Saturday, July 28, 2007
RAMARAJAN
Ramarajan is a Tamil film actor who specialised in making films on village-based subjects. His films include Karagaattakkaaran (1989), Raasave Unnai Nambi (1988), and Enga Ooru Paattukkaaran (1987).
At the peak of his career he decided to produce films, but was unsuccessful. Then he became an MP (AIDMK) of Lok Sabha in 1998. He was elected from Tiruchendur (a traditional stronghold for ex-minister Danushkoodi Adithan). Ramarajan defeated him and entered into the Lok Sabha.
At the peak of his career he decided to produce films, but was unsuccessful. Then he became an MP (AIDMK) of Lok Sabha in 1998. He was elected from Tiruchendur (a traditional stronghold for ex-minister Danushkoodi Adithan). Ramarajan defeated him and entered into the Lok Sabha.
Friday, July 27, 2007
SOURCE:www.tamilgfx.comThursday, July 26, 2007
Holoplatys semiplanata
Holoplatys semiplanata (Salticidae), jumping spider taken in Swifts Creek in January 2007. Specimen is approx 12mm in length
Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.2 or any later version published by the Free Software Foundation; with no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. A copy of the license is included in the section entitled "GNU Free Documentation License".
Taken by Fir0002
An adult house fly, musca domestica on an aloe vera leaf. Specimen is approx 10mm in length. Taken in Swifts Creek, Victoria in February 2007
GNU head Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.2 or any later version published by the Free Software Foundation; with no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. A copy of the license is included in the section entitled "GNU Free Documentation License".
Taken by Fir0002
A mammatus cloud formation over Swifts Creek, Victoria, Australia. The name "mammatus" derives from the Latin mamma, or breast, due to their rounded, hanging shape. Mammatus clouds only occur where cumulonimbus are present and are often the byproduct of strong storm activity. Detailed observations of mammatus have been meager and usually occur only by chance, since they do not pose a meteorological threat to society.
Photo credit: Fir0002
On this day: JULY 26
* 811 - Bulgarian forces led by Krum defeated a Byzantine invasion in the Battle of Pliska, killed Byzantine Emperor Nikephoros I and severely wounded his son and co-emperor Staurakios.
* 1139 - After a victory over the Almoravid Moors in the Battle of Ourique, Afonso the Conqueror was proclaimed the first king of an independent Portugal.
* 1822 - José de San Martín met with Simón Bolívar in Guayaquil to plan for the future of Peru and South America in general.
* 1882 - Richard Wagner's opera Parsifal (pictured) premiered at the Festspielhaus in Bayreuth, Germany.
* 1953 - Fidel Castro and his brother Raúl led a group of approximately 160 rebels in an unsuccessful attack on the Moncada Barracks, thus beginning the Cuban Revolution.
SOURCE:WIKIPEDIA
* 1139 - After a victory over the Almoravid Moors in the Battle of Ourique, Afonso the Conqueror was proclaimed the first king of an independent Portugal.
* 1822 - José de San Martín met with Simón Bolívar in Guayaquil to plan for the future of Peru and South America in general.
* 1882 - Richard Wagner's opera Parsifal (pictured) premiered at the Festspielhaus in Bayreuth, Germany.
* 1953 - Fidel Castro and his brother Raúl led a group of approximately 160 rebels in an unsuccessful attack on the Moncada Barracks, thus beginning the Cuban Revolution.
SOURCE:WIKIPEDIA
Whitetip reef shark
The whitetip reef shark, Triaenodon obesus, is a requiem shark of the family Carcharhinidae, the only member of the genus Triaenodon.
Contents
[hide]
* 1 Habitat and distribution
* 2 Anatomy and appearance
* 3 Diet
* 4 Behaviour
* 5 Reproduction
* 6 See also
* 7 References
* 8 External links
[edit] Habitat and distribution
The whitetip reef shark is one of the most common sharks found in shallow tropical and warm temperate water around coral reefs in the Indian and Pacific oceans. It occurs at depths down to 330 m.
[edit] Anatomy and appearance
Whitetip reef shark head.
Whitetip reef shark head.
Whitetip reef shark.
Whitetip reef shark.
As its name suggests, the tips of the shark's first dorsal fin and upper caudal fin are white. The upper body is grey/brownish. Their average length is about 140 to 160 cm and the maximum reported length is 244 cm. Its head is broad and flat.
[edit] Diet
The whitetip reef shark feeds primarily on crustaceans, octopuses and fish.
[edit] Behaviour
This bottom dwelling shark is nocturnal and is often seen resting on the bottom during the day, sometimes in small groups. It is not aggressive and will generally swim away if disturbed, although it may bite if harassed. At night it hunts among crevices in the reef.
[edit] Reproduction
Reproduction is viviparous, with 1 to 5 pups in a litter, the gestation period being at least 5 months. The shark's size at birth ranges from 50 to 60 cm. It is estimated that this shark can live for about 25 years and it reaches maturity after about 5 years.
SOURCE:WIKIPEDIA
Contents
[hide]
* 1 Habitat and distribution
* 2 Anatomy and appearance
* 3 Diet
* 4 Behaviour
* 5 Reproduction
* 6 See also
* 7 References
* 8 External links
[edit] Habitat and distribution
The whitetip reef shark is one of the most common sharks found in shallow tropical and warm temperate water around coral reefs in the Indian and Pacific oceans. It occurs at depths down to 330 m.
[edit] Anatomy and appearance
Whitetip reef shark head.
Whitetip reef shark head.
Whitetip reef shark.
Whitetip reef shark.
As its name suggests, the tips of the shark's first dorsal fin and upper caudal fin are white. The upper body is grey/brownish. Their average length is about 140 to 160 cm and the maximum reported length is 244 cm. Its head is broad and flat.
[edit] Diet
The whitetip reef shark feeds primarily on crustaceans, octopuses and fish.
[edit] Behaviour
This bottom dwelling shark is nocturnal and is often seen resting on the bottom during the day, sometimes in small groups. It is not aggressive and will generally swim away if disturbed, although it may bite if harassed. At night it hunts among crevices in the reef.
[edit] Reproduction
Reproduction is viviparous, with 1 to 5 pups in a litter, the gestation period being at least 5 months. The shark's size at birth ranges from 50 to 60 cm. It is estimated that this shark can live for about 25 years and it reaches maturity after about 5 years.
SOURCE:WIKIPEDIA
Oceanic whitetip shark
The oceanic whitetip shark, Carcharhinus longimanus, is a large pelagic shark of tropical and warm temperate seas. It is a stocky shark, most notable for its long, white-tipped, rounded fins.
This aggressive but slow-moving fish dominates feeding frenzies, and is a suspected danger to survivors of oceanic shipwrecks and downed aircraft.[1][2] Recent studies[3][4] have shown that its numbers are in steep decline — its large fins are highly valued as the chief ingredient of shark fin soup and, as with other shark species, the oceanic whitetip faces mounting pressure from fishing throughout its range.
Contents
[hide]
* 1 Taxonomy
* 2 Distribution and habitat
* 3 Anatomy and appearance
* 4 Diet
* 5 Behaviour
* 6 Reproduction
* 7 Relationship to humans
* 8 Conservation status
* 9 See also
* 10 References
* 11 External links
[edit] Taxonomy
The oceanic whitetip shark was first described by naturalist René-Primevère Lesson in his account of observations made during Louis Duperrey's 1822–1825 circumnavigation of the world on the corvette Coquille. Lesson described two specimens found in the Tuamotu Archipelago in French Polynesia, and named the shark Squalus maou after a Polynesian word for "shark". However, Lesson's description and name were forgotten.[5]
It was next described by Cuban Felipe Poey in 1861 as Squalus longimanus.[5] The name Pterolamiops longimanus has been used during its history. The species epithet, longimanus, refers to the size of its pectoral fins (longimanus translates from Latin as "long hands").[6] The oceanic whitetip shark has many common names in English: Brown Milbert's sand bar shark, brown shark, nigano shark, whitetip whaler, and whitetip shark.[6]
The rules of the International Commission on Zoological Nomenclature are that in general the first-published description has priority; therefore the valid scientific name for the oceanic whitetip shark should be Carcharhinus maou. However, Lesson's name remained forgotten for so long that Carcharhinus longimanus is the widely accepted scientific name.[7]
[edit] Distribution and habitat
The oceanic whitetip is found globally in deep, open water, with a temperature greater than 18 °C (64 °F).[8] It prefers waters between 20 °C (68 °F) and 28 °C (82 °F) and tends to withdraw from areas when temperatures fall below this.[7] They were once extremely common and widely distributed, and still inhabit a wide band around the globe; however, recent studies suggest that their numbers have drastically declined.[3] An analysis of the US pelagic longline logbook data between 1992–2000 (covering the Northwest and Western Central Atlantic) estimated a decline of 70% over that period.[4]
They are found worldwide between 45° north and 43° south latitude.[5][8] In 2004, an oceanic whitetip was discovered dead on the west coast of Sweden—far beyond what was once considered the northern boundary of its range.[9]
The shark spends most of its time in the upper layer of the ocean—to a depth of 150 metres (490 ft)[8]—and prefers off-shore, deep-ocean areas. According to longline capture data, increasing distance from land correlates to a greater population of sharks.[6] Occasionally it is found close to land, in waters as shallow as 37 metres (120 ft), mainly around mid-ocean islands such as Hawaii, or in areas where the continental shelf is narrow and there is access to deep water nearby. It is typically solitary, though gatherings have been observed where food is available.[7] Unlike many animals, it does not have a diurnal cycle, but is active during both day and night.[6] Its swimming style is slow, with the pectoral fins widely spread. Despite their habitual isolation from members of their own species, they may be observed with pilot fish, dolphin fish, and remora.[6] In 1988, Jeremy Stafford-Deitsch reported seeing an individual accompanied by a shortfin pilot whale.[10]
[edit] Anatomy and appearance
Oceanic whitetip shark with a small school of Pilot fish.
Oceanic whitetip shark with a small school of Pilot fish.
The most distinguishing characteristic of C. longimanus is its long, winglike pectoral and dorsal fins. The fins are significantly larger than in most other shark species, and are conspicuously rounded. The shark's nose is rounded and its eyes are circular, with nictitating membranes.[6]
C. longimanus has a 'typical', although somewhat flattened requiem shark body, often with a mildly humpbacked aspect. It is bronze, brown, bluish or grey dorsally (the color varies by region), and white ventrally (although it may occasionally have a yellow tint). The maximum size of the oceanic whitetip shark is 4 metres (13 ft), although usually it does not exceed 3 metres (10 ft). Its maximum weight is 170 kilograms (370 pounds). The female is larger than the male (although typically only by 10 centimetres (4 in)) with males about 1.8 metres (71 in) and females about 1.9 metres (75 in).[6][7]
Most of the fins on its body (dorsal, pectoral, pelvic, and caudal) have white tips (juvenile specimens and occasional adults may lack these). As well as the white tips, the fins may be mottled—and in young specimens can even have black marks. A saddle-like marking may be apparent between first and second dorsal fins.[6] The shark has several kinds of teeth—those in the mandible (lower jaw) have a thin serrated tip and are relatively small and triangular (somewhat fang-like). There are between 13 and 15 teeth on either side of the symphysis. The teeth in the upper jaw are triangular, but much larger and broader with entirely serrated edges—there are 14 or 15 along each side of the symphysis.[6] The denticles lie flat and typically have between five and seven ridges.[6]
[edit] Diet
C. longimanus feeds mainly on pelagic cephalopods and bony fish.[8] However, its diet can be far more varied and less selective—it is known to eat threadfins, stingrays, sea turtles, sea birds, gastropods, crustaceans, mammalian carrion, and even rubbish dumped from ships. The bony fish it feeds on include lancetfish, oarfish, barracuda, jacks, dolphinfish, marlin, tuna, and mackerel. Its methods of predation include biting into groups of fish and swimming through schools of tuna with an open mouth. When feeding with other species, it becomes aggressive.[7] Peter Benchley, author of Jaws, observed this shark swimming among pilot whales and eating their feces.[11]
[edit] Behaviour
The oceanic whitetip is usually solitary and slow-moving, and tends to cruise near the top of the water column, covering vast stretches of empty water scanning for possible food sources.[6] Until the 16th century,[12] sharks were known to mariners as 'sea dogs'[13] and the oceanic whitetip, the most common ship-following shark,[7] exhibits dog-like behaviour when its interest is piqued: when attracted to something that appears to be food, its movements become more avid and it will approach cautiously but stubbornly, retreating and maintaining the minimum safe distance if driven off, but ready for a rush of boldness if the opportunity presents itself. Oceanic whitetips are not fast sharks, but they are capable of surprising bursts of speed. It is commonly found competing for food with silky sharks, making up for its comparatively leisurely swimming style with an aggressive attitude.[7]
Groups are often formed when nearby individuals converge on a food source, whereupon the fabled "feeding frenzy" may occur. This seems to be triggered not by blood in the water per se, or by bloodlust, but by the species' highly strung and goal-directed nature (conserving energy between infrequent feeding opportunities when it is not slowly plying the open ocean). The oceanic whitetip is a competitive, opportunistic predator with great incentive to exploit the resource at hand, rather than avoiding trouble in favour of a possibly easier meal in the future.[7]
There does not seem to be a segregation by sex and size as with some other species. Whitetips will follow schools of tuna or squid, and will trail groups of cetaceans such as dolphins and pilot whales as scavengers of their prey. Their instinct to follow is so strongly imprinted, as the result of countless millennia of baitfish migrations, that they will accompany ocean-going ships. When whaling took place in warm waters, oceanic whitetips were often responsible for much of the damage to floating carcasses.[7]
[edit] Reproduction
Mating season is in early summer in the northwest Atlantic Ocean and southwest Indian Ocean, although females captured in the Pacific have been found with embryos year round, suggesting a longer mating season in this region.[7] The shark is viviparous — the embryos develop in utero and are fed by a placental sac. It has a gestation period of one year. Litter sizes vary from one to 15 with the young born at a length of about 0.6 metres (24 in).[4] Sexual maturity is reached at close to 1.75 metres (69 in) for males and 2 metres (80 in) for females.[4]
[edit] Relationship to humans
It is a commercially important species to the extent that its fins are prized for soup and its meat and oil frequently utilized. It is used fresh, smoked, dried and salted for human consumption and its hide is utilised for leather.[7] It is subject to fishing pressure throughout virtually its whole range[4] — although it is more often taken as bycatch than by design, since it takes bait from longlines intended for other species.[7]
Famed oceanographic researcher Jacques Cousteau described the oceanic whitetip as "the most dangerous of all sharks".[14] Despite the greater notoriety of the great white shark and other sharks habitually found nearer the shore, the oceanic whitetip is considered responsible for more fatal attacks on humans than all other species combined, as a result of predation on those shipwrecked or from aircraft downed in the open ocean.[7] These incidents are not included in common shark-attack indices for the 20th and 21st centuries, but would appear to total in the thousands worldwide, with one incident alone, the torpedoing of USS Indianapolis on July 30, 1945, giving a minimum figure of between 60 and 80 sailors killed by sharks.[1] Also during World War II, the Nova Scotia, a steamship carrying approximately 1,000 people near South Africa was torpedoed and sunk by a German submarine. There were only 192 survivors, and many deaths were attributed to the oceanic whitetip shark.[2]
These stories have led to a traditional negative image of sharks even though the risk of being killed by a shark is 1 in 300 million.[15]
Even though the oceanic whitetip is highly opportunistic and aggressive, and has been known to attack humans for food in very rare incidents,[1] divers have swum with this shark repeatedly without being harmed. Divers are advised to approach the shark only with extreme caution, not spear fish near this shark and, if the shark comes too close or gets too inquisitive, to get out of the water as soon as possible. It is generally suggested that if a shark starts to push the diver, then to hit it on the snout, gills or eyes, but anecdotal evidence suggests that this may be less effective in deterring whitetips than with other species of sharks.[7]
[edit] Conservation status
In 1969, Lineaweaver and Backus wrote of the oceanic whitetip: "[it is] extraordinarily abundant, perhaps the most abundant large animal, large being over 100 pounds [45 kg], on the face of the earth".[16] There was little further population study until 2003 when the numbers were estimated to have dropped by as much as 70% in the Northwest and Western Central Atlantic between 1992–2000.[4] Another study focusing on the Gulf of Mexico, using a mix of data from US pelagic longline surveys from the mid-1950s and observations from the late-1990s, estimated a decline in numbers in this location of 99.3% over this period.[17] However, neither changes in fishing practices nor differences in the data collection methods were fully considered. Because of this there is debate as to the validity of the estimations.[18] As a result of these findings its status on the IUCN Red List was moved to "Vulnerable" globally (from "Lower Risk/Near Threatened") and "Critically Endangered" in the Northwest and Western Central Atlantic areas.[4] Under the 1995 UN Agreement on the Conservation and Management of Straddling Fish Stocks and Highly Migratory Fish Stocks (UNFSA), coastal and fishing states are specifically required to adopt measures to ensure the conservation of listed species, but little progress has been made in this area with regard to the oceanic whitetip.[4]
SOURCE:WIKIPEDIA
This aggressive but slow-moving fish dominates feeding frenzies, and is a suspected danger to survivors of oceanic shipwrecks and downed aircraft.[1][2] Recent studies[3][4] have shown that its numbers are in steep decline — its large fins are highly valued as the chief ingredient of shark fin soup and, as with other shark species, the oceanic whitetip faces mounting pressure from fishing throughout its range.
Contents
[hide]
* 1 Taxonomy
* 2 Distribution and habitat
* 3 Anatomy and appearance
* 4 Diet
* 5 Behaviour
* 6 Reproduction
* 7 Relationship to humans
* 8 Conservation status
* 9 See also
* 10 References
* 11 External links
[edit] Taxonomy
The oceanic whitetip shark was first described by naturalist René-Primevère Lesson in his account of observations made during Louis Duperrey's 1822–1825 circumnavigation of the world on the corvette Coquille. Lesson described two specimens found in the Tuamotu Archipelago in French Polynesia, and named the shark Squalus maou after a Polynesian word for "shark". However, Lesson's description and name were forgotten.[5]
It was next described by Cuban Felipe Poey in 1861 as Squalus longimanus.[5] The name Pterolamiops longimanus has been used during its history. The species epithet, longimanus, refers to the size of its pectoral fins (longimanus translates from Latin as "long hands").[6] The oceanic whitetip shark has many common names in English: Brown Milbert's sand bar shark, brown shark, nigano shark, whitetip whaler, and whitetip shark.[6]
The rules of the International Commission on Zoological Nomenclature are that in general the first-published description has priority; therefore the valid scientific name for the oceanic whitetip shark should be Carcharhinus maou. However, Lesson's name remained forgotten for so long that Carcharhinus longimanus is the widely accepted scientific name.[7]
[edit] Distribution and habitat
The oceanic whitetip is found globally in deep, open water, with a temperature greater than 18 °C (64 °F).[8] It prefers waters between 20 °C (68 °F) and 28 °C (82 °F) and tends to withdraw from areas when temperatures fall below this.[7] They were once extremely common and widely distributed, and still inhabit a wide band around the globe; however, recent studies suggest that their numbers have drastically declined.[3] An analysis of the US pelagic longline logbook data between 1992–2000 (covering the Northwest and Western Central Atlantic) estimated a decline of 70% over that period.[4]
They are found worldwide between 45° north and 43° south latitude.[5][8] In 2004, an oceanic whitetip was discovered dead on the west coast of Sweden—far beyond what was once considered the northern boundary of its range.[9]
The shark spends most of its time in the upper layer of the ocean—to a depth of 150 metres (490 ft)[8]—and prefers off-shore, deep-ocean areas. According to longline capture data, increasing distance from land correlates to a greater population of sharks.[6] Occasionally it is found close to land, in waters as shallow as 37 metres (120 ft), mainly around mid-ocean islands such as Hawaii, or in areas where the continental shelf is narrow and there is access to deep water nearby. It is typically solitary, though gatherings have been observed where food is available.[7] Unlike many animals, it does not have a diurnal cycle, but is active during both day and night.[6] Its swimming style is slow, with the pectoral fins widely spread. Despite their habitual isolation from members of their own species, they may be observed with pilot fish, dolphin fish, and remora.[6] In 1988, Jeremy Stafford-Deitsch reported seeing an individual accompanied by a shortfin pilot whale.[10]
[edit] Anatomy and appearance
Oceanic whitetip shark with a small school of Pilot fish.
Oceanic whitetip shark with a small school of Pilot fish.
The most distinguishing characteristic of C. longimanus is its long, winglike pectoral and dorsal fins. The fins are significantly larger than in most other shark species, and are conspicuously rounded. The shark's nose is rounded and its eyes are circular, with nictitating membranes.[6]
C. longimanus has a 'typical', although somewhat flattened requiem shark body, often with a mildly humpbacked aspect. It is bronze, brown, bluish or grey dorsally (the color varies by region), and white ventrally (although it may occasionally have a yellow tint). The maximum size of the oceanic whitetip shark is 4 metres (13 ft), although usually it does not exceed 3 metres (10 ft). Its maximum weight is 170 kilograms (370 pounds). The female is larger than the male (although typically only by 10 centimetres (4 in)) with males about 1.8 metres (71 in) and females about 1.9 metres (75 in).[6][7]
Most of the fins on its body (dorsal, pectoral, pelvic, and caudal) have white tips (juvenile specimens and occasional adults may lack these). As well as the white tips, the fins may be mottled—and in young specimens can even have black marks. A saddle-like marking may be apparent between first and second dorsal fins.[6] The shark has several kinds of teeth—those in the mandible (lower jaw) have a thin serrated tip and are relatively small and triangular (somewhat fang-like). There are between 13 and 15 teeth on either side of the symphysis. The teeth in the upper jaw are triangular, but much larger and broader with entirely serrated edges—there are 14 or 15 along each side of the symphysis.[6] The denticles lie flat and typically have between five and seven ridges.[6]
[edit] Diet
C. longimanus feeds mainly on pelagic cephalopods and bony fish.[8] However, its diet can be far more varied and less selective—it is known to eat threadfins, stingrays, sea turtles, sea birds, gastropods, crustaceans, mammalian carrion, and even rubbish dumped from ships. The bony fish it feeds on include lancetfish, oarfish, barracuda, jacks, dolphinfish, marlin, tuna, and mackerel. Its methods of predation include biting into groups of fish and swimming through schools of tuna with an open mouth. When feeding with other species, it becomes aggressive.[7] Peter Benchley, author of Jaws, observed this shark swimming among pilot whales and eating their feces.[11]
[edit] Behaviour
The oceanic whitetip is usually solitary and slow-moving, and tends to cruise near the top of the water column, covering vast stretches of empty water scanning for possible food sources.[6] Until the 16th century,[12] sharks were known to mariners as 'sea dogs'[13] and the oceanic whitetip, the most common ship-following shark,[7] exhibits dog-like behaviour when its interest is piqued: when attracted to something that appears to be food, its movements become more avid and it will approach cautiously but stubbornly, retreating and maintaining the minimum safe distance if driven off, but ready for a rush of boldness if the opportunity presents itself. Oceanic whitetips are not fast sharks, but they are capable of surprising bursts of speed. It is commonly found competing for food with silky sharks, making up for its comparatively leisurely swimming style with an aggressive attitude.[7]
Groups are often formed when nearby individuals converge on a food source, whereupon the fabled "feeding frenzy" may occur. This seems to be triggered not by blood in the water per se, or by bloodlust, but by the species' highly strung and goal-directed nature (conserving energy between infrequent feeding opportunities when it is not slowly plying the open ocean). The oceanic whitetip is a competitive, opportunistic predator with great incentive to exploit the resource at hand, rather than avoiding trouble in favour of a possibly easier meal in the future.[7]
There does not seem to be a segregation by sex and size as with some other species. Whitetips will follow schools of tuna or squid, and will trail groups of cetaceans such as dolphins and pilot whales as scavengers of their prey. Their instinct to follow is so strongly imprinted, as the result of countless millennia of baitfish migrations, that they will accompany ocean-going ships. When whaling took place in warm waters, oceanic whitetips were often responsible for much of the damage to floating carcasses.[7]
[edit] Reproduction
Mating season is in early summer in the northwest Atlantic Ocean and southwest Indian Ocean, although females captured in the Pacific have been found with embryos year round, suggesting a longer mating season in this region.[7] The shark is viviparous — the embryos develop in utero and are fed by a placental sac. It has a gestation period of one year. Litter sizes vary from one to 15 with the young born at a length of about 0.6 metres (24 in).[4] Sexual maturity is reached at close to 1.75 metres (69 in) for males and 2 metres (80 in) for females.[4]
[edit] Relationship to humans
It is a commercially important species to the extent that its fins are prized for soup and its meat and oil frequently utilized. It is used fresh, smoked, dried and salted for human consumption and its hide is utilised for leather.[7] It is subject to fishing pressure throughout virtually its whole range[4] — although it is more often taken as bycatch than by design, since it takes bait from longlines intended for other species.[7]
Famed oceanographic researcher Jacques Cousteau described the oceanic whitetip as "the most dangerous of all sharks".[14] Despite the greater notoriety of the great white shark and other sharks habitually found nearer the shore, the oceanic whitetip is considered responsible for more fatal attacks on humans than all other species combined, as a result of predation on those shipwrecked or from aircraft downed in the open ocean.[7] These incidents are not included in common shark-attack indices for the 20th and 21st centuries, but would appear to total in the thousands worldwide, with one incident alone, the torpedoing of USS Indianapolis on July 30, 1945, giving a minimum figure of between 60 and 80 sailors killed by sharks.[1] Also during World War II, the Nova Scotia, a steamship carrying approximately 1,000 people near South Africa was torpedoed and sunk by a German submarine. There were only 192 survivors, and many deaths were attributed to the oceanic whitetip shark.[2]
These stories have led to a traditional negative image of sharks even though the risk of being killed by a shark is 1 in 300 million.[15]
Even though the oceanic whitetip is highly opportunistic and aggressive, and has been known to attack humans for food in very rare incidents,[1] divers have swum with this shark repeatedly without being harmed. Divers are advised to approach the shark only with extreme caution, not spear fish near this shark and, if the shark comes too close or gets too inquisitive, to get out of the water as soon as possible. It is generally suggested that if a shark starts to push the diver, then to hit it on the snout, gills or eyes, but anecdotal evidence suggests that this may be less effective in deterring whitetips than with other species of sharks.[7]
[edit] Conservation status
In 1969, Lineaweaver and Backus wrote of the oceanic whitetip: "[it is] extraordinarily abundant, perhaps the most abundant large animal, large being over 100 pounds [45 kg], on the face of the earth".[16] There was little further population study until 2003 when the numbers were estimated to have dropped by as much as 70% in the Northwest and Western Central Atlantic between 1992–2000.[4] Another study focusing on the Gulf of Mexico, using a mix of data from US pelagic longline surveys from the mid-1950s and observations from the late-1990s, estimated a decline in numbers in this location of 99.3% over this period.[17] However, neither changes in fishing practices nor differences in the data collection methods were fully considered. Because of this there is debate as to the validity of the estimations.[18] As a result of these findings its status on the IUCN Red List was moved to "Vulnerable" globally (from "Lower Risk/Near Threatened") and "Critically Endangered" in the Northwest and Western Central Atlantic areas.[4] Under the 1995 UN Agreement on the Conservation and Management of Straddling Fish Stocks and Highly Migratory Fish Stocks (UNFSA), coastal and fishing states are specifically required to adopt measures to ensure the conservation of listed species, but little progress has been made in this area with regard to the oceanic whitetip.[4]
SOURCE:WIKIPEDIA
How to Become an Early Riser
It is well to be up before daybreak, for such habits contribute to health, wealth, and wisdom.
- Aristotle
Are morning people born or made? In my case it was definitely made. In my early 20s, I rarely went to bed before midnight, and I’d almost always sleep in late. I usually didn’t start hitting my stride each day until late afternoon.
But after a while I couldn’t ignore the high correlation between success and rising early, even in my own life. On those rare occasions where I did get up early, I noticed that my productivity was almost always higher, not just in the morning but all throughout the day. And I also noticed a significant feeling of well-being. So being the proactive goal-achiever I was, I set out to become a habitual early riser. I promptly set my alarm clock for 5AM…
… and the next morning, I got up just before noon.
Hmmm…
I tried again many more times, each time not getting very far with it. I figured I must have been born without the early riser gene. Whenever my alarm went off, my first thought was always to stop that blasted noise and go back to sleep. I tabled this habit for a number of years, but eventually I came across some sleep research that showed me that I was going about this problem the wrong way. Once I applied those ideas, I was able to become an early riser consistently.
It’s hard to become an early riser using the wrong strategy. But with the right strategy, it’s relatively easy.
The most common wrong strategy is this: You assume that if you’re going to get up earlier, you’d better go to bed earlier. So you figure out how much sleep you’re getting now, and then just shift everything back a few hours. If you now sleep from midnight to 8am, you figure you’ll go to bed at 10pm and get up at 6am instead. Sounds very reasonable, but it will usually fail.
It seems there are two main schools of thought about sleep patterns. One is that you should go to bed and get up at the same times every day. It’s like having an alarm clock on both ends — you try to sleep the same hours each night. This seems practical for living in modern society. We need predictability in our schedules. And we need to ensure adequate rest.
The second school says you should listen to your body’s needs and go to bed when you’re tired and get up when you naturally wake up. This approach is rooted in biology. Our bodies should know how much rest we need, so we should listen to them.
Through trial and error, I found out for myself that both of these schools are suboptimal sleep patterns. Both of them are wrong if you care about productivity. Here’s why:
If you sleep set hours, you’ll sometimes go to bed when you aren’t sleepy enough. If it’s taking you more than five minutes to fall asleep each night, you aren’t sleepy enough. You’re wasting time lying in bed awake and not being asleep. Another problem is that you’re assuming you need the same number of hours of sleep every night, which is a false assumption. Your sleep needs vary from day to day.
If you sleep based on what your body tells you, you’ll probably be sleeping more than you need — in many cases a lot more, like 10-15 hours more per week (the equivalent of a full waking day). A lot of people who sleep this way get 8+ hours of sleep per night, which is usually too much. Also, your mornings may be less predictable if you’re getting up at different times. And because our natural rhythms are sometimes out of tune with the 24-hour clock, you may find that your sleep times begin to drift.
The optimal solution for me has been to combine both approaches. It’s very simple, and many early risers do this without even thinking about it, but it was a mental breakthrough for me nonetheless. The solution was to go to bed when I’m sleepy (and only when I’m sleepy) and get up with an alarm clock at a fixed time (7 days per week). So I always get up at the same time (in my case 5am), but I go to bed at different times every night.
I go to bed when I’m too sleepy to stay up. My sleepiness test is that if I couldn’t read a book for more than a page or two without drifting off, I’m ready for bed. Most of the time when I go to bed, I’m asleep within three minutes. I lie down, get comfortable, and immediately I’m drifting off. Sometimes I go to bed at 9:30pm; other times I stay up until midnight. Most of the time I go to bed between 10-11pm. If I’m not sleepy, I stay up until I can’t keep my eyes open any longer. Reading is an excellent activity to do during this time, since it becomes obvious when I’m too sleepy to read.
When my alarm goes off every morning, I turn it off, stretch for a couple seconds, and sit up. I don’t think about it. I’ve learned that the longer it takes me to get up, the more likely I am to try to sleep in. So I don’t allow myself to have conversations in my head about the benefits of sleeping in once the alarm goes off. Even if I want to sleep in, I always get up right away.
After a few days of using this approach, I found that my sleep patterns settled into a natural rhythm. If I got too little sleep one night, I’d automatically be sleepier earlier and get more sleep the next night. And if I had lots of energy and wasn’t tired, I’d sleep less. My body learned when to knock me out because it knew I would always get up at the same time and that my wake-up time wasn’t negotiable.
A side effect was that on average, I slept about 90 minutes less per night, but I actually felt more well-rested. I was sleeping almost the entire time I was in bed.
I read that most insomniacs are people who go to bed when they aren’t sleepy. If you aren’t sleepy and find yourself unable to fall asleep quickly, get up and stay awake for a while. Resist sleep until your body begins to release the hormones that rob you of consciousness. If you simply go to bed when you’re sleepy and then get up at a fixed time, you’ll cure your insomnia. The first night you’ll stay up late, but you’ll fall asleep right away. You may be tired that first day from getting up too early and getting only a few hours of sleep the whole night, but you’ll slog through the day and will want to go to bed earlier that second night. After a few days, you’ll settle into a pattern of going to bed at roughly the same time and falling asleep right away.
So if you want to become an early riser (or just exert more control over your sleep patterns), then try this: Go to bed only when you’re too sleepy to stay up, and get up at a fixed time every morning.
SOURCE :http://www.stevepavlina.com/blog/2005/05/how-to-become-an-early-riser/
How to Become an Early Riser
It is well to be up before daybreak, for such habits contribute to health, wealth, and wisdom.
- Aristotle
Are morning people born or made? In my case it was definitely made. In my early 20s, I rarely went to bed before midnight, and I’d almost always sleep in late. I usually didn’t start hitting my stride each day until late afternoon.
But after a while I couldn’t ignore the high correlation between success and rising early, even in my own life. On those rare occasions where I did get up early, I noticed that my productivity was almost always higher, not just in the morning but all throughout the day. And I also noticed a significant feeling of well-being. So being the proactive goal-achiever I was, I set out to become a habitual early riser. I promptly set my alarm clock for 5AM…
… and the next morning, I got up just before noon.
Hmmm…
I tried again many more times, each time not getting very far with it. I figured I must have been born without the early riser gene. Whenever my alarm went off, my first thought was always to stop that blasted noise and go back to sleep. I tabled this habit for a number of years, but eventually I came across some sleep research that showed me that I was going about this problem the wrong way. Once I applied those ideas, I was able to become an early riser consistently.
It’s hard to become an early riser using the wrong strategy. But with the right strategy, it’s relatively easy.
The most common wrong strategy is this: You assume that if you’re going to get up earlier, you’d better go to bed earlier. So you figure out how much sleep you’re getting now, and then just shift everything back a few hours. If you now sleep from midnight to 8am, you figure you’ll go to bed at 10pm and get up at 6am instead. Sounds very reasonable, but it will usually fail.
It seems there are two main schools of thought about sleep patterns. One is that you should go to bed and get up at the same times every day. It’s like having an alarm clock on both ends — you try to sleep the same hours each night. This seems practical for living in modern society. We need predictability in our schedules. And we need to ensure adequate rest.
The second school says you should listen to your body’s needs and go to bed when you’re tired and get up when you naturally wake up. This approach is rooted in biology. Our bodies should know how much rest we need, so we should listen to them.
Through trial and error, I found out for myself that both of these schools are suboptimal sleep patterns. Both of them are wrong if you care about productivity. Here’s why:
If you sleep set hours, you’ll sometimes go to bed when you aren’t sleepy enough. If it’s taking you more than five minutes to fall asleep each night, you aren’t sleepy enough. You’re wasting time lying in bed awake and not being asleep. Another problem is that you’re assuming you need the same number of hours of sleep every night, which is a false assumption. Your sleep needs vary from day to day.
If you sleep based on what your body tells you, you’ll probably be sleeping more than you need — in many cases a lot more, like 10-15 hours more per week (the equivalent of a full waking day). A lot of people who sleep this way get 8+ hours of sleep per night, which is usually too much. Also, your mornings may be less predictable if you’re getting up at different times. And because our natural rhythms are sometimes out of tune with the 24-hour clock, you may find that your sleep times begin to drift.
The optimal solution for me has been to combine both approaches. It’s very simple, and many early risers do this without even thinking about it, but it was a mental breakthrough for me nonetheless. The solution was to go to bed when I’m sleepy (and only when I’m sleepy) and get up with an alarm clock at a fixed time (7 days per week). So I always get up at the same time (in my case 5am), but I go to bed at different times every night.
I go to bed when I’m too sleepy to stay up. My sleepiness test is that if I couldn’t read a book for more than a page or two without drifting off, I’m ready for bed. Most of the time when I go to bed, I’m asleep within three minutes. I lie down, get comfortable, and immediately I’m drifting off. Sometimes I go to bed at 9:30pm; other times I stay up until midnight. Most of the time I go to bed between 10-11pm. If I’m not sleepy, I stay up until I can’t keep my eyes open any longer. Reading is an excellent activity to do during this time, since it becomes obvious when I’m too sleepy to read.
When my alarm goes off every morning, I turn it off, stretch for a couple seconds, and sit up. I don’t think about it. I’ve learned that the longer it takes me to get up, the more likely I am to try to sleep in. So I don’t allow myself to have conversations in my head about the benefits of sleeping in once the alarm goes off. Even if I want to sleep in, I always get up right away.
After a few days of using this approach, I found that my sleep patterns settled into a natural rhythm. If I got too little sleep one night, I’d automatically be sleepier earlier and get more sleep the next night. And if I had lots of energy and wasn’t tired, I’d sleep less. My body learned when to knock me out because it knew I would always get up at the same time and that my wake-up time wasn’t negotiable.
A side effect was that on average, I slept about 90 minutes less per night, but I actually felt more well-rested. I was sleeping almost the entire time I was in bed.
I read that most insomniacs are people who go to bed when they aren’t sleepy. If you aren’t sleepy and find yourself unable to fall asleep quickly, get up and stay awake for a while. Resist sleep until your body begins to release the hormones that rob you of consciousness. If you simply go to bed when you’re sleepy and then get up at a fixed time, you’ll cure your insomnia. The first night you’ll stay up late, but you’ll fall asleep right away. You may be tired that first day from getting up too early and getting only a few hours of sleep the whole night, but you’ll slog through the day and will want to go to bed earlier that second night. After a few days, you’ll settle into a pattern of going to bed at roughly the same time and falling asleep right away.
So if you want to become an early riser (or just exert more control over your sleep patterns), then try this: Go to bed only when you’re too sleepy to stay up, and get up at a fixed time every morning.
Wednesday, July 25, 2007
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