, ornamental fish, aquaculture, and the provision of active substances for medicines. Fish also contributes to seed dispersal, disease and pest control, and decomposition, helping in nutrient cycling, and maintenance of water quality. In addition, fish are often part of the cultural heritage through activities such as recreational fishing, tourism, fish farming, education and scientific research, and are highly valued in traditional communities through religious ceremonies, beliefs and stories.
Therefore, it is imperative to enhance our understanding of fish diversity, their ecology, and the impact of human activities on ecosystem services. This is essential not only for safeguarding the known biodiversity but also for protecting the unseen and yet-to-be-described fish species.