Impurest's guide to Animals #3 – Salmon Shark
Well it’s time for Issue #3 of Impurest Cheese’s Guide to Animals. Last week the deceptive Milk Snake was in the spotlight. This time we have a more ancient predator is in the spotlight. Hope you guys enjoy.
_______________________________________________________________________________________________________________________________________________________________________
Issue #3 – Salmon Shark
Kingdom – Animalia
Phylum – Chordata
Class – Chondrichthyes
Order – Lamniforme
Family – Lamnidae
Genus – Lamma
Species – ditropis
Related Species – One of the Mackerel Sharks whose ranks include the infamous Great White Shark (Charcaradon charcaris) (1)
Range
Like Jaws but in miniature.
The Salmon Shark is a medium sized fish which grows up to 3m long and may weight up to 250kg and while there are reports of large individuals these reports are assumed to be sightings of the closely related Great White Shark. As the name suggests salmon is one of the key prey species of this species of shark but like its relatives any fish it can catch is on the menu. While large enough to prey on marine mammals in addition there is no evidence that the Salmon Shark preys on seals. Like all large animals the Salmon Shark has the potential to be dangerous to humans although to date there are no attacks attributed to this species.
Salmon Sharks are among the small group of unrelated fish to practice homeothermy (warm bloodedness) using an organ called the retia maribila to keep its core temperature at a constant level. Not only does this allow the Salmon Shark to be active in cold water it also appears to give it extended stamina when hunting. While usually solitary Salmon Sharks do gather in groups when there is abundant prey with the largest gathering exceeding a hundred animals.(2)
Like most mackerel sharks the Salmon Shark gives birth to live young called pups which practice their hunting skills in the womb by hunting their brothers and sisters. Like most shark species the Salmon Shark matures slowly reaching maturity at around eight years old. Salmon Sharks are among the species hunted for shark fin soup and sashimi in Japan, with the heart being a particular delicacy.
Five Fun Salmon Shark Facts
Salmon Sharks have a reputation of being pests in Canada and Alaska. The species often follows boats and steals bait or hooked fish from lines.
Salmon Sharks are one of the most cold tolerant species of shark thanks to the retia maribila (wonderful nets translated from Latin) and are able to remain active in water as cold as 2 degrees Celsius
The Salmon Shark has suffered from misidentification for a long time only being named as a new species in 1947 despite being know to science for longer. Even today they are confused with immature Great Whites and the closely related Atlantic Porbegale (Lamna nasus).
Salmon Sharks practice population imbalance within their range. The Western population (Russia, Japan and Korea) has a high percentage of male animals while the Eastern population (Canada and Alaska) is made up mostly of females (3)
Juvenile Salmon Sharks occasionally suffer from a bacterial infection similar to meningitis that causes them to become stranded on beaches. Weather the infection effects the sharks navigation system or if they simply die at sea and are washed onto shore is still under investigation. (4)
______________________________________________________________________________________________________________________________________________________________________
Bibliography
(1) - www.arkive.org
(2) - Goldman, Kenneth; Anderson, Scot; Latour, Robert; Musick, John A. (2004). "Homeothermy in adult salmon sharks, Lamna ditropis". Environmental Biology of Fishes (Kluwer Academic Publishers) 71 (4): 403–411
(3) - Goldman, Kenneth; Musick, John A. (2006). "Growth and maturity of salmon sharks (Lamna ditropis) in the eastern and western North Pacific, and comments on back-calculation methods". Fishery Bulletin104 (2): 278–292.
(4) - http://sanctuarysimon.org/news/index.php/2013/12/salmon-shark-strandings/
Picture References
[1] - http://cdn2.arkive.org/media/9A/9A8BD962-336C-4EFD-AD1A-2B8F323A02A6/Presentation.Large/Salmon-shark-.jpg
[2] - http://en.wikipedia.org/wiki/File:Lamna_ditropis_distmap.png
[3] - http://cdn.phys.org/newman/gfx/news/2005/shark_f.jpg
[4] - http://sanctuarysimon.org/news/index.php/2013/12/salmon-shark-strandings/
Hope you guys enjoyed the insight into this varacious predator. Drop me a comment with an animal you want explored in the next issue.
Log in to comment