Day Ten: The Angel Shark

I first saw these guys on Shark week a couple weeks back. They are really cool sharks. I’m excited to tell you about how they eat. It’s really cool. I’ll make sure to link a video of them eating.

Statistics

• Commonly grow to a length of 5 feet
• Found in shallow tropical water

The angel sharks are an unusual genus of sharks with flattened bodies and broad pectoral fins that give them a strong resemblance to skates and rays. The 16+ known species are in the genus Squatina, the only genus in its family, Squatinidae. They occur worldwide in temperate and tropical seas. Most species inhabit shallow temperate or tropical seas, but one species inhabits deeper water, down to 4,300 ft.

Feeding

Although this shark is a bottom dweller and appears harmless, it should be respected due to its powerful jaws and sharp teeth which can inflict painful lacerations if provoked. It may bite if a diver approaches the head or grabs the tail. If they are left alone they will not attack.

They bury themselves in sand or mud lying in wait for prey, which includes fish, crusteaceans, and various types of mollusks.

I think this is the coolest thing! Watch this!

AWESOME!! I could watch that over and over again. That thing is RAD!

Reproduction

I couldn’t find much about the reproduction of angel sharks. I did find that they are ovoviviparous (give birth to live young) and have litters of up to 13 pups.

Sources

http://en.wikipedia.org/wiki/Angel_shark
http://schools-wikipedia.org/wp/a/Angel_sharks.htm

Day Nine: No Blog

I didn't blog yesterday, which was day nine. I was busy and tired and a little burned out. I'll do my best to get one up today. :)

Day Eight: The Galapagos Shark

Statistics

• Can grow to 12 feet in length
• Can weigh as much as 200 pounds
• Found off tropic oceanic islands
• Lifespan is at least 24 years

According to the International Shark Attack File, the Galapagos shark has been responsible for one fatal attack on a swimmer in the Virgin Islands. Inquisitive and persistent, the Galapagos shark is regarded as dangerous to humans and diving unprotected is not advisable in areas where they are abundant. They are known to approach close to swimmers, showing interest in swim fins or hands, and are drawn in large numbers by fishing activities.

Feeding

This shark feeds primarily on bottom-dwelling fishes as well as on squid and octopus. These fish include eels, flatheads, groupers, flatfish, and triggerfish. The Galapagos shark displays threat gestures to warn competitors in the search for food. Large sharks are potential predators of the Galapagos shark. Cannibalism is also reported within this species.

Reproduction

Galapagos sharks are "viviparous", or livebearing, with embryos nourished by a yolksac-placenta during gestation. Mating and birth occurs early in the year within Hawaiian waters. Female individuals often have mating scars from males biting the gills, fins, and body. After gestation during which the embryos develop inside the mother, live birth results in a litter size of 4-16 pups. Each pup measures 24-31 inches in length. The pups stay in shallow water nursery areas to avoid predation and cannibalism from members of their own species, eventually moving out to deeper waters as they mature. Males mature at 7-8 feet long and 6–8 years old, while females mature at 7½-8½ feet long and 7–9 years old. Neither sex is thought to reproduce until 10 years of age.

These sharks are very beautiful. Here’s a video of one up close.

Sources

http://en.wikipedia.org/wiki/Galapagos_shark
http://www.flmnh.ufl.edu/fish/Gallery/Descript/galapagosshark/galapagosshark.html

Day Seven: Epaulette shark

I’ll be honest with you; until I started doing research for this blog, I had never heard of the Epaulette shark. So today, we learn together!

Statistics

• Typically 27-35 inches long
• Common in Australian waters
• Found in shallow water

These are some pretty cool looking sharks. The colors seem very vivid from what I can tell in the pictures.

Feeding

They are opportunistic predators, and their prey items include worms, small fishes and crabs. Something I found interesting in my reading is that, unlike other sharks, they will chew their food for up to 10 minutes. They are of no danger to humans, and are easily caught by beach goers because of their slow movement and their fearless nature. They hunt using primarily their sense of smell and electro-receptive senses. It is capable of sucking prey into its mouth.

Reproduction

Unlike the other sharks I’ve blogged about, this shark does not give birth to live pups. Mating takes place from July until December. The female drops her egg capsules two at a time every 14 days, producing a total of 20–50 eggs per year. The young emerge after 120–130 days, at a length of 5½ to 6 inches.

Interesting Facts

The epaulette shark moves by seemingly walking, bending its body from side-to-side and pushing off of the substrate with its paddle-shaped pectoral and pelvic fins. The shark only swims to escape from a threat, and then not very far.

Epaulette sharks are found in shallow water to a maximum depth 160 ft, and are often seen in water barely deep enough to cover their bodies.

Adult epaulette sharks are beige to brownish above with many widely-spaced brown spots and subtle darker bands. There is a very large black spot ringed in white located behind each pectoral fin; this pair of spots are the origin of this shark's common name.

Because plants in tide pools don’t produce oxygen at night, creatures that live there use up all or most of the oxygen during the night. Epaulette sharks caught in tide pools by the receding tide can turn off enough body functions to survive several hours with little or no oxygen.

Video of Epaulette Shark

Sources

http://en.wikipedia.org/wiki/Epaulette_shark#Description
http://www.montereybayaquarium.org/animals/AnimalDetails.aspx?id=780268

Day Six - No Shark Blog today

It's 11:30 PM on Sunday, and I am really tired. I'm going to have to figure out a schedule for fitting all of these sharks in within my time frame and still give room for skipping a day. I might take Sundays off. I'd like to take weekends off completely, but that's going to give me quite a bit of catching up to do every week.

I'll be back tomorrow with another shark blog, but for now... I must sleep!

Have a great week everyone.

Day Five – The Tiger Shark

I don’t know what it is about them, but the worse the shark’s reputation, the more I find myself interested in them. That’s kind of how I used to pick boyfriends, too. So, leaving that alone… let’s talk about the Tiger Shark!

Statistics

• One of the largest species of shark
• Commonly reaches 10-14 feet in length
• Can weigh as much as 1,400 pounds


I love this shark. It’s beautiful, first of all. It is known for its spots, which can also look like stripes. The markings are vivid in young sharks, but fade as the shark matures. Its other common names are leopard shark, maneater shark, and spotted shark. This shark is big, strong, mean and scary. Ok, maybe not mean. To say its mean indicates that there’s some sort of malice in its mind. Tiger sharks are non-discriminate hunters. Unlike the Great White, they will eat just about anything. Most of the stories you would hear about sharks ingesting non-digestible items, come from Tiger sharks. Their stomach contents has been known to include a chicken coop, a roll of tar paper, a license plate, tires, and a suit of armor. These sharks literally will eat anything.

Tiger sharks typically prefer murky waters in coastal areas. Tiger sharks undergo seasonal migrations. They move into temperate waters from the tropics for the warmer months and return during the winter. These sharks also make long oceanic migrations between islands and are capable of traveling long distances in a short amount of time.

Reproduction

The gestation period ranges from 14-16 months, at which time a female can give birth to anywhere from 10 to (get this!!) 80 pups. Eighty!! No wonder they don’t stick around to mother them! When pups are born they are between 12 and 18 inches in length.

Danger to Humans

The Tiger shark has been implicated in 158 attacks worldwide between 1580 and 2008. Their eyesight in water is ten times better than human eyesight. Not to worry though, their main food items are fish, crustaceans, sea birds, marine mammals and sea turtles.

Tonic Immobility

The tiger shark seems to be receptive to human touch. I saw this video of Mike Rutzen and his camera man/safety diver attempting tonic immobility on a tiger shark. It is amazing how easily it happens once they find the right spot. Isn’t that cool? How could one not love these animals?

The tiger shark generally hunts at night, and is a solitary hunter. It is an opportunistic hunter, taking advantage of anything it thinks will be an easy meal. It has been known to feast on dead whale carcasses as well as its typical prey items.

I'm swimming with these sharks some day. They are so amazing to me!

Sources

http://www.flmnh.ufl.edu/fish/Gallery/Descript/Tigershark/tigershark.htm
http://elasmo-research.org/education/ecology/coral-tiger.htm
http://www.flmnh.ufl.edu/fish/sharks/statistics/species2.htm

Day Four: The Greenland Shark

I’m going to be completely honest; I don’t feel well today and I have about a million things to do, so this may be shorter than the others. But I wanted to fulfill my commitment, so I am blogging anyway!

Statistics

• Can grow to more than 20 feet in length
• Also called the “sleeper shark”
• Prefers cold water around 30-35 degrees F
• Found at depths of 2,000 feet or more

The largest recorded Greenland shark was 21 feet and weighed in at 2,250 pounds. As its name indicates, it is found off Greenland, and also parts of the north Atlantic near Iceland.

According to the International Shark Attack File there has only been one reported attack of the Greenland shark on a human. Around 1859 in Pond Inlet, Canada, it was reported that a Greenland shark was caught containing a human leg in its stomach. This story, however, was only a report and was never scientifically investigated or proven. The lack of recorded attacks may only be due to the shark's habitat, which is much to cold to be populated by common swimmers, therefore, significantly reducing the chance of an attack on a human.

Reproduction

The Greenland shark can have litters of up to 10 pups, which are about 15 inches in length when born.

The Greenland shark is a slow moving shark due to its cold environment. As I usually try to do, I have found a video of the Greenland shark, so you can see it in action.


Sources

http://dsc.discovery.com/sharks/greenland-shark.html
http://www.marinebiodiversity.ca/shark/english/greenland.htm
http://www.flmnh.ufl.edu/fish/Gallery/Descript/GreenlandShark/GreenlandShark.html

Day Three: The Oceanic Whitetip

This is one of the sharks I’ve wanted to learn more about. I first learned of this shark several months ago when I was watching a documentary on the USS Indianapolis. It is thought that the Oceanic Whitetip is responsible for the majority of shark-related deaths in that accident. Tiger sharks have been thought to have been involved as well, but the Oceanic Whitetip is estimated to have killed 60-80 sailors and marines in that one instance.

Statistics

• Males mature at 5½ to 6½ feet
• Females mature at 6 to 6½ feet
• Maximum recorded weight: 370 pounds
• Reach maturity at 6 to 7 years
• Found worldwide in deep water, near 500 feet

The Oceanic Whitetip shark is said to be the most dangerous of all sharks. Opinions vary of course, but the oceanic whitetip is responsible for more fatal attacks on humans than all other species combined, as a result of predation on survivors of shipwrecks or downed aircraft. Such incidents are not included in common shark-attack files, and as a result of this, the oceanic whitetip does not have the highest number of recorded incidents.

Check out this short video of a pair of Oceanic Whitetips swimming near divers off Brothers Islands in the Red Sea. They're beautiful!


Hunting

These sharks are generally slow moving, but are opportunistic feeders. They are capable of fast bursts of speed when hunting. They will eat pretty much anything. They are solitary hunters, but have been known to feed together on large marine mammals, such as dead whale carcasses. They are aggressive, competitive, and fearless. I would conclude that if there is a shark to be feared, it would be this shark. However, you are unlikely to ever encounter this shark unless you have the unfortunate occurance of being involved in a crash landing in the ocean. These sharks, like most sharks, are susceptible to being sensitive on the nose area. Many potential attacks on divers have been averted by fast thinking on the part of the diver, and an action involving hitting or bumping the shark's nose.

Reproduction

Their mating season is early summer. They typically travel to the northwest Atlantic Ocean and the southwest Indian Ocean to breed. Their gestation period is 12 months, and they produce litters of up to 15 pups. Pups are 26-30 inches long at birth.

So, I’m thinking that if I were ever in an airplane crash that landed me in the ocean, supposing I survive the crash in the first place, I am going to be on a keen lookout for these dudes. They’re beautiful. They’re probably very smart. But they also would want to eat me for dinner.

Sources

http://www.flmnh.ufl.edu/fish/Gallery/Descript/OceanicWT/OceanicWT.html
http://en.wikipedia.org/wiki/Oceanic_whitetip_shark
http://www.worldofsharks.net/oceanic_whitetip.htm
http://creationwiki.org/Oceanic_whitetip_shark

Day Two – Part Two – Lemon Shark

These little fellas are adorable!! Check 'em out.

Statistics

• Mature length – 7-9 feet
• Mature weight – 200 lbs
• Lifespan is approximately 20 years
• Found in subtropical, shallow water


It’s called Lemon Shark for its pale yellow-brown color. This shark is found in Atlantic waters, and the Gulf of Mexico and the Caribbean. It can be aggressive if provoked, but is generally thought to be of little threat to humans. According to the International Shark Attack Files, there have been 10 recorded bites on humans by lemon sharks. Statistically speaking, you are more likely to drown when going to the beach than to be bitten by a shark - any shark. On United States beaches in the year 2000, there were 132 beach fatalities. Seventy-four of the fatalities were caused by drowning. There were twenty-three shark bites, total. Not all of them were fatal. The chances of drowning while at the beach are 1 in 3.5 million. The chances of being bitten by a shark: 1 in 11.5 million. Just food for thought.

According to the Florida Museum of Natural History, there is some evidence that two separate populations of lemon shark exist within the western Atlantic Ocean; one in the Caribbean and one in the Gulf of Mexico.

The lemon shark is found typically in shallow inland waters, in depths of 300 feet. They like to hang out in coral reefs and enclosed bays.

Reproduction

Lemon sharks give birth to live, free-swimming pups. Their gestation period is 9-12 months, and result in litters of 4-17 pups. When they are born, lemon sharks are only 24-26 inches long. I think they are of the prettier shark species. Watch this video of a lemon shark giving birth!


Tonic Immobility

Tonic Immobility was first discovered by Dr. Sam Gruber, accidently, during research on shark eyesight. He found that he could induce tonic on some sharks by turning them upside down, and gently touching the sensory area located on their nose and the front of their face. From what I’ve seen, lemon sharks seem to be susceptible to a much deeper state of Tonic Immobility. Being smaller than a lot of other sharks, they can sometimes be flipped on their back, resulting in a deep state of tonic. I saw a video where a baby lemon shark was flipped onto its back, causing it to go into tonic, then a minor surgery was performed to insert a tracking transmitter into the shark. There was no anesthesia involved, and the shark didn’t even flinch. It was amazing how deep the “trance” was. I looked for the video online to share, but I couldn’t find it.

I hope you enjoyed this blog on the Lemon Shark!

Sources

http://marinebio.org/species.asp?id=490
http://www.flmnh.ufl.edu/fish/sharks/statistics/beachattacks.htm
http://www.wavescape.co.za/sharks/sharkman.html

Day Two – Part One – Nurse Shark

Today I will blog about two species of shark.

Statistics

• Can reach lengths of 14 feet
• Can weigh up to 330 pounds
• Found in tropical and subtropical waters
• Bottom-dwelling shark

What I find interesting about the Nurse Shark is that they look a lot like a catfish.

They are nocturnal. Unlike most sharks, Nurse sharks are able to breathe while stationary by pumping water through their mouths and out their gills. Their prey primarily consists of bottom fishes and invertebrates including lobsters, crabs, snails, octopuses and squids. They seem lethargic during the day. However, at night they transform themselves into determined predators that routinely knock over coral heads and big boulders to get to their intended prey that they “vacuum” into their mouths while using a powerful, suction-feeding technique. This feeding method has earned them the nickname “sucker shark”.

Here is an interesting video about how nurse sharks bite.

To clear up a point of potential confusion, the gray nurse shark (a.k.a. sand tiger and ragged tooth) is not a type of nurse shark. The gray nurse is described in a different family of sharks than true nurse sharks.

According to the International Shark Attack Files the nurse shark has been attributed with a total of 27 recorded attacks since 1580 with no deaths reported.

Reproduction:

Nurse sharks eggs are carried and hatch inside the body of the female, and their young are born alive. Their gestation period is 6 months, and a typical litter is 21-28 pups.
I’ll admit, the Nurse Shark hasn’t really captured my attention so much, and I had a hard time finding a lot of information on them. I have learned that they are generally harmless unless provoked.

Sources

http://en.wikipedia.org/wiki/Nurse_shark
http://www.dtmag.com/Stories/Marine%20Life/06-03-whats_that.htm

Day One: The Great White

I realized last night that I might have a harder time than I expected getting together a complete list of all 375 shark species. I know enough of them to keep me busy for a while though, and give me a chance to put together a list. There are several web sites that already have a number of them listed, so I will probably have to compile my own list based on the pieces of lists already available.

Today I will start with my favorite shark, and probably the most feared shark: The Great White.

Statistics:

• Males reach maturity at 11-13 feet
• Females reach maturity at 15-16 feet
• Their adult weight averages anywhere between 1,500 and 2,400 lbs
• The largest of the White sharks tend to be around 20 feet in length, weighing up to 4,200 lbs
• They are primarily solitary hunters
• They usually prefer colder water
• Found in every major ocean

Hunting:

All sharks are good hunters. It’s what they do. But I am fascinated by what I’ve learned about the White shark’s hunting techniques and abilities. Their hunting is anything but random and mindless. There is a process involved. They are stealthy. They are smart. They hunt using many senses. It is commonly known that sharks can smell blood, but that is only part of it. One of my favorite episodes of shark week was one where I was first introduced to the ampullae of Lorenzini. The ampullae of Lorenzini are located in the nose or front of the face. They are special sensing organs called electroreceptors, forming a network of jelly-filled canals. They help the shark to sense electricity fields in the water. Prey gives off electricity. The sharks can sense that electricity, in combination with the smell of dead fish or blood. They also use their eyesight. Their eyesight is so keen that they can even hunt by moonlight. They can detect sound waves in the water using a sense organ called the lateral line. The lateral line runs down the sides of the shark, on either side of the dorsal fin from the gills to the tail.

A shark will stalk its prey. It will sense it from quite a ways off, and watch it to see what it is and what it might do. If it decides the prey is worthy of a closer look, and potentially becoming a meal, the shark will drop down to the ocean floor, and ambush its prey at speeds of up to 20 miles per hour. It hits its prey from the bottom, with such great force that sometimes the shark (and the prey) will breach the water, making itself visible to anyone around.

Sharks don’t have hands, so they test things out with their mouths. On humans, they usually inflict what is called an exploratory bite. They are checking it out to see what it is, and if it’s food. I believe that a White shark could consume pretty much anything it wanted to, but they are actually more picky eaters. Due to their large size and constant activity, they prefer to eat high-fat meals, such as seals. When they bite a human and realize it’s not a food item, they usually let go. I don’t believe a human could survive a Great White attack if the shark’s intent was to eat.

Gentle Giants

Yes, a shark can kill you. Yes, it can eat you. I don’t believe it prefers to. I believe that, given the right circumstances, sharks will tolerate humans in the water. Below is a clip from an episode of Shark Week, called The Sharkman. Here, Mike Rutzen free dives with a 15 foot female Great White shark, and even hitches a ride on her back. I would suggest you watch it with the sound off, because the music that has been put with the video is menacing, and instead of seeing the beauty of what is happening, might cause some to be dissuaded.

Mike Rutzen taking a ride on a shark


What he was originally trying to attempt is to put the sharks into a trance-like state called Tonic Immobility. A shark’s nose area is so sensitive that the lightest touch from a human hand can cause the shark to go catatonic. It's thought that this is due to the ampullae of Lorenzini. When touched, its body will go limp and it will become completely docile. Once the touch has been removed, the shark will continue on as if nothing happened, and swim on its way.

Sharks Killed

This quote is taken directly from news.mongobay.com:

Between 26 million and 73 million sharks are killed each year for their fins according to a new paper published in the October 2006 edition of Ecology Letters.

Shark fins are used primarily in Asian dishes, such as Shark Fin Soup. These animals are being killed, dismembered, and their bodies thrown back in the ocean, for nothing more than their fins. I am personally disgusted by this fact.

So, there you have it; my first shark blog. I hope you have enjoyed it, and I hope you learned something about these amazing animals.

Sources:

http://en.wikipedia.org/wiki/Great_white_shark#Size
http://www.jawshark.com/great_white_recorded_sizes.html
http://en.wikipedia.org/wiki/Ampullae_of_Lorenzini
http://news.mongabay.com/2006/1003-sharks.html

The Journey Begins

I’ve decided to write a blog. I’ve never written one before. I’ve written a lot of other stuff, but never a blog. I’m not even sure how to begin.

I will start with who I am and why I’m doing this. I’m going to assume that at some point someone will read this who doesn’t know me, so I will give some basic information that will be repetitive and probably boring for those who already do know me. I’m a married mother of 5. I’m a homemaker. I am apprehensive about taking risks, and won’t so much as ride a roller coaster out of fear of being injured or even killed in some freak accident. In a lot of cases, fear controls my life. It stops me from doing things that I may have otherwise enjoyed. That is why I have really surprised myself with my recent interest; the reason for writing this blog in the first place; Sharks. Yes, sharks - those toothy predators of the deep - the same ones who strike fear in many, many people. They have been fascinating to me most of my life, but it hasn’t been until recently that I have started to fall in love with them. Yes, I’m sure it sounds strange. But I am drawn to them. I want to be near them. Study them. Swim with them. Touch them. Get to know them.

It all started about two months ago. I was watching some old episodes of Shark Week on Netflix. I’ll admit it – at first I started watching it to see the stories of the shark “attacks”. I think I was trying to fuel my own fear, while somehow nurturing my interest in them. But then I realized that I was finding things out about them that I’d never known. They are methodical. They are intelligent. They can even be gentle. Yes, gentle. As I watched humans interacting with these animals, I started to feel a soft-spot developing. My curiosity quickly turned into a craving to know more. I started to absorb everything I heard. I wanted to remember it. I wanted to tell people that they aren’t all bad. They’ve been given a bad rap. I started to feel defensive of them.

But how can I ever pursue this? I am not a scientist. I don’t even like science. I’m terrible at math, which is associated with science, especially when thinking about becoming a scien-tist. Truth be told, I’m not even a good swimmer. But who else gets to be so close with these animals? If I can’t be a Scientist, what can I do? Well, I still don’t know. So this is where I’m going to start. A blog. I’ll probably never be an Erich Ritter or Rocky Strong, but I want to learn as much about sharks as I can. And I want to do what I can to inform others that they aren’t the man-eating, boat chomping, mindless killers they’ve been made out to be.

This is what I’m going to do. It’s an idea similar to what Julie Powell did with Julia Child’s cook book. She wanted to get through the entire cook book, and try every recipe. There were 524 recipes in the cookbook. She wanted to complete them all in one year. She did.

According to the Florida Museum of Natural History Ichthyology Department, currently there are 375 described species of sharks. I am going to attempt to study, and blog, something about each one of them in one year’s period of time. I am going to get my information primarily from the Internet, and possibly from books. Maybe TV shows, articles or magazines. I will do my best to cite each reference. If you choose to follow along with me on this journey, please be aware that I am an amateur; a newbie; wet behind the ears. I may cite incorrect information, and I am completely open to correction from any knowledgeable source. If you are a studied shark professional, please feel free to correct any errors I may make.

I have two goals with this project.

1) Learn about this animal that has captured my attention, and pass on that knowledge to anyone who reads (or comes within earshot - haha).

2) Test my own seriousness. If I am looking to study these animals, and maybe even swim or dive with them some day, I need to be serious. I want to make sure this isn’t some fly-by-night fascination that will dissipate when something new comes along.

So, here we go. I hope you’ll join me. I’m scared to death I won’t be able to do this, but I’m going to try.