Myxini

By: Elliott Pilcher, Nathan Wilson, Litsa Doumakis, & Lindsey Larder-Hylands

Introduction• Myxini is a class• Hagfish or

Hyperotreti • Living fossils• Over 67 different

species • Only animal in the

world to have only a cranium

Evolution of the Myxini

• Approximately 500 million years old• Scientists originally thought that the Hagfish was a

parasite• They are now known to be predators and scavengers • Vertebrates and Hagfish evolved seperately for the

past 500 million years• Only one fossil has been found from 330 million years

ago• The fossilized version of the Hagfish was very similar

to the Hagfish we see today• Hagfish and Lampreys are the only surviving lineages

of jawless fish.• Considered an Ancestral Fish

Characteristics • eel shaped• no jaw or any bone structure. • has two rows of sharp teeth.• they usually average around 18 inches• brown color • has poor eyesight but a good sense of smell • no scales but has soft skin• four pairs of sensing tentacles around its mouth• spineless. • has a skull to enclose its brain and a notochord made of

cartilage• digestive system lacks a stomach • has four hearts• produces a slime to protect itself from its predators

Habitat• Reside in deep water regions where there is mud to burrow in• Can be found throughout both northern and southern

hemispheres• The warmer the region they are found, the deeper they will

reside in the water • Can be found at very great depths, with the deepest to date

being 1700m into the ocean• Lack osmoregulation, meaning they require salinity in their

environment at all times. Any sudden change in the salinity of a hagfish region could result in a sharp decline in population

• Can occasionally be found on rocky bottoms, where the rocks serve the same purpose as the mud, the hagfish use them to hide under and in-between from predators

• Most typically found in temperate and cold waters

Video Of Hagfish Slime

• http://youtu.be/pmaal7Hf0WA

Reproduction• The hagfish has direct development, it goes directly from the

fertilized egg to a young stage without going through the larvae stage, which means it does not have a larvae stage, compared to a lamprey

• Only the Japanese Hagfish so far has a regular annual reproductive cycle and undergoes a regular

• The Hagfish’s kidney(s) are drained through a duct. Unlike many other vertebrates, this duct is separate from the reproductive tract.

• Unlike all other vertebrates, the proximal tubule of the nephron is also connected with the coelom, provided lubrication.

• The single testicle or ovary has no transportation duct. • Instead, the gametes are released into the coelom until they find

their way to the posterior end of the caudal region, whereby they find an opening in the digestive system.

Fun Facts• In many parts of the

world, including the US, hagfish-skin clothing, belts, or other accessories are advertised and sold as "yuppie leather" or "eel-skin”(hagfish are not true eels, which are bony fish with jaws).

• Hagfish is eaten in Korea and other Asian countries, along with its eggs and its slime.

• The section of the fishing industry devoted to hagfish-fishing has grown in recent years.

Fun Facts• Swarms of hagfish

will descend upon and penetrate the carcass of its prey and devour it from the inside out.

• As well the hagfish covers the carcass they are devouring in slime to deter other predators from finding it.

• Sneezing is a way it prevents the hagfish from choking on its own slime

Sources• "Animal Diversity Web." Animal Diversity Web. N.p., n.d.

Web. 25 Mar. 2014. <http://animaldiversity.ummz.umich.edu/accounts/Eptatretus_stoutii/>.

• "Atlantic Hagfish." - Deep Sea Creatures on Sea and Sky. N.p., n.d. Web. 25 Mar. 2014. <http://www.seasky.org/deep-sea/atlantic-hagfish.html>.

• "Atlantic Hagfish - Myxine Glutinosa." Atlantic Hagfish - Myxine Glutinosa. N.p., n.d. Web. 25 Mar. 2014. <http://www.seawater.no/fauna/chordata/glutinosa.html>.

• "Atlantic Hagfish: Natural History Notebooks." Atlantic Hagfish: Natural HistoryNotebooks. N.p., n.d. Web. 25 Mar. 2014. <http://nature.ca/notebooks/english/atlantichagfish.htm>.

Sources• "Hagfish." Hagfish. N.p., n.d. Web. 25 Mar. 2014.

<http://www.aquaticcommunity.com/mix/hagfish.php>.• "Introduction to the Myxini." Introduction to the Myxini.

N.p., n.d. Web. 25 Mar. 2014. <http://www.ucmp.berkeley.edu/vertebrates/basalfish/myxini.html>.

• "MODERN JAWLESS FISH: HAGFISH & LAMPREYS." Natural History Collections:. N.p., n.d. Web. 25 Mar. 2014. <http://www.nhc.ed.ac.uk/index.php?page=493.470.480>.

• "Why Evolution Is True." Why Evolution Is True. N.p., n.d. Web. 25 Mar. 2014. <http://whyevolutionistrue.wordpress.com/2011/11/21/hagfish-hagfish-hagfish/>.