|Black Seadevil, Melanocetus johnsonii|
Anglerfishes are members of the teleost order Lophiiformes //. They are bony fishes named for their characteristic mode of predation, wherein a fleshy growth from the fish's head (the esca or illicium) acts as a lure; this is considered analogous to angling.
Some anglerfishes are pelagic (live in the open water), while others are benthic (bottom-dwelling). Some live in the deep sea (e.g., Ceratiidae) and others on the continental shelf (e.g., the frogfishes Antennariidae and the monkfish/goosefish Lophiidae). They occur worldwide. Pelagic forms are most laterally (sideways) compressed whereas the benthic forms are often extremely dorsoventrally compressed (depressed) often with large upward pointing mouths.
Ranging in color from dark gray to dark brown, these carnivores have huge heads with enormous crescent-shaped mouth filled with long, fang-like teeth angled inward for efficient prey grabbing. Their length can vary from 8 in (20 cm) to over 3 ft (1 m) with weight of up to 100 pounds (50 kg).
- Suborder Lophioidei
- Suborder Antennarioidei
- Suborder Chaunacoidei
- Suborder Ogcocephaloidei
- Ogcocephalidae (batfishes)
- Suborder Ceratioidei (deepsea families)
- Centrophrynidae (prickly seadevils — monotypic)
- Ceratiidae (warty seadevils)
- Himantolophidae (footballfishes)
- Diceratiidae (doublespine seadevils)
- Melanocetidae (black seadevils)
- Thaumatichthyidae (wolf-trap seadevils)
- Oneirodidae (dreamers)
- Caulophrynidae (fanfin seadevils)
- Neoceratiidae (needlebeard seadevil — monotypic)
- Gigantactinidae (whipnose seadevils)
- Linophrynidae (leftvent seadevils)
The fish are named for their characteristic method of predation. Anglerfish typically have at least one long filament sprouting from the middle of the head; termed the illicium, these are the detached and modified three first spines of the anterior dorsal fin. 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) at the tip of the spine. The spine is movable in all directions, and the esca can be wiggled so as to resemble a prey animal, and thus to act as bait to lure other predators close enough for the anglerfish to devour them whole. The jaws are triggered in automatic reflex by contact with the tentacle.
Some deep-sea anglerfishes of the bathypelagic zone emit light from their escas to attract prey. This bioluminescence is a result of symbiosis with bacteria. The bacteria may enter the esca from the seawater through small pores; however, this is speculative and the mechanism by which ceratioids harness these bacteria is unknown. In the confines of the esca, they can multiply until their density is such that their collective glow is very bright.
In most species, a wide mouth extends all around the anterior circumference of the head, and both jaws are armed with bands of long pointed teeth, which are inclined inwards, and 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 (its bones are thin and flexible) to enormous size, allowing it to swallow prey up to twice as large as its entire body.
Some anglerfish, like those of the Ceratioid group (Ceratiidae, or sea devils), employ an unusual mating method. Because individuals are presumably locally rare and encounters at least doubly so, 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 attached to them. It turned out that these "parasites" were highly reduced male ceratioids. The presence of multiple males breeding with a single female makes this a good example of polyandry.
At birth, male ceratioids are already equipped with extremely well-developed olfactory organs that detect scents in the water. The male ceratioid lives solely to find and mate with a female. They are significantly smaller than a female angler fish, and may have trouble finding food in the deep sea. Furthermore, the growth of the alimentary canals of some males becomes stunted, preventing them from feeding. These features necessitate his quickly finding a female anglerfish to prevent death. The sensitive olfactory organs help the male to detect the pheromones that signal the proximity of a female anglerfish. When he finds a female, he bites into her skin, and releases an enzyme 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, receiving nutrients via their shared circulatory system, and provides sperm to the female in return. This extreme sexual dimorphism 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.
The spawn of the anglerfish of the genus Lophius consists of a thin sheet of transparent gelatinous material 25 cm wide and greater than 10 metres long. 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. Such an egg sheet is rare among fish.
Northwest European Lophius spp. are listed by the ICES as "outside safe biological limits." Additionally, anglerfish are known to occasionally rise to the surface during El Niño, leaving large groups of dead anglerfish floating on surface.
In 2010, Greenpeace International added the American angler (Lophius americanus), the angler (Lophius piscatorius) and the black-bellied angler (Lophius budegassa) to its seafood red list. The Greenpeace International seafood red list is a list of fish commonly sold worldwide which have a very high likelihood of being sourced from unsustainable fisheries.
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One family, Lophiidae, is of commercial interest with fisheries found in north-western Europe, eastern North America, Africa and the Far East. 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 tail in taste and texture. In Asia, especially Korea and Japan, it is a delicacy.
Timeline of genera
- Froese, Rainer, and Daniel Pauly, eds. (2006). "Lophiiformes" in FishBase. February 2006 version.
- Miya, M.; T. Pietsch, J. Orr, R. Arnold, T. Satoh, A. Shedlock, H. Ho, M. Shimazaki, M. Yabe (2010). "Evolutionary history of anglerfishes (Teleostei: Lophiiformes): a mitogenomic perspective". BMC Evolutionary Biology 10: 58. doi:10.1186/1471-2148-10-58. PMC 2836326. PMID 20178642.
- "Anglerfish". deepseacreatures.org. Retrieved 17 October 2012.
- Joseph S. Nelson. Fishes of the World. John Wiley & Sons. ISBN 0-471-54713-1.
- Theodore W. Pietsch (2009). Oceanic Anglerfishes: Extraordinary Diversity in the Deep Sea. University of California Press. ISBN 978-0-520-25542-5.
- "Lophiiformes". Integrated Taxonomic Information System. Retrieved 3 April 2006.
- Boschma's frogfish and the four-armed frogfish are included in Antennariidae in ITIS.
- Piper, Ross (2007), Extraordinary Animals: An Encyclopedia of Curious and Unusual Animals, Greenwood Press.
- Gould, Stephen Jay (1983). Hen's Teeth and Horse's Toes. New York: W. W. Norton & Company. p. 30. ISBN 0-393-01716-8. "ceratioid males develop gigantic nostrils...relative to body size, some ceratioids have larger nasal organs than any other vertebrate"
- Theodore W. Pietsch. "Precocious sexual parasitism in the deep sea ceratioid anglerfish, Cryptopsaras couesi Gill". Archived from the original on 28 August 2008. Retrieved 31 July 2008.
- Prince, E. E. 1891. Notes on the development of the angler-fish (Lophius piscatorius). Ninth Annual Report of the Fishery Board for Scotland (1890), Part III: 343–348.
- Clover, Charles (2004). The End of the Line: How overfishing is changing the world and what we eat. London: Ebury Press. ISBN 0-09-189780-7.
- Greenpeace International Seafood Red list
- "Goosefish". All the Sea. Retrieved April 20, 2012.
- Sepkoski, Jack (2002). "A compendium of fossil marine animal genera". Bulletins of American Paleontology 364: p.560. Retrieved 2011-05-17.
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