Also known as a blue dog or blue whaler, blue sharks are stunning, slender and inquisitive sharks that inhabit the Atlantic, Pacific and Indian Oceans
What do blue sharks look like?
Their super-streamlined body makes use of counter-shading – the upper body is indigo blue and the underside is white. This coloration hides the shark against the sky when seen from below, and against the deep blue when seen from above.
Their extremely long, conical snout is unmistakable. However, the mouth and jaws are relatively small compared to other requiem sharks in the family Carcharhinidae.
Their dorsal fin is set well back from the pectorals. This is the classic fin seen breaking the surface, but it is smaller and more compact than in related requiem sharks.
Eyes are large and round, with a white surround. Like other sharks, they possess a reflector-like structure called the tapetum lucidum behind the retina, which enhances vision in low light.
Freckle-like pores are scattered over the shark’s head are linked to electrosensory organs known as ampullae of Lorenzini. These pick up the weak bioelectrical fields produced by fish and other prey.
Pectoral fins are very long, slender and pointed. These scythe through the water, providing steering at speed, and also help with balance and positioning.
How big are blue sharks?
They are around 3.8m in length
What do blue sharks eat?
Blue sharks feed on small fish, squid and opportunistic prey, such as seabirds; also carrion, including floating
large mammals
How long do blue sharks live?
In the wild blue sharks usually live to about 15 years old.
When do they reach sexual maturity?
4–6 years (male);
5–7 years (female)
How long is a blue shark's gestation period?
A blue shark's gestation period is usually 9–12 months; embryos fed internally by a yolk that takes on a placenta-like function within the womb.
An average litter is 35 pups, however the largest recorded numbered 135
Where do blue sharks live?
Blue sharks are widespread in the Atlantic, Pacific and Indian Oceans, however blue sharks are also the world’s most heavily fished sharks. Because they roam across international borders, they are hard to protect.
The Shark Trust is calling for limits to catches of blue sharks, as well as for shortfin mako, tope, smooth-hounds and catsharks, none of which are regulated.
Do blue sharks migrate?
The blue shark migrates to the UK in the summer months, from the Caribbean via the via the Gulf Stream.
What is there IUCN status?
Near-threatened
Main image © Getty Images