Lamna

Taxobox
name = Mackerel sharks [ITIS|ID=506801|year=2007|date=11 January]
fossil_range = Fossil range|65|0 Danian to Present [cite journal
last = Sepkoski
first = Jack
authorlink =
coauthors =
title = A compendium of fossil marine animal genera (Chondrichthyes entry)
journal = Bulletins of American Paleontology
volume = 364
issue =
pages = p.560
publisher =
location =
date = 2002
url = http://strata.ummp.lsa.umich.edu/jack/showgenera.php?taxon=575&rank=class
doi =
id =
accessdate = 2008-01-09 ]

---

image_caption = "Lamna nasus"
regnum = Animalia
phylum = Chordata
classis = Chondrichthyes
subclassis = Elasmobranchii
ordo = Lamniformes
familia = Lamnidae
genus = "Lamna"
genus_authority = Cuvier, 1816
subdivision_ranks = Species
subdivision = "Lamna ditropis"
"Lamna nasus"

Mackerel sharks ("Lamna") are a genus of shark.

Endothermic ability

The two species of this genus can keep their blood temperature higher above that of the water surrounding them than other cartilaginous fish, with temperature differences recorded up to 15.6 °C. [ [http://links.jstor.org/sici?sici=0045-8511(20010806)3%3A2001%3A3%3C794%3ATMFSSL%3E2.0.CO%3B2-X#abstract Abstract] for S. D. Anderson, K. J. Goldman: “Temperature Measurements from Salmon Sharks, "Lamna ditropis", in Alaskan Waters”, "Copeia", Vol. 2001, No. 3, 2001-08-06] ] [marinebio|id=379|name=Salmon shark, "Lamna ditropis" ] [ [http://www.jbc.org/cgi/reprint/278/33/30741.pdf C. Larsen, H. Malte, R. E. Weber: “ATP-induced Reverse Temperature Effect in Isohemoglobins from the Endothermic Porbeagle Shark”] , "Journal of Biological Chemistry" vol. 278, issue 33, 30741–30747, 2003-08-15] ] Among fish, blood temperature regulation only occurs in large, fast species – bluefin tuna and swordfish are bony fish with similar abilities.

Species

The genus contains two species: [FishBase_genus|genus=Lamna|year=2007|month=01]
* Porbeagle, "Lamna nasus" (Bonnaterre, 1788)
Occurs in Atlantic and Southern Pacific coastal areas and open waters.
* Salmon shark, "Lamna ditropis" (Hubbs & Follett, 1947)
Occurs near Northern Pacific coasts.

References