An introduction to the magnificent world of sharks

These marine hunters belong to a super-order called Selachimorpha, which is made up of approximately different species. These diverse species can be found in waters all over the planet and are believed to have existed even before the time that dinosaurs roamed the earth, millions of years ago.

An introduction to the magnificent world of sharks

Tuna, originating from the Greek word meaning "to rush," usually swim at speeds of 1. These are one of the most magnificent fishes in the sea. One fish can sell for hundreds of thousands of dollars. Atlantic bluefin tuna are the largest member of the Scombridae Family albacores, bonitos, mackerels, tunas.

They are one of the largest bony fishes and can reach lengths of up to 3 m, although they are more commonly found from 0. Adult weights range from kg, although the upper weight range is rare, especially now.

They can dive as deep as m, and are known to swim long distances as they are a highly migratory species. Atlantic bluefins are dark blue to black on their dorsal upper surface and silvery ventrally underneath. Bluefins are known for their finlets that run down their dorsal upper and ventral lower sides toward their anal fin.

There are spines in their first dorsal fin and rays in their second dorsal fin. Their anal fin has rays.

Shark - Wikipedia

The average natural lifespan of bluefin tunas is years. Atlantic bluefins are homeothermic "warm-blooded" and are therefore able to thermoregulate keeping their body temperatures higher than the surrounding water, which is why they are so well adapted to colder waters.

Bluefins are highly migratory and limited numbers of individuals may cross the Atlantic in as little as 60 days and are widely distributed throughout the Atlantic and can be found from Newfoundland all the way to the coast of Brazil. They range in the eastern Atlantic as far north as Norway and down to northern West Africa.

Bluefins tagged in the Bahamas have been captured in Norway as well as off the coast of Brazil. Bluefins in the South Atlantic belong to a distinct southern population, with known spawning areas south of Java, Indonesia.

The bluefin is a pelagicschooling fish. They tend to group together according to size. Feeding Behavior Ecology Atlantic bluefin tuna consume smaller fishes such as mackerelherringwhitingflying fishesand mullet as well as squideelsand crustaceans.

Life History Although Atlantic bluefin are widely distributed and migrate thousands of kilometers, there are two confirmed spawning locations — the Gulf of Mexico in the western Atlantic and the Mediterranean Sea in the eastern Atlantic.

Although many ecological and environmental variables undoubtedly affect both the location and productivity of spawning in these two areas, relatively little is known concerning why bluefin spawn where they do.

Spawning in the Gulf of Mexico occurs between mid-April and mid-June when females, which mature around age 8, release approximately 30 million eggs each. The highest density of bluefin larvae, the primary indicator of spawning, occurs in the northern Gulf of Mexico with lesser larval concentrations appearing off the Texas coast and in the Straits of Florida.

In the eastern Atlantic, spawning occurs exclusively in the Mediterranean and Adriatic Seas from June through August, with the highest larvae concentrations appearing around southern Italy. Although some fishery biologists believe that eastern Atlantic bluefin reach sexual maturity several years earlier than western Atlantic bluefin possibly as young as agesthis understanding has been criticized.The winghead shark (Eusphyra blochii) is a species of hammerhead shark, and part of the family Sphyrnidae.

Reaching a length of m ( ft), this small brown to gray shark has a slender body with a tall, sickle-shaped first dorsal initiativeblog.com name comes from its exceptionally large "hammer", or cephalofoil, which can be as wide as half of the shark's . Facts about Great White Sharks, Tiger Sharks, Bull Sharks, Whale Sharks, Bull Shark, Hammerhead Shark, Mako Shark and more.

Introduction to Sharks Sharks are a large group of fish that have inhabited the oceans for over million years, even before dinosaurs populated our planet. BLUE WHALE FACT SHEET STATUS: Endangered DESCRIPTION: The blue whale is the largest animal ever to inhabit the Earth.

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Everyone's heard of the Great Whites. But most people know little of the hundreds of other types of sharks that inhabit the world's oceans.

An introduction to the magnificent world of sharks

Written by two of the world's leading authorities and superbly illustrated by wildlife artist Marc Dando, this is the first comprehensive field guide to all plus shark species.

Candide | Introduction & Summary | initiativeblog.com