can there are only terrestrial creatures instead of having aquatic creatures existing on the world

In a hypothetical scenario where aquatic creatures do not exist, the world would be drastically different from what we know today, and the absence of aquatic life would have profound implications:

1. Limited Biodiversity: The Earth's biodiversity would be significantly reduced. Aquatic ecosystems are incredibly diverse and include a vast array of species, from microscopic plankton to the largest known animals like the blue whale.

2. Impact on Food Chains: Aquatic organisms form the base of many food chains in both freshwater and marine environments. Without these organisms, many predatory fish and other aquatic animals would not exist, which would have cascading effects on the food web, potentially leading to the extinction of many species that depend on aquatic life.

3. Loss of Ecosystem Services: Aquatic ecosystems provide essential services such as water filtration, nutrient cycling, and carbon sequestration. Without aquatic creatures, these services could be compromised, potentially leading to poorer water quality and other environmental issues.

4. Human Impacts: Many human cultures and economies rely heavily on aquatic resources, from fishing to tourism. A world without aquatic creatures would have significant social and economic consequences for many communities around the world.

5. Evolutionary Gaps: Aquatic environments have driven unique evolutionary adaptations and have been crucial for the development of certain physiological and anatomical traits in animals. Without aquatic life, the evolutionary history of terrestrial creatures might have taken a very different path.

6. Habitat Loss: Aquatic habitats, such as wetlands, mangroves, and coral reefs, provide critical habitats for countless species. Without aquatic creatures, these habitats might lose some of their ecological functions, altering the overall structure and health of these ecosystems.

7. Cultural and Spiritual Significance: Aquatic creatures have cultural and spiritual significance for many societies. A world without aquatic life would lack the richness and diversity of these connections.

However, it's important to note that this is a purely hypothetical scenario. In reality, aquatic and terrestrial ecosystems are deeply interconnected, and the loss of one would have far-reaching consequences for the other. Life on Earth has evolved to fill a wide range of niches, both in and out of water, creating a complex and interdependent web of life.