Pacific hagfish are a member of one of the most primitive craniate groups. Pacific hagfish have changed little over the past 330 million years, and closely resemble the first craniates. The evolutionary path leading to Homo sapiens probably diverged from hagfish approximately 530 million years ago. Hagfish can go several months without eating. One adult Pacific hagfish can fill a seven-liter bucket with slime in minutes.
Pacific hagfish produce large amounts of mucilaginous slime, and can tie and untie knots in their body to evade predators. The primary predators of Pacific hagfish are harbor seals (Phoca vitulina) and humans. They have also been found in the stomachs of sablefish (Anoplopoma fimbria).
Known Predators:
Pacific hagfish resemble lampreys, being long, tubular, and pinkish grey in color. They lack fins, except for a primitive tail fin that proves useless for propulsion. Their eyes are small and reduced, but Pacific hagfish have a good sense of smell and touch. Their mouth contains a ring of short and sensitive tentacles. Hagfish do not have true jaws, but instead have two pair of rasps on the tongue used for pulling and tearing. Large slime glands run the length of their body near the degenerate lateral line. Hagfish have a partial skull and cartilagenous skeleton. They are from 30 to 63.5 cm in length and from 0.8 to 1.4 kg. Females are typically larger than males.
Range mass: 0.8 to 1.4 kg.
Range length: 30.48 to 63.5 cm.
Other Physical Features: ectothermic ; bilateral symmetry
Sexual Dimorphism: female larger
Estimated life span of Pacific hagfish in the wild is 40 years, and 17 years in captivity.
Typical lifespan
Status: wild: 40 (high) years.
Typical lifespan
Status: captivity: 17 (high) years.
Pacific hagfish are found typically on muddy bottoms to depths of 633 meters, but can also be found occasionally on rocky bottoms. They are more common at shallower depths, from 40 to 100 meters. Pacific hagfish may make small migrations from shallow waters in the fall into deeper water. Although this is unconfirmed, it is consistent with seasonal migrations in other hagfish.
Range depth: 16 to 633 m.
Habitat Regions: temperate ; saltwater or marine
Aquatic Biomes: benthic
Eptatretus stoutii (Pacific hagfish) are found in cold marine waters of the antitropical north and south Pacific Ocean on muddy sea floors.
Biogeographic Regions: pacific ocean (Native )
Pacific hagfish have two pair of primitive, yet effective, rasps on the tongue used primarily for grasping. After establishing a firm hold on a food source, the hagfish ties and unties a knot within its own body to generate a ripping force. Pacific hagfish feed on a variety of dead or dying organisms, including fish and mammals, but also probably include marine invertebrates in their diet. Male hagfish may eat hagfish eggs.
Animal Foods: mammals; fish; eggs; carrion ; aquatic or marine worms; other marine invertebrates
Primary Diet: carnivore (Scavenger )
Pacific hagfish are crucial for eliminating dead and dying organsims, and the effect of large-scale removal on the ecosystem could be significant as hagfish are important for recycling nutrients.
Ecosystem Impact: biodegradation ; parasite
In Korea, approximately 5 million pounds of Pacific hagfish meat is consumed yearly, and in many countries the skin is commonly processed into "eelskin" accessories such as purses, wallets, and boots. Hagfish are sometimes found in public aquariums, and their very low metabolic rate is of specific research interest.
Positive Impacts: food ; body parts are source of valuable material; research and education
There are no negative impacts of Pacific hagfish on humans.
Pacific hagfish hatch from an egg in fully functional form without any intermediate larval stage. Determining the sex of Pacific hagfish below 35 cm in length is difficult as a copulatory organ is absent. Despite over a century of searching, only 200 fertilized eggs of Eptatretus stoutii have been found in Monterey Bay, California.
Pacific hagfish remain common throughout their range.
US Federal List: no special status
CITES: no special status
IUCN Red List of Threatened Species: no special status
A system of sensory organs resembling taste buds, called Schreiner organs, are found throughout the epidermis. The distribution of these organs is more extensive than taste buds in nearly any vertebrate, giving hagfish the ability to sense prey in dark and muddy habitats. This sensory system has no direct homologue in vertebrates and seems specific to hagfish. Hagfish also have well-developed nasal organs used in olfaction.
Perception Channels: chemical
Hagfish reproduction is poorly understood, but evidence has been found indicating sequential hermaphroditic periods thought to arise from population pressures.
Sexes are separate, but hermaphroditic adults can be found. No specific spawning season has been identified as males and females are found at various maturation stages throughout the year. Some females have been found with distinctly separate egg batches in them. Smaller sized egg batches do not develop further until the larger batch has completed development. From 20 to 30 eggs are usually deposited at a time. Eggs have been found at depths of 15 to 25 meters. Age is difficult to determine, as hagfish have a cartilagenous skeleton.
Breeding interval: Breeding intervals are unknown, but there is some evidence that individuals breed once yearly.
Breeding season: There is no evidence of a breeding season.
Range number of offspring: 20 to 30.
Key Reproductive Features: gonochoric/gonochoristic/dioecious (sexes separate); sequential hermaphrodite; sexual ; oviparous
Pacific hagfish hatch into fully functional, small hagfish. There is no parental involvement after egg-laying.
Parental Investment: pre-fertilization (Provisioning, Protecting: Female)
The Pacific hagfish (Eptatretus stoutii) is a species of hagfish. It lives in the mesopelagic to abyssal Pacific ocean, near the ocean floor. It is a jawless fish, a throwback to the Paleozoic Era when fish evolved. Deep-sea diving equipment is known to have been fouled by large amounts of hagfish slime near the bottom of the ocean, extruded by the eel-like fish when they are alarmed.
The hagfish is notorious for its slimy skin. When disturbed, it oozes proteins from slime glands in its skin that respond to water by becoming a slimy outer coating, expanding it into a huge mass of slime. This makes them very unsavory to predators. Hagfish create large amounts of slime in just minutes. One scientist researching this protein excretion concluded that a single hagfish could fill an entire barrel with slime in less than 100 minutes.[1]
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"[2] (hagfish are not true eels, which are bony fish with jaws).
The 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.
The hagfish has feelers that enable it to find food more easily. It is an opportunistic feeder, and eats dead and rotting animals that float down from the pelagic zone of the ocean. Swarms of hagfish will descend upon and penetrate the carcass and devour it from the inside out. This mode of marine waste disposal allows the hagfish to efficiently gain nutrients. The resultant rarity of rotting animals on the sea floor is one of the factors that modulates global cycles of phosphorus, carbon and nitrogen.
This fish is often referred to as the "slime eel". This is an incorrect common name / nickname.
From Wikipedia 2013
The Pacific hagfish (Eptatretus stoutii) 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 fish. They are able to excrete prodigious amounts of slime in self-defense.
The Pacific hagfish has a long, eel-like body, but is not closely related to eels. Maximum body lengths of 63 cm (25 in) have been reported; typical length at maturity is around 42 cm (17 in). It is dark brown, gray or brownish red, often tinted with blue or purple. The belly is lighter and sometimes has larger white patches. It has no true fins, but there is a dorsal fin-fold. The head, as in all agnathans, does not have jaws, and the sucker-like mouth is always open.[4] The Pacific hagfish confused the scientists at first because Linnaeus mistakenly classified the organism as an "intestinal worm".[5]
Hagfish have loosely fitting, slimy skins, and are notorious for their slime-production capability. When disturbed, they ooze proteins from slime glands in the skin that respond to water by becoming a slimy outer coating, expanding into a huge mass of slime. This makes the fish very unsavory to predators, and can even be used to clog the gills of predatory fish. Pacific hagfish can create large amounts of slime in just minutes.[6] The slime is notoriously difficult to remove from fishing gear and equipment, and has led to Pacific fishermen bestowing the nickname of 'slime eel' on the species.[7]
Hagfish also possess the unique ability to tie their bodies into knots. This adaptation becomes useful when the fish needs to remove the suffocating nature of its own slime by pulling itself through a knot. The knots also provide aid in the process of ripping apart meat.[8]
The Pacific hagfish occurs in the Eastern North Pacific from Canada to Mexico. It inhabits fine silt and clay bottoms on the continental shelves and upper slopes at depths from 16–966 metres (52–3,169 ft). The species appears to be abundant within its range.[1]
While Pacific hagfish likely take polychaete worms and other invertebrates from the sea floor, they are also known to enter dead, dying or inhibited large fish through the mouth or the anus, and feed on their viscera.[4]
The diet of other hagfish species includes shrimps, hermit crabs, cephalopods, brittlestars, bony fishes, sharks, birds and whale flesh,[9] but specific information about the Pacific hagfish is lacking.
The Pacific hagfish's skin can absorb amino acids.[10]
Hagfish fertilise their eggs externally after the female has laid them. On average females lay about 28 eggs, about 5 mm (0.20 in) in diameter, which are carried around after they have been fertilised. Females will however try to stay in their burrows during this period to ensure the protection of their eggs.[11]
There is a well-developed hagfish fishery on the US West Coast that mostly supplies the Asian leather-market. Hagfish-skin clothing, belts, or other accessories are advertised and sold as "yuppie leather" or "eel-skin".[11][1]
The Pacific hagfish (Eptatretus stoutii) 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 fish. They are able to excrete prodigious amounts of slime in self-defense.
