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Thresher Shark  Wikimedia image
Named for and easily recognized by their exceptionally
long, thresher-like tail or caudal fins (which account for
1/3 (33%) of their total body length), thresher sharks are
active predators; the tail is actually used as a weapon to
stun prey. By far the largest of the three species is the
Common thresher, Alopias vulpinus, which may reach a length
of 5.45 m (18 ft) and a weight of 348 kg (767 lb). The Bigeye
thresher, Alopias superciliosus, is next in size, reaching
a length of 4.9 m (16 ft); at just 3 m (10 ft), the Pelagic
thresher, Alopias pelagicus, is the smallest.
Thresher sharks
are fairly slender, with small dorsal fins and large, recurved pectoral
fins. With the exception of the Bigeye thresher, these sharks have
relatively small eyes. Coloration ranges from brownish, bluish or
purplish gray dorsally with lighter shades ventrally. The three species
can be roughly distinguished by the main color of the dorsal surface of
the body. Common threshers are dark green, Bigeye threshers are brown
and Pelagic threshers are generally blue. Lighting conditions and water
clarity can affect how any one shark appears to an observer, but the
color test is generally supported when other features are examined.
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Porbeagle Shark  Wikimedia image
The most distinguishing characteristic of the porbeagle
is a white patch on the trailing edge of the dorsal fin. This
distinguishes it from both the salmon shark and the great
white shark. It has two keels on the caudal fin, in common
with the salmon shark.
The porbeagle
is a stout and heavy shark, dark
blue-grey on top and white underneath, with a conical snout. The
porbeagle can grow to about 3.7 m (12 ft), weighing about 160 to 250 kg
(350 to 550 lb).
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Shortfin Mako  NOAA image
The shortfin mako shark, Isurus oxyrinchus, ("sharp
nose") is a large shark of the Lamnidae family. Along with
the closely related longfin mako, Isurus paucus, it is commonly
called just mako shark. With a full-grown length of 2.75 –
4 m (9 – 13 ft) it has been reported to weigh up to
800 kg (1,750 lb) and has a bluish back and white underside.
Although the sexes grow at about the same rate, females are
thought to have a longer life span, and grow larger and weigh
more than the males.
Shortfin makos
are renowned for their speed
and their ability to leap out of the water. In fact, there are cases
that when an angry mako will jump out of the water and into the boat
after it has been caught on the hook. Mako sharks have a better
hydrodynamic shape than all other sharks, and this, combined with the
lamnidae's typical high aerobic muscle mass, reflects in the
spectacular speed and agility of both the longfin and shortfin makos.
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Great white shark (Protected)  NOAA image
The great white shark, Carcharodon carcharias, also
known as white pointer, white shark, or white death, is an
exceptionally large lamniforme shark found in coastal surface
waters in all major oceans. Reaching lengths of about 6 metres
(20 ft) and weighing up to 2,250 kilograms (5,000 lb), the
great white shark is the world's largest known predatory fish.
It is the only known surviving species of its genus, Carcharodon.
The great white shark has a robust large conical-shaped snout.
It has almost the same size upper and lower lobes on the tail
fin (like most mackerel sharks, but unlike most other sharks).
Great white
sharks have a white belly and a
grey back (sometimes in a brownish or bluish shade). The colouration
makes it difficult for prey to spot the shark because it breaks up the
shark's outline when seen from a lateral perspective. When viewed from
above, the darker shade blends in with the sea. Great white sharks,
like many other sharks, have rows of teeth behind the main ones,
allowing any that break off to be rapidly replaced. A great white
shark's teeth are serrated and when the shark bites it will shake its
head side to side and the teeth will act as a saw and tear off large
chunks of flesh. Great white sharks often swallow their own broken off
teeth along with chunks of their prey's flesh. These teeth frequently
cause damage to the great white shark's digestive tract.However great
white sharks often feed on stingrays and swallow the 'sting' as well,
the barbed sting often getting stuck in the shark's intestines.
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Basking Shark (Protected)  Wikimedia image
The basking shark is one of the largest known sharks,
second only to the whale shark. The largest specimen accurately
measured was trapped in a herring net in the Bay of Fundy,
Canada in 1851. Its total length was 12.27 metres (40 ft 3
in), and weighed an estimated 19 tons. There are reports from
Norway of three basking sharks over 12 m (the largest being
13.7 m), but those are considered dubious since few if any
sharks anywhere near such size have been caught in the area
since. Normally the basking shark reaches a length of between
6 metres (20 feet) and a little over 8 m (26 ft). Some specimens
surpass 9 or even 10 m, but after years of hard fishing, specimens
of this size have become exceedingly rare.
These sharks
possess the typical lamniform
body plan and have been mistaken for great white sharks. The two
species can be easily distinguished, however, by the basking shark's
cavernous jaw (up to 1 m in width, held wide open whilst feeding),
longer and more obvious gill slits (which nearly encircle the head and
are accompanied by well-developed gill raker), smaller eyes, and
smaller average girth. Great whites possess large, dagger-like teeth,
whilst those of the basking shark are much smaller (5–6 mm)
and hooked;
only the first 3–4 rows of the upper jaw and 6–7
rows of the lower jaw
are functional. There are also several behavioural differences between
the two.
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Tiger Shark  Wikimedia image / Terry Goss
The tiger shark, Galeocerdo cuvier, one of the largest
sharks, is the only member of the genus Galeocerdo. Mature
sharks average 3.25 metres (11 ft) to 4.25 metres (14 ft)
and weigh 385 to 635 kg (850 to 1400 lb). It is found in many
of the tropical and temperate regions of the world's oceans,
and is especially common around islands in the central Pacific.
This shark is a solitary hunter, usually hunting at night.
Its name is derived from the dark stripes down its body, which
fade as the shark matures.
The tiger shark is a dangerous predator, known for
eating a wide
range of items. Its usual diet consists of fish, seals, birds, smaller
sharks, squid, and turtles. It has sometimes been found with man-made
waste such as license plates or pieces of old tires in its digestive
tract. It is notorious for attacks on swimmers, divers and surfers in
Hawaii; and is often referred to as the "bane of Hawaiian surfers" and
"the wastebasket of the sea".
The tiger shark is second only to the great white
in number of
recorded human fatalities and is considered, along with the great
white, bull shark and the oceanic whitetip shark to be one of the
sharks most dangerous to humans.
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Sandbar Shark  NOAA image
The sandbar shark, Carcharhinus plumbeus, comes from
the Carcharhinidae family of sharks, also called requiem sharks.
The sandbar shark is also called the thickskin shark or brown
shark. It is one of the biggest coastal sharks in the world,
and is closely related to the dusky shark, the bignose shark,
and the bull shark. Its dorsal fin is triangular and very
high, and weighs as much as 18% of the shark's whole body.
Sandbar sharks usually have heavy-set bodies and rounded snouts
that are shorter than the average shark's snout. Their upper
teeth have broadly uneven cusps with sharp edges. Its second
dorsal fin and anal fin are close to the same height. Females
can grow to 7 or 8 feet, males up to 6 feet. Its body color
can vary from a bluish to a brownish grey to a bronze, with
a white or pale underside. Sandbar sharks swim alone or gather
in sex-segregated schools that vary in size. They are most
active at night, at dawn, and at dusk
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Sand Tiger Shark (Protected)
 NOAA image
Sand sharks, also known as sand tigers or ragged
toothed sharks, are lamniform sharks of the family Odontaspididae
(or sometimes - but incorrectly - referred to as Carchariidae).
They are found on both sides of the Atlantic coast, but most
notably in the Western Indian Ocean and in the Gulf of Maine.
There are four species in two genera.
Sand sharks have a large second dorsal fin. They
typically grow to 5
to 9 ft. on average. The body tends to be brown in color with dark
markings in the upper half. They possess a rudimentary swim bladder - a
highly unusual feature in sharks - which enables them to have exquisite
control over their buoyancy compared with other sharks. Their
needle-like teeth are highly adapted for impaling fish - their main
prey.
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Angel
Sharks NOAA image
The angel sharks are an unusual group of sharks with flattened bodies
and broad pectoral fins that give them a strong resemblance to skates
and rays. The 16-odd known species are all classified in a single
genus, Squatina, belonging to its own family, Squatinidae, and order
Squatiniformes. They occur worldwide in temperate and tropical seas.
Appearence, While the forward part of the angel
shark's body is
broad and flattened, the rear part retains a muscular appearance more
typical of other sharks. The eyes and spiracles are on top, and the
five gill slits are on bottom. Both the pectorals and the pelvic fins
are large and held horizontally. There are two dorsal fins, no anal
fin, and unusually for sharks, the lower lobe of the caudal fin is
longer than the upper lobe. Most types grow to a length of 1.5 m (5
ft), with the Japanese angelshark, Squatina japonica, known to reach 2
meters.
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Smooth Hammerhead shark  Wikimedia image
The smooth hammerhead, Sphyrna zygaena, is a large
hammerhead shark living in temperate and tropical seas. It
is differentiated from other species of hammerhead by the
smooth shape of its cephalophoil (head) and its lack of a
central indentation. Its coloration varies from brownish-gray
to deep olive (as with most hammerhead sharks), fading to
a pale whitish color on its underside. The shark's teeth are
similar on both the upper and lower jaws, are triangular and
smooth edged. Adults of the smooth species attain lengths
up to 4 meters, and can weigh more than 400 kilograms.
The smooth hammerhead shark is the only species of
hammerhead that
appears in Canadian coastal waters, having been reported off the coast
of Nova Scotia, Canada near Herring Cove, Sambro Light, Brier Island,
and St. Margaret's bay.
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Atlantic Sharpnose Shark
 Wikimedia image
The Atlantic sharpnose shark, Rhizoprionodon terraenovae, is a requiem
shark of the family Carcharhinidae, found in the subtropical waters of
the western Atlantic Ocean between latitudes 43° N and
25° S, at depths
of from 10 to 280 m. Its length is up to about 1.1 m.
The Atlantic sharpnose shark is a small, generally
grey, streamlined
shark, with a long pointed snout. The posterior margin of the anal fin
is straight or slightly concave. The second dorsal fin origin is well
behind the anal fin origin. It is abundant on the continental shelves,
from the intertidal to deeper waters, and often occurs close to the
surf zone off sandy beaches, and also enclosed bays, sounds, and
harbours, in estuaries and river mouths. It feeds on small bony fishes,
shrimps, crabs, segmented worms, molluscs and gastropods. It is
viviparous, having 1 to 7 young in a litter, with the size at birth
about 29 to 37 cm. It is utilized for human consumption.
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Spiny Dogfish  NOAA image
The spiny dogfish or piked dogfish, Squalus acanthias, is one of the
best known of the dogfish, members of the family Squalidae in the order
Squaliformes. There are actually several species to which the names are
applied, but all are readily distinguished by their having two spines
(one anterior to each dorsal fin) and their lack of an anal fin. It is
found in shallow waters and offshore in most parts of the world,
especially in temperate waters.
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Dusky Shark (Protected)  Wikimedia image
The dusky shark, Carcharhinus obscurus, is one of
the larger species of shark, reaching 350 kg. The dusky shark
is also known as the black whaler and dusky whaler. Less frequently
used names include bay-shark, brown dusky shark, brown shark,
common whaler, dusky ground shark. The dusky shark has a long
streamlined body that is brown or gray above and white below.
On the side of the body a stripe can be seen from the pelvic
fins to the head. They can reach 3.65 m.
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Smooth Dogfish  Wikimedia image
The smooth dogfish, Mustelus canis, is a species
of shark. This shark is an olive grey or brown, and may have
shades of yellow or grayish white. Females live to 16 years
and males have a life span of 10 years.
A common resident in bays, and other inshore
waters, the smooth
dogfish prefers shallow waters of less than 18 m (60 ft) in depth but
may be found to depths of 200 m (650 ft). This species has also been
found on occasion in freshwater although it is unlikely they can
survive freshwater for extended periods of time. The smooth dogfish
migrates seasonally, moving north in the spring and south in the
autumn. It is primarily a nocturnal species.
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Check out the following links to
learn more about sharks:
New England shark information
International Shark Attack File
First hand account of an attack by a white
shark on a diver
YouTube video of white shark attacking a seal
YouTube video of hammerhead eating a tarpon
(some ***# language)
Sources
:
New England Sharks
Wikipedia
Image
Sources
NOAA
Wikipedia
Images have been collected from what we believe are public domain
sources. Please inform admin@morebeach.com
if we have used an image protected by copyright in error.
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