“While males return to Californian waters, female white sharks often appear to remain offshore.”īut he warned against engaging with sharks as closely as the divers did, stressing that the species can be “unpredictable.” “While white shark sightings are rare in Hawaii, satellite tagging shows they make annual migrations from the Californian coast to the middle of the Pacific each winter – including Hawaii,” Richardson said. He added: “If Deep Blue does prove to be pregnant, this is even more significant.” John Richardson, conservation officer at UK organization The Shark Trust, told CNN that the spotting of Deep Blue is “incredibly exciting.” Although often timid, they are potentially harmful due to their dentition, and have been implicated in a few accidents.Diver Ocean Ramsey swims alongside the shark. Recent reports of approximately 60-80% decline in catch rates and reductions in sightings frequency, but data are inadequate to assess global population decline. Their meat is low of value, but their large, valuable fins are kept and enter the international shark fin trade (often after the carcasses are discarded at sea). īlue sharks are the most heavily fished shark in the world many millions are taken annually, mainly as bycatch. Pacific blue sharks may migrate up to 5716.6 miles. Tagging studies have demonstrated that Atlantic Blue Sharks undertake numerous trans-Atlantic migrations, swimming slowly with the major current systems. They have frequent vertical excursions made into deep water or to the thermocline, returning regularly to the surface (possibly to prevent body cooling). The sharks move seasonally to higher latitudes where prey is more abundant in productive oceanic convergence or boundary zones. Blue sharks segregate by age, sex, and reproductive phase: juveniles, sub-adults, mature sharks, and pregnant females are usually found in separate areas, with adult males and females meeting only briefly to mate. They are highly migratory with complex movements related to prey availability and reproductive cycles. They form large aggregations (where still sufficiently abundant) to feed on shoals of prey or carrion. These sharks are most active in the early evening and at night when they may move inshore. They have anywhere between 4-135 pups per litter (usually 15-30), which are born in the spring and summer after a 9-12 month gestation period.īlue sharks cruise slowly at the surface with the tips of their dorsal and tail fins out of the water, and long pectoral fins extended. Reproduction – Viviparous, yolk-sac placenta. They sometimes take seabirds at the surface of the water. Prey – Feeds on relatively small prey: usually squid and pelagic fish, but also invertebrates and bottom-dwelling fish and small sharks. Their longevity is approximately 20 years. Mature females may breed annually, or on alternate years. Males mature at 4-6 years: females at 5-7. General – In European waters, pups remain in offshore nursery areas until they reach about 4.3 ft in length, when they begin to migrate with other sharks of the same age and sex. Possibly the most wide-ranging of sharks because they live in such a broad range of areas. The shark is located world-wide in temperate and tropical oceanic waters (temperature 44.6 to 77✯, preferably 53.6 to 68✯, latitude 60ºN to 50ºS. They occasionally venture inshore at night, particularly around oceanic islands or where the continental shelf is narrow. Migrations often follow major trans-oceanic currents. Oceanic and pelagic, usually off the edge of the continental shelf from 0 to 1148.3 ft (deeper in warmer waters). Ĭurved, saw-edged, triangular upper teeth. Males mature at 6 to 9.2 ft, while females mature at about 7.2 ft. This shark has a dark blue back, bright blue flanks and sharp demarcation to a white underside.Īt birth, the shark is 1.1 to1.4 ft in length. Mature females often bear bite wounds (mating scars). It is a slim, graceful shark with a long, conical snout, large eyes (no spiracles), and long, narrow scythe-shaped pectoral fins well in front of the first dorsal win with no interdorsal ridge. This shark is BLUE, and it is one of the most beautiful sharks.
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