The once distinct neck vertebrae of cetaceans have fused, giving them a sleek, torpedo-shaped body that moves effortlessly through the water. This group is not a single taxonomic family but a collection of species from different lineages that converged on a similar lifestyle.
Breath Hold Diving in Marine Mammals: Mastering Underwater Respiration
The Mechanics of Underwater Breathing Respiration is perhaps the most glaring contradiction for mammals in water. Unlike fish, which extract oxygen from water using gills, these animals must hold their breath for extended periods to dive deep and hunt.
The concept of mammals in water challenges the very definition of what it means to be a terrestrial creature. Similarly, pinnipeds retain the ability to rotate their rear flippers forward, allowing them to "walk" on all fours in a laborious gallop, while their webbed front limbs act like paddles for swimming.
Breath Hold Diving in Marine Mammals: How They Defy Respiration Underwater
Without this air layer, the otter would quickly succumb to hypothermia even in relatively mild waters. Elephant seals and sperm whales can dive for over an hour, descending to depths where the pressure would crush a human lung instantly.
More About Mammals in water
Looking at Mammals in water from another angle can help expand the discussion and give readers a second clear paragraph under the same section.
More perspective on Mammals in water can make the topic easier to follow by connecting earlier points with a few simple takeaways.
