Instruct: Given a question, retrieve relevant documents that answer the question.
Query: What is the most abundant fish species in the Indian ocean?
The giant trevally is abundant in the central Indo-Pacific region, found throughout all the archipelagos and offshore islands including Indonesia, Philippines and Solomon Islands. Along continental Asia, the species has been recorded from Malaysia to Vietnam, but not China.[5] Despite this, its offshore range does extend north to Hong Kong, Taiwan and southern Japan.[11][14] In the south, the species reaches as far south as New South Wales in Australia[20] and even to the northern tip of New Zealand in the southern Pacific. Its distribution continues throughout the western Pacific, including Tonga, Western Samoa and Polynesia, with its westernmost limits known to be the Pitcairn and Hawaiian Islands.[10][15]
Sardinella is a genus of fish in the family Clupeidae found in the Atlantic, Indian and Pacific Ocean. They are abundant in warmer waters of the tropical and subtropical oceans. Adults are generally coastal, schooling, marine fish but juveniles are often found in lagoons and estuaries. These species are distinguished by their ranges and by specific body features, but they are often confused with one another. Fish of the genus have seven to 14 striped markings along the scales of the top of the head. The paddle-shaped supramaxilla bones are characteristic; they separate "Sardinella" from other genera and their shapes help distinguish species. They have paired predorsal scales and enlarged fin rays.
Gonatopsis borealis, the Boreopacific armhook squid, is a species of squid from the North Pacific Ocean. It is a member of the family Gonatidae. It is an abundant species which is currently caught mainly as a bycatch by fishing boats targeting other quarry. It is an important prey species for many commercially important species of fish, as well as for marine mammals.
Among the tropical oceans, the western Indian Ocean hosts one of the largest concentration of phytoplankton blooms in summer, due to the strong monsoon winds. The monsoonal wind forcing leads to a strong coastal and open ocean upwelling, which introduces nutrients into the upper zones where sufficient light is available for photosynthesis and phytoplankton production. These phytoplankton blooms support the marine ecosystem, as the base of the marine food web, and eventually the larger fish species. The Indian Ocean accounts for the second largest share of the most economically valuable tuna catch. Its fish are of great and growing importance to the bordering countries for domestic consumption and export. Fishing fleets from Russia, Japan, South Korea, and Taiwan also exploit the Indian Ocean, mainly for shrimp and tuna.
Herring often move in large schools around fishing banks and near the coast. The most abundant and commercially important species belong to the genus "Clupea", found particularly in shallow, temperate waters of the North Pacific and the North Atlantic oceans, including the Baltic Sea, as well as off the west coast of South America. Three species of "Clupea" are recognised, and provide about 90% of all herrings captured in fisheries. Most abundant of all is the Atlantic herring, providing over half of all herring capture. Fishes called herring are also found in the Arabian Sea, Indian Ocean, and Bay of Bengal.
The Scotian Shelf Large Marine Ecosystem (LME) contains numerous species, including a broad range of shellfish and fishes that use the area as spawning and nursery grounds. This abundance is the reason that the Scotian Shelf is one of the Atlantic Ocean's most fished areas. 
The shortbill spearfish ("Tetrapturus angustirostris") is a species of marlin native to the Indian and Pacific Oceans, with occasional records from the Atlantic Ocean. This species occurs in open waters not far from the surface. This species can reach a length of , though most do not exceed . The maximum recorded weight for this species is . It is of minor importance to commercial fisheries and is also a game fish.
The torpedo scad is distributed throughout the tropical and subtropical waters of the Indian and west Pacific Oceans. In the west, the range of the species extends from the tip of South Africa north along the east African coastline to the Persian Gulf and Red Sea. Records of the fish are common from most Indian Ocean islands including the Maldives, Seychelles and Madagascar. The species is found along the Indian and Asian coastlines, extending north to China and South Korea on the mainland. It is abundant through the central Indo-Pacific and the Indonesian Archipelago, with its offshore range extending to Taiwan and Japan in the north. Around Australia, torpedo scad have been recorded as far south as Fremantle on the west coast and Sydney on the east coast. The range of the species extends to several eastern Pacific islands including Samoa, New Caledonia and Tonga.
Merluccius paradoxus, the deep-water Cape hake, is a merluccid hake of the genus "Merluccius", found in the south-eastern Atlantic Ocean, along the coast of Southern Africa, south of Angola. Its range extends in decreasing abundance around the southern coast of Africa and into the Indian Ocean, but it is at its most plentiful in the cold, nutrient-rich fishing grounds of the Benguela Current.
About 510 (23%) of the 2,200 fin fish species in Indian waters are found in the Gulf, making it the most highly diverse fish habitat in India. Coral associated ornamental fishes belonging to the family Chaetodontidae, (butterfly fish); Parrotfish; Amphiprion spp (clown fish), Holocentrus spp (squirrel fish), Scarus spp (parrot fish), Lutjanus spp (snappers) and Abudefduf saxatilis (sergeant Major) are abundant.
"Gigantocypris" are ubiquitous in open oceans around the world, ranging from tropical to polar regions. Although locally abundant, the distributions of the individual species are often not well known. "G. dracontovalis" is found worldwide, mostly deeper than the other species. "G. agassizii" is essentially a widespread Pacific species, and "G. muelleri" a widespread Atlantic and Southern Ocean species, but there are also a few possible records of the former in the Atlantic, and a few records of the latter in the Pacific and Indian oceans. "G. australis" and "G. danae" are only known from the Southwestern Pacific and Western Indian Ocean, respectively.
Though forage fish are abundant, there are relatively few species. There are more species of primary producers and apex predators in the ocean than there are forage fish.
The Pillar Point Harbor at the northern edge of Half Moon Bay offers a protected landing for boats and provides other marine infrastructure. In the late 1980s a new master plan was developed for the Harbor. A variety of fish species have been identified in the harbor area. The most abundant fish include flatfish, particularly the speckled sanddab (Citharichthys stigmaeus) and the commercially important English sole (Parophrys vetulus), several species of rockfish (Sebastes sp.) with boccacio (S. paucispinis) most abundant, many members of the surfperch family, the most abundant being shiner (Cymanogaster aggregata) and dwarf surfperches (Micrometrus minimus), and the commercially important Pacific herring (Clupea harengus). Smaller populations of many other species, including significant commercial or sport species such as various surfperch, flatfish including halibut (Paralichthys californicus), lingcod (Ophiodon elongatus), and cabezon (Scoraenichthys marmotarus) also are found in the harbor during the summer. Abundant winter species include starry flounder (Platichthys stellatus) and topsmelt (Atherinops affinis). At Pillar Point Harbor, fishermen sell crab and fish catches straight off their boats at discount prices directly to the public, and restaurants will fillet the fish for purchasers.
The marine waters of the Houtman Abrolhos, an island chain off the coast of Western Australia, are unusual in containing a mix of tropical, subtropical and warm-temperate fish species. This mix is largely due to the Leeuwin Current, which brings warm tropical water to the Houtman Abrolhos, especially in winter. Tropical species are the most abundant, eleven of the sixteen most abundant species being tropical fishes. However, there are also a large number of tropical species with populations so small that they are thought not to maintain populations be breeding at the Houtman Abrolhos.
Though the number of species is limited, epipelagic fishes are abundant. What they lack in diversity they make up in numbers. Forage fish occur in huge numbers, and large fish that prey on them are often sought after as premier food fish. As a group, epipelagic fishes form the most valuable fisheries in the world.
Fish are abundant in most bodies of water. They can be found in nearly all aquatic environments, from high mountain streams (e.g., char and gudgeon) to the abyssal and even hadal depths of the deepest oceans (e.g., gulpers and anglerfish), although no species has yet been documented in the deepest 25% of the ocean. With 33,600 described species, fish exhibit greater species diversity than any other group of vertebrates.
The Peruvian anchoveta ("Engraulis ringens") is a species of fish of the anchovy family, Engraulidae, from the Southeast Pacific Ocean. It has yielded greater catches than any other single wild fish species in the world, with annual harvests varying between 4.2 and 8.3 million tonnes in 2008–2012. Almost all of the production is used for the fishmeal industry. The Peruvian anchoveta may be the world's most abundant fish species.
Found in the Pacific Ocean from Japan and Baja California to the Bering Sea, it is the most common species of lanternfish in the northwestern Pacific, and one of the most abundant larval fish in the California Current. Like all lanternfish, this is a deep sea species; it spends the day in the ocean's deeper bathypelagic and mesopelagic zones and ascends to or near the ocean's surface during the night. It is a cool-water fish.
Atlantic herring ("Clupea harengus") is a herring in the family Clupeidae. It is one of the most abundant fish species in the world. Atlantic herrings can be found on both sides of the Atlantic Ocean, congregating in large schools. They can grow up to in length and weigh up to . They feed on copepods, krill and small fish, while their natural predators are seals, whales, cod and other larger fish.
The Indian oil sardine ("Sardinella longiceps") is a species of ray-finned fish in the genus "Sardinella". It is one of the two most important commercial fishes in India (with the mackerel). The Indian oil sardine is one of the more regionally limited species of "Sardinella" and can be found in the northern regions of the Indian Ocean. These fish feed on phytoplankton (diatoms) and zooplankton (copepods).
The black jack has a circumtropical distribution, meaning their range extends around the Earth's equatorial oceans, thereby inhabiting the tropical and subtropical regions of the Atlantic, Pacific and Indian Oceans. In the Indian Ocean, they are found from Natal, South Africa in the west to northern Australia in the east. They are patchily distributed along the east African and Asian coastline in the Indian Ocean, being absent from both the Persian Gulf and Red Sea, as well as several countries bordering the ocean. The species is widely known from many Indian Ocean islands including the Seychelles, Réunion, Mauritius and Cargados Carajos In the Pacific Ocean, the black jack is known from parts of the Indonesian-Australian archipelago north to Japan, and through many of the Pacific Islands such as Hawaii, New Caledonia and Tonga. The species range in the eastern Pacific has been ranges from Mexico and the Revillagigedo Islands in the north to Costa Rica in the south. In the western Atlantic Ocean, black jack have been found from North Carolina in the U.S. south to Rio de Janeiro, with the species most common in the Caribbean and the northern Gulf of Mexico. In the eastern Atlantic, the species has been reported from the Azores, Madeira St. Paul's Rocks, Ascension Island, and the Gulf of Guinea.
In the plankton samples from the Meteor Expedition studied by Richter (1974), "Atlanta echinogyra" was the fourth most abundant species of heteropod (accounting for 9.1% of the total). By contrast, the species was uncommon off northeastern Australia (ranking ninth, accounting for 1.5% of the total number of heteropods collected) in a study by Seapy et al. (2003). In Hawaiian waters "Atlanta echinogyra" was variable in its presence and numbers among different collections, ranking eleventh out of thirteen species of atlantids (Seapy, 1990a); from five different sampling periods between 1984 and 1986, it was not collected twice, was represented by a single individual once, and by 27 and 19 individuals in two collections. In eastern Australian waters, Newman (1990) recorded "Atlanta echinogyra" as rare in northern and central Great Barrier Reef waters. Thus, it would appear that in the Pacific and Indian Oceans, "Atlanta echinogyra" is only abundant in the northern Indian Ocean.
The results of their study showed that a total of 234 individual fish from 36 species and 13 families were collected. Both the black and brown water habitats showed different fish species compositions. In the brown water, a total of 152 fish from among 32 species were caught, with 25 being exclusive to the habitat. The fish in the brown water were primarily made up of the family Cyprinidae. Oxygaster anomalura was the most abundant fish collected. Meanwhile, in the black water river, 82 individual fish from 12 species were caught. The most abundant fish caught was the Helostoma temminckii. During this study, only seven species of families were found in both habitats. This list included Oxygaster anomalura
The Indian threadfish ("Alectis indica"), also known as the Indian threadfin, diamond trevally, mirror fish or plumed trevally, is a large species of coastal marine fish of the jack family, Carangidae. The species is widespread in the waters of the tropical Indo-West Pacific Ocean, ranging from east Africa to India, Asia, Indonesia and Australia. Adult fish tend to inhabit coastal waters over reefs down to 100 m in depth, while juveniles inhabit a variety of environments including estuaries and seagrass beds. The Indian threadfish is similar to the other two species in the genus "Alectis", with a slight concavity in the profile of the head the most obvious distinguishing feature. It is a large species, growing to 165 cm and 25 kg in weight. The species is carnivorous, consuming fishes, cephalopods and crustaceans.
The Indian threadfish is of minor commercial importance, and has been the subject of aquaculture in Singapore.
The great hammerhead is extremely vulnerable to overfishing due to its low overall abundance and long generation time. Assessment of its conservation status is difficult as few fisheries separate the great hammerhead from other hammerheads in their reported catches. This species is listed as globally Endangered on the IUCN Red List. It is Endangered in the northwestern Atlantic and the Gulf of Mexico, where though it is a non-targeted species, populations have dropped 50% since the 1990s due to bycatch. It is also Endangered in the southwestern Indian Ocean, where large numbers of longline vessels operate illegally along the coasts for hammerheads and the giant guitarfish ("Rhynchobatus djiddensis"). The great hammerhead catch rate in Indian Ocean has declined 73% from 1978 to 2003, though it is yet undetermined whether these represent localized or widespread depletion. The great hammerhead is Critically Endangered along the western coast of Africa, where stocks have collapsed with an estimated 80% decline in the past 25 years. The West African Sub-Regional Fishing Commission (SRFC) has recognized the great hammerhead as one of the four most threatened species in the region, though fishing continues unmonitored and unregulated. Off northern Australia, this species was assessed as Data Deficient but at "high risk". Concern has arisen there over a substantial increase in illegal, unreported, and unregulated (IUU) fishing, reflecting the raising value of this shark's fins.