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The blue runner, ''Caranx crysos'' (also known as the bluestripe jack, Egyptian scad, hardtail jack and hardnose), is a common species of moderately large marine fish classified in the jack family, Carangidae. The blue runner is distributed across the Atlantic Ocean, ranging from Brazil to Canada in the western Atlantic and from Angola to Great Britain including the Mediterranean in the east Atlantic. The blue runner is distinguished from similar species by several morphological features, including the extent of the upper jaw, gill raker count and lateral line scale counts. The blue runner is known to reach a maximum length of 70 cm and 5.05 kg in weight, but is much more common below 35 cm. The species inhabits both inshore and offshore environments, predominantly over reefs, however it is known to congregate around large man made offshore structures such as oil platforms. Juveniles tend to inhabit shallower reef and lagoon waters, before moving to deeper waters as adults. The blue runner is a schooling, predatory fish, predominantly taking fish in inshore environments, as well as various crustaceans and other invertebrates. Fish living offshore feed nearly exclusively on zooplankton. The species reaches sexual maturity at between 225 and 280 mm across its range, with spawning occurring offshore year round, although this peaks during the warmer months. Larvae and juveniles live pelagically, often under sargassum mats or jellyfish until they move inshore. The blue runner is of high importance to fisheries, with an annual catch of between 6000 and 7000 tonnes taken from the Americas in the last five years. The species is also a light tackle gamefish, taking baits lures and flies, but is often used as bait itself being a mediocre table fish. There has been some suggestion that the eastern Pacific species ''Caranx caballus'', the green jack, may be conspecific with ''C. crysos'', although this currently remains unresolved. ==Taxonomy and naming== The blue runner is classified within the genus ''Caranx'', one of a number of groups known as the jacks or trevallies. ''Caranx'' itself is part of the larger jack and horse mackerel family Carangidae, a group of percoid fishes in the order Perciformes. The species was first scientifically described by the American ichthyologist Samuel L. Mitchill in 1815, based on a specimen taken from the waters of New York Bay, USA which was designated to be the holotype. He named the species ''Scomber crysos'' and suggested a common name of 'yellow mackerel', with the specific epithet reflecting this, meaning "gold" in Greek.〔 The taxon has been variably placed in either ''Caranx'', ''Carangoides'' or ''Paratractus'', but is now considered valid as ''Caranx crysos''. The species has been independently redescribed three times, first as ''Caranx fusus'', which is still incorrectly used by some authors (occasionally as ''Carangoides fusus''), and later as ''Caranx pisquetus'' and ''Trachurus squamosus''. These names are considered invalid junior synonyms under ICZN rules. The species has many common names, with the most common being 'blue runner'. Other less commonly used names include 'bluestripe jack', 'Egyptian scad', 'hardtail jack', 'hardnose', 'white back cavalli', 'yellow tail cavalli', as well as a variety of broad names such as 'mackerel', 'runner' and 'crevalle'.〔 There has been suggestions that the blue runner may be conspecific with the eastern Pacific species ''Caranx caballus'' (green jack), although no specific studies have been undertaken to examine this relationship. Both species were included in a recent genetic analysis of the entire Carangidae family, with results showing both species are very closely related, although the authors did not comment on genetic distance between the two. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Blue runner」の詳細全文を読む スポンサード リンク
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