Cristina Zenato

Cristina Zenato Instagram – If sharks stop swimming, they sink.
All species are slightly negative in weight, which means they sink.
Regular bony fish have a buoyancy system known as a swim bladder. Fish can regulate the amount of gas, usually oxygen, injected into the chamber through a combination of the circulatory system and other combined actions and deflate it when needed. That’s why we can observe fish floating in stationary positions and are able to move back and forth, up and down, without swimming.
Sharks compensate for their lack of a swimming bladder and tendency to sink with their livers. These contain large amounts of oil that is less dense than seawater and provide them with some buoyancy, yet not enough to keep them afloat.
Some scientists believe that certain shark species, known as ‘obligate ram ventilators’ such as the great white, mako, and great hammerhead, have unique sleeping habits. These sharks may sleep with half their brain active, or position themselves to face ocean currents. Even while resting, their eyes remain open, and their pupils continue to monitor the motion of creatures swimming around them.
Sharks that possess ‘buccal pumping, a method of pumping water through their gills, are able to rest on the ocean floor, under coral heads, or on rock outcroppings, thanks to this unique adaptation.
Video of Liz, Caribbean Reef shark, sinking into my lap as she stops swimming by @kewinlorenzen
@isotta_underwater_housings @neptunic_com @waterproofinternational @diveshearwater | Posted on 28/Aug/2024 22:36:18