What percentage of fish species are known to live in freshwater?

The proportion of fish species that inhabit freshwater environments is significant, with around 45% of all fish species known to be living in these habitats. Freshwater ecosystems, which include rivers, lakes, ponds, and wetlands, support a diverse range of species that have adapted to varied conditions such as water flow, temperature, and salinity.

This diversity is crucial for maintaining ecological balance and supporting both local ecosystems and human economies. Freshwater habitats can be quite different from marine environments, leading to the evolution of unique adaptations among freshwater fish species. Understanding the percentage of species that thrive in freshwater can inform conservation efforts, as these environments are often more vulnerable to pollution, habitat loss, and climate change compared to marine ecosystems.

The other percentages provided do not reflect the current scientific understanding of fish biodiversity in freshwater habitats, making 45% the most accurate figure among the choices given.