The butterfly kingfish (Gasterochisma melampus) is an ocean-dwelling ray-finned bony fish in the mackerel family, Scombridae – a family which it shares with the tunas, mackerels, Spanish mackerels, and bonitos. Unlike the 50 species from those four tribes, however, this species is unique in that it is the only scombrid to be classified apart from the rest, into the subfamily Gasterochismatinae and genus Gasterochisma.
Although taxonomists and the Food and Agriculture Organization of the United Nations have accepted the name "butterfly kingfish", this fish has had many common names, including big-scaled mackerel, bigscale mackerel, butterfly mackerel, butterfly tuna, scaled tunny, scaly tuna, and others. In 1993, the U.S. Food and Drug Administration gave approval for this fish to be marketed simply as "mackerel".
The juveniles of the butterfly kingfish are characterized by enormous pelvic fins that are longer than the length of its head, and that become more proportional as the fish grows. At any size, the pelvic fin tucks into a deep ventral groove, in much the same way as the first dorsal spines do in all scombrids. This species has very large cycloid scales, below which is a thick layer of fat. The swim bladder has two anterior projections that extend into the back of the skull, near the inner ear. This fish lacks the median keel on the caudal peduncle – it only has the characteristic pair of small keels on each side of the base of the caudal fin, as do other scombrids. It has 21 precaudal vertebrae, plus 23 caudal vertebrae.
This fish can be found around the world in southern temperate waters of 8–15 °C (46–59 °F), but most commonly under 10 °C (50 °F), and at depths to 200 m (660 ft) in the open ocean. It grows to a length of 1.64 m (5.4 ft).
Most bony fishes are ectothermic, or cold-blooded, but this species, much like the related tunas, is endothermic and is able to raise its body temperature to achieve a degree of thermoregulation. It has a brain heater organ derived from the lateral rectus eye muscle, which is distinct from that of the billfishes, whose heater is derived from their superior rectus muscles.
The evolutionary lineage of the butterfly kingfish is more primitive and quite different from that of the rest of the scombrids. Additionally, the morphology of this species is substantially different from that of the others – some suggest that it might belong in a different family altogether. At present, however, morphology and nuclear phylogeny provide support that Gasterochisma is the basal scombrid, and that both its genus, Gasterochisma, and its subfamily, Gasterochismatinae, remain as monotypic taxa under the family Scombridae.
The following cladogram shows the most likely evolutionary relationships between the butterfly kingfish and the tunas, mackerels, Spanish mackerels, and bonitos.
Bonitos are a tribe of medium-sized, ray-finned predatory fish in the family Scombridae – a family it shares with the mackerel, tuna, and Spanish mackerel tribes, and also the butterfly kingfish. Also called the Sardini tribe, it consists of eight species across four genera; three of those four genera are monotypic, having a single species each.Fish
Fish are gill-bearing aquatic craniate animals that lack limbs with digits. They form a sister group to the tunicates, together forming the olfactores. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish as well as various extinct related groups. Tetrapods emerged within lobe-finned fishes, so cladistically they are fish as well. However, traditionally fish are rendered paraphyletic by excluding the tetrapods (i.e., the amphibians, reptiles, birds and mammals which all descended from within the same ancestry). Because in this manner the term "fish" is defined negatively as a paraphyletic group, it is not considered a formal taxonomic grouping in systematic biology, unless it is used in the cladistic sense, including tetrapods. The traditional term pisces (also ichthyes) is considered a typological, but not a phylogenetic classification.
The earliest organisms that can be classified as fish were soft-bodied chordates that first appeared during the Cambrian period. Although they lacked a true spine, they possessed notochords which allowed them to be more agile than their invertebrate counterparts. Fish would continue to evolve through the Paleozoic era, diversifying into a wide variety of forms. Many fish of the Paleozoic developed external armor that protected them from predators. The first fish with jaws appeared in the Silurian period, after which many (such as sharks) became formidable marine predators rather than just the prey of arthropods.
Most fish are ectothermic ("cold-blooded"), allowing their body temperatures to vary as ambient temperatures change, though some of the large active swimmers like white shark and tuna can hold a higher core temperature.Fish can communicate in their underwater environments through the use of acoustic communication. Acoustic communication in fish involves the transmission of acoustic signals from one individual of a species to another. The production of sounds as a means of communication among fish is most often used in the context of feeding, aggression or courtship behaviour. The sounds emitted by fish can vary depending on the species and stimulus involved. They can produce either stridulatory sounds by moving components of the skeletal system, or can produce non-stridulatory sounds by manipulating specialized organs such as the swimbladder.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.Fish are an important resource for humans worldwide, especially as food. Commercial and subsistence fishers hunt fish in wild fisheries (see fishing) or farm them in ponds or in cages in the ocean (see aquaculture). They are also caught by recreational fishers, kept as pets, raised by fishkeepers, and exhibited in public aquaria. Fish have had a role in culture through the ages, serving as deities, religious symbols, and as the subjects of art, books and movies.List of least concern perciformes
There are 3878 species and 18 subspecies in the order Perciformes assessed as least concern.Mackerel
Mackerel is a common name applied to a number of different species of pelagic fish, mostly from the family Scombridae. They are found in both temperate and tropical seas, mostly living along the coast or offshore in the oceanic environment.
Mackerel species typically have vertical stripes on their backs and deeply forked tails. Many are restricted in their distribution ranges and live in separate populations or fish stocks based on geography. Some stocks migrate in large schools along the coast to suitable spawning grounds, where they spawn in fairly shallow waters. After spawning they return the way they came in smaller schools to suitable feeding grounds, often near an area of upwelling. From there they may move offshore into deeper waters and spend the winter in relative inactivity. Other stocks migrate across oceans.
Smaller mackerel are forage fish for larger predators, including larger mackerel and Atlantic cod. Flocks of seabirds, whales, dolphins, sharks, and schools of larger fish such as tuna and marlin follow mackerel schools and attack them in sophisticated and cooperative ways. Mackerel flesh is high in omega-3 oils and is intensively harvested by humans. In 2009, over 5 million tons were landed by commercial fishermen. Sport fishermen value the fighting abilities of the king mackerel.Scombridae
The Scombridae family of the mackerels, tunas, and bonitos includes many of the most important and familiar food fishes. The family consists of 51 species in 15 genera and two subfamilies. All species are in the subfamily Scombrinae, except the butterfly kingfish, which is the sole member of subfamily Gasterochismatinae.Scombrids have two dorsal fins and a series of finlets behind the rear dorsal fin and anal fin. The caudal fin is strongly divided and rigid, with a slender, ridged base. The first (spiny) dorsal fin and the pelvic fins are normally retracted into body grooves. Species lengths vary from the 20 cm (7.9 in) of the island mackerel to the 4.58 m (15.0 ft) recorded for the immense Atlantic bluefin tuna.
Scombrids are generally predators of the open ocean, and are found worldwide in tropical and temperate waters. They are capable of considerable speed, due to a highly streamlined body and retractable fins. Some members of the family, in particular the tunas, are notable for being partially endothermic (warm-blooded), a feature that also helps them to maintain high speed and activity. Other adaptations include a large amount of red muscle, allowing them to maintain activity over long periods. Two of the fastest recorded scombrids are the wahoo and the yellowfin tuna, which can each attain speeds of 75 km/h (47 mph).Scombrinae
The Scombrinae are a subfamily of ray-finned bony fishes in the family Scombridae. Of the 51 species in the Scombridae, 50 are in Scombrinae – with the sole exception being the butterfly kingfish, which is placed in the monospecific subfamily Gasterochismatinae.The Scombrinae, therefore, comprise 50 extant species in 14 genera, grouped into four tribes:
Subfamily ScombrinaeTribe Scombrini – mackerels
Tribe Scomberomorini – Spanish mackerels
Tribe Sardini – bonitos
Tribe Thunnini – tunas
Scombrini, commonly called the true mackerels, is a tribe of ray-finned bony fishes in the mackerel family, Scombridae – a family it shares with the Spanish mackerel, tuna and bonito tribes, plus the butterfly kingfish.This tribe consists of seven species in two genera:
Scomber Linnaeus, 1758
Scomber australasicus Cuvier, 1832, Blue mackerel
Scomber colias Gmelin, 1789, Atlantic chub mackerel
Scomber japonicus, Houttuyn, 1782, Chub mackerel
Scomber scombrus Linnaeus, 1758, Atlantic mackerelRastrelliger Jordan & Starks in Jordan & Dickerson, 1908
Rastrelliger brachysoma (Bleeker, 1851), Short mackerel
Rastrelliger faughni Matsui, 1967, Island mackerel
Rastrelliger kanagurta (Cuvier, 1816), Indian mackerelSpanish mackerel
Scomberomorini is a tribe of ray-finned saltwater bony fishes that is commonly known as the Spanish mackerels or seerfishes. This tribe is a subset of the mackerel family (Scombridae) – a family that it shares with three sister tribes, the tunas, mackerels, and bonitos, and the butterfly kingfish. Scomberomorini comprises 21 species across three genera.