Hagfish - biography
Set Your Country Content Preference (What is this?Choose the language in which you want to view YouTube.Don't worry the Hagfish is not hurt, it's just ...Don't worry the Hagfish is not hurt, it's just anaesthetised.The video has been added to your playlist.Want to add to Playlists?Sign in with your Google Account!This video has no Responses.Well, maybe if it was eatin'...Set Your Country Content Preference (What is this?This will only change the interface, not any text entered by other users.Sign in with your Google Account!Hagfish are amazing ocean fishes!Hagfish are amazing ocean fishes!Hagfish are blind, although they possess eyespots on either side of their heads.This slime allows them to escape potential predators, and consists of a filamentous protein that is highly hydrophilic.This video will appear on your blog shortly.Thank you for sharing this video!Want to add to Favorites?Sign in with your Google Account!This is really interesting and educational; thanks for the post!Why do you think you have the right to take animals from their natural surroundings and kill them just for scientific curiosity?There's going to be no benefit to human survival from killing hagfish is there?Better understanding every facet of our world is better understanding of ourselves.How is catching a load of hagfish going to save the oceans?They're just in it for themselves.How many of these hagfish do you have to catch before you stop an oil rig getting dropped??How else do you expect them to understand their subject?Hagfish are long, slender and pinkish, and are best known for the large
quantities of sticky slime which they produce.Hagfish have three accessory hearts, no cerebrum or cerebellum,
no jaws or stomach, and will "sneeze" when their nostrils clog with
their own slime.Hagfish are almost blind, but have well developed senses of touch and smell.As this tongue is pulled back into
the hagfish's mouth, the pairs of rasps pinch together.By far, the
largest part of their diet is polychaete worms,
but because of their slow metabolism, hagfish may go for up to seven months
without eating any food.Hagfish eggs are approximately one inch long, and encased in a tough shell.Despite the low number of eggs laid, hagfish exist in large numbers,
with populations of up to 15,000 occurring in a relatively small area.This
suggests that hagfish have a low mortality rate.Hagfish also
lack jaws, and for this reason were long classified together with the
lampreys in a group called the Agnatha
("no jaws") or the Cyclostomata ("round mouth").Jawlessness is the
primitive state for fish however, and so any such group based on a lack
of jaws is paraphyletic.View a cladogram of the groups of
basal vertebrates for better
understanding.The only fossil hagfish is Myxinikela siroka, a Pennsylvanian
find from the Francis Creek Shale of northeastern Illinois (Bardack, 1991).The similarity to modern hagfishes is striking, and suggests that there
has been little evolutionary change in this group over the last 300
million years.Gilpichthys,
has been tentatively included with the hagfish, but lacks the distinctive
tentacles of all other species.More complex fish show up as far back
as 400 million years ago, so why weren't there any hagfish fossils?Read about other fossils of the Francis Creek Shale at the Illinois State Museum.For more hagfish information visit the Hagfish page on the
Tree of Life.First fossil hagfish (Myxinoidea): a record from the Pennsylvanian of Illinois.The Hagfishes and Lampreys.Hags vary in color, perhaps to correspond with the color of the bottom, being grayish brown or reddish gray above, variously
suffused, mottled, or piebald with darker or paler gray, with brown, or with bluish; they are whitish or pale gray below.It is not a true parasite, as has sometimes been suggested, their being no
reason to believe it ever attacks living, uninjured fish, but is a scavenger.Being blind, it doubtless finds its food by its greatly specialized olfactory apparatus.In fact, it is only in this
way, or entangled on lines, that hags ordinarily are taken or seen.In American waters the commercial fishes most often damaged by it are haddock and the hakes (Urophycis), these being the species most often fished for with long lines or with gill nets over the type of bottom the hag frequents.But it sometimes damages cod also, and European authors describe it as attacking ling (Molva) and other members of the cod tribe, herring, mackerel, sturgeon, and even mackerel sharks under similar circumstances.The hag was formerly believed to be a functional hermaphrodite, with its single sex organ first developing sperm in the posterior
portion, eggs later in the anterior portion.The few eggs
so far reported have been from depths of 50 to 150 fathoms, most of them trawled on mud, clay, or sand bottom.Murman Coast and northern Norway south regularly to the Irish Sea, and
to Morocco as a stray in the East; northern part of Davis Strait, south to the latitude of Cape Fear, N.Fishermen report it as equally numerous in the deeper parts of Massachusetts Bay.Michael Sars North Atlantic Exped.Lawrence though it is to be expected in the deeper parts of the latter.The Hagfishes and Lampreys.The hagfish, scientifically known as Myxine glutinosa, is a true monster of the deep.In fact, a single hagfish can produce enough slime at one time to fill a milk jug.Hagfish slime is different that any other natural slime secretions in that it is reinforces with tiny fibers.It is believed that the hagfish uses this slime to protect itself from predators.It can easily produce a protective cocoon of slime.This slime can actually suffocate predators by clogging their gills if they come in contact with it.The hagfish has a trick for escaping this slime cocoon.The hagfish's skeleton is made up entirely of cartilage.What really makes the hagfish a monster is its eating habits.The hagfish feeds by attaching itself to a passing fish.Once inside, the hagfish will actually eat the fish's flesh with a specialized rasping tongue.In addition to fish, they will also eat small invertebrates and will scavenge dead and dying fish.Food is scarce at these depths, so the hagfish will eat just about anything it can find.Send "Hagfish" Ringtones to Cell Phone!This tree diagram shows the relationships between several groups of organisms.Myxinidae: pair of common external branchial openings.There are about 20 species of hagfish, referred to four genera: Myxine, Neomyxine, Paramyxine, and Eptatretus.The former two possess a single pair of common external gill openings, a character of the Myxinidae.Among craniates, hagfishes are unique in many respects, and this has long been regarded as a consequence of degeneracy due to presumed parasitic habits.However, if hagfishes may penetrate inside dead fishes to eat the liver (their favourite dish!On the contrary, they can be active predators and prey on small invertebrates at night.There is now a broad consensus over the idea that most of these unique anatomical and physiological features of hagfishes are in fact primitive and approach the condition of the common ancestor to all craniates.Hagfishes have an antitropical distribution, most species living in relatively cold waters of the northern and southern hemispheres.Hagfishes are characterized by: Four pairs of tentacles surrounding the mouth and the opening for the nasopharyngeal duct.There are several other characteristics by which hagfishes differ from all other vertebrates, but these are either absences (lack of extrinsic eye muscles, lack of eye lens, lack of cardiac innervation, lack of radial muscles, etc.In both cases, these apparently unique hagfish features are likely to be primitive for all craniates.Instead, the water is inhalated through the nasopharyngeal duct, which opens at the anterior tip of the head.The skeleton of hagfishes is made up by a complex assemblage of cartilaginous bars (see figure on the Craniata page), which serve as antagonists to an equally complex head musculature.There is no detailed phylogeny of hagfishes.However, Myxine and Neomyxine can reasonably be regarded as forming a clade, the Myxinidae, because of their unique pair of external branchial openings.The only fossil hagfishes known to date are Late Carboniferous in age (about 330 million years).They are represented by Myxinikela, from the Pennsylvanian of Illinois, which shares with extant hagfishes the tentacles and long nasopharyngeal duct, but differs from them by its stout body shape and larger caudal fin.Another fossil, Gilpichthys, from the same locality and age, displays nearly the same morphology, except for the tentacles, and is questionably referred to hagfishes.Vertebrata in the current sense.First fossil hagfish (Myxinoidea): a record from the Pennsylvanian of Illinois.New agnathous fishes from the Pennsylvanian of Illinois.The Biology of Myxine, Universitetsforlaget, Oslo.Lampreys and hagfishes: Analysis of cyclostome relationships.Vergleichende Anatomie und Morphologie der Wirberltiere.Feeding mechanisms as evidence for cyclostome monophyly.Zoological Journal of the Linnean Society.Evidence from 18S ribosomal RNA that lampreys and hagfishes form a natural group.Pacific hagfish Eptatretus (top), shows some of the diagnostic features of the group: the tentacles surrounding the snout, the left oesophagocutaneous opening (in the rear of the gill openings), and the series of large, ventrolateral slime glands.The earliest known fossil hagfish, Myxinikela, from the Late Carboniferous of Illinois, had a much stouter body shape but clearly shows the tentacles.First fossil hagfish (Myxinoidea): a record from the Pennsylvanian of Illinois.Page: Tree of Life
Hyperotreti.This page is a
Tree of Life Branch Page.
