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How does our vision compare to some animals?
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Do animals see the same way we do? Do some animals have better vision than humans? The senses of animals have evolved to give members of the species an optimum chance for survival. Here are a few examples: Some animals, such as cats, have a reflective surface ( tapetum) on the back of the eye behind the sensory receptors (left image above). When light first enters the eye, some light is detected by the sensory receptors. The light not detected by the sensory receptors continues onto the reflective surface at the back of the eye. This light is then reflected outward toward the sensory receptors, providing a second opportunity for detection. This feature produces two results. First, the outward reflection results in the shining of the cat's ey ...
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14928 |
Biology Forums |
A year ago |
Memory-enhancing foods to help you study
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There's more to studying than simply memorization and practice. It turns out that your diet also plays a pivotal role in recalling key bits of information, while keeping you energized and focused in the process. We're not talking about those scam-ridden supplements that promise a boost in brain power, but simple natural foods such as milk, nuts, seeds, rice, and oats. The nutrients found in these items help your study efforts by releasing natural memory enhancers called CCKs ( cholecystokinin). When CCK crosses the blood-brain barrier, it acts as a neurotransmitter associated with memory. Studies have shown that learning and memory processes are severely damaged (in rats) that genetically do not respond to the presence of CCK. And in people ...
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20820 |
bio_man |
4 years ago |
Eyeless fish
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The Mexican tetra ( Astyanax mexicanus) is a blind, freshwater cave fish native to central and eastern parts of Mexico. Growing to a maximum total length of 12 cm (4.7 in), this species is notable for having no eyes or pigment; it has a pinkish-white color to its body (resembling an albino). The Mexican tetra spends most of its time in midlevel water above the rocky and sandy bottoms of pools and backwaters of creeks and rivers of its native environment. Coming from a subtropical climate, it prefers water with 6.5–8 pH and a temperature range of 20 to 25 °C (68 to 77 °F). In the winter, some populations migrates to warmer waters. Its natural diet consists of crustaceans, insects, and annelids. Given their peaceful nature, this species is popu ...
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2355 |
bio_man |
5 years ago |
Time lapse of neural development
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The video below shows 16 hours of neural development compressed into 40 seconds of a developing zebrafish's nervous system. Notice how the neurons branch to make connections with other neurons – a process vital to information transmission. To obtain such accurate footage, the animal's embryo was suspended in water, rather than gel, and its photographers used gentle light sheet technology to capture the specimen in 3D, at a high temporal resolution. ...
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1233 |
bio_man |
5 years ago |
What does a box and these fish have in common?
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Their name and shape!Ostraciidae is a family of squared, bony fish closely related to the pufferfishes and filefishes. Members of this family occur in a variety of different colors (e.g. right - Hawaiian Blue Boxfish, Ostracion meleagris and the Yellow Boxfish, Ostracion cubicus), and are notable for the hexagonal or "honeycomb" patterns on their skin. Boxfish swim in a rowing manner. Their hexagonal plate-like scales are fused together into a solid, triangular or box-like carapace, from which the fins, tail, eyes and mouth protrude. Because of these heavy armoured scales, Ostraciidae are limited to slow movements, but few other fish are able to eat the adults. Some boxfish also secrete poisons from their skin into the surrounding water, fu ...
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6156 |
bio_man |
6 years ago |
One hairy situation
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The hairy frogfish ( Antennarius striatus) is a marine fish with spines resembling strands of hair - and it can change color. This small fish grows up to 22 cm (8.7 in) long, and has a rounded, extensible body. Its large mouth is forwardly extensible, allowing it to swallow prey as large as itself! The coloring of its body is extremely variable because individual fish tend to match their living environments. Frogfishes have the capacity to change coloration and pigment pattern, taking only a few weeks to adapt. The dominant coloration varies from yellow to brownish-orange, passing through a range of shades, but it can also be green, gray, brown, almost white, or even completely black without any pattern. Body and fins can be marked with roug ...
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7168 |
duddy |
7 years ago |
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4874 |
duddy |
7 years ago |
The ghost fish has been captured on video for the first time
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A living, swimming ghost fish has been seen live for the first time ever. The fish, part of the family Aphyonidae, was caught on camera during an ongoing National Oceanic and Atmospheric Administration (NOAA) exploration by the ship Okeanos Explorer. The exploration centers on the deep ocean at Mariana Trench Marine National Monument, a protected area spanning 95,216 square miles (246,608 square kilometers) east of the Philippines. The secretive fish was swimming along a ridge 8,202 feet (2,500 meters) down, according to NOAA. The animal is about 4 inches (10 centimeters) long, with translucent, scale-less skin and eerie, colorless eyes. No fish in the family Aphyonidae has ever been seen alive before. ...
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4948 |
duddy |
7 years ago |
What do elephants and fish have in common?
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Nothing, except for this fish, appropriately named the elephantnose fish ( Gnathonemus petersii) for its peculiar, elongated spout. The fish is widespread in the flowing waters of West Africa and hunts insect larva at dawn and dusk. Its nose is actually a sensitive extension of its mouth, that it uses for self-defense, communication, navigation, and finding worms and insects to eat. This organ is covered in electroreceptors, as is much of the rest of its body. The elephantnose uses a weak electric field, which it generates with specialized cells called electrocytes, which evolved from muscle cells, to find food, to navigate in dark or turbid waters, and to find a mate. The elephantnose fish live to about 6 to 10 years. ...
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5500 |
duddy |
7 years ago |
Parrotfish make a cocoon of mucus and wrap themselves like a sleeping bag each night
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Gnathiids are a family of isopod crustaceans whose larvae feed on the blood of fish. During the day, infected parrotfish seek out cleaner fish to consume the parasites; however, at night they are relatively vulnerable to attack. Parrotfish overcome this vulnerability by secreting a mucus cocoon before sleeping which envelopes their bodies with a protective biopolymer that functions similar to a mosquito net. The mucus is secreted from large glands in the gill cavity and is composed of small glycoproteins which are extensively cross-linked through pyrosulfate bonds. This exopolymer net allows small molecules to permeate but prevents the parasitic gnathiids from entering. The process is thought to involve a combination of blocking odorants ...
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4945 |
duddy |
7 years ago |
This baby fish will grow up to be one of the fastest fish in the sea
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While it may look small now, this baby swordfish ( Xiphias gladius) grows fast and can reach 14 feet in length and weigh up to 1,200 pounds as an adult. They are found in the Atlantic, Pacific and Indian oceans and sometimes cold waters, including the Mediterranean Sea, the Sea of Marmara, the Black Sea, and the Sea of Azov. They are highly migratory, moving to warmer waters in the winter and cooler waters in the summer. While they are not at the top of the food chain, it is not a fish to be messed with; apparently, even sharks are wary of them! ...
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17621 |
duddy |
8 years ago |
Piranhas, meet your match
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Shown above are vampire fish caught in Corona Falls, Guyana. Also called payara by locals, these Amazon Basin predators feed on other fish, especially piranhas, which they impale on their long fangs.
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6536 |
duddy |
8 years ago |
What some fish will do to survive
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Shallow waters will sometimes get too hot, forcing one fish to make a break for the shore. The tiny mangrove rivulus (shown above) avoids neurological damage from hot swamps by escaping to land. Retreating to land allows the fish to cool down through a process called evaporative cooling, which is akin to human sweating but using water from the environment. Previously, scientists had suggested that the fish, besides simply escaping hot water, might be taking advantage of evaporative cooling. Source: http://rsbl.royalsocietypublishing.org/content/11/10/20150689 ...
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20469 |
duddy |
8 years ago |
Turns out that fish oil only benefits those who have the right genes
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Most foods today are fortified with essential oils like omega-3 fatty acids. Naturally, these oils are found in fish, and are known to benefit many parts of the body, including the eyes, brain, heart, and joints. So, are these so-called beneficial oils important for people who lack the DNA profile needed to metabolise them? It turns out that the extra omega-3 might not do much good at all. According to a study published in Science, Inuit people living in Greenland whose traditional diet of fish and marine mammals have the right enzymes in their bodies needed to metabolise these foods that are very high fat content. The researchers reported that their DNA that was most different was on chromosome 11, specifically among genes that control the ...
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15450 |
duddy |
8 years ago |
Coolest elevator ride ever
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The AquaDom is a 25 m (82 ft) tall cylindrical acrylic glass aquarium built at the Radisson Blu Hotel in Berlin, Germany. You can ride the transparent elevator it has in the center!
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4209 |
duddy |
8 years ago |
The Ozark cavefish has no eyes
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The Ozark cavefish ( Amblyopsis rosae) is a small subterranean freshwater fish native to the United States. The fish has no pelvic fin; the dorsal and anal fins are farther back than on most fish. It has only rudimentary eyes and no optic nerve.
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4727 |
duddy |
8 years ago |
What's the ocean's equivalent to the cheetah?
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The shortfin mako ( Isurus oxyrinchus) is probably the champion speedster among sharks. Its speed has been recorded at 40 km/h (25 mph) with bursts of up to 74 km/h (46 mph). What's more, this high-leaping fish can leap approximately 9 m (30 ft) high or higher in the air. With its highly streamlined body, a lunate tail supported by keels, a sharply pointed snout, large eyes and some of the wickedest-looking teeth in its class, the mako shark is a highly sought-after game fish worldwide. ...
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9427 |
duddy |
8 years ago |
What mechanism allowed early terrestrial animals to transition from water to land?
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A new study finds that Mudskipper fish carry water in their mouths in order to eat prey outside of water. As seen in the video below, the hidden water is expelled at the moment of eating and it serves as a suction to move the water and their meal back toward the esophagus. The water suction, or “hydrostatic” tongue, may serve as the evolutionary bridge that allowed our aquatic ancestors to begin feeding on land.
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35978 |
duddy |
9 years ago |
Ever been inside a fish before?
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National Freshwater Fishing Hall of Fame has a 143-foot muskie fish building. It's lower jaw is an observation deck.
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17896 |
duddy |
9 years ago |
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2 |
4675 |
duddy |
9 years ago |
Spitting fish
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Why do these fish look like they’re spouting puffs of magic dust out of their mouths? The tiny crustaceans (1 millimetre-long crustacean called an ostracod) that these transparent fish try to eat light them up, causing the fish to be at risk of predation themselves, so they spit them out! ...
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3748 |
duddy |
9 years ago |
This fish looks like a melon
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This is the red-eyed gaper, a type of anglerfish that can be found up to 2km below the ocean's surface. Its large head and red blobby face may not look too attractive, but the gaper lures prey in with the shiny patch between its eyes.
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5844 |
duddy |
9 years ago |
Would you eat this mysterious blue fish?
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Lingcods are sometimes found with amazing, edible blue flesh. A bile pigment called biliverdin seems to be the cause, but exactly how it gets into the flesh of the fish remains a mystery.
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5210 |
duddy |
9 years ago |
How a heron bird catches fish - hilarious
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Herons also have surprising intellectual abilities; they can use bread to catch fish! It is thought that the birds learn the technique from watching fisherman throw baited hooks and tourists tossing bread to attract fish.
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2649 |
duddy |
9 years ago |
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2011 |
duddy |
9 years ago |
A fish that resembles a bird
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This bright blue fish, named the blue parrotfish, can be found in the waters of the Atlantic Ocean, and spends 80% of its time searching for food.
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2400 |
duddy |
9 years ago |
A fish that doubles as a camera stand
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Found all around the world, including off the coast of Australia, the tripod fish can live in depths of up to 6 km below the surface. The purpose of those super-long fins is to elevate the tripod fish to about a metre above the seabed, where the ocean's current is strong. This means that small prawns and crabs are ushered right into the tripod fish's gaping mouth, and all it has to do is stand there.
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3221 |
duddy |
10 years ago |
How apes go fishing
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This is the first photograph taken of an orangutan using a tool to fish in Borneo. The photo captures a moment when this male was using the pole to catch fish trapped in the locals’ fishing lines.
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3121 |
duddy |
10 years ago |
My new favourite animal
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Meet the guineafowl puffer ( Arothron meleagris), all puffed-up and poisonous to deter any would-be predators. Found throughout the Indo-Pacific and Eastern Pacific Oceans, this spotty species loves feeding on tiny marine invertebrates and the tips of coral.
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7558 |
duddy |
10 years ago |
A fish that spits
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Besides what we probably have seen while watching The Little Mermaid - fish singing and playing instruments, Finding Nemo, Shark Tale - whale being cleaned at a whale wash! , or even Spongebob Square pants - making hamburgers that is, have you ever seen or heard of a spitting fish? Well, I have not, until today.. Apparently, the archerfish from the family Toxotidea, literally "spit" to catch their prey. It is like a frog, but upgraded, in the sense that it catches insects and land based prey without a weapon, or a physical means. It just teleports its prey from above water, into the water by knocking it out via shooting water droplets. The missile strength of the water droplet is created and altered based on how far and how big their prey is ...
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6248 |
ehd123 |
10 years ago |
Some fish celebrate Halloween everyday
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While we're talking about Halloween, this is the Atlantic wolffish ( Anarhichas lupus), very appropriately and otherwise known as the ‘devil fish’. The hefty fish grows up to 1.5 metres long and over 20kg, and they’re named for those unmistakable fangs. If they're not scary enough, their throats are also lined with a spattering of small, serrated teeth.
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4572 |
duddy |
10 years ago |
How to withstand a piranha attack
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The arapaima ( Arapaima gigas) is one of the biggest freshwater fish on the planet and has evolved a multi-layer defence against the piranha. Its scales have an ultra-tough outer shell, which promotes tooth fracture at the point of penetration. The scales are also a corrugated shape, which deflect pressure to overlapping layers of collagen underneath.
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5037 |
duddy |
10 years ago |
A new species of giant fish as been discovered
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The new species is member of the arapaima genus, which contains some of the world’s biggest freshwater fish that breathe air and weigh up to 200kg. Found in the central Amazon of Brazil, the new fish has been named Arapaima leptosoma and is the first new species of arapaima described since 1847.
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3941 |
duddy |
10 years ago |
What accounts for blue blood found in invertebrates
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Hemocyanins are proteins that transport oxygen throughout the bodies of some invertebrate animals. These metalloproteins contain two copper atoms that reversibly bind a single oxygen molecule (O 2). They are second only to hemoglobin in frequency of use as an oxygen transport molecule. Unlike the hemoglobin in red blood cells found in vertebrates, hemocyanins are not bound to blood cells but are instead suspended directly in the hemolymph. Oxygenation causes a color change between the colorless Cu(I) deoxygenated form and the blue Cu(II) oxygenated form. ...
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5242 |
bio_man |
10 years ago |
How do fish see in the dark?
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The angry-looking deep sea angler fish has a right to be cranky. It is quite possibly the ugliest animal on the planet, and it lives in what is easily Earth's most inhospitable habitat: the lonely, lightless bottom of the sea. There are more than 200 species of anglerfish, most of which live in the murky depths of the Atlantic and Antarctic oceans, up to a mile below the surface, although some live in shallow, tropical environments. Generally dark gray to dark brown in color, they have huge heads and enormous crescent-shaped mouths filled with sharp, translucent teeth. Some angler fish can be quite large, reaching 3.3 feet (1 meter) in length. Most however are significantly smaller, often less than a foot. Their mouths are so big and their bo ...
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4464 |
duddy |
10 years ago |
World's largest fish species
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This photo shows a diver almost being eaten by a whale shark, the world's largest fish species. Marine photographer Mauricio Handler captured the intense moment during a dive in Isla Mujeres, Mexico, when more than 600 of the 12-metre-long animals gathered to feed on tuna spawn.
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3088 |
duddy |
10 years ago |
This fish looks like it can perform hypnosis
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Stargazer fish have their eyes situated on the tops of their heads and can bury themselves in the sediment with only their faces sticking out. Some species lure prey with a worm-shaped projection that comes out of their mouths. They are toxic and some can deliver a 50 volt shock!
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3902 |
savio |
10 years ago |
Meet the black swallower
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This is the aptly-named "black swallower" ( Chiasmodon niger), a fish known for eating bony fish up to 10x its mass and 2x its length. It's found worldwide in tropical and subtropical waters at a depth of 700-2,745 meters. Most specimens of this fish have been collected after one attempted to swallow prey too large for it to handle, and the prey could not be digested before decomposition set it. The release of gases forces the black swallower to the surface. This particular specimen was found washed up on the shore in 2007. The black swallower measures 19 cm long. The fish in its stomach is a snake mackerel measuring 86 cm. ...
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2874 |
savio |
10 years ago |
One ugly fish
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The coelacanth is known as a “living fossil” because it looks very much like its ancestors from 300 million years ago. Its genome has been sequenced, and it, in fact, has been found to be evolving at a very slow rate. The genetic sequence also might help give some insight into the transition from fins to limbs.
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3 |
2782 |
duddy |
10 years ago |
A white-blooded ice fish
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This is a white-blooded ice fish, or "crocodile fish" ( Chaenocephalus aceratus). They lack both red blood cells and hemoglobin, and so have white blood. They have translucent bodies, and absorb oxygen directly from the water around them.
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2655 |
duddy |
10 years ago |
A fish that looks like a butterfly
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This is a butterfly gurnard fish. They have a large bony head and a bony rostrum on the snout with a very small median notch with tiny spines. They are sandy with reddish bands and blotches and often turn red on capture. The greenish pectoral fins are round with bright blue spots and margins, and a roundish black blotch with a bright blue margin and scattered blue spots inside.
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6454 |
duddy |
11 years ago |