10 facts about sharks

1. According to the ReefQuest Centre for Shark Research, sharks date back between 455 million and 425 million years in the fossil records.
2. Despite rumors to the contrary, most species of sharks actually have good eyesight, at least according to the Florida Museum of Natural History. Some species of sharks have better eyesight than others, but generally speaking sharks have eyesight at least as good as humans. Some scientists suggest sharks can see objects better at a distance, which could help with hunting prey. Also, the eyes of sharks are more sensitive to light than the eyes of humans, which gives sharks an advantage in darker waters.
3. Do sharks sleep? This question continues to stump scientists across the globe. R. Aidan Martin, former Director of the ReefQuest Centre for Shark Research, offers no direct answers, but there is some evidence that some species of sharks sleep from time to time while others never sleep. Generally speaking, most species of sharks need to keep on the move to flood their gills with water, thus providing them with live-giving oxygen. But all animals need rest, including sharks and other fishes. Witnesses have given reports of what they believed were sleeping sharks, but at the same time the eyes of the sharks appeared to follow movement. Martin reports that the part of the nervous system that co-ordinates swimming in sharks is not found in the brain, but in the spinal column, which theoretically might make it possible for sleeping sharks to continue swimming. The truth to the question about sleeping sharks is that sciences does not know. At least not yet.
4. Science generally accepts the whale shark as the largest fish on the planet. Whale sharks have been known to grow as long as 42 feet and weigh nearly 80,000 pounds.
5. What is the smallest shark? That's somewhat debatable. Why? Because several species of sharks are quite small. The Dwarf Lanternfish shark is usually between six and eight inches in length. The pygmy ribbontail catshark is usually between six and seven and a half inches in length. Also, the spined pygmy shark is often between seven and eight inches in length.
6. The shortfin make shark is considered the fastest shark on the planet. It has been recorded swimming at a swimming speed of 31 miles per hour. More impressive is the fact these sharks have been recorded going as fast as 46 miles per hour for short durations.
7. According to National Geographic, there is an average between 50 and 70 shark attacks worldwide each year. Of those attacks, an average between five and 15 are fatal.
8. How long do sharks live? There is no definitive answer. According to sharks-world.com, sharks average living between 20 and 30 years, but scientists suspect some species of sharks live as long as a hundred years, and some species might live even longer.
9. How many different kinds of sharks are there? Science generally accepts there are about 440 different species of sharks currently swimming in Earth's waters.
10. The megalodon is an extinct species of shark that supposedly existed between one and a half million and nearly 30 million years ago. It is believed to be the largest shark species to ever exist, having been more than 50 feet in length.

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10 tips for avoiding shark attack while swimming


Image via Wikipedia

10 tips to avoid shark attack

1. Watch the clock: Sharks feed most often at twilight and at night. Avoid swimming in the ocean during those times.
2. Avoid bleeding in water: Yes, it's true, blood draws sharks. If you have a fresh cut that's bleeding, or if you've accidentally cut yourself on corral or something else in the water, you need to stay on the beach. Also, menstruating woman should avoid swimming.
3. Animal signs: Other sea creatures know when sharks are approaching. If you see a school of fish jumping into the air, that means you need to head to the beach because those fish are trying to avoid a shark. Other animals to watch are sea turtles and seals because they will try to flee an area when they know a shark is coming for lunch.
4. Don't wear bright colors: Sharks can't see real well, so anything bright will catch their attention, especially shiny objects. So don't wear jewelry in the water. And try to avoid wearing bright colors like yellow and orange.
5. Keep your eyes open: If you see a dorsal fin out in the water, you obviously shouldn't go swimming. Also pay attention to any beach signs posted that warn of sharks. Heed those warnings.
6. Don't swim alone: Swim with at least one person, but it's even better if you're swimming with a large group of people. Because sharks can't see very well, they are less likely to attack a group of swimmers because it may appear to be one large creature to the shark. Also, much like lions, sharks have a tendency to go after any creature that has strayed from the pack because it looks like easy pickings.
7. Scuba diving: Avoid diving near any seals. That wet suit makes you look like a seal, and possibly so do your swimming motions.
8. Remain calm: This is obviously easier said than done, but if you should spot a shark near you in the water, try to stay calm. Panic will attract the shark, especially sharp movements of kicking and swinging of the arms.
9. Listen: Keep your ears open. If you hear someone yell "shark," try not to panic and head to the shore.
10. Avoid murky water: If the water where you plan to swim looks muddy or cloudy, don't go swimming there. Remember sharks can't see real well, so in murky water they're more likely to bite into anything they sense.

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10 facts about starfish

1. The majority of species of starfish have five arms, though some have more. The Antarctic starfish known as Labidiaster annulatus sometimes has as many as 50 arms.
2. Science estimates there are between 1,800 and 2,000 different species of starfish in the world.
3. Starfish can regenerate a limb. That's right! If a starfish loses one of its arms, it has the natural healing ability for that arm to grow back.
4. There is not a major body of salt water in the world that does not contain starfish. These sea creatures are found in the hottest and coldest climes, in all oceans and seas.
5. Starfish are carnivores. Tiny tubes in the animal's arms are used to pry open oysters and clams and other generally stationary creatures like mussels. The mouth of a starfish is found beneath and in the center of the animal.
6. Starfish often have bright colors. This is a natural defense mechanism to warn off other animals, or to act as camouflage in some circumstances.
7. Starfish also have a bonelike, calcified exoskeleton, basically a hardened skin, that protects them from predators.
8. These marine animals are not to be found in fresh water.
9. Starfish do not have a brain. Instead, they have a central ring of nerves that branches out into their arms.
10. Larger starfish tend to live longer, especially in the wild. The longevity of starfish varies greatly depending upon the species. Some starfish will live a couple of decades while others can live as long as 50 years. There have even been rumors, though no scientific evidence as of yet, of some starfish living a century or longer.

10 facts about seahorses

1. Science knows of almost 50 different seahorse species throughout the world.
2. Seahorses, unlike most fish, do not have scales. Instead, they have bony plates beneath their thin skins.
3. The oldest fossil of a seahorse is a distant relative found in Slovenia that is estimated to be about 13 million years old.
4. In traditional Chinese herbology, dried seahorses are considered an aphrodisiac and good for kidney problems. The seahorses are dried and ground into powders which can then be placed in pill forms.
5. In seahorses, it is the male that actually carries the fertilized eggs to gestation.
6. The number of young seahorses who are born from each father varies upon the size and species of seahorse. Some seahorses only expel a half dozen or so baby seahorses, while the larger species can expel as many as 1,500 baby seahorses.
7. Seahorses generally eat small shrimp or other small crustaceans. They have been known to diet on extremely small fish at times.
8. Wild seahorses do not fare well in captivity. Disease is one culprit, but wild seahorses are also thought to be under immense stress when limited to their surroundings. However, seahorses bred in captivity fare much better.
9. Dried seahorses on a stick are not uncommon foods to be found in China as street food.
10. The slowest moving fish in the world is the dwarf seahorse, two inches long, which reportedly only swims approximately five feet per hour.

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