The porbeagle (Lamna nasus) is a species of mackerel shark; an order it shares with the goblin shark, the megamouth shark and the Great white. They occur in most temperate waters but are rarely seen due to their timid nature.

Identification: The porbeagle is commonly mistaken for a Great white shark. It is grey above and white below and has a very stout midsection that tapers towards the long, pointed snout and the narrow base of the tail.

Size and Life span: The porbeagle typically reaches 2.5 m (8.2 ft) in length and a weight of 135 kg (298 lb); North Atlantic sharks grow larger than Southern Hemisphere sharks and differ in coloration and aspects of life history. The Porbeagle lives around 30 years.

Distribution: The porbeagle has an almost global amphitemperate distribution, i.e. it is absent from the tropics. Unlike most fish Porbeagles have the ability to maintain their body temperature above ambient water temperature (up to up 10°C) through thermoregulation. This helps them adapt to the cold waters they prefer.

Habitat: Offshore fishing banks are the favoured habitat of the porbeagle, though it can be found anywhere from a depth of 1,360 m (4,460 ft) in oceanic basins to littoral (close to shore) waters less than 1 m (3.3 ft) deep, over the entire water column.

Diet and Prey: The porbeagle is an active predator that predominantly feeds on small to medium-sized bony fishes. It chases down pelagic fishes such as lancet fish, mackerel, pilchards, herring, and sauries, and forages near the bottom for ground fishes such as cod, hake, icefish, dories, sand lances, lump suckers, and flatfish. Cephalopods, particularly squid, also form an important component of its diet while smaller sharks such as spiny dogfish (Squalus acanthias) and tope sharks (Galeorhinus galeus) are sometimes taken.

Predators: Great white sharks (Carcharodon carcharias) and killer whales (Orcinus orca) are plausible, albeit undocumented, predators of the porbeagle.

Behaviour: The porbeagle is a shy species and natural encounters are rare. Interestingly they are among the few fishes that exhibit apparent play behaviour. There are reports from the Cornish coast of this species rolling and repeatedly wrapping itself in long kelp fronds near the surface. This activity may have a self-stimulatory purpose, though alternatively the sharks may have been attempting to feed on small kelp organisms or scrape off parasites.

Attack History: The porbeagle has very rarely, if ever, bitten swimmers or boats. As of 2016, the International Shark Attack File attributes just two unprovoked attacks to the Porbeagle both of which were non-fatal.

IUCN rating: Porbeagle sharks are currently listed as ‘Vulnerable’ to extinction and as either ‘Endangered’ or ‘Critically Endangered’ in some parts of its northern range.

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Video credits (Timestamp/Video link/Source):

00:16 - www.youtube.com/watch?v=UowynFqyGBY (AtlanticSharks21)
00:31 - www.youtube.com/watch?v=AQ04OeNNSlA (National Geographic Wild)
00:48 - www.mirror.co.uk/news/uk-news/biggest-porbeagle-shark-ever-caught-3768392 (The Mirror)
01:08 - en.wikipedia.org/wiki/Porbeagle (Wikipedia)
01:31 - americanhistory.si.edu/onthewater/exhibition/3_4.html (Smithsonian)
01:37 - www.youtube.com/watch?v=C2s7HenvFyE (Phil Rogers)
01:48 - www.fishwallpapers.com/lancetfish/lancetfish-in-sea-pic.html (FishWallpapers)
01:53 - www.youtube.com/watch?v=61TmpthegVY (dssnappers)
02:10 - mpora.com/outsiders/killer-whales-attack-kill-great-white-shark-australia (Mpora)
02:14 - www.youtube.com/watch?v=dbbtaJs8AWw (Smithsonian Channel)
02:26 - scubadivingezine.com/giant-kelp-forests-of-britain-might-be-gone-in-100-years/ (Scuba Diving Electronic Magazine)
02:31 - www.youtube.com/watch?v=Eq4GiBkavTo (ScotNaturalHeritage1)
03:09 - sharkyear.com/2011/new-porbeagle-shark-record-in-denmark.html (Shark Year)

Thumbnail Image Credit: travel.aol.co.uk/2013/07/22/porbeagle-sharks-spotted-north-yorkshire-coast-heatwave/ (AOL)

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