The Incredible World of Hagfish

In a moment of chaos, a truck screeched to a halt, causing one of its containers to slide off and collide with an approaching Prius. To everyone's surprise, the container held thousands of kilograms of live hagfish, famously known as slime eels. The aftermath of the 2017 car accident was a messy sight—the highway was strewn with wriggling fish, and a thick layer of slime covered the entire area, taking the fire department seven painstaking hours to clean.

Beyond their astonishing appearance, hagfishes possess a remarkable attribute—their slime. In fact, they are arguably the slimiest creatures on Earth. But what purpose does this excessive slime serve? Let's delve into their world and find out.

Using their keen sense of smell and taste bud-like organs on their skin, hagfish can detect the scent of a dead fish. With imposing rows of tooth-like structures, they eagerly take the first bite.

Suddenly, a shark emerges and launches an attack. Caught in the powerful jaws of the predator, the hagfish seems destined for certain doom. However, these resilient creatures have tricks up their sleeve. Unlike other animals, the hagfish lacks bones, having only flexible cartilage. Additionally, its skin is loosely attached to its body. When the shark bites down, the pressure causes the hagfish's vital organs to slide out of harm's way, avoiding damage. It's the advantage of being a "noodle" in a baggy wetsuit.

Simultaneously, the hagfish employs an active defense mechanism by unleashing an extraordinary amount of slime. Along each side of its body, approximately a hundred slime glands are present. These glands contain mucus and thread cells. The mucus cells store condensed mucus within vesicles, while the thread cells harbor intricately coiled protein fibers.

By contracting the muscles surrounding its slime glands, the hagfish triggers the ejection of cell contents into the surrounding seawater. Within a fraction of a second, mucus vesicles expand and burst, and protein fibers unravel. The combination of mucus and numerous fine, strong fibers causes the slime to expand instantly by 10,000 times its original volume. This resulting slime is incredibly soft yet resilient. It ensnares the shark's delicate gills, leading to choking and attempts to clear the slime, ultimately releasing the hagfish. Now free from the jaws of death, the hagfish finds itself entangled in its own suffocating slime. But fear not—its solution is to tie itself in a knot, effectively wiping away the slime by passing its body through the knot. Unfazed by the encounter, the hagfish returns to its meal. When faced with a tougher part of the carcass, it once again ties itself in a knot to gain leverage and extract the meat.

The remarkable properties of hagfish slime have sparked interest in emulating it for practical applications. Many athletic and safety gears currently rely on non-renewable petroleum-based fibers. However, hagfish slime threads exhibit comparable properties to materials like nylon. Thus, developing fibers inspired by hagfish slime could offer a more sustainable alternative. Additionally, hagfish slime is being explored in military contexts as a non-lethal weapon capable of immobilizing boats by coating their propellers.

In addition to their mastery of slime and knot-tying, hagfish possess four little hearts and can survive up to 36 hours without oxygen unscathed. Furthermore, they contribute to ecosystem health by cleaning the seafloor and cycling essential nutrients in the deep sea. Proto-hagfish have navigated the ocean's depths for over 300 million years, predating the reign of dinosaurs and the existence of Pangea. Having withstood multiple mass extinction events, hagfish have truly witnessed it all. And it seems they continue to thrive, leaving us in awe of their wondrous slime-filled world.

Henrik Leandro