Many sizes of sharks

This weekend I'm in Charleston, SC, and I have learned that sharks can be tiny.  I was standing on the boardwalk at Folly Beach, and I saw a fisherman catch something, and it was a super tiny shark!  The shark I saw was a bit smaller than this:

(from Peter Metzger's flickr photostream)

The fisher threw the shark back, but I was all excited about sharks at that point.  I thought that perhaps the Talus Slopes blog could introduce you to the many sizes of shark this week!

The smallest shark is the dwarf lantern shark.  It's only 6-8 inches long.  You could keep it in your kitchen sink and feed it sardines.  I don't have any good lantern shark pictures, but here is a tiny dead shark to look at.

(from bac_clin's flickr photostream)

The biggest shark is, of course, the whale shark:

(from pelican's flickr photostream)

Whale sharks are huge.  The heaviest one ever weighed was over 79,000 pounds!  I have no idea how they weighed it.  The longest one was over 40 feet long!  They mostly eat plankton, though (lots and lots of plankton).  You might not think it, given what they look like:

(from Olivier Roux's flickr photostream)

 (from KAZ2.0's flickr photostream)

I can imagine fitting my entire body into that thing's mouth before it realized I wasn't plankton.

I think it is time to talk about teeth.  Sharks are made entirely of teeth.  Don't let their smiley faces fool you...

 (from Hermanus Backpackers' flickr photostream)

...sharks are made of teeth.

(from Herman Yung's flickr photostream)

Sharks have multiple rows of teeth, as you can sort of see above, and they keep growing more teeth and shedding their old ones throughout their lifetimes.  Newly-grown teeth are moved into place on a terrifying "conveyor belt-like structure," apparently.  A little shark called a "lemon shark" replaces its teeth every 8-10 days, while the great white replaces its teeth every 100-230 days, depending on age.  Apparently, some sharks can shed up to 35,000 teeth in their lifetime!

(from kecko's flickr photostream)

Grr.  The shark above is suspended in formaldehyde, for some reason...

Shark teeth are kind of useful because they turn into fossils eventually.  There were sharks around 450 million years ago, and these days they're mostly known because of their teeth.  Shark teeth have also been weaponized:

(From the Peabody Museum, Salem)

Here are some pictures of people holding sharks.  A medium-sized blacktip shark:

(from vgm8383's flickr photostream)

And here's a shark that was dragged onto shore to be measured, and is now being dragged back out to sea:

(from Eliott Gilfix's flickr photostream)

More fun facts about sharks: 

• Sharks don't have an air bladder for buoyancy.  Rather, they have a large liver filled with buoyant oil, and some very lightweight cartilage.
• Some sharks keep their eyes open when they sleep, and their eyes will actively follow divers that pass by.

Sizes of sharks:

(from Popoto, Wikimedia Commons)

Some sharks, such as the Port Jackson shark, also have some very neat spiral egg cases:

(From Golden Wattle, Wikimedia Commons)

Thanks for joining me on this trip through the wonderful world of small and large sharks!  Ending on a responsible note, I'd like to encourage everyone who reads this blog to avoid eating sharkfin soup.  It's very expensive and classy, yes, but it's generally made by cutting the fins off of sharks and then throwing the shark back into the ocean to die.  Be humane to our toothy friends!

(from Peter Smithson's flickr photostream)