The Hagfish or the “slime eel” is probably one of the oddest sea creatures that you will ever encounter due to the fact that they are the only living organism with a skull but without a vertebral column. They may reach an average length of 18 inches and are extremely flexible, allowing them to tie themselves into knots. Their colors may range from pink to black and they also do not contain true fins, have six to eight barbells around their mouths, and have a single nostril.

Hagfish excrete a large amount of mucus which is used as a defense mechanism. When captured, they release the mucus substance and tie into a knot, which allows the mucus to drip down from head to tail until the Hagfish can slip out of the predator’s mouth.

Little is known about the Hagfish, although there are some thoughts of species being hermaphroditic and other species having a ratio as high as 100:1 in favor of females. Researchers believe that the ovaries remain stagnant until they have reached maturity and are around a particular environmental factor in the case of the hemophroditic species, however in other species; hagfish containing ovaries are given sperm by another containing testicles. In this case the females lay 20 to 30 eggs after both sexes mate.

Did You Know? A Hagfish has four hearts and two brains.