Shark tooth fairy would earn a good living

Sharks are part of the class chondrichthyes, meaning their skeleton is made of cartilage, rather than bone.

  • Aug. 23, 2014 8:00 p.m.

In light of Discovery Channel’s annual Shark Week, it felt timely to discuss the prehistoric cartilaginous creatures.

Since the feature film Jaws was released, sharks have been stereotyped by media as man-eating killers and have intrinsically been feared. While Shark Week 2014 was full of exaggerated images of Megalodon and far-fetched thrillers like Sharkageddon; sharks are remarkable and their true beauty is known to few.

Sharks are part of the class chondrichthyes, meaning their skeleton is made of cartilage, rather than bone. There are hundreds of species of sharks that range in size from only 17 centimeters to 12 metres in length. Sharks are found in every ocean region around the world, including off the coast of British Columbia, and are known to exist to depths of 2,000 metres.

I distinctly remember loosing my first tooth – and boy was I excited when the tooth fairy left a shiny dollar under my pillow. If ocean tooth fairies existed, they would have a full time job with sharks, which have up to 30,000 teeth over their lifetime.

Sharks have rows of teeth, which lay in a groove on the inside of their jaw. When a tooth (or teeth) is lost, another tooth from the row below simply pops up, almost like a conveyor belt.

Depending on the species, sharks can loose teeth anywhere from every eight days to every couple of months. Just like other animals, the shape of the shark’s teeth reflect their food choices; for example, sharks with flatter teeth use them for crushing shelled animals, whereas sharks with sharp-serrated teeth use theirs to tear through the tough skin of larger fish and mammals.

When sharks are filmed in the wild they are almost always moving. In fact, most sharks move at approximately eight km/h, but can increase their speed upwards of 19 km/h when hunting. If sharks don’t constantly move they can sink.

Most fish in the ocean have something called a swim-bladder, which is a gas-filled organ that allows fish to change their buoyancy and remain at a specific depth without swimming. Sharks do not have swim-bladders and instead they have a very large liver filled with a special oil called squalene. However, the liver is still often too heavy and thus most sharks must continually swim to stay buoyant.

Senses are an important part of survival and sharks are no exception. Like many other ocean animals, sharks have a keen sense of smell, sight and sound.

Sharks have such a keen sense of smell that they can even determine the direction from which it came.

A shark’s sense of sight is often debated. While sharks have relatively good eyesight and some unique adaptations, it is unconfirmed how much they actually use their eyesight in hunting compared to their other senses.

While testing a shark’s sense of hearing is difficult, it is thought they can hear prey from miles away. Furthermore, like many other fish, sharks can detect vibrations in the water.

Sharks however, have a “sixth sense” that is, sharks can detect electromagnetic fields that are produced by living creatures, using specialized electroreceptor organs called, ampullae of Lorenzini. Sharks have the greatest electrical sensitivity of any animal and use this special sense to find prey, orient themselves and possibly even navigate throughout the ocean based on the Earth’s magnetic field.

Sharks brood their young in three different ways. Some species bare live young, others nourish the embryo internally, while other species lay eggs. “Egg laying” sharks (and skates) produce a special pouch, called a Mermaid’s Purse that protects the eggs until they hatch. Mermaid’s purses have a leathery texture and resemble dried up seaweed; they can be found washed up on the beach, so keep an eye out for them.

Although sharks often don’t get a lot of empathy, they are remarkable animals and have outlived many species over the last 400 million years. As scientists continue to study and understand these creatures, I hope the public’s perception of them will continue to change for the positive – from feared to loved.

There is still much to learn about sharks and protecting the remaining populations is crucial for their survival. To learn more about these sea giants and to share your voice for their protection, check out the following links: sharkwater.com and fin-free.com.

Combining her passions for education and the marine ecosystem Natasha Ewing inspires K-12 teachers and students to incorporate hands-on experiential ocean science into the classroom for Ocean Networks Canada.

 

 

Just Posted

A screenshot of the First Peoples Cultural Councils First Peoples’ Map. (First Peoples Cultural Council)
Online resource blends B.C.’s Indigenous language, art and culture

North Saanich advisor says initiative supports urgent need to preserve Indigenous languages

General manager Lindsey Pomper says Sidney’s Star Cinema cannot wait welcome audiences when it reopens June 18, amid an easing of public health measures. (Wolf Depner/News Staff)
Sidney’s Star Cinema raises curtain for the first time after months in the darkness

Iconic theatre to reopen at half capacity for Friday night showing

A dogs in parks pilot study unanimously approved by Saanich council will evaluate how park space can best be shared between dog owners and non-owners alike. (Photo by Megan Atkins-Baker/News Staff)
Saanich to study park-sharing strategy between those with and without pets

District-wide People, Parks and Dogs study to produce recommendations by fall

Staff member Lena Laitinen gives the wall at BoulderHouse a workout during a media tour on June 16. (Rick Stiebel/News Staff)
BoulderHouse raring to rock Langford

Popularity of bouldering continues to climb across Greater Victoria

GardenWorks nursery in Oak Bay at its home until August. (Black Press Media file photo)
GardenWorks puts down new roots in Oak Bay this summer

Nursery shifts down The Avenue to fill former fitness studio space

The BC SPCA Wild Animal Rehabilitation Centre in Metchosin saw 16 fawns come through in May, with another four in the first four days of June. (Courtesy Wild ARC)
An abandoned fawn doesn’t mean it’s orphaned, reminds Greater Victoria wildlife expert

20 orphaned fawns turned in to Wild ARC in Metchosin so far this season

(Black Press Media file photo)
POLL: When was the last time you visited the mainland?

The films are again lighting the screens at local theatres, the wine… Continue reading

Anyone with information on any of these individuals is asked to call 1-800-222-TIPS (8477) or visit the website victoriacrimestoppers.ca for more information.
Greater Victoria Crime Stoppers wanted list for the week of June 15

Greater Victoria Crime Stoppers is seeking the public’s help in locating the… Continue reading

Tk’emlups te Secwepemc Chief Rosanne Casimir stands outside the former Kamloops Indian Residential School after speaking to reporters, in Kamloops, B.C., on Friday, June 4, 2021.THE CANADIAN PRESS/Darryl Dyck
Kamloops chief says more unmarked graves will be found across Canada

Chief Rosanne Casimir told a virtual news conference the nation expects to release a report at the end of June

A woman wears a vaccinated sticker after receiving a COVID-19 vaccine at a vaccination clinic run by Vancouver Coastal Health, in Richmond, B.C., Saturday, April 10, 2021. THE CANADIAN PRESS/Jonathan Hayward
B.C. ranks among highest in world in COVID-19 first-dose shots: health officials

More than 76% of eligible people have received their 1st shot

An artists conception of the new terminal building at the Pitt Meadows Regional Airport.
Air travel taking off in B.C., but lack of traffic controllers a sky-high concern

There will be demand for more air traffic controllers: Miller

Canadian Armed Forces experts are on their way to North Vancouver after a local homeowner expressed worry about a military artifact he recently purchased. (Twitter DNV Fire and Rescue)
Military called in to deal with antique ‘shell’ at North Vancouver home

‘The person somehow purchased a bombshell innocently believing it was an out-of-commission military artifact’

Amy Kobelt and Tony Cruz have set their wedding date for February, hoping that more COVID-19 restrictions will have lifted. (The Macleans)
B.C. couples ‘gambling’ on whether COVID rules will let them dance at their wedding

Amy Kobelt and Tony Cruz pushed back their wedding in hopes of being able to celebrate it without the constraints of COVID-19

Most Read