Lamna is a 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...

 of mackerel sharks

Lamniformes

Lamniformes is an order of sharks commonly known as mackerel sharks . It includes some of the most familiar species of sharks, such as the great white shark, as well as more unusual representatives, such as the goblin shark and the megamouth shark.Members of the order are distinguished by...

 in the family Lamnidae

Lamnidae

Lamnidae is a family of sharks, commonly known as mackerel sharks or white sharks. They are large, fast-swimming sharks, found in oceans worldwide....

, containing two extant species: the porbeagle

Porbeagle

The porbeagle is a species of mackerel shark in the family Lamnidae, distributed widely in the cold and temperate marine waters of the North Atlantic and Southern Hemisphere. In the North Pacific, its ecological equivalent is the closely related salmon shark...

 (L. nasus) of the North Atlantic and Southern Hemisphere

Southern Hemisphere

The Southern Hemisphere is the part of Earth that lies south of the equator. The word hemisphere literally means 'half ball' or "half sphere"...

, and the salmon shark

Salmon shark

The salmon shark, Lamna ditropis, is a species of shark occurring in the north Pacific ocean. As an apex predator, the salmon shark feeds on salmon, and also on squid, sablefish, and herring...

 (L. ditropis) of the North Pacific.

Endothermy

The two species of this genus can keep their blood temperature higher above that of the water surrounding them than other cartilaginous fish

Chondrichthyes

Chondrichthyes or cartilaginous fishes are jawed fish with paired fins, paired nares, scales, two-chambered hearts, and skeletons made of cartilage rather than bone...

, with temperature differences recorded up to 15.6 °C. Among fish, blood temperature regulation only occurs in large, fast species – bluefin tuna and swordfish

Swordfish

Swordfish , also known as broadbill in some countries, are large, highly migratory, predatory fish characterized by a long, flat bill. They are a popular sport fish of the billfish category, though elusive. Swordfish are elongated, round-bodied, and lose all teeth and scales by adulthood...

 are bony fish

Osteichthyes

Osteichthyes , also called bony fish, are a taxonomic group of fish that have bony, as opposed to cartilaginous, skeletons. The vast majority of fish are osteichthyes, which is an extremely diverse and abundant group consisting of over 29,000 species...

  with similar abilities.

Species

• Lamna ditropis Carl Hubbs
  Carl Leavitt Hubbs
  -Youth:He was born in Williams, Arizona. He was the son of Charles Leavitt and Elizabeth Hubbs. His father had a wide variety of jobs . The family moved several times before settling in San Diego where he got his first taste of natural history...
  
   & Follett, 1947 (Salmon shark)
• Lamna nasus (Bonnaterre
  Pierre Joseph Bonnaterre
  Abbé Pierre Joseph Bonnaterre was a French naturalist who contributed sections on cetaceans, mammals, birds, reptiles, amphibians, and insects to the Tableau encyclopédique et méthodique...
  
  , 1788) (Porbeagle)