Grey Nurse Shark - Scuba Diving Shark Point Clovelly Sydney
he grey nurse shark, Carcharias taurus, also called the ragged-tooth shark, is an elasmobranch and belongs to the odontaspididae (ragged-tooth) shark family. It can easily be recognized by its characteristic conical snout and under hung jaw. Both jaws are laden with sharp, long and pointed teeth. The head is flattened and it has a large and stout body which ranges up to 3.2m and may weigh up to 300 kg. The body is grey to grey-brown dorsally and off-white on the belly. The juveniles (young sharks) usually have dark spots on the upper two thirds of the body. The first and second dorsal fins are of similar size and the caudal fin is asymmetric. Once believed to be a man-eater it is now known that this shark rarely attacks humans and if it does it is only in defense; or if it is baited.
Sharks are the top predators in our oceans, and as such they are important for the marine ecosystems as important regulators of other species. They eat the weak, the old and the dead animals. The grey nurse sharks eat mainly lobsters, crabs, smaller sharks, fish, rays and squid.
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Octopus. Scuba Diving in Eilat, Red Sea
Octopus (pl. octopuses, see below for variants) are soft-bodied, eight-limbed molluscs of the order Octopoda (/ɒkˈtɒpədə/, ok-TOP-ə-də[3]). The order consists of some 300 species and is grouped within the class Cephalopoda with squids, cuttlefish, and nautiloids. Like other cephalopods, an octopus is bilaterally symmetric with two eyes and a beaked mouth at the center point of the eight limbs.[a] The soft body can radically alter its shape, enabling octopuses to squeeze through small gaps. They trail their eight appendages behind them as they swim. The siphon is used both for respiration and for locomotion, by expelling a jet of water. Octopuses have a complex nervous system and excellent sight, and are among the most intelligent and behaviourally diverse of all invertebrates.
Octopuses inhabit various regions of the ocean, including coral reefs, pelagic waters, and the seabed; some live in the intertidal zone and others at abyssal depths. Most species grow quickly, mature early, and are short-lived. In most species, the male uses a specially adapted arm to deliver a bundle of sperm directly into the female's mantle cavity, after which he becomes senescent and dies, while the female deposits fertilised eggs in a den and cares for them until they hatch, after which she also dies. Strategies to defend themselves against predators include the expulsion of ink, the use of camouflage and threat displays, the ability to jet quickly through the water and hide, and even deceit. All octopuses are venomous, but only the blue-ringed octopuses are known to be deadly to humans.
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Scuba Diving Panglao Lionfish Balicasag Island | Pata Negra Dive Center
Lionfish are known for their venomous fin rays, an uncommon feature among reef-dwelling fish along the American East Coast and Caribbean. The potency of their venom makes them excellent predators and hazardous to fishermen and divers.[2] Pterois venom produced negative inotropic and chronotropic effects when tested in both frog and clam hearts[29] and has a depressive effect on rabbit blood pressure.[30] These results are thought to be due to nitric oxide release.[9] In humans, Pterois venom can cause systemic effects such as extreme pain, nausea, vomiting, fever, breathing difficulties, convulsions, dizziness, redness on the affected area, headache, numbness, paresthesia (pins and needles), heartburn, diarrhea, and sweating. Rarely, such stings can cause temporary paralysis of the limbs, heart failure, and even death. Fatalities are common in very young children, the elderly, those with a weak immune system, or those who are allergic to their venom. Their venom is rarely fatal to healthy adults, but some species have enough venom to produce extreme discomfort for a period of several days. However, Pterois venom poses a danger to allergic victims as they may experience anaphylaxis, a serious and often life-threatening condition that requires immediate emergency medical treatment. Severe allergic reactions to Pterois venom include chest pain, severe breathing difficulties, a drop in blood pressure, swelling of the tongue, sweating, runny nose, or slurred speech. Such reactions can be fatal if not treated.
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Scuba Diving Underwater Ninjutsu - scuba diving kata
Scuba diving is a mode of underwater diving where the diver uses an apparatus which is completely independent of surface supply to breathe underwater.[1] The name "scuba", an acronym of "Self-Contained Underwater Breathing Apparatus", was first used by Christian J. Lambertsen in a patent submitted in 1952. Scuba divers carry their own source of breathing gas, usually compressed air,[2] allowing them greater independence and freedom of movement than surface-supplied divers, and longer underwater endurance than breath-hold divers.[1] Although the use of compressed air is common, a mixture of air and oxygen called enriched air or nitrox has become popular due to its benefit of reduced nitrogen intake during long or repetitive dives. Breathing gas diluted with helium may be used to reduce nitrogen narcosis.
Open circuit scuba systems discharge the breathing gas into the environment as it is exhaled, and consist of one or more diving cylinders containing breathing gas at high pressure which is supplied to the diver through a diving regulator. They may include additional cylinders for range extension, decompression gas or emergency breathing gas .[3] Closed-circuit or semi-closed circuit rebreather scuba systems allow recycling of exhaled gases. The volume of gas used is reduced compared to that of open circuit, so a smaller cylinder or cylinders may be used for an equivalent dive duration. Rebreathers extend the time spent underwater compared to open circuit for the same gas consumption; they produce fewer bubbles and less noise than open circuit scuba which makes them attractive to covert military divers to avoid detection, scientific divers to avoid disturbing marine animals, and media divers to avoid bubble interference.
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12 Reasons Why Mads Mikkelsen Is The Best Hannibal Lecter
12 Reasons Why Mads Mikkelsen Is The Best Hannibal Lecter
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The Most Mysterious Unsolved Murders of All Time: Jack The Ripper
The Most Mysterious Unsolved Murders of All Time: Jack The Ripper
Murders are always disturbing, but some are even worse than that. These killings were brutal, almost unimaginable in their depravity. The crimes horrified communities and stumped police — leaving questions that lingered for decades afterward, as years passed without an arrest or even a credible suspect.
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