What is a Hagfish you ask? Well, it’s a fish without jaws that is covered in slime and ties itself into knots. It is also called the “slime eel". Now, you might think the fish, having no jaws, would have a hard time eating and would soon become extinct. These fish have thrived for half a billion years. Today, there are about 60 species of jawless fish. I am not doing this report on just all of the jawless fish, but 1 in particular, and it is called the Hagfish. Even though the Hagfish has a partial skull, it has no backbone, so it is not a true vertebrate; instead, its skeleton is made of cartilage. So how does it eat if it doesn’t have jaws you might ask? Hagfish eat dead or dying fish by boring into the fish with its raspy horned tongue, then literally sucking out their innards.

Sometimes, Hagfish tie themselves into knots for leverage against their prey. One very useful trick that it has developed is the ability to tie itself into a knot, and be able to slide out of the knot. This can be used to escape predators, clean themselves of slime, and work its way into a carcass. Though the Hagfish is mainly a scavenger, it also eats marine worms and a few other invertebrates. The eyes of a Hagfish have neither lenses nor lids, and are covered by several layers of flesh, and slime which lessens their sight so much; they can only detect light to dark. They also have light detecting spots scattered around their body. Some particular traits that are somewhat strange are that they secret incredible amounts of slime, have six hearts, have an open circulatory system, and tie themselves into knots. Hagfishes can be found in the chilly waters of the anti-tropical north and south.

They tend to live on and in muddy sea floors in very dense groups (Up to 15,000!). Because females tend to produce large eggs in small numbers, their population sizes suggest a low death rate. Newly hatched hagfishes look just like adults, but have both male and female sex organs. When mature, they will be either male or female, but have the ability to change from one to the other, if the population structure demands it. Jawless fish are different other invertebrates because, obviously, they have no jaws, but instead, have developed a more complex way of eating. All other have jaws, there are bony jawed fish and cartilaginous jawed fish. Bony jawed fish have skeletons made of bone (obviously). Cartilaginous fish have a softer material called cartilage, instead of bone. Sharks, Rays and Chimeras are cartilaginous fish.

Author: Kaitlyn N.

Published: April 2006

Sources:

Wikipedia.com/ Google.com