Opah
Encyclopedia
Opah are large, colorful, deep-bodied pelagic
Lampriform fish
comprising the small family
Lampridae (also spelled Lamprididae). There are only two living species
in a single genus
: Lampris (from the Greek
lamprid-, "brilliant" or "clear"). One species is found in tropical to temperate waters of most oceans, while the other is limited to a circumglobal distribution in the Southern Ocean
, with the 34th parallel
as its northern limit. Two additional species, one in the genus Lampris and the other in the monotypic
Megalampris
, are only known from fossil
remains. The extinct family, Turkmenidae
, from the Paleogene
of Central Asia, is closely related, though much smaller.
Opah are rarely caught by recreational anglers. They are prized trophies for deep-water angler
s as their large size and attractive form lend themselves well to taxidermy
. Opah are frequently caught as bycatch
in many longline tuna
fisheries. Opah is becoming increasingly popular in seafood markets. It first became popular as a sushi and sashimi
in the late 1980s and early 1990s. The meat is lightly flavored, delicious and lends itself well to a variety of preparations, principally saute. Opah flesh has a light pink to orange color, but turns white when cooked. It is popular in Hawaii
, especially in restaurants. An average of 35 percent of an opah's weight is consumable, with the remaining 65% being bone and thick skin.
. The large eyes stand out as well, ringed with golden yellow. The body is covered in minute cycloid scale
s and its silvery, iridescent
guanine
coating is easily abraded.
Opah closely resemble in shape the unrelated butterfish (family Stromateidae). Both have falcate pectoral fins and forked, emarginate caudal fins. Aside from being significantly larger than butterfish, opah have enlarged, falcate pelvic fins—with ca. 14–17 rays, which distinguish opah from superficially similar carangids
—positioned thoracically; adult butterfish lack pelvic fins. The pectorals of opah are also inserted (more or less) horizontally rather than vertically. The anterior portion of an opah's single dorsal fin
(with ca. 50–55 rays) is greatly elongated, also in a falcate profile similar to the pelvic fins. The anal fin (ca. 34–41 rays) is about as high and as long as the shorter portion of the dorsal fin, and both fins have corresponding grooves into which they can be depressed.
The snout is pointed and the mouth small, tooth
less and terminal. The lateral line
forms a high arch over the pectoral fins before sweeping down to the caudal peduncle. The larger species, Lampris guttatus, may reach a total length of 2 metres (6.6 ft) and a weight of 270 kilograms (595.2 lb). The lesser-known Lampris immaculatus reaches a recorded total length of just 1.1 metres (3.6 ft).
and ecology
. They are presumed to live out their entire lives in the open ocean, at mesopelagic depths of ca. 50–500 metres, with possible forays into the bathypelagic zone. They are apparently solitary but are known to school
with tuna
and other scombrid
s. Opah propel themselves via a lift-based labriform mode of swimming; that is, by flapping their pectoral fins. This, together with their forked caudal fins and depressible median fins, indicates that opah—like tuna—maintain themselves at constantly high speeds.
Squid
and euphausiids (krill
) make up the bulk of the opah diet; small fish are also taken. Pop-up archival transmitting (PAT) tagging operations have indicated that (aside from humans) large pelagic sharks, such as great white shark
s and mako sharks, are primary predators of opah. The tetraphyllidea
n tapeworm Pelichnibothrium speciosum has been found in L. guttatus, which may be an intermediate
or paratenic
host (Scholz et al. 1998).
The plankton
ic larvae of opah initially resemble those of certain ribbonfishes (Trachipteridae), but are distinguished by the former's lack of dorsal and pelvic fin ornamentation. The slender hatchlings later undergo a marked and rapid transformation from a slender to deep-bodied form; this transformation is complete by 10.6 millimetres standard length in Lampris guttatus. Opah are believed to have a low population resilience.
show Iron Chef America
, opah was chosen as the secret ingredient. A clip from this battle provided a memorable moment when Iron Chef Mario Batali
jokingly danced with a whole opah en route to his station in the beginning of the program.
Pelagic zone
Any water in a sea or lake that is not close to the bottom or near to the shore can be said to be in the pelagic zone. The word pelagic comes from the Greek πέλαγος or pélagos, which means "open sea". The pelagic zone can be thought of in terms of an imaginary cylinder or water column that goes...
Lampriform fish
Fish
Fish are a paraphyletic group of organisms that consist of all gill-bearing aquatic vertebrate 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...
comprising the small family
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...
Lampridae (also spelled Lamprididae). There are only two living species
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
in a single genus
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
: Lampris (from the Greek
Greek language
Greek is an independent branch of the Indo-European family of languages. Native to the southern Balkans, it has the longest documented history of any Indo-European language, spanning 34 centuries of written records. Its writing system has been the Greek alphabet for the majority of its history;...
lamprid-, "brilliant" or "clear"). One species is found in tropical to temperate waters of most oceans, while the other is limited to a circumglobal distribution in the Southern Ocean
Southern Ocean
The Southern Ocean comprises the southernmost waters of the World Ocean, generally taken to be south of 60°S latitude and encircling Antarctica. It is usually regarded as the fourth-largest of the five principal oceanic divisions...
, with the 34th parallel
34th parallel south
The 34th parallel south is a circle of latitude that is 34 degrees south of the Earth's equatorial plane. It crosses the Atlantic Ocean, Africa, the Indian Ocean, Australasia, the Pacific Ocean and South America....
as its northern limit. Two additional species, one in the genus Lampris and the other in the monotypic
Monotypic
In biology, a monotypic taxon is a taxonomic group with only one biological type. The term's usage differs slightly between botany and zoology. The term monotypic has a separate use in conservation biology, monotypic habitat, regarding species habitat conversion eliminating biodiversity and...
Megalampris
Megalampris
Megalampris keyesi is an extinct Opah from the late Oligocene of New Zealand about 26 million years ago. It was recovered from the Otekaike Limestone in North Otago, by a team from the University of Otago. Its spectacular remains, mostly caudal skeleton, are on display in the Otago Museum,...
, are only known from fossil
Fossil
Fossils are the preserved remains or traces of animals , plants, and other organisms from the remote past...
remains. The extinct family, Turkmenidae
Turkmenidae
Turkmenidae is an extinct family of lamprids from the Paleogene of Turkmenistan. They were small, disk-shaped fish that bore a strong resemblance to their closest living relatives, the opahs....
, from the Paleogene
Paleogene
The Paleogene is a geologic period and system that began 65.5 ± 0.3 and ended 23.03 ± 0.05 million years ago and comprises the first part of the Cenozoic Era...
of Central Asia, is closely related, though much smaller.
Opah are rarely caught by recreational anglers. They are prized trophies for deep-water angler
Fishing
Fishing is the activity of trying to catch wild fish. Fish are normally caught in the wild. Techniques for catching fish include hand gathering, spearing, netting, angling and trapping....
s as their large size and attractive form lend themselves well to taxidermy
Taxidermy
Taxidermy is the act of mounting or reproducing dead animals for display or for other sources of study. Taxidermy can be done on all vertebrate species of animals, including mammals, birds, fish, reptiles, and amphibians...
. Opah are frequently caught as bycatch
Bycatch
The term “bycatch” is usually used for fish caught unintentionally in a fishery while intending to catch other fish. It may however also indicate untargeted catch in other forms of animal harvesting or collecting...
in many longline tuna
Tuna
Tuna is a salt water fish from the family Scombridae, mostly in the genus Thunnus. Tuna are fast swimmers, and some species are capable of speeds of . Unlike most fish, which have white flesh, the muscle tissue of tuna ranges from pink to dark red. The red coloration derives from myoglobin, an...
fisheries. Opah is becoming increasingly popular in seafood markets. It first became popular as a sushi and sashimi
Sashimi
Sashimi is a Japanese delicacy. It consists of very fresh raw meat, most commonly fish, sliced into thin pieces.-Origin:The word sashimi means "pierced body", i.e...
in the late 1980s and early 1990s. The meat is lightly flavored, delicious and lends itself well to a variety of preparations, principally saute. Opah flesh has a light pink to orange color, but turns white when cooked. It is popular in Hawaii
Hawaii
Hawaii is the newest of the 50 U.S. states , and is the only U.S. state made up entirely of islands. It is the northernmost island group in Polynesia, occupying most of an archipelago in the central Pacific Ocean, southwest of the continental United States, southeast of Japan, and northeast of...
, especially in restaurants. An average of 35 percent of an opah's weight is consumable, with the remaining 65% being bone and thick skin.
Physical description
Opah are deeply keeled, compressed and discoid fish with conspicuous coloration: the body is a deep red-orange grading to rosy on the belly, with white spots covering the flanks. Both the median and paired fins are a bright vermillionVermilion
Vermilion is an opaque orangish red pigment, similar to scarlet. As a naturally occurring mineral pigment, it is known as cinnabar, and was in use around the world before the Common Era began. Most naturally produced vermilion comes from cinnabar mined in China, and vermilion is nowadays commonly...
. The large eyes stand out as well, ringed with golden yellow. The body is covered in minute cycloid scale
Scale (zoology)
In most biological nomenclature, a scale is a small rigid plate that grows out of an animal's skin to provide protection. In lepidopteran species, scales are plates on the surface of the insect wing, and provide coloration...
s and its silvery, iridescent
Iridescence
Iridescence is generally known as the property of certain surfaces which appear to change color as the angle of view or the angle of illumination changes...
guanine
Guanine
Guanine is one of the four main nucleobases found in the nucleic acids DNA and RNA, the others being adenine, cytosine, and thymine . In DNA, guanine is paired with cytosine. With the formula C5H5N5O, guanine is a derivative of purine, consisting of a fused pyrimidine-imidazole ring system with...
coating is easily abraded.
Opah closely resemble in shape the unrelated butterfish (family Stromateidae). Both have falcate pectoral fins and forked, emarginate caudal fins. Aside from being significantly larger than butterfish, opah have enlarged, falcate pelvic fins—with ca. 14–17 rays, which distinguish opah from superficially similar carangids
Carangidae
Carangidae is a family of fish which includes the jacks, pompanos, jack mackerels, and scads.They are marine fish found in the Atlantic, Indian and Pacific Oceans...
—positioned thoracically; adult butterfish lack pelvic fins. The pectorals of opah are also inserted (more or less) horizontally rather than vertically. The anterior portion of an opah's single dorsal fin
Dorsal fin
A dorsal fin is a fin located on the backs of various unrelated marine and freshwater vertebrates, including most fishes, marine mammals , and the ichthyosaurs...
(with ca. 50–55 rays) is greatly elongated, also in a falcate profile similar to the pelvic fins. The anal fin (ca. 34–41 rays) is about as high and as long as the shorter portion of the dorsal fin, and both fins have corresponding grooves into which they can be depressed.
The snout is pointed and the mouth small, tooth
Tooth
Teeth are small, calcified, whitish structures found in the jaws of many vertebrates that are used to break down food. Some animals, particularly carnivores, also use teeth for hunting or for defensive purposes. The roots of teeth are embedded in the Mandible bone or the Maxillary bone and are...
less and terminal. The lateral line
Lateral line
The lateral line is a sense organ in aquatic organisms , used to detect movement and vibration in the surrounding water. Lateral lines are usually visible as faint lines running lengthwise down each side, from the vicinity of the gill covers to the base of the tail...
forms a high arch over the pectoral fins before sweeping down to the caudal peduncle. The larger species, Lampris guttatus, may reach a total length of 2 metres (6.6 ft) and a weight of 270 kilograms (595.2 lb). The lesser-known Lampris immaculatus reaches a recorded total length of just 1.1 metres (3.6 ft).
Life history
Almost nothing is known of opah biologyBiology
Biology is a natural science concerned with the study of life and living organisms, including their structure, function, growth, origin, evolution, distribution, and taxonomy. Biology is a vast subject containing many subdivisions, topics, and disciplines...
and ecology
Ecology
Ecology is the scientific study of the relations that living organisms have with respect to each other and their natural environment. Variables of interest to ecologists include the composition, distribution, amount , number, and changing states of organisms within and among ecosystems...
. They are presumed to live out their entire lives in the open ocean, at mesopelagic depths of ca. 50–500 metres, with possible forays into the bathypelagic zone. They are apparently solitary but are known to school
Swarm
Swarm behaviour, or swarming, is a collective behaviour exhibited by animals of similar size which aggregate together, perhaps milling about the same spot or perhaps moving en masse or migrating in some direction. As a term, swarming is applied particularly to insects, but can also be applied to...
with tuna
Tuna
Tuna is a salt water fish from the family Scombridae, mostly in the genus Thunnus. Tuna are fast swimmers, and some species are capable of speeds of . Unlike most fish, which have white flesh, the muscle tissue of tuna ranges from pink to dark red. The red coloration derives from myoglobin, an...
and other scombrid
Scombridae
Scombridae is the family of the mackerels, tunas, and bonitos, and thus includes many of the most important and familiar food fishes. The family consists of about 55 species in 15 genera and two subfamilies...
s. Opah propel themselves via a lift-based labriform mode of swimming; that is, by flapping their pectoral fins. This, together with their forked caudal fins and depressible median fins, indicates that opah—like tuna—maintain themselves at constantly high speeds.
Squid
Squid
Squid are cephalopods of the order Teuthida, which comprises around 300 species. Like all other cephalopods, squid have a distinct head, bilateral symmetry, a mantle, and arms. Squid, like cuttlefish, have eight arms arranged in pairs and two, usually longer, tentacles...
and euphausiids (krill
Krill
Krill is the common name given to the order Euphausiacea of shrimp-like marine crustaceans. Also known as euphausiids, these small invertebrates are found in all oceans of the world...
) make up the bulk of the opah diet; small fish are also taken. Pop-up archival transmitting (PAT) tagging operations have indicated that (aside from humans) large pelagic sharks, such as great white shark
Great white shark
The great white shark, scientific name Carcharodon carcharias, also known as the great white, white pointer, white shark, or white death, is a large lamniform shark found in coastal surface waters in all major oceans. It is known for its size, with the largest individuals known to have approached...
s and mako sharks, are primary predators of opah. The tetraphyllidea
Tetraphyllidea
Tetraphyllidea is a large tapeworm order that contains some 60 genera and about 800 described species. Tetraphyllideans are remarkable for their scolex morphologies, which are the most varied and morphologically complex amongst all tapeworm orders....
n tapeworm Pelichnibothrium speciosum has been found in L. guttatus, which may be an intermediate
Intermediate host
A secondary host or intermediate host is a host that harbors the parasite only for a short transition period, during which some developmental stage is completed. For trypanosomes, the cause of sleeping sickness, humans are the primary host, while the tsetse fly is the secondary host...
or paratenic
Paratenic
In parasitology, the term paratenic describes a host which is not needed for the development of the parasite, but nonetheless serves to maintain the life cycle of the parasite. Alaria americana may serve as an example: the so-called mesocercarial stages of this parasite reside in tadpoles, which...
host (Scholz et al. 1998).
The plankton
Plankton
Plankton are any drifting organisms that inhabit the pelagic zone of oceans, seas, or bodies of fresh water. That is, plankton are defined by their ecological niche rather than phylogenetic or taxonomic classification...
ic larvae of opah initially resemble those of certain ribbonfishes (Trachipteridae), but are distinguished by the former's lack of dorsal and pelvic fin ornamentation. The slender hatchlings later undergo a marked and rapid transformation from a slender to deep-bodied form; this transformation is complete by 10.6 millimetres standard length in Lampris guttatus. Opah are believed to have a low population resilience.
Species and range
- Lampris guttatus (Brünnich, 1788) [Opah] — from the Grand BanksGrand BanksThe Grand Banks of Newfoundland are a group of underwater plateaus southeast of Newfoundland on the North American continental shelf. These areas are relatively shallow, ranging from in depth. The cold Labrador Current mixes with the warm waters of the Gulf Stream here.The mixing of these waters...
to ArgentinaArgentinaArgentina , officially the Argentine Republic , is the second largest country in South America by land area, after Brazil. It is constituted as a federation of 23 provinces and an autonomous city, Buenos Aires...
in the Western AtlanticAtlantic OceanThe Atlantic Ocean is the second-largest of the world's oceanic divisions. With a total area of about , it covers approximately 20% of the Earth's surface and about 26% of its water surface area...
; from NorwayNorwayNorway , officially the Kingdom of Norway, is a Nordic unitary constitutional monarchy whose territory comprises the western portion of the Scandinavian Peninsula, Jan Mayen, and the Arctic archipelago of Svalbard and Bouvet Island. Norway has a total area of and a population of about 4.9 million...
and GreenlandGreenlandGreenland is an autonomous country within the Kingdom of Denmark, located between the Arctic and Atlantic Oceans, east of the Canadian Arctic Archipelago. Though physiographically a part of the continent of North America, Greenland has been politically and culturally associated with Europe for...
to SenegalSenegalSenegal , officially the Republic of Senegal , is a country in western Africa. It owes its name to the Sénégal River that borders it to the east and north...
and south to AngolaAngolaAngola, officially the Republic of Angola , is a country in south-central Africa bordered by Namibia on the south, the Democratic Republic of the Congo on the north, and Zambia on the east; its west coast is on the Atlantic Ocean with Luanda as its capital city...
(also in the MediterraneanMediterranean SeaThe Mediterranean Sea is a sea connected to the Atlantic Ocean surrounded by the Mediterranean region and almost completely enclosed by land: on the north by Anatolia and Europe, on the south by North Africa, and on the east by the Levant...
) in the Eastern Atlantic; from the Gulf of AlaskaGulf of AlaskaThe Gulf of Alaska is an arm of the Pacific Ocean defined by the curve of the southern coast of Alaska, stretching from the Alaska Peninsula and Kodiak Island in the west to the Alexander Archipelago in the east, where Glacier Bay and the Inside Passage are found.The entire shoreline of the Gulf is...
to southern CaliforniaCaliforniaCalifornia is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...
in the Eastern PacificPacific OceanThe Pacific Ocean is the largest of the Earth's oceanic divisions. It extends from the Arctic in the north to the Southern Ocean in the south, bounded by Asia and Australia in the west, and the Americas in the east.At 165.2 million square kilometres in area, this largest division of the World...
; in temperate waters of the Indian OceanIndian OceanThe Indian Ocean is the third largest of the world's oceanic divisions, covering approximately 20% of the water on the Earth's surface. It is bounded on the north by the Indian Subcontinent and Arabian Peninsula ; on the west by eastern Africa; on the east by Indochina, the Sunda Islands, and...
; and rare forays into the Southern OceanSouthern OceanThe Southern Ocean comprises the southernmost waters of the World Ocean, generally taken to be south of 60°S latitude and encircling Antarctica. It is usually regarded as the fourth-largest of the five principal oceanic divisions...
. - Lampris immaculatus Gilchrist, 1904 [Southern opah] — confined to the Southern Ocean from the 34th parallel south34th parallel southThe 34th parallel south is a circle of latitude that is 34 degrees south of the Earth's equatorial plane. It crosses the Atlantic Ocean, Africa, the Indian Ocean, Australasia, the Pacific Ocean and South America....
to the Antarctic Polar Front - Lampris zatimaLampris zatimaLampris zatima is the oldest known opah of the genus Lampris, from the Late Miocene of Southern California . Its fossil record is rather poor, known primarily from isolated vertebral columns, and a few headless specimens...
, also known as "Diatomœca zatima," a very small, extinct species from the late MioceneMioceneThe Miocene is a geological epoch of the Neogene Period and extends from about . The Miocene was named by Sir Charles Lyell. Its name comes from the Greek words and and means "less recent" because it has 18% fewer modern sea invertebrates than the Pliocene. The Miocene follows the Oligocene...
of what is now Southern CaliforniaSouthern CaliforniaSouthern California is a megaregion, or megapolitan area, in the southern area of the U.S. state of California. Large urban areas include Greater Los Angeles and Greater San Diego. The urban area stretches along the coast from Ventura through the Southland and Inland Empire to San Diego...
. Known primarily from fragments, and the occasional headless specimens. - Megalampris keyesi, an extinct species estimated to be about 4 meters in length. Fossil remains date back to the Late OligoceneOligoceneThe Oligocene is a geologic epoch of the Paleogene Period and extends from about 34 million to 23 million years before the present . As with other older geologic periods, the rock beds that define the period are well identified but the exact dates of the start and end of the period are slightly...
of what is now New ZealandNew ZealandNew Zealand is an island country in the south-western Pacific Ocean comprising two main landmasses and numerous smaller islands. The country is situated some east of Australia across the Tasman Sea, and roughly south of the Pacific island nations of New Caledonia, Fiji, and Tonga...
, and is the first fossil lampridiform found in the Southern Hemisphere.
In popular culture
On one episode of the Food NetworkFood Network
Food Network is a television specialty channel that airs both one-time and recurring programs about food and cooking. Scripps Networks Interactive owns 70 percent of the network, with Tribune Company controlling the remaining 30 percent....
show Iron Chef America
Iron Chef America
Iron Chef America: The Series is an American cooking show based on Fuji Television's Iron Chef, and is the second American adaptation of the series, following the failed Iron Chef USA. The show is produced by Food Network, which also carried a dubbed version of the original Iron Chef. Like the...
, opah was chosen as the secret ingredient. A clip from this battle provided a memorable moment when Iron Chef Mario Batali
Mario Batali
Mario Batali is an American chef, writer, restaurateur and media personality. In addition to his classical culinary training, he is an expert on the history and culture of Italian cuisine, including regional and local variations. Batali co-owns restaurants in New York City, Las Vegas, Los Angeles,...
jokingly danced with a whole opah en route to his station in the beginning of the program.