The Electric Ray
The electric rays are a group of rays, flattened cartilaginous fish with enlarged pectoral fins, that comprise the order Torpediniformes. They are known for being capable of producing an electric discharge, ranging from as little as 8 volts up to 220 volts depending on species, used to stun prey and for defense. There are 69 species in four families.
Perhaps the most known members are those of the genus Torpedo, also called crampfish and numbfish, after which the device called a torpedo is named. The name comes from the Latin "torpere", to be stiffened or paralyzed, referring to the effect on someone who handles or steps on a living electric ray.
Torpedo rays are excellent swimmers. Their round disk shaped bodies allow them to remain suspended in the water or roam for food with minimal swimming effort.
Description
Electric rays have a rounded pectoral disc with two moderately large rounded-angular (not pointed or hooked) dorsal fins (reduced in some narkids), and a stout, muscular tail with a well-developed caudal fin. The body is thick and flabby, with soft, loose skin devoid of dermal denticles and thorns. A pair of kidney-shaped electric organs are found at the base of the pectoral fins. The snout is broad, large in the Narcinidae but reduced in all other families. The mouth, nostrils, and five pairs of gill slits are located underneath the disc.
They are bottom dwelling fish, found from shallow coastal waters down to at least 1,000 metres (3,300 ft) depth. They are sluggish and slow moving, propelling themselves along with their tails, rather than using their disc-shaped bodies, as other rays do. They feed on invertebrates and small fish. They lie in wait for prey below the sand or other substrate, using their electricity to stun and capture it.
Relationship to humans
The electrogenic properties of electric rays have been known since antiquity. The ancient Greeks used electric rays to numb the pain of childbirth and operations. Scribonius Largus, a Roman physician, recorded the use of torpedo fish for treatment of headaches and gout in his Compositiones Medicae of 46 AD.
Bioelectricity
The electric ray is known to be the most electro-sensitive of all zoological organisms and their eyes are situated on the top of their head, providing for poor vision which must be balanced by use of other senses, including the detection of electricity. Many species of rays and skates outside the family of the electric ray have electric organs located in the tail, however, the electric ray possesses two large electric organs on each side of its head, where current passes from the lower to the upper surface of the body. The organs are governed by four central nerves from each side of the electric lobe, or specialized brain lobe, which is of a different colour than the rest of the brain. The main nerves branch continuously then attach to the lower side of each plate in the batteries, which are composed of hexagonal columns, in honeycomb formation: each column consists of one hundred and forty to half a million gelatinous plates. In marine fish, these batteries are connected as a parallel circuit where freshwater batteries are found in series, transmitting discharges of higher voltage, as fresh water cannot conduct electricity as well as salt water. It is with such a battery that an average electric ray may electrocute a large fish with a current until 30 amps with a voltage from 50 up to 200 Volts, which gives the effect of a hair dryer being dropped into a tub of water.
Systematics
The four families of the Torpediniformes are typically grouped into two superfamilies: Hypnidae and Torpedinidae in the Torpedinoidea, and Narkidae and Narcinidae in the Narcinoidea. The Torpedinoidea specialize on large prey, which are stunned using their electric organs and swallowed whole, while the Narcinoidea specialize on small prey on or in the bottom substrate. Both groups use electricity for defense, but it is unclear whether the Narcinoidea use electricity in feeding.
Classification
The order contains over 60 species, grouped into twelve genera and two to four families:
Order Torpediniformes
Family Hypnidae (coffin rays) - sometimes placed in Torpedinidae
Genus Hypnos
Family Narcinidae (numbfishes)
Genus Benthobatis
Genus Crassinarke
Genus Diplobatis
Genus Discopyge
Genus Narcine
Family Narkidae (sleeper rays) - sometimes placed in Narcinidae
Genus Electrolux
Genus Heteronarce
Genus Narke
Genus Temera
Genus Typhlonarke
Family Torpedinidae (electric rays)
Genus Torpedo
Torpedo (genus)
Torpedo is a group of rays, commonly called electric rays or torpedoes. It is the only genus in the family Torpedinidae, in the order Torpediniformes. They are slow-moving bottom-dwellers capable of generating electricity as a defense and feeding mechanism. There are between fifteen and twenty-two extant species.
The naval weapon known as the torpedo was named after this genus, whose own name is derived from the Latin word meaning "numb" or "paralysed", presumably the sensations one would feel after experiencing the ray's electric shock.
Electricity
The largest species is the Atlantic torpedo, Torpedo nobiliana, which can grow to a weight of 90 kilograms (200 lb) and deliver a 220-volt electric shock. Electric rays have patches of modified muscle cells called electroplaques that make up an electric organ. These generate an electric gradient, similar to the normal electric potential across most cell membranes, but amplified greatly by its concentration into a very small area. The electricity can be stored in the tissues, which act as a battery. The shock can be discharged in pulses. A ray can emit a shock into the body of a prey animal to stun it and make it easier to capture and eat, or into the body of a predator. Tissue from electric rays is often used in neurobiological research because of its unique properties.
Description
Torpedo rays are flat like other rays, disc-shaped, with caudal fins that vary in length. Their mouths and gill slits are located on their undersides. Males have claspers near the base of the tail. Females are ovoviviparous, meaning they form eggs but do not lay them. The young emerge from the eggs within the body of the female, and she gives live birth.
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The Torpedo Ray
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The Quagga
The quagga (Equus quagga quagga) is an extinct subspecies of the Plains zebra, which was once found in great numbers in South Africa's Cape Province and the southern part of the Orange Free State. It was distinguished from other zebras by having the usual vivid marks on the front part of the body only. In the mid-section, the stripes faded and the dark, inter-stripe spaces became wider, and the rear parts were a plain brown. The name comes from a Khoikhoi word for zebra and is onomatopoeic, being said to resemble the quagga's call. The only quagga to have ever been photographed alive was a mare at the Zoological Society of London's Zoo in Regent's Park in 1870.
Range and habitat
The Quagga lived in the drier parts of South Africa, on grassland. The northern limit seems to have been the Orange River in the west and the Vaal River in the east; the south-eastern border may have been the Great Kei River.It was hunted for its meat and fur, and is one of many victims of the modern mass extinction.
Taxonomy
The quagga was originally classified as an individual species, Equus quagga, in 1778. Over the next 50 years or so, many other zebras were described by naturalists and explorers. Because of the great variation in coat patterns (no two zebras are alike), taxonomists were left with a great number of described "species", and no easy way to tell which of these were true species, which were subspecies, and they were simply natural variants.
Long before this confusion was sorted out, the quagga had been hunted to extinction for meat, hides, and to preserve feed for domesticated stock. The last wild quagga was probably shot in the late 1870s, and the last specimen in captivity, a mare, died on August 12, 1883 at the Artis Magistra zoo in Amsterdam. Because of the confusion between different zebra species, particularly among the general public, the quagga had become extinct before it was realized that it appeared to be a separate species.
1793 illustration of the quagga stallion of Louis XVI's menagerie at Versailles.The quagga was the first extinct creature to have its DNA studied. Recent genetic research at the Smithsonian Institution has demonstrated that the quagga was in fact not a separate species at all, but diverged from the extremely variable plains zebra, Equus burchelli, between 120,000 and 290,000 years ago, and suggests that it should be named Equus burchelli quagga. However, according to the rules of biological nomenclature, where there are two or more alternative names for a single species, the name first used takes priority. As the quagga was described about thirty years earlier than the plains zebra, it appears that the correct terms are E. quagga quagga for the quagga and E. quagga burchelli for the plains zebra, unless "Equus burchelli" is officially declared to be a nomen conservandum.
Quagga specimen at Natural History Museum, London.After the very close relationship between the quagga and surviving zebras was discovered, the Quagga Project was started by Reinhold Rau in South Africa to recreate the quagga by selective breeding from plains zebra stock, with the eventual aim of reintroducing them to the wild. This type of breeding is also called breeding back. In early 2006, it was reported that the third and fourth generations of the project have produced animals which look very much like the depictions and preserved specimens of the quagga, though whether looks alone are enough to declare that this project has produced a true "re-creation" of the original quagga is controversial.
DNA from mounted specimens was successfully extracted in 1984, but the technology to use recovered DNA for breeding does not yet exist. In addition to skins such as the one held by the Natural History Museum in London, there are 23 known stuffed and mounted quagga throughout the world. A twenty-fourth specimen was destroyed in Königsberg, Germany (now Kaliningrad), during World War II.
Quagga hybrids and similar animals
Zebras have been cross-bred to other equines such as donkeys and horses. There are modern animal farms which continue to do so. The offspring are known as zeedonks, zonkeys and zorses (the term for all such zebra hybrids is zebroid). Zebroids are often exhibited as curiosities although some are broken to harness or as riding animals. On January 20, 2005, Henry, a foal of the Quagga Project, was born. He most resembles the quagga.
There is a record of a quagga bred to a horse in the 1896 work Anomalies and Curiosities of Medicine by George M. Gould and Walter L. Pyle:
“ In the year 1815 Lord Morton put a male quagga to a young chestnut mare of seven-eighths Arabian blood, which had never before been bred from. The result was a female hybrid which resembled both parents. ”
In his 1859 The Origin of Species, Charles Darwin recalls seeing coloured drawings of zebra-donkey hybrids, and mentions "Lord Moreton's famous hybrid from a chesnut [sic] mare and male quagga..." Darwin mentioned this particular hybrid again in 1868 in The Variation of Animals and Plants under Domestication, and provides a citation to the journal in which Lord Morton first described the breeding.
Okapi markings are nearly the reverse of the quagga, with the forequarters being mostly plain and the hindquarters being heavily striped. However, the okapi is no relation of the quagga, horse, donkey, or zebra. Its closest taxonomic relative is the giraffe
In popular culture
A quagga appears in a sequence in the Soviet Union's animated film The Cat Who Walked by Herself, in which a dog tracks the hoofprints of one, and a cat tells a boy of the Red Book of endangered species, and how Quagga had "her track severed" (that is, made extinct) due to Man's selfish actions.
A Quagga is one of the main characters in The Katurran Odyssey, a fantasy children's book by David Michael Wieger.
The Quagga has had a part in the book Artemis Fowl: The Time Paradox, by author Eoin Colfer, where the protagonist, Artemis Fowl, is made to ride a Quagga in his attempts to flee the clutches of an evil pixie, Opal Koboi.
The Quagga can be unlocked in the computer game Zoo Tycoon 2: Extinct Animals. This is the only unlockable that is a real extinct animal. The quagga can be earned through fossil hunting before unlocking it. It is also able to be unlocked in freeform (after you have managed to release all the extinct animals), which is rare for rewards in the game. It is able to interbreed with the common zebra. Once unlocked, it will become available at Challenge and Campaign games at 1.5 stars in Zoo Tycoon 2: Extinct Animals.
The Quagga is also seen in the book Skybreaker by Kenneth Oppel when a stuffed specimen is found on the abandoned airship Hyperion.
The Quagga is mentioned in Jurassic Park as one of the animals that could be recreated by InGen or Biosyn using DNA extracted from the hides of the Quagga.
In King Solomon's Mines by H. Rider Haggard, Captain Good startles a sleeping herd of quagga on their journey across the desert.
The Quagga will be featured in the 2010 remake of The Lost World.[citation needed]
The Quagga is also mentioned as one of the species "re-created" in Philip José Farmer's short story, "King of the Beasts."
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![An Zonky: half donkey & half zebra. |Source=[http://www.flickr.com/photos/22198030@N00/407938980/ A zonky] |Date=August 06, 2006 at 01:49 |Author=[http://www.flickr.com/people/22198030@N00 Ruth boraggina] from Belleville, USA )](A_zonky.jpg "An Zonky: half donkey & half zebra. |Source=[http://www.flickr.com/photos/22198030@N00/407938980/ A zonky] |Date=August 06, 2006 at 01:49 |Author=[http://www.flickr.com/people/22198030@N00 Ruth boraggina] from Belleville, USA )")
The Quagga rebuilding a Species
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Mike the Headless Chicken
Mike the Headless Chicken (April 1945 – March 1947), also known as Miracle Mike,was a Wyandotte rooster that lived for 18 months after its head had been mostly cut off. Thought by many to be a hoax, the bird was taken by its owner to the University of Utah in Salt Lake City to establish its authenticity.
Beheading
On September 10, 1945, farmer Lloyd Olsen of Fruita, Colorado, had his mother-in-law around for supper and was sent out to the yard by his wife to bring back a chicken. Olsen chose a five-and-a-half month old cockerel named Mike, but failed to completely decapitate the bird. The axe missed the jugular vein, leaving one ear and most of the brain stem intact.
Despite Olsen's botched handiwork, Mike was still able to balance on a perch and walk clumsily; it even attempted to preen and crow, although it could do neither. After the bird did not die, a surprised Mr. Olsen decided to continue to care permanently for Mike, feeding it a mixture of milk and water via an eyedropper; it was also fed small grains of corn. Mike occasionally choked on its own mucus, which the Olsen family would clear using a syringe.
When used to its new and unusual center of mass, Mike could easily get itself to the highest perches without falling. Its crowing, though, was less impressive and consisted of a gurgling sound made in its throat, leaving it unable to crow at dawn. Mike also spent its time preening and attempting to peck for food with its neck.
Being semi-headless did not keep Mike from putting on weight; at the time of its partial beheading it weighed two and a half pounds, but at the time of its death this had increased to nearly eight pounds.
Fame
Once its fame had been established, Mike began a career of touring sideshows in the company of such other creatures as a two-headed calf. It was also photographed for dozens of magazines and papers, featuring in Time and Life magazines. Olsen drew criticism from some for keeping the semi-headless chicken alive.
Mike was on display to the public for an admission cost of 25 cents. At the height of its popularity the chicken earned princely $4,500 USD per month ($50,000 in 2005 dollars) and was valued at $10,000. Olsen's success resulted in a wave of copycat chicken beheadings, but no other chicken lived for more than a day or two. A pickled chicken head was also on display with Mike, but this was not Mike's original head, as a cat had already eaten it. Mike was later examined by the officers of several humane societies and was declared to have been free from any suffering.
A children's playground chant soon emerged: "Mike, Mike, where's your head? Even without it, you're not dead!"
Death
In March 1947, at a motel in Phoenix on a stopover while traveling back home from tour, Mike started choking in the middle of the night. As the Olsens had inadvertently left their feeding and cleaning syringes at the sideshow the day before, they were unable to save Mike. Lloyd Olsen claimed that he had sold the bird off, resulting in stories of Mike still touring the country as late as 1949. Other sources, including the Guinness Book of World Records,say that the chicken's severed trachea could not take in enough air properly to be able to breathe; and therefore choked to death in the motel.
Post mortem, it was determined that the axe blade had missed the carotid artery and a clot had prevented Mike from bleeding to death. Although most of its head was severed, most of its brain stem and one ear was left on its body. Since basic functions (breathing, heart-rate, etc) as well as most of a chicken's reflex actions are controlled by the brain stem, Mike was able to remain quite healthy.
Legacy in Fruita
Mike the Headless Chicken is now an institution in Fruita, Colorado, with an annual "Mike the Headless Chicken Day", the third weekend of May, starting in 1999. Events held include the "5K Run Like a Headless Chicken Race", egg toss, "Pin the Head on the Chicken", the "Chicken Cluck-Off", and "Chicken Bingo", in which chicken droppings on a numbered grid choose the numbers. There is also a song about Mike by the band Radioactive Chickenheads.
More on Mike the Headless Chicken : Homepage : miketheheadlesschicken.org
Source : Wikipedia
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The Palm Cockatoo
The Palm Cockatoo (Probosciger aterrimus), also known as the Goliath Cockatoo, is a large smoky-grey or black parrot of the cockatoo family. It is the only member in subfamily Microglossinae and the only member of the monotypic genus, Probosciger. Its unique position within the cockatoo family has been confirmed by molecular studies.
The Palm Cockatoo is distributed in rainforests and woodlands of New Guinea and northern Queensland, Australia. A majority of all captive-bred Palm Cockatoos are currently owned by Natalie Copp, David Roberts, Mike Tyson, Thomas Woodward and Ina Zuncke. The collective breeding program has been deemed a success by the Palm Cockatoo Conservation in Papua New Guinea.
Taxonomy
The Palm Cockatoo was originally described by German naturalist Gmelin in 1788. Its specific name aterrimus is the Latin superlative adjective for ater "black", hence "very black" or "blackest". It is the earliest offshoot from the ancestors of what have become the cockatoo family.
Description
The Palm Cockatoo is 55–60 cm (22–24 in) in length and weighs 910–1,200 gm. It is a distinctive bird with a large crest and has one of the largest bills of any parrots (only the Hyacinth Macaw's is larger). This powerful bill enables Palm Cockatoos to eat very hard nuts and seeds that other species have difficulty accessing. The bill is unusual as the lower and upper mandibles do not meet for much of its length, allowing the tongue to hold a nut against the top mandible while the lower mandible works to open it. The Palm Cockatoo also has a distinctive red cheek patch that changes colour when the bird is alarmed or excited.
Behaviour
Calls
The Palm Cockatoo makes four different kinds of vocalisations, including a "hellow" call that is surprisingly human-like. There are distinct dialects throughout the species' range. It has a unique display where the bird (typically the male) drums a large branch against a dead bough or tree, creating a loud noise that can be heard up to 100 m away. It is possible that females can assess the durability of the nesting hollow by the resonance of this drumming display.
Breeding
Palm Cockatoos only lay one egg and have one of the lowest breeding success rate reported for any species of parrot. Off-setting this is their very long life-span. A male commenced breeding at age 29 in Taronga Zoo in Sydney, and another was 40 when she laid he first egg at London Zoo in 1966. There is anecdotal evidence of a Palm Cockatoo reaching 80 or 90 years of age in an Australian zoo,although the oldest confirmed individual was aged 56 in London Zoo in 2000. Breeding takes place inside tree hollows, which are typically like standing pipes. Fires play an important role in the destruction and creation of nest hollows. Fires allow the colonisation of microorganisms and termites which enter the tree and start hollowing out the inside. Cyclones are important in the final stage of nest hollow development.
Status
The Palm Cockatoo is still relatively common in Cape York, but is threatened there by habitat loss, particularly bauxite mining around Weipa and altered fire regimes elsewhere. Palm Cockatoos are hunted in New Guinea. This species is in high demand for the pet trade due to its unusual appearance. The Palm Cockatoo is currently evaluated as Least Concern on the IUCN Red List of Threatened Species. It is listed on Appendix I of CITES.
More on The Palm Cockatoo : birdlife.org
Source : Wikipedia
The Palm Cockatoo
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The Weedy Sea Dragon
Phyllopteryx taeniolatus, the weedy sea dragon or common sea dragon, is a marine fish related to the seahorse. It is the only member of the genus Phyllopteryx. It is found in water 3 to 50 m deep around the southern coastline of Australia, approximately between Port Stephens, New South Wales and Geraldton, Western Australia, as well as around Tasmania. Weedy sea dragons are named for the weed-like projections on their bodies that camouflage them as they move among the seaweed beds where they are usually found.
Weedy sea dragons can reach 45 cm in length. They feed on tiny crustaceans and other zooplankton, from places such as crevices in reef, which are sucked into the end of their long tube-like snout. They lack a prehensile tail that enables similar species to clasp and anchor themselves. Phyllopteryx taeniolatus swim in shallow reefs and weed beds, and resemble drifting weed when moving over bare sand.
Sea dragons, sea horses and pipefish are the only known species where the male carries the eggs.
The male of the species carries the fertilized eggs, attached under his tail, where they are incubated for about eight weeks. The young are independent at birth, beginning to eat shortly after. Mating in captivity is rare since researchers have yet to understand what biological or environmental factors trigger them to reproduce. In captivity the survival rate for weedy sea dragons is about 60%.
A more cryptic relative of the weedy sea dragon is the leafy sea dragon Phycodurus eques. In the November 2006 issue of National Geographic magazine, marine biologist Greg Rouse is reported as investigating the DNA variation of the two sea dragon species across their ranges.
The Aquarium of the Pacific in Long Beach, California in the USA, Melbourne Aquarium in Australia and the Tennessee Aquarium in Chattanooga, Tennessee in the USA are the only facilities in the world to have successfully bred weedy sea dragons in captivity, though others occasionally report egg laying. As of June 2008, the Georgia Aquarium in Atlanta, USA had a pregnant sea dragon, which was expected to give birth in early-mid July.
The weedy sea dragon is the marine emblem of the State of Victoria
More on Mike the Weedy Sea Dragon : birdlife.org
Source : Wikipedia
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The Weedy Sea dragon
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