![Representatives of ceratioid families](https://upload.wikimedia.org/wikipedia/commons/5/5a/Representatives_of_ceratioid_families.jpg)
The anglerfish are
fish
Fish are aquatic, craniate, gill-bearing animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish as well as various extinct related groups. Approximately 95% of li ...
of the
teleost
Teleostei (; Greek ''teleios'' "complete" + ''osteon'' "bone"), members of which are known as teleosts ), is, by far, the largest infraclass in the class Actinopterygii, the ray-finned fishes, containing 96% of all extant species of fish. Tel ...
order Lophiiformes ().
They are
bony fish
Osteichthyes (), popularly referred to as the bony fish, is a diverse superclass of fish that have skeletons primarily composed of bone tissue. They can be contrasted with the Chondrichthyes, which have skeletons primarily composed of cartilag ...
named for their characteristic mode of
predation
Predation is a biological interaction where one organism, the predator, kills and eats another organism, its prey. It is one of a family of common feeding behaviours that includes parasitism and micropredation (which usually do not kill the ...
, in which a modified luminescent
fin ray
Fins are distinctive anatomical features composed of bony spines or rays protruding from the body of a fish. They are covered with skin and joined together either in a webbed fashion, as seen in most bony fish, or similar to a flipper, as see ...
(the esca or illicium) acts as a
lure for other fish. The luminescence comes from symbiotic bacteria, which are thought to be acquired from seawater,
that dwell in and around the sea.
Some anglerfish are notable for extreme
sexual dimorphism
Sexual dimorphism is the condition where the sexes of the same animal and/or plant species exhibit different morphological characteristics, particularly characteristics not directly involved in reproduction. The condition occurs in most ani ...
and sexual
symbiosis
Symbiosis (from Greek , , "living together", from , , "together", and , bíōsis, "living") is any type of a close and long-term biological interaction between two different biological organisms, be it mutualistic, commensalistic, or parasit ...
of the small male with the much larger female, seen in the suborder
Ceratioidei, the deep sea anglerfish. In these species, males may be several
orders of magnitude
An order of magnitude is an approximation of the logarithm of a value relative to some contextually understood reference value, usually 10, interpreted as the base of the logarithm and the representative of values of magnitude one. Logarithmic dis ...
smaller than females.
Anglerfish occur worldwide. Some are
pelagic
The pelagic zone consists of the water column of the open ocean, and can be further divided into regions by depth (as illustrated on the right). The word ''pelagic'' is derived . The pelagic zone can be thought of as an imaginary cylinder or wa ...
(dwelling away from the sea floor), while others are
benthic
The benthic zone is the ecological region at the lowest level of a body of water such as an ocean, lake, or stream, including the sediment surface and some sub-surface layers. The name comes from ancient Greek, βένθος (bénthos), meaning "t ...
(dwelling close to the sea floor). Some live in the deep sea (such as the
Ceratiidae), while others on the
continental shelf
A continental shelf is a portion of a continent that is submerged under an area of relatively shallow water, known as a shelf sea. Much of these shelves were exposed by drops in sea level during glacial periods. The shelf surrounding an island ...
, such as the
frogfishes and the
Lophiidae (monkfish or goosefish). Pelagic forms are most often
laterally compressed, whereas the benthic forms are often extremely
dorsoventrally
Standard anatomical terms of location are used to unambiguously describe the anatomy of animals, including humans. The terms, typically derived from Latin or Greek roots, describe something in its standard anatomical position. This position prov ...
compressed (depressed), often with large upward-pointing mouths.
Evolution
A
mitochondrial genome
Mitochondrial DNA (mtDNA or mDNA) is the DNA located in mitochondria, cellular organelles within eukaryotic cells that convert chemical energy from food into a form that cells can use, such as adenosine triphosphate (ATP). Mitochondrial D ...
phylogenetic study suggested the anglerfishes diversified in a short period of the early to mid-
Cretaceous
The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of th ...
, between 130 and 100 million years ago.
Classification
FishBase
FishBase is a global species database of fish species (specifically finfish). It is the largest and most extensively accessed online database on adult finfish on the web. ,
Nelson, and Pietsch
list 18 families, but
ITIS
The Integrated Taxonomic Information System (ITIS) is an American partnership of federal agencies designed to provide consistent and reliable information on the taxonomy of biological species. ITIS was originally formed in 1996 as an interagenc ...
lists only 16. The following taxa have been arranged to show their evolutionary relationships.
* Suborder Lophoiodei
**
Lophiidae (goosefishes or monkfishes)
* Suborder Antennarioidei
**
Antennariidae (frogfishes)
**
Tetrabrachiidae
Tetrabrachiidae, or the four-armed frogfishes, is a family of anglerfishes found in relatively shallow waters of the eastern Indian Ocean and western Pacific Ocean reaching from Indonesia and New Guinea to Australia
Australia, officiall ...
(four-armed frogfishes)
Boschma's frogfish
''Lophichthys boschmai'', also known as Arafura frogfish or Boschma's frogfish, is a species of anglerfishes closely related to frogfish. ''L. boschmai'' is the only species in the Lophichthydae family. ''L. boschmai'' were first reported by M ...
and the four-armed frogfish
''Tetrabrachium ocellatum'' (four-armed frogfish) is a species of anglerfish, closely related to the true frogfishes. It is the only member of its genus.
Like the true frogfishes, it is a small fish, no more than in length, with a flattened ...
are included in the Antennariidae in ITIS.
**
Brachionichthyidae (handfishes)
**
Lophichthyidae (Boschma's frogfish)
* Suborder Chaunacoidei
**
Chaunacidae (sea toads)
* Suborder Ogcocephaloidei
**
Ogcocephalidae
Ogcocephalidae is a family of anglerfish specifically adapted for a benthic lifestyle of crawling about on the seafloor. Ogcocephalid anglerfish are sometimes referred to as batfishes,[Centrophrynidae
The horned lantern fish or prickly seadevil (''Centrophryne spinulosa'') is a deep-sea anglerfish found worldwide. It is the monotypic, sole species in the family Centrophrynidae, distinguished from other deep-sea anglerfishes by various characte ...]
(prickly seadevils)
**
Ceratiidae (warty seadevils)
**
Himantolophidae
The footballfish form a family, Himantolophidae, of globose, deep-sea anglerfishes found in tropical and subtropical waters of the Atlantic, Indian, and Pacific Ocean. The family contains about 22 species all in a single genus, ''Himantolophus'' ...
(footballfishes)
**
Diceratiidae (doublespine seadevils)
**
Melanocetidae
Black seadevils are small, deepsea lophiiform fishes of the family Melanocetidae. The five known species (with only two given common names) are all within the genus ''Melanocetus''. They are found in tropical to temperate waters of the Atlantic, ...
(black seadevils)
**
Thaumatichthyidae
Thaumatichthyidae, the wolftrap anglers, is a small family of deep-sea anglerfishes, containing two genera and eight species found in all oceans. They are commonly known as wolftrap anglers or wolftrap seadevils because of their distinctive uppe ...
(wolf-trap seadevils)
**
Oneirodidae
The dreamers are a family, Oneirodidae, of deep-sea anglerfishes in the order Lophiiformes. They are the largest and most diverse group of deep-sea anglerfish, and also the least well known with 16 genera represented by only one, two, or three ...
(dreamers)
**
Caulophrynidae (fanfin seadevils)
**
Neoceratiidae (needlebeard seadevil)
**
Gigantactinidae (whipnose seadevils)
**
Linophrynidae (leftvent seadevils)
Anatomy
All anglerfish are
carnivorous
A carnivore , or meat-eater (Latin, ''caro'', genitive ''carnis'', meaning meat or "flesh" and ''vorare'' meaning "to devour"), is an animal or plant whose food and energy requirements derive from animal tissues (mainly muscle, fat and other sof ...
and are thus adapted for the capture of prey. Ranging in color from dark gray to dark brown, deep-sea species have large heads that bear enormous, crescent-shaped mouths full of long, fang-like teeth angled inward for efficient prey grabbing. Their length can vary from , with a few types getting as large as , but this variation is largely due to sexual dimorphism, with females being much larger than males.
Frogfish and other shallow-water anglerfish species are ambush predators, and often appear camouflaged as rocks, sponges or seaweed.
Most adult female ceratioid anglerfish have a luminescent organ called the esca at the tip of a modified dorsal ray (the illicium or fishing rod; derived from
Latin
Latin (, or , ) is a classical language belonging to the Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through the power of the ...
''ēsca'', "bait"). The organ has been hypothesized to serve the obvious purpose of luring prey in dark, deep-sea environments, but also serves to call males' attention to the females to facilitate mating.
The source of luminescence is
symbiotic
Symbiosis (from Greek , , "living together", from , , "together", and , bíōsis, "living") is any type of a close and long-term biological interaction between two different biological organisms, be it mutualistic, commensalistic, or parasit ...
bacteria that dwell in and around the esca, enclosed in a cup-shaped reflector containing crystals, probably consisting of
guanine
Guanine () ( symbol G or Gua) is one of the four main nucleobases found in the nucleic acids DNA and RNA, the others being adenine, cytosine, and thymine (uracil in RNA). In DNA, guanine is paired with cytosine. The guanine nucleoside is called ...
. Only a handful of luminescent symbiont species can associate with deep-sea anglerfishes.
In some species, the bacteria recruited to the esca are incapable of luminescence independent of the anglerfish, suggesting they have developed a symbiotic relationship and the bacteria are unable to synthesize all of the chemicals necessary for luminescence on their own. They depend on the fish to make up the difference. Electron microscopy of these bacteria in some species reveals they are
Gram-negative
Gram-negative bacteria are bacteria that do not retain the crystal violet stain used in the Gram staining method of bacterial differentiation. They are characterized by their cell envelopes, which are composed of a thin peptidoglycan cell wall ...
rods that lack
capsules,
spore
In biology, a spore is a unit of sexual or asexual reproduction that may be adapted for dispersal and for survival, often for extended periods of time, in unfavourable conditions. Spores form part of the life cycles of many plants, algae, f ...
s, or
flagella
A flagellum (; ) is a hairlike appendage that protrudes from certain plant and animal sperm cells, and from a wide range of microorganisms to provide motility. Many protists with flagella are termed as flagellates.
A microorganism may have f ...
. They have double-layered cell walls and
mesosome
Mesosomes or chondrioids are folded invaginations in the plasma membrane of bacteria that are produced by the chemical fixation techniques used to prepare samples for electron microscopy. Although several functions were proposed for these struc ...
s. A pore connects the esca with the seawater, which enables the removal of dead bacteria and cellular waste, and allows the
pH and
tonicity
In chemical biology, tonicity is a measure of the effective osmotic pressure gradient; the water potential of two solutions separated by a partially-permeable cell membrane. Tonicity depends on the relative concentration of selective membrane-im ...
of the
culture medium
A growth medium or culture medium is a solid, liquid, or semi-solid designed to support the growth of a population of microorganisms or cells via the process of cell proliferation or small plants like the moss ''Physcomitrella patens''. Differe ...
to remain constant. This, as well as the constant temperature of the
bathypelagic zone
The bathypelagic zone or bathyal zone (from Greek βαθύς (bathýs), deep) is the part of the open ocean that extends from a depth of below the ocean surface. It lies between the mesopelagic above, and the abyssopelagic below. The bathypelagi ...
inhabited by these fish, is crucial for the long-term viability of bacterial cultures.
The light gland is always open to the exterior, so it is possible that the fish acquires the bacteria from the seawater. However, it appears that each species uses its own particular species of bacteria, and these bacteria have never been found in seawater. Haygood (1993) theorized that esca discharge bacteria during spawning and the bacteria are thereby transferred to the eggs.
Some evidence shows that some anglerfish acquired their bioluminescent symbionts from the local environment. Genetic materials of the symbiont bacteria is found near the anglerfish, indicating that the anglerfish and their associated bacteria are most likely not evolved together and the bacteria take difficult journeys to enter the host.
In a study on Ceratioid anglerfish in the Gulf of Mexico, researchers noticed that the confirmed host-associated bioluminescent microbes are not present in the larval specimens and throughout host development. The Ceratioids likely acquired their bioluminescent symbionts from the seawater.
''
Photobacterium phosphoreum
''Photobacterium phosphoreum'' or ''Vibrio phosphoreum'' is a Gram-negative bioluminescence, bioluminescent bacterium living in symbiosis with marine organisms, such as anglerfish. It can emit bluish-green light (490 nm) due to a chemical r ...
'' and members from kishitanii clade constitute the major or sole bioluminescent symbiont of several families of deep-sea luminous fishes.
It is known that genetic makeup of the symbiont bacteria has undergone changes since they became associated with their host.
Compared to their free-living relatives, deep-sea anglerfish symbiont genomes are reduced in size by 50%. Reductions in amino acid synthesis pathways and abilities to utilize diverse sugars are found. Nevertheless, genes involved in
chemotaxis
Chemotaxis (from '' chemo-'' + ''taxis'') is the movement of an organism or entity in response to a chemical stimulus. Somatic cells, bacteria, and other single-cell or multicellular organisms direct their movements according to certain chemica ...
and motility that are thought to be useful only outside the host are retained in the genome. Symbiont genome contains very high numbers of
pseudogenes
Pseudogenes are nonfunctional segments of DNA that resemble functional genes. Most arise as superfluous copies of functional genes, either directly by DNA duplication or indirectly by reverse transcription of an mRNA transcript. Pseudogenes are ...
and show massive expansions of
transposable elements
A transposable element (TE, transposon, or jumping gene) is a nucleic acid sequence in DNA that can change its position within a genome, sometimes creating or reversing mutations and altering the cell's genetic identity and genome size. Trans ...
. The process of genome reduction is still ongoing in these symbionts lineages, and the gene loss may lead to host dependence.
In most species, a wide mouth extends all around the anterior circumference of the head, and bands of inwardly inclined teeth line both jaws. The teeth can be depressed so as to offer no impediment to an object gliding towards the stomach, but prevent its escape from the mouth.
The anglerfish is able to distend both its jaw and its stomach, since its bones are thin and flexible, to enormous size, allowing it to swallow prey up to twice as large as its entire body.
Behavior
Swimming and energy conservation
In 2005, near
Monterey, California
Monterey (; es, Monterrey; Ohlone: ) is a city located in Monterey County on the southern edge of Monterey Bay on the U.S. state of California's Central Coast. Founded on June 3, 1770, it functioned as the capital of Alta California under bo ...
, at 1,474 metres depth, an
ROV filmed a female ceratioid anglerfish of the genus ''Oneirodes'' for 24 minutes. When approached, the fish retreated rapidly, but in 74% of the video footage, it drifted passively, oriented at any angle. When advancing, it swam intermittently at a speed of 0.24 body lengths per second, beating its pectoral fins in-phase. The lethargic behavior of this
ambush predator
Ambush predators or sit-and-wait predators are carnivorous animals that capture or trap prey via stealth, luring or by (typically instinctive) strategies utilizing an element of surprise. Unlike pursuit predators, who chase to capture prey us ...
is suited to the energy-poor environment of the deep sea.
Another in situ observation of three different whipnose anglerfish showed unusual inverted swimming-behavior. Fish were observed floating inverted completely motionless with the illicium hanging down stiffly in a slight arch in front of the fish. The illicium was hanging over small visible burrows. It was suggested this is an effort to entice prey and an example of low-energy opportunistic foraging and predation. When the ROV approached the fish, they exhibited burst swimming, still inverted.
The jaw and stomach of the anglerfish can extend to allow it to consume prey up to twice its size. Because of the limited amount of food available in the anglerfish's environment, this adaptation allows the anglerfish to store food when there is an abundance.
Predation
![Lophius piscatorius MHNT](https://upload.wikimedia.org/wikipedia/commons/6/6f/Lophius_piscatorius_MHNT.jpg)
The name "anglerfish" derives from the species' characteristic method of predation. Anglerfish typically have at least one long filament sprouting from the middle of their heads, termed the illicium. The illicium is the detached and modified first three spines of the
anterior
Standard anatomical terms of location are used to unambiguously describe the anatomy of animals, including humans. The terms, typically derived from Latin or Greek roots, describe something in its standard anatomical position. This position prov ...
dorsal fin
A dorsal fin is a fin located on the back of most marine and freshwater vertebrates within various taxa of the animal kingdom. Many species of animals possessing dorsal fins are not particularly closely related to each other, though through conv ...
. In most anglerfish species, the longest filament is the first. This first spine protrudes above the fish's eyes and terminates in an irregular growth of flesh (the esca), and can move in all directions. Anglerfish can wiggle the esca to make it
resemble a prey animal, which lures the anglerfish's prey close enough for the anglerfish to devour them whole.
Some deep-sea anglerfish of the
bathypelagic zone
The bathypelagic zone or bathyal zone (from Greek βαθύς (bathýs), deep) is the part of the open ocean that extends from a depth of below the ocean surface. It lies between the mesopelagic above, and the abyssopelagic below. The bathypelagi ...
also emit light from their
esca
The anglerfish are fish of the teleost order Lophiiformes (). They are bony fish named for their characteristic mode of predation, in which a modified luminescent fin ray (the esca or illicium) acts as a lure for other fish. The luminescence ...
to attract prey.
Because anglerfish are opportunistic foragers, they show a range of preferred prey with fish at the extremes of the size spectrum, whilst showing increased selectivity for certain prey. One study examining the stomach contents of threadfin anglerfish off the Pacific coast of Central America found these fish primarily ate two categories of
benthic
The benthic zone is the ecological region at the lowest level of a body of water such as an ocean, lake, or stream, including the sediment surface and some sub-surface layers. The name comes from ancient Greek, βένθος (bénthos), meaning "t ...
prey:
crustaceans
Crustaceans (Crustacea, ) form a large, diverse arthropod taxon which includes such animals as decapods, seed shrimp, branchiopods, fish lice, krill, remipedes, isopods, barnacles, copepods, amphipods and mantis shrimp. The crustacean group ...
and
teleost
Teleostei (; Greek ''teleios'' "complete" + ''osteon'' "bone"), members of which are known as teleosts ), is, by far, the largest infraclass in the class Actinopterygii, the ray-finned fishes, containing 96% of all extant species of fish. Tel ...
fish. The most frequent prey were
pandalid shrimp. 52% of the stomachs examined were empty, supporting the observations that anglerfish are low energy consumers.
Reproduction
![Antennarius striatus](https://upload.wikimedia.org/wikipedia/commons/3/3d/Antennarius_striatus.jpg)
Some anglerfish, like those of the Ceratiidae, or sea devils employ an unusual mating method.
Because individuals are locally rare, encounters are also very rare. Therefore, finding a mate is problematic. When scientists first started capturing ceratioid anglerfish, they noticed that all of the specimens were female. These individuals were a few centimetres in size and almost all of them had what appeared to be
parasites
Parasitism is a Symbiosis, close relationship between species, where one organism, the parasite, lives on or inside another organism, the Host (biology), host, causing it some harm, and is Adaptation, adapted structurally to this way of lif ...
attached to them. It turned out that these "parasites" were highly reduced male ceratioids. This indicates some taxa of anglerfish use a
polyandrous
Polyandry (; ) is a form of polygamy in which a woman takes two or more husbands at the same time. Polyandry is contrasted with polygyny, involving one male and two or more females. If a marriage involves a plural number of "husbands and wives" ...
mating system. In some species of anglerfish, fusion between male and female when reproducing is possible due to the lack of immune system keys that allow antibodies to mature and create receptors for T-cells.
Certain ceratioids rely on
parabiotic reproduction. Free-living males and unparasitized females in these species never have fully developed gonads. Thus, males never mature without attaching to a female, and die if they cannot find one.
At birth, male ceratioids are already equipped with extremely well-developed
olfactory organs that detect scents in the water. Males of some species also develop large, highly specialized eyes that may aid in identifying mates in dark environments. The male ceratioids are significantly smaller than a female anglerfish, and may have trouble finding food in the deep sea. Furthermore, growth of the
alimentary canals of some males becomes stunted, preventing them from feeding. Some taxa have jaws that are never suitable or effective for prey capture.
These features mean the male must quickly find a female anglerfish to prevent death. The sensitive olfactory organs help the male to detect the
pheromone
A pheromone () is a secreted or excreted chemical factor that triggers a social response in members of the same species. Pheromones are chemicals capable of acting like hormones outside the body of the secreting individual, to affect the behavio ...
s that signal the proximity of a female anglerfish.
The methods anglerfish use to locate mates vary. Some species have minute eyes that are unfit for identifying females, while others have underdeveloped nostrils, making them unlikely to effectively find females by scent.
When a male finds a female, he bites into her skin, and releases an
enzyme
Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as products. A ...
that digests the skin of his mouth and her body, fusing the pair down to the blood-vessel level.
The male becomes dependent on the female host for survival by receiving nutrients via their shared circulatory system, and provides sperm to the female in return. After fusing, males increase in volume and become much larger relative to free-living males of the species. They live and remain reproductively functional as long as the female lives, and can take part in multiple spawnings.
This extreme
sexual dimorphism
Sexual dimorphism is the condition where the sexes of the same animal and/or plant species exhibit different morphological characteristics, particularly characteristics not directly involved in reproduction. The condition occurs in most ani ...
ensures that when the female is ready to spawn, she has a mate immediately available.
Multiple males can be incorporated into a single individual female with up to eight males in some species, though some taxa appear to have a "one male per female" rule.
Symbiosis is not the only method of reproduction in anglerfish. In fact, many families, including the
Melanocetidae
Black seadevils are small, deepsea lophiiform fishes of the family Melanocetidae. The five known species (with only two given common names) are all within the genus ''Melanocetus''. They are found in tropical to temperate waters of the Atlantic, ...
,
Himantolophidae
The footballfish form a family, Himantolophidae, of globose, deep-sea anglerfishes found in tropical and subtropical waters of the Atlantic, Indian, and Pacific Ocean. The family contains about 22 species all in a single genus, ''Himantolophus'' ...
,
Diceratiidae, and
Gigantactinidae, show no evidence of male symbiosis.
Females in some of these species contain large, developed ovaries and free-living males have large testes, suggesting these sexually mature individuals may spawn during a temporary sexual attachment that does not involve fusion of tissue. Males in these species also have well-toothed jaws that are far more effective in hunting than those seen in symbiotic species.
Sexual symbiosis may be an optional strategy in some species of anglerfishes.
In the
Oneirodidae
The dreamers are a family, Oneirodidae, of deep-sea anglerfishes in the order Lophiiformes. They are the largest and most diverse group of deep-sea anglerfish, and also the least well known with 16 genera represented by only one, two, or three ...
, females carrying symbiotic males have been reported in ''Leptacanthichthys'' and ''Bertella''—and others that were not still developed fully functional gonads.
One theory suggests the males attach to females regardless of their own reproductive development if the female is not sexually mature, but when both male and female are mature, they spawn then separate.
One explanation for the
evolution
Evolution is change in the heritable characteristics of biological populations over successive generations. These characteristics are the expressions of genes, which are passed on from parent to offspring during reproduction. Variation ...
of sexual symbiosis is that the relatively low density of females in deep-sea environments leaves little opportunity for
mate choice
Mate choice is one of the primary mechanisms under which evolution can occur. It is characterized by a "selective response by animals to particular stimuli" which can be observed as behavior.Bateson, Paul Patrick Gordon. "Mate Choice." Mate Choic ...
among anglerfish. Females remain large to accommodate
fecundity
Fecundity is defined in two ways; in human demography, it is the potential for reproduction of a recorded population as opposed to a sole organism, while in population biology, it is considered similar to fertility, the natural capability to pr ...
, as is evidenced by their large ovaries and eggs. Males would be expected to shrink to reduce metabolic costs in resource-poor environments and would develop highly specialized female-finding abilities. If a male manages to find a female, then symbiotic attachment is ultimately more likely to improve life-time fitness relative to free living, particularly when the prospect of finding future mates is poor. An additional advantage to symbiosis is that the male's sperm can be used in multiple fertilizations, as he always remains available to the female for mating. Higher densities of male-female encounters might correlate with species that demonstrate
facultative symbiosis or simply use a more traditional temporary contact mating.
The spawn of the anglerfish of the genus ''
Lophius
Members of the genus ''Lophius'', also sometimes called monkfish, fishing-frogs, frog-fish, and sea-devils, are various species of lophiid anglerfishes found in the Atlantic and Indian Oceans. ''Lophius'' is known as the "monk" or "monkfish" ...
'' consists of a thin sheet of transparent gelatinous material wide and greater than long. Such an egg sheet is rare among fish. The eggs in this sheet are in a single layer, each in its own cavity. The spawn is free in the sea. The larvae are free-swimming and have the pelvic fins elongated into filaments.
Threats
Northwest European ''
Lophius
Members of the genus ''Lophius'', also sometimes called monkfish, fishing-frogs, frog-fish, and sea-devils, are various species of lophiid anglerfishes found in the Atlantic and Indian Oceans. ''Lophius'' is known as the "monk" or "monkfish" ...
'' species are listed by the
ICES as "outside safe biological limits".
Additionally, anglerfish are known to occasionally rise to the surface during
El Niño
El Niño (; ; ) is the warm phase of the El Niño–Southern Oscillation (ENSO) and is associated with a band of warm ocean water that develops in the central and east-central equatorial Pacific (approximately between the International Date L ...
, leaving large groups of dead anglerfish floating on the surface.
In 2010,
Greenpeace
Greenpeace is an independent global campaigning network, founded in Canada in 1971 by Irving Stowe and Dorothy Stowe, immigrant environmental activists from the United States. Greenpeace states its goal is to "ensure the ability of the Earth t ...
International added the American angler (''
Lophius americanus
''Lophius americanus'' is a goosefish in the family Lophiidae, also called all-mouth, American anglerfish, bellows-fish, devil-fish, headfish, molligut, satchel-mouth, or wide-gape. It is native to the eastern coast of North America.
Descr ...
''), the angler (''
Lophius piscatorius
''Lophius piscatorius'', commonly known as the angler, European angler or common monkfish, is a monkfish in the family Lophiidae. It is found in coastal waters of the northeast Atlantic, from the Barents Sea to the Strait of Gibraltar, the Medit ...
''), and the black-bellied angler (''
Lophius budegassa
''Lophius budegassa'', the blackbellied angler, is a species of anglerfish in the family Lophiidae. It was described by Maximilian Spinola in 1807. The fish is found in a depth range of in the eastern Ionian Sea while in the inshore waters o ...
'') to its seafood red list—a list of fish commonly sold worldwide with a high likelihood of being sourced from unsustainable fisheries.
Human consumption
One family, the
Lophiidae, is of commercial interest with fisheries found in western Europe, eastern North America, Africa, and East Asia. In Europe and North America, the tail meat of fish of the genus ''Lophius'', known as monkfish or goosefish (North America), is widely used in cooking, and is often compared to
lobster
Lobsters are a family (biology), family (Nephropidae, Synonym (taxonomy), synonym Homaridae) of marine crustaceans. They have long bodies with muscular tails and live in crevices or burrows on the sea floor. Three of their five pairs of legs ...
tail in taste and texture.
In Asia, especially Korea and Japan, monkfish liver, known as ''
ankimo
is a Japanese dish made with monkfish liver.
The liver is first rubbed with salt, then rinsed with sake. Then its veins are picked out and the liver is rolled into a cylinder and steamed. ''Ankimo'' is often served with ''momiji-oroshi'' ( c ...
'', is considered a delicacy. Anglerfish is especially heavily consumed in South Korea, where it is featured as the main ingredient in dishes such as ''
Agujjim
''Agwi-jjim''
* () or ''agu-jjim'' () is a Korean cuisine, Korean ''jjim'' dish made with Lophiomus setigerus, blackmouth angler, the fish known as ''agwi'' in Korean. The name of the dish is usually translated as "braised spicy angler".
The d ...
''.
Timeline of genera
Anglerfish appear in the
fossil record
A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved in ...
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color:eocene bar:NAM1 from: -55.8 till: 0 text: Lophius
Members of the genus ''Lophius'', also sometimes called monkfish, fishing-frogs, frog-fish, and sea-devils, are various species of lophiid anglerfishes found in the Atlantic and Indian Oceans. ''Lophius'' is known as the "monk" or "monkfish" ...
color:eocene bar:NAM2 from: -55.8 till: 0 text: Brachionichthys
''Brachionichthys'' is the type genus of the handfish family Brachionichthyidae. Originally, all species of handfish were included in ''Brachionichthys'', but researchers have since split species off into five additional genera.
Species of han ...
color:eocene bar:NAM3 from: -55.8 till: 0 text: Antennarius
''Antennarius'' is a genus of 11 species of fish in the family Antennariidae. These fish spend most of their lives on the bottom in relatively shallow water between 20 and 100 m. They can be found worldwide in tropical and subtropical waters. Th ...
color:eocene bar:NAM4 from: -48.6 till: 0 text: Ogcocephalus
''Ogcocephalus'' is an anglerfish genus in the batfish family Ogcocephalidae.
Species
There are currently 13 recognized species in this genus:
* '' Ogcocephalus corniger'' Bradbury, 1980 (Longnose batfish)
* '' Ogcocephalus cubifrons'' J. Ri ...
color:eocene bar:NAM5 from: -37.2 till: 0 text: Dibranchus
''Dibranchus'' is a fish genus in the family Ogcocephalidae.
Species
There are currently 14 recognized species in this genus:
* '' Dibranchus accinctus'' Bradbury, 1999
* '' Dibranchus atlanticus'' W. K. H. Peters, 1876 (Atlantic batfish)
* '' ...
color:eocene bar:NAM6 from: -37.2 till: 0 text: Chaunax
''Chaunax'' is a genus of bony fish in the sea toad family Chaunacidae. They are found in tropical and subtropical oceans around the world and most species are found at depths between , but ''C. endeavouri'' occurs as shallow as and ''C. fim ...
color:miocene bar:NAM7 from: -11.63 till: 0 text: Oneirodes
color:miocene bar:NAM8 from: -8.6 till: 0 text: Borophryne
color:miocene bar:NAM9 from: -8.6 till: 0 text: Chaenophryne
color:miocene bar:NAM10 from: -8.6 till: 0 text: Leptacanthichthys
color:miocene bar:NAM11 from: -8.6 till: 0 text: Linophryne
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from: -33.9 till: -23.03 color:oligocene text:Oligocene
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from: -23.03 till: -5.332 color:miocene text:Miocene
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from: -5.332 till: -2.588 color:pliocene text: Plio.
from: -2.588 till: -0.0117 color:pleistocene text:Pleist.
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bar:era
from: -65.5 till: -23.03 color:paleogene text:Paleogene
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from: -23.03 till: -2.588 color:neogene text:Neogene
The Neogene ( ), informally Upper Tertiary or Late Tertiary, is a geologic period and system that spans 20.45 million years from the end of the Paleogene Period million years ago ( Mya) to the beginning of the present Quaternary Period Mya. ...
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References
Further reading
* Anderson, M. Eric, and Leslie, Robin W. 2001
Review of the deep-sea anglerfishes (Lophiiformes: Ceratioidei) of southern Africa.Ichthyological Bulletin of the J.L.B. Smith Institute of Ichthyology; No. 70. J.L.B. Smith Institute of Ichthyology, Rhodes University
External links
Tree of Life web project: Lophiiformes*
* Lu, D. Anglerfish immune system lets them fuse with their mate. New Scientist 247, 19 (2020).
{{Taxonbar, from=Q206948
Bioluminescent fish
Articles which contain graphical timelines
Extant Early Cretaceous first appearances
Taxa named by Samuel Garman