The evolutionary importance of slime

The evolutionary importance of slime

Susanne Wedlich writes:

The weather in Morro Bay, California is too good, the coastline too picturesque, and the wildlife seem to have waltzed straight out of a Disney film. Sea otters play in the waves with their young, herons bask on the beach, and seals stretch their plump bellies in the sun. And yet amid the tranquility of Morro Bay lurks a monster straight from H.P. Lovecraft’s playbook, as slimy as a creature from Sartre’s nightmares. It doesn’t get much more extraterrestrial than this. Two hearts? Tentacles coming out of its head? Four rows of pointed teeth? A vertical smile on its face? But would you call it a smile? Or a face? Why, it’s the hagfish of course.

The writer and Nobel Prize winner John Steinbeck was not a fan of the monster. He found it “disgusting” and “nauseating,” while noting that his close friend, the marine biologist Ed Ricketts, “did not feel this, because the hagfish has certain functions which he found fascinating.” And I find them fascinating too.

The hagfish has certain peculiarities, including its German name, Schleimaal (slime eel), which is misleading, since this elongated creature is not an eel—but neither is it a true fish, as its English name suggests. In fact, hagfish, like the parasitic and similarly unpleasant lamprey, are the last remaining members of the primeval cyclostomata, which translates as “round mouths.” The name is better suited to lampreys, which possess disc-shaped suckermouths with far too many teeth, enabling them to latch on to fish and shred flesh from their flanks. A sensational find confirmed the unique evolutionary journey of cyclostomes. It was the first time a fossilized hagfish emerged, 100 million years old and fantastically well preserved, complete with traces of slime, like a “sneeze in stone.” It underlined the close relationship between these creatures and lampreys and proved that they are not primitive ancestors of us vertebrates, as some scientists had previously assumed. [Continue reading…]

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