Cold Water

Despite immense pressure, the water in the deepest parts of the ocean, like the Mariana Trench, remains incredibly cold, typically between 1-4°C (34-39°F). This is because sunlight cannot penetrate these depths, and cold, dense surface waters eventually sink to fill these abyssal plains, creating a perpetually frigid environment.

These elusive sharks inhabit the frigid waters of the North Atlantic and grow incredibly slowly, reaching sexual maturity around 150 years old. Their extremely long lifespan is attributed to their slow metabolism in the deep, cold ocean environment, making them the longest-living vertebrate known.