A tuna is a saltwater fish that belongs to the tribe Thunnini,a subgrouping of the Scombridae (mackerel) family. The Thunnini comprise 15 species across five genera,the sizes of which vary greatly,ranging from the bullet tuna up to the Atlantic bluefin tuna. The Atlantic bluefin averages 2 m (6.6 ft),and is believed to live up to 50 years.
Many types of fish migrate on a regular basis,on time scales ranging from daily to annually or longer,and over distances ranging from a few metres to thousands of kilometres. Fish usually migrate to feed or to reproduce,but in other cases the reasons are unclear.
The albacore,known also as the longfin tuna,is a species of tuna of the order Perciformes. It is found in temperate and tropical waters across the globe in the epipelagic and mesopelagic zones. There are six distinct stocks known globally in the Atlantic,Pacific,and Indian oceans,as well as the Mediterranean Sea. The albacore has an elongate,fusiform body with a conical snout,large eyes,and remarkably long pectoral fins. Its body is a deep blue dorsally and shades of silvery white ventrally. Individuals can reach up to 1.4 m in length.
The Atlantic bluefin tuna is a species of tuna in the family Scombridae. It is variously known as the northern bluefin tuna,giant bluefin tuna [for individuals exceeding 150 kg (330 lb)],and formerly as the tunny.
The yellowfin tuna is a species of tuna found in pelagic waters of tropical and subtropical oceans worldwide.
Marine conservation,also known as ocean conservation,is the protection and preservation of ecosystems in oceans and seas through planned management in order to prevent the over-exploitation of these resources. Marine conservation is informed by the study of marine plants and animal resources and ecosystem functions and is driven by response to the manifested negative effects seen in the environment such as species loss,habitat degradation and changes in ecosystem functions and focuses on limiting human-caused damage to marine ecosystems,restoring damaged marine ecosystems,and preserving vulnerable species and ecosystems of the marine life. Marine conservation is a relatively new discipline which has developed as a response to biological issues such as extinction and marine habitats change.
The term billfish refers to a group of predatory fish characterised by prominent bills,or rostra,and by their large size;some are longer than 4 m (13 ft). Billfish include sailfish and marlin,which make up the family Istiophoridae,and swordfish,sole member of the family Xiphiidae. They are apex predators which feed on a wide variety of smaller fish,crustaceans,and cephalopods. These two families are sometimes classified as belonging to the order Istiophoriformes,a group with origins in the Late Cretaceous around 71 million years ago with the two families diverging from one and another in the Late Miocene around 15 million years ago. However,they are also classified as being closely related to the mackerels and tuna within the suborder Scombroidei of the order Perciformes. However,the 5th edition of the Fishes of the World does recognise the Istiophoriformes as a valid order,albeit including the Sphyraenidae,the barracudas.
Pelagic fish live in the pelagic zone of ocean or lake waters –being neither close to the bottom nor near the shore –in contrast with demersal fish that do live on or near the bottom,and reef fish that are associated with coral reefs.
A fish aggregatingdevice (FAD) is a man-made object used to attract ocean-going pelagic fish such as marlin,tuna and mahi-mahi. They usually consist of buoys or floats tethered to the ocean floor with concrete blocks. FADs attract fish for numerous reasons that vary by species.
The bigeye tuna is a species of true tuna of the genus Thunnus,belonging to the wider mackerel family Scombridae.
The southern bluefin tuna is a tuna of the family Scombridae found in open southern Hemisphere waters of all the world's oceans mainly between 30°S and 50°S,to nearly 60°S. At up to 2.5 metres (8.2 ft) and weighing up to 260 kilograms (570 lb),it is among the larger bony fishes.
The White Shark Café is a remote mid-Pacific Ocean area noted as a winter and spring habitat of otherwise coastal great white sharks.
Thunnus is a genus of ocean-dwelling,ray-finned bony fish from the mackerel family,Scombridae. More specifically,Thunnus is one of five genera which make up the tribe Thunnini –a tribe that is collectively known as the tunas. Also called the true tunas or real tunas,Thunnus consists of eight species of tuna,divided into two subgenera. The word Thunnus is the Middle Latin form of the Greek thýnnos –which is in turn derived from thynō. The first written use of the word was by Homer.
The Pacific bluefin tuna is a predatory species of tuna found widely in the northern Pacific Ocean,but it is migratory and also recorded as a visitor to the south Pacific.
Natal homing,or natal philopatry,is the homing process by which some adult animals return to their birthplace to reproduce. This process is primarily used by aquatic animals,such as sea turtles and Pacific salmon. Scientists believe that the main cues used by the animals are geomagnetic imprinting and olfactory cues. The benefits of returning to the precise location of an animal's birth may be largely associated with its safety and suitability as a breeding ground. When seabirds,like the Atlantic puffin,return to their natal breeding colony,which are mostly on islands,they are assured of a suitable climate and a sufficient lack of land-based predators.
Tagging of Pacific Predators (TOPP) began in 2000 as one of many projects formed by Census of Marine Life,an organization whose goal is to help understand and explain the diversity and abundances of the ocean in the past,present,and future. After they were formed,TOPP began by building a coalition of researchers from all over the world to find and study predators of the Pacific Ocean. Since then,they have satellite-tagged 22 different species and more than 2,000 animals. These animals include elephant seals,great white sharks,leatherback turtles,squid,albatrosses,and more.
Pop-up satellite archival tags (PSATs) are used to track movements of marine animals. A PSAT is an archival tag that is equipped with a means to transmit the collected data via the Argos satellite system. Though the data are physically stored on the tag,its major advantage is that it does not have to be physically retrieved like an archival tag for the data to be available making it a viable,fishery independent tool for animal behavior and migration studies. They have been used to track movements of ocean sunfish,marlin,blue sharks,bluefin tuna,swordfish and sea turtles to name a few species. Location,depth,temperature,oxygen levels,and body movement data are used to answer questions about migratory patterns,seasonal feeding movements,daily habits,and survival after catch and release,for examples.
Thunnus tonggol is a species of tuna of tropical Indo-West Pacific waters.
The following outline is provided as an overview of and topical guide to fish:
Thunnus (Thunnus) is a subgenus of ray-finned bony fishes in the Thunnini,or tuna,tribe. More specifically,Thunnus (Thunnus) is a subgenus of the genus Thunnus,also known as the "true tunas". Thunnus (Thunnus) is sometimes referred to as the bluefin group and comprises five species:
