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Hagfish

life science Maturity 5-7 Next article →

Hagfish are strange marine animals that look like long, pink worms.

Eptatretus stoutii
Eptatretus stoutii

They are often called slime eels because of their amazing skin. These creatures are predators and scavengers in the ocean. They are very unique because they have a skull but no backbone. Instead, they use a rod called a notochord for support.

Hagfish trunk
Hagfish trunk

This makes them very different from most other fish. They are part of a group called Cyclostomi. This group includes hagfish and lampreys. Scientists believe these two are more closely related to each other than to fish with jaws.

Hagfish have a very clever way to protect themselves.

Hagfish Slime Predator Deterrence
Hagfish Slime Predator Deterrence

They have special glands in their skin that release mucus. When this mucus hits seawater, it expands very quickly. It can grow 10,000 times its size in just 0.4 seconds! This thick slime can clog the gills of a predator fish. This makes it hard for the predator to breathe. The predator will then let the hagfish go to avoid suffocation. If a hagfish gets stuck in its own slime, it can tie itself into a knot. It slides the knot from its head to its tail to scrape the slime off.

Pacific hagfish Myxine
Pacific hagfish Myxine

Hagfish have been living in our oceans for a very long time.

Eptatretus polytrema
Eptatretus polytrema

Scientists have found fossils of stem group hagfish from the Late Carboniferous period. This was about 310 million years ago. Modern types of hagfish were first recorded around 100 million years ago. This was during the mid-Cretaceous period. They have survived through many changes in the Earth's history. Their simple bodies have remained effective for millions of years.

There are many different kinds of hagfish with different sizes.

Black hagfish, Eptatretus deani gonads 01
Black hagfish, Eptatretus deani gonads 01

The largest species is called Eptatretus goliath. One specimen of this species was recorded at 1 meter long. Other species like Myxine kuoi and Myxine pequenoi are much smaller. Some hagfish can be as tiny as 10 centimeters. Their colors can range from pink to blue-grey. Some even have black or white spots on their skin. They have simple eyespots that can sense light but cannot see clear images.

Dorsal, left lateral views of dissected hagfish brain
Dorsal, left lateral views of dissected hagfish brain

Learning about hagfish helps us understand how life began.

Hagfish skull Fig 74 in Kingsley 1912
Hagfish skull Fig 74 in Kingsley 1912

Their brains and eyes are very important to study. Scientists look at them to see how complex eyes and brains evolved. Even their slime is being studied today. The proteins in the slime are being looked at as a possible material for body armor. This is because the slime fibers are very strong when stretched. It is amazing how a small sea creature can teach us so much about the world.

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🖼️ Images & Media (13)
File:NIE 1905 Hagfish - Myxine glutinosa.jpg
NIE 1905 Hagfish - Myxine glutinosa.jpg
File:Eptatretus stoutii.jpg
Eptatretus stoutii.jpg
File:Hagfish Slime Predator Deterrence.jpg
Hagfish Slime Predator Deterrence.jpg
File:Eptatretus stoutii 1.jpg
Eptatretus stoutii 1.jpg
File:Dorsal, left lateral views of dissected hagfish brain.jpg
Dorsal, left lateral views of dissected...
File:Hagfish trunk.jpg
Hagfish trunk.jpg
File:Hagfish skull Fig 74 in Kingsley 1912.png
Hagfish skull Fig 74 in Kingsley 1912.png
File:Black_hagfish,_Eptatretus_deani_gonads_01.jpg
Black_hagfish,_Eptatretus_deani_gonads_01.jpg
File:Eptatretus polytrema.jpg
Eptatretus polytrema.jpg
File:Eptatretus cirrhatus (New Zealand hagfish).gif
Eptatretus cirrhatus (New Zealand hagfish).gif
File:Pacific hagfish feeding 01.jpg
Pacific hagfish feeding 01.jpg
File:Pacific_hagfish_Myxine.jpg
Pacific_hagfish_Myxine.jpg

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