Myxine glutinosa

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Myxine glutinosa
Atlantic Hagfish (Myxine glutinosa).jpg
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Myxini
Order: Myxiniformes
Family: Myxinidae
Genus: Myxine
Species:
M. glutinosa
Binomial name
Myxine glutinosa
Synonyms [1] [2]
  • Gasterobranchus glutinosus(Linnaeus, 1758)
  • Gastrobranchus coecusBloch, 1791
  •  ?Myxine glutinosa var. septentrionalisPutnam, 1874
  • Myxine glutinosa var. limosaPutnam, 1874
  • Myxine glutinosa var. australisPutnam, 1874
  • Myzinus glutinosus(Linnaeus, 1758)
  • Petromyzon myxineWalbaum, 1792

Myxine glutinosa, also known as the Atlantic hagfish, is a type of jawless fish belonging to the class Myxini. .

Contents

Description

The Atlantic hagfish may grow up to .75 metres (2+1⁄2 ft) long, with no eyes and no jaws; its star-shaped mouth is surrounded by 6 mouth barbels. [3] Their eyes also lack a lens and pigment (features found in the eyes of all other living vertebrates. [4] There is a single gill slit on each side of the eel-like body. [3] It has a total of 88–102 pores fro which it can exude a slimy mucus. [5] Hagfish have very flexible bodies which allow them to manipulate themselves into knots. The knots created by the hagfish remove mucus from the body, allow them to escape tight spaces, pull potential prey from burrows, and because they have no opposable jaws it helps create leverage while they eat. [6]

Similar species

A related species, the Gulf hagfish ( Eptatretus springeri ), occurs in the Gulf of Mexico. [7] To distinguish these two types of hagfishes, we can look at their lateral line and eyes, the Myxine glutinosa has no lateral line system and also an unpigmented, cornea-like window in the skin overlying the eye. [8]

Distribution

The distribution of Myxine glutinosa in the eastern Atlantic Ocean extends from the western Mediterranean Sea and Portugal to the North Sea, Skagerrak, Kattegat and the Varanger Fjord. [5] It is also found in the western Atlantic Ocean from Baffin Island, Canada south to North Carolina. [3] They live on muddy ocean floors at depth ranges of about 20 to 1000 meters. [9]

Biology

Just like most fish that live on the bottom, the Atlantic Hagfish’s body color on the dorsal side varies depending on the color of the bottom of the ocean. The most common colors are brown, reddish or purplish, brown, or grey, as for the ventral side the color will be paler. [9]

There are differences in the lateral line system among different types of hagfish as well. Instead of having a simple form of a lateral system like the hagfish Eptatretus, an adult Myxine glutinosa has no lateral line system. [10]

What’s more, there are lots of special things about the Atlantic Hagfish. Plenty of discussions on the evolutional information and the morphology of the Myxine Glutinosa eyes, some scientists were trying to compare it with the retina of lampreys- the Atlantic Hagfish possesses a more ancestral vertebrate eye form, and the lamprey possesses a more derived form. Some other scientists were suggesting the Atlantic Hagfish may have possessed more complex eyes that regressed due to the environmental factors like little to no light or the need of burrowing. [11] Besides the fact that the eyes of Myxine glutinosa lack both a lens and a vitreous body, experimental studies carried out by Newth and Ross (1955) also suggested that the eye of Myxine glutinosa lacks a photoreceptive function. [11] Kaj Holmberg mentioned how each hagfish species has differentiated external appearances, and the Myxine glutinosa has an unpigmented, cornea-like window in the skin overlying the eye. Finally, some previous works on Myxine glutinosa have led to the conclusion that the retina in these animals is functionless, but the electrophysiological experiments by Kobayashi (1964) showed the eye of Myxine garmani (a close-related species) can respond to light stimulation, which makes it conceivable to think that Myxine glutinosa can respond to light stimulation. [11]

The respiratory anatomy for the Myxine glutinosa is similar to other hagfish- with a single, median nostril at the tip of the snout surrounded by two pairs of barbels. During the process, water will flow into this median nasal into the pharynx and reach every gill pouch. [12]

Mucus

The Atlantic Hagfish are known for their ability to produce slime- a thick, transparent gel that is cohesive and substantial. [13] Myxine glutinosa can secrete 2 types of slimes, one of them is the epidermal mucus and the second one is the extruded slime. Epidermal mucus helps the prevention of pathogen and is produced all the time while the extruded slime is only observed during feeding, provocation or stress. [14]

This slime is not produced by the hagfish directly, the glands inside the hagfish’s body excrete things called "pre-slime", which are a bunch of protein molecules that can expand in volume when react with water. Another thing that is involved in producing those slimes is the "threads" that are produced by the thread cells in their glands, those threads will unravel when they touch the seawater. When those 2 things mix at the same time to the seawater, the slime appears in just a fraction of a second. [13] [15]

Different species of hagfish also have different slime compositions, and, of course, the slime refilling time, it is believed that it usually takes about 3 to 4 weeks for the slime glands to fully refill. [16] This slime is vital to the survival of the Atlantic hagfish, it can distract and affect predators’ respiratory system, reducing the force of squeezing into big food. And when the hagfish no longer need the slime, they will form the "body knot" to scrape off all the slime on the body from the head to the tail. [13]

More recent research has revealed the active-hunting activities that this species of hagfish has. Furthermore, although this type of hagfish seems to be primitive, its simple body displays a great amount of dexterity. This is also related to how they can form the body knot- as the previous part indicates, the knot can be forcefully propagated in both directions to escape from predators or gain leverage for tearing apart large chunks of food. This leads to the continuous study of hagfish locomotion and keep improving our understanding of the collective diversity in elongate animals. [17]

Additionally, there are differences in the lateral line system among different types of hagfish. Instead of having a simple form of a lateral system like the hagfish Eptatretus, an adult Myxine glutinosa has no lateral line system. [10]

Scientists often compare Hagfish and lampreys because both are referred to as jawless fish (agnathans). They are the only survivors from the Agnathan stage during the vertebrate evolution. [18] Gnathostomes (jawed vertebrates) also share a common ancestor with those hagfish. [18] [19]

Reproduction

While there are no documented answers as to how hagfish reproduce, some scientists suggested that the Atlantic hagfish’s reproduction takes place at a depth more than 30 fathoms 50 meters and the eggs are fertilized externally and anchored by hooks not far from where they were extruded. Although some elements are still missing, there are some pieces of new evidence saying that the Myxine glutinosa may have a seasonal reproductive cycle. [20] This evidence includes data corresponding to gonadal reproductive stages. This recent data provides important information for the East Coast fisheries management department as there aren’t many policies regarding fishing on these hagfish. [20]

Ecology

The Atlantic hagfish, M. glutinosa can be found within the Gulf of Maine at depths greater than 50, with soft bottom sediments. Those hagfish usually occupy shallow burrows parallel to the surface. The environment they prefer usually contains a high volume of clay, silt, sand or gravel and this explains why we usually find a muddy and flocculent layer covering these substrata. It is believed that this layer reduces the friction on hagfish skin.  This leads to the Atlantic hagfish’s adaptations of the hypoxic environment, they have a larger blood volume, about 3 times that of other fishes. [21] Its notochord is also studied a lot due to the unique characteristics on the unusual biochemical, molecular and biomechanical properties. Some reasons for the unique kinematic characteristics of the Atlantic hagfish swimming are also related to its notochord physical properties. [22]

The Atlantic Hagfish, Myxine glutinosa has a scavenging feeding style and they primarily feed on dead or dying marine animals. [9] [23] Some recent studies also suggest that they are more likely an opportunistic feeder as they will eat smaller crustaceans and worms. [13] Moreover, Myxine glutinosa also will bury themselves into the mud to rest like other hagfishes during the day and emerge out at night to hunt. [13] They have an excellent sense of smell and touch as food resources deep in the ocean are scarce, this can help them feed on the ocean bottom. And when they are eating, the hagfish will first protract and retract their plates to create a hole for securing purpose. The consuming process begins by them entering the existing hole and [they also prefer to eat from inside]. Those hagfish used to be believed to be parasites due to this behavior. [9]

When it comes to its tolerance towards the water parameter. The Atlantic hagfish cannot stand sudden changes in temperature but the range of their tolerances on temperature can vary from 0 °C to 20 °C, the Atlantic hagfish is generally believed to be the species that can tolerate the coldest temperatures from 0–4 °C. [23] And for salinity, it is a liming factor for all hagfish, the Atlantic hagfish favors ppt at around 32 to 32ppt or a little bit above. From previous studies, salinity with 20–25ppt is lethal to those hagfish and with a salinity of 29–31 ppt they can survive a few weeks but won’t eat anything at all. For the Atlantic Hagfish, salinity changes are just as lethal as the temperature, when M.glutinosa was exposed to salinities below 31ppt they will start struggling and become moribund. [23]

As for the predation of the Atlantic Hagfish. Some predators that consume M.glutinosa are Harbor porpoise (consumes more adult hagfish), and Codfish with many other fishes that feed on small hagfish eggs. [23]

The Atlantic hagfish population is hard to estimate due to their burrowing habits. This is further tested by scientists when they placed bait, Cole (1913) states that ‘they may be as plentiful as earthworms’. [12] There were also shifts for the population, their population is currently affected by changes in the local ecosystem, substrate alternation, and fishing pressure. [23]

Conservation

Although the Atlantic hagfish are in IUCN’s Least Concern group, it is important to keep their Population. This is also related to their limited reproduction potential. [24]

Not to mention, there are also no specific conservation actions on the Atlantic Hagfish.

Relationship with humans

There are way more things people can do to these hagfish rather than fishing as food resources.

For example, the experiment conducted on the dumped chemical warfare agents in the Skagerrak, scientists used the Atlantic hagfish as the bioindicator species to test the contamination on the chemical at certain sites. By comparing their liver lesions (abnormal cell growths in the liver) they can have a better look at the influence those chemical agents have towards the environment. [25]

Related Research Articles

<span class="mw-page-title-main">Overhand knot</span> Type of knot

The overhand knot is one of the most fundamental knots, and it forms the basis of many others, including the simple noose, overhand loop, angler's loop, reef knot, fisherman's knot, half hitch, and water knot. The overhand knot is a stopper, especially when used alone, and hence it is very secure, to the point of jamming badly. It should be used if the knot is intended to be permanent. It is often used to prevent the end of a rope from unraveling. An overhand knot becomes a trefoil knot, a true knot in the mathematical sense, by joining the ends. It can also be adjusted, faired, or mis-tied as a half hitch.

<span class="mw-page-title-main">Hagfish</span> Family of eel-shaped, slime-producing animal

Hagfish, of the class Myxini and order Myxiniformes, are eel-shaped jawless fish. Hagfish are the only known living animals that have a skull but no vertebral column, although they do have rudimentary vertebrae. Hagfish are marine predators and scavengers who can defend themselves against other larger predators by releasing copious amounts of slime from mucous glands in their skin.

<span class="mw-page-title-main">Agnatha</span> Infraphylum of jawless fish

Agnatha is a paraphyletic infraphylum of non-gnathostome vertebrates, or jawless fish, in the phylum Chordata, subphylum Vertebrata, consisting of both living (cyclostomes) and extinct. Among recent animals, cyclostomes are sister to all vertebrates with jaws, known as gnathostomes.

<span class="mw-page-title-main">Fish anatomy</span> Study of the form or morphology of fishes

Fish anatomy is the study of the form or morphology of fish. It can be contrasted with fish physiology, which is the study of how the component parts of fish function together in the living fish. In practice, fish anatomy and fish physiology complement each other, the former dealing with the structure of a fish, its organs or component parts and how they are put together, such as might be observed on the dissecting table or under the microscope, and the latter dealing with how those components function together in living fish.

<span class="mw-page-title-main">Craniate</span> Clade of chordates, member of the Craniata

A craniate is a member of the Craniata, a proposed clade of chordate animals with a skull of hard bone or cartilage. Living representatives are the Myxini (hagfishes), Hyperoartia, and the much more numerous Gnathostomata. Formerly distinct from vertebrates by excluding hagfish, molecular and anatomical research in the 21st century has led to the reinclusion of hagfish as vertebrates, making living craniates synonymous with living vertebrates.

<span class="mw-page-title-main">Ostracoderm</span> Armored jawless fish of the Paleozoic

Ostracoderms are the armored jawless fish of the Paleozoic Era. The term does not often appear in classifications today because it is paraphyletic and thus does not correspond to one evolutionary lineage. However, the term is still used as an informal way of loosely grouping together the armored jawless fishes.

<span class="mw-page-title-main">Cyclostomi</span> Superclass of jawless fishes

Cyclostomi, often referred to as Cyclostomata, is a group of vertebrates that comprises the living jawless fishes: the lampreys and hagfishes. Both groups have jawless mouths with horny epidermal structures that function as teeth called ceratodontes, and branchial arches that are internally positioned instead of external as in the related jawed fishes. The name Cyclostomi means "round mouths". It was named by Joan Crockford-Beattie.

<i>Eptatretus springeri</i> Species of jawless fish

Eptatretus springeri, the Gulf hagfish, is a bathydemersal vertebrate which lives primarily in the northeastern Gulf of Mexico. It has been observed feeding at and around brine pools: areas of high salinity which resemble lakes on the ocean floor that do not mix with the surrounding water due to difference in density. The high salt content, approximately 200 ppt compared to 35 ppt for standard seawater, creates a buoyant surface which renders oceanic submersibles unable to descend into the pool. It is believed that the inside of the pools only supports microbial life, while the majority of macroscopic life, such as methane-utilizing mussels, exists on the edges. The Gulf hagfish feeds on the primary producers of these environments, as well as other predators.

The snubnosed eel, Simenchelys parasitica, also known as the pug-nosed eel, slime eel, or snub-nose parasitic eel, is a species of deep-sea eel and the only member of its genus. Some authors classify it as the sole member of the subfamily Simenchelyinae of the family Synaphobranchidae, or cutthroat eels, while others place it in its own monotypic family, the Simenchelyidae. It is found in the Atlantic and Pacific Oceans, typically at a depth of 500–1,800 m (1,600–5,900 ft) near the bottom. Although typically a scavenger, it is better known for using its powerful jaws and teeth to burrow into larger fishes as a parasite. This species is harmless to humans and of no interest to fisheries. The generic name Simenchelys translates literally as "pug-nosed eel".

<span class="mw-page-title-main">Broadgilled hagfish</span> Species of jawless fish

The broadgilled hagfish or New Zealand hagfish, also known by its Māori language name tuere, is a hagfish found around New Zealand and the Chatham Islands as well as around the south and east coasts of Australia, at depths between 1 and 900 metres.

<span class="mw-page-title-main">Pacific hagfish</span> Species of jawless fish

The Pacific hagfish is a species of hagfish. It lives in the mesopelagic to abyssal Pacific Ocean, near the ocean floor. It is a jawless fish and has a body plan that resembles early Paleozoic fishes. They can excrete copious amounts of slime in self-defense.

<i>Eptatretus</i> Genus of jawless fishes

Eptatretus is a large genus of hagfish.

<span class="mw-page-title-main">Inshore hagfish</span> Species of jawless fish

The inshore hagfish is a hagfish found in the Northwest Pacific, from the Sea of Japan and across eastern Japan to Taiwan. It has six pairs of gill pouches and gill apertures. These hagfish are found in the sublittoral zone. They live usually buried in the bottom mud and migrate into deeper water to spawn. The inshore hagfish is the only member of the Myxinidae family having a seasonal reproductive cycle.

<i>Myxine</i> Genus of jawless fishes

Myxine is a genus of hagfish, from the Greek μυξῖνος. It is the type genus of the class Myxini.

<span class="mw-page-title-main">Southern hagfish</span> Species of jawless fish

The southern hagfish is a hagfish of the genus Myxine.

<span class="mw-page-title-main">Fish scale</span> Hard skeletal covering of fish

A fish scale is a small rigid plate that grows out of the skin of a fish. The skin of most jawed fishes is covered with these protective scales, which can also provide effective camouflage through the use of reflection and colouration, as well as possible hydrodynamic advantages. The term scale derives from the Old French escale, meaning a shell pod or husk.

Rubicundus is a genus of hagfishes, the only extant member of the subfamily Rubicundinae. All species in it were formerly classified in Eptatretus. R. eos, R. lakeside, and R. rubicundus are known from single specimens caught in the Tasman Sea, Galápagos, and Taiwan, respectively. They are named after the distinctive red coloration that all species share.

The white-headed hagfish is a species of jawless fish of the family Myxinidae (hagfish).

Myxine limosa, or Girard's Atlantic hagfish, is a jawless fish in the genus Myxine.

Rubicundus lopheliae, the lophelia hagfish, is a species of jawless fish in the family Myxinidae.

References

  1. ↑ Froese, R.; Pauly, D. (2017). "Myxinidae". FishBase version (02/2017). Retrieved 18 May 2017.
  2. ↑ Van Der Laan, Richard; Eschmeyer, William N.; Fricke, Ronald (11 November 2014). "Family-group names of Recent fishes". Zootaxa. 3882 (1): 1–230. doi: 10.11646/zootaxa.3882.1.1 . PMID   25543675.
  3. 1 2 3 Michael Filisky & Roger Tory Peterson (1998). "Atlantic Hagfish". Peterson First Guide to Fishes of North America (2nd ed.). Houghton Mifflin Harcourt. p. 10. ISBN   978-0-395-91179-2.
  4. ↑ Kaj, Holmberg (1971). The hagfish retina: Electron microscopic study comparing receptor and epithelial cells in the Pacific hagfish, Polistotrema Stouti, with those in the Atlantic hagfish, Myxine glutinosa. Ecology of the Hagfish.
  5. 1 2 P. J. P. Whitehead; M.-L. Bauchot; J.-C. Hureau; J. Nielsen; E. Tortonese, eds. (1986) [1984]. "Hagfish (Myxine glutinosa)". Fishes of the NE Atlantic and the Mediterranean.
  6. ↑ Haney, W. A., Clark, A. J., & Uyeno, T. A. (2019). Characterization of body knotting behavior used for escape in a diversity of hagfishes. Journal of Zoology. doi: 10.1111/jzo.12752
  7. ↑ Edwin S. Iversen & Renate H. Skinner (2006). "Atlantic hagfish Myxine glutinosa". Dangerous Sea Life of the West Atlantic, Caribbean, and Gulf of Mexico: A Guide for Accident Prevention and First Aid. Pineapple Press. p. 72. ISBN   978-1-56164-370-7.
  8. ↑ Holmberg, Kaj (1971). The hagfish retina: Electron microscopic study comparing receptor and epithelial cells in the Pacific hagfish, Polistotrema Stouti, with those in the Atlantic hagfish, Myxine glutinosa (121 ed.). Ecology of the Hagfish, Myxine Glutinosa L. in the Gulf of Maine. pp. 249–269.
  9. 1 2 3 4 "Pacific Hagfish Enhanced Status Report". CA Marine Species Portal. 2024.
  10. 1 2 Andres, K.H., and M. Von Düring (March 1993). "Lamellated receptors in the skin of the hagfish, Myxine glutinosa". Neuroscience Letters. 151 (1): 74–76. doi:10.1016/0304-3940(93)90049-Q. PMID   8469440.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  11. 1 2 3 Bradshaw, Sarah N., and W. Ted Allison. (2022). "Hagfish to illuminate the developmental and evolutionary origins of the vertebrate retina". Frontiers in Cell and Developmental Biology. 10. doi: 10.3389/fcell.2022.822358 . PMC   8826474 . PMID   35155434.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  12. 1 2 Lesser, M. P., F. H. Martini, and J. B. Heiser. (1997). "Ecology of the hagfish, Myxine glutinosa L. in the Gulf of Maine I. metabolic rates and Energetics". Journal of Experimental Marine Biology and Ecology. 208 (1–2): 215–225. doi:10.1016/s0022-0981(96)02665-2.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  13. 1 2 3 4 5 Alaska department of fish and game. (2024). "Hagfish Species Profile".
  14. ↑ Subramanian, S., N. W. Ross, and S. L. MacKinnon. (2008). "Comparison of the biochemical composition of normal epidermal mucus and extruded slime of hagfish (Myxine glutinosa L.)". Fish & Shellfish Immunology. 25 (5): 625–632. doi:10.1016/j.fsi.2008.08.012. PMID   18817881.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  15. ↑ Jørgensen, Jørgen Mørup; et al. (2012). Biology of Hagfishes. Springer Netherlands. pp. 57–68.
  16. ↑ Schorno, S., T. E. Gillis, and D. S. Fudge. (1 January 2018). "Emptying and refilling of slime glands in Atlantic (myxine glutinosa) and Pacific (eptatretus stoutii) hagfishes". Journal of Experimental Biology. 221 (Pt 7). doi:10.1242/jeb.172254. PMID   29487153.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  17. ↑ Lim, J.L., and T.M. Winegard. (2015). "Diverse anguilliform swimming kinematics in Pacific hagfish (eptatretusstoutii) and Atlantic Hagfish (myxineglutinosa)". Canadian Journal of Zoology. 93 (3): 213–223. doi:10.1139/cjz-2014-0260.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  18. 1 2 Grant, M. A., D. L. Beeler, K. C. Spokes, J. Chen, H. Dharaneeswaran, T. E. Sciuto, A. M. Dvorak, G. Interlandi, J. A. Lopez, and W. C. Aird. (7 December 2017). "Identification of extant vertebrate myxine glutinosa VWF: Evolutionary conservation of primary hemostasis". Blood. 130 (23): 2548–2558. doi:10.1182/blood-2017-02-770792. PMC   5721281 .{{cite journal}}: CS1 maint: multiple names: authors list (link)
  19. ↑ Foster, Glen D., and T. W. Moon. (1986). "Enzyme activities in the Atlantic hagfish, myxine glutinosa: Changes with captivity and food deprivation". Canadian Journal of Zoology. 64 (5): 1080–1085. doi:10.1139/z86-162.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  20. 1 2 Powell, M. L. (1 January 2005). "Current knowledge of hagfish reproduction: Implications for fisheries management". Integrative and Comparative Biology. 45 (1): 158–165. doi:10.1093/icb/45.1.158. PMID   21676757.
  21. ↑ Lesser, M. P., F. H. Martini, and J. B. Heiser. (2012). "Ecology of the hagfish, Myxine glutinosa L. in the Gulf of Maine I. metabolic rates and Energetics". Journal of Experimental Marine Biology and Ecology. 208 (1–2): 215–225. doi:10.1016/s0022-0981(96)02665-2.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  22. ↑ Long, J. H., Jr., M. Koob-Emunds, B. Sinwell, and T. J. Koob (15 December 2002). "The notochord of hagfishmyxine glutinosa: Visco-elastic properties and mechanical functions during steady swimming". Journal of Experimental Biology. 205 (24): 3819–3831. doi:10.1242/jeb.205.24.3819.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  23. 1 2 3 4 5 Jorgensen, Jørgen Mørup (2012). Biology of Hagfishes. Springer Netherlands. pp. 57–68.
  24. ↑ Powell, M. L. (1 January 2005). "Current knowledge of hagfish reproduction: Implications for fisheries management". Integrative and Comparative Biology. 45 (1): 158–165. doi:10.1093/icb/45.1.158. PMID   21676757.
  25. ↑ Ahvo, A., K. K. Lehtonen, A. Lastumäki, K. Straumer, M. Kraugerud, S. W. Feist, T. Lang, and J. A. Tørnes. (December 2020). "The use of Atlantic hagfish (Myxine glutinosa) as a bioindicator species for studies on effects of dumped chemical warfare agents in the Skagerrak. 2. biochemical biomarkers". Marine Environmental Research. 162: 105097. doi:10.1016/j.marenvres.2020.105097. PMID   32992222.{{cite journal}}: CS1 maint: multiple names: authors list (link)

Haney, W. A., Clark, A. J., & Uyeno, T. A. (2019). Characterization of body knotting behavior used for escape in a diversity of hagfishes. Journal of Zoology. doi: 10.1111/jzo.12752

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