Hagfish: The only animal that eats with its mouth shout
The Pacific hagfish is the only vertebrate that can obey the cardinal rule of the dinner table - don't eat with your mouth open
Uniquely among the 50,000 vertebrate species alive today, it can absorb nutrients through its skin
Vertebrate skin is impermeable to minimise chemical exchanges between the body and its surroundings.
This is why backboned animals can live in salty or fresh water – and how they avoid excess water loss on land.
But the primitive hagfish, thought to be as close as we can get in a living animal to the first vertebrate, has an internal salinity that matches its surroundings
In the Pacific hagfish (Eptatretus stoutii) this could double as a gut, as it likes to dine inside carcasses, exposing its skin to a nutrient-rich soup.
The hagfish’s dining habits may have led to the adaptation, but as some invertebrates also possess a “gut skin”