Tuesday, May 21, 2013

Distribution Maps IX: Hammerhead Sharks

One day I was reading about hammerhead sharks on Wikipedia.[1] There are two genera of hammerhead shark: Eusphyra and Sphyrna. Eusphyra has a single species, while Sphyrna has eight species. The characteristic shape of their heads improves their peripheral vision and their ability to detect electrical charges (electroreception). As I was reading, I noticed that they had distribution maps for the different species, but they were all ugly, low-resolution .png images. So I created new, crisp .svg images and inserted them into the appropriate articles. You can see them below.

Winghead Shark (Eusphyra blochii)

Scalloped Bonnet Shark (Sphyrna corona)

Whitefin Hammerhead Shark (Sphyrna couardi)

Scalloped Hammerhead Shark (Sphyrna leweni)

Scoophead Shark (Sphyrna media)

Great Hammerhead Shark (Sphyrna mokarran)

Bonnethead Shark (Sphyrna tiburo)

Smalleye Hammerhead Shark (Sphyrna tudes)

Smooth Hammerhead Shark (Sphyrna zygaena)
That takes care of individual species. But I also took on a few more maps:

Hammerhead Sharks (Genus Sphyrna)

Since I had maps for all known species of Sphyrna, I went ahead and combined them all into a map for the genus as a whole.

Hammerhead Sharks (Family Sphyrnidae)

And then, since there's just one more species of hammerhead (Eusphyra blochii), I also made a distribution map for all hammerhead sharks. The only difference between this map and the previous one is the seas around the islands of Borneo and Sulawesi.


Notes:

[1] See http://en.wikipedia.org/wiki/Hammerhead shark.

Image attributions:

Winghead Shark distribution is by Ninjatacoshell, available at http://commons.wikimedia.org/wiki/File:Eusphyra blochii distribution map.svg.

Scalloped Bonnethead Shark distribution is by Ninjatacoshell, available at http://commons.wikimedia.org/wiki/File:Sphyrna corona distribution map.svg.

Whitefin Hammerhead Shark distribution is by Ninjatacoshell, available at http://commons.wikimedia.org/wiki/File:Sphyrna couardi distribution map.svg.

Scalloped Hammerhead Shark is by Barry Peters`, available at http://en.wikipedia.org/wiki/File:Scalloped hammerhead cocos.jpg.

Scalloped Hammerhead Shark distribution is by Ninjatacoshell, available at http://commons.wikimedia.org/wiki/File:Sphyrna lewini distribution map.svg.

Scoophead Shark distribution is by Ninjatacoshell, available at http://commons.wikimedia.org/wiki/File:Sphyrna media distribution map.svg.

Great Hammerhead Shark distribution is by Ninjatacoshell, available at http://commons.wikimedia.org/wiki/File:Sphyrna mokarran distribution map.svg.

Bonnethead shark distribution is by Ninjatacoshell, available at http://commons.wikimedia.org/wiki/File:Sphyrna tiburo distribution map.svg.

Smalleye Hammerhead Shark distribution is by Ninjatacoshell, available at http://commons.wikimedia.org/wiki/File:Sphyrna tudes distribution map.svg.

Smooth Hammerhead Shark distribution is by Ninjatacoshell, available at http://commons.wikimedia.org/wiki/File:Sphyrna zygaena distribution map.svg.

Distribution of Hammerhead Sharks in the genus Sphyrna is by Ninjatacoshell, available at http://commons.wikimedia.org/wiki/File:Sphyrna distribution map.svg.

Distribution of All Hammerhead Sharks is by Ninjatacoshell, available at http://commons.wikimedia.org/wiki/File:Sphyrnidae distribution map.svg.

2 comments:

  1. So I'm wondering, are these sharks really only around shores, or is that the information we have because that's where humans encounter them? Would we be safe from sharks out in the middle of the ocean?

    Also...oh my goodness! When I saw you updated your blog I thought (and hoped) you had written about your ultrasound! Not that sharks aren't exciting!

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  2. Per your first question, those are only areas where they have been observed. Since some of them are found on both sides of the Atlantic it is assumed that they can be found on the open sea, but that is not indicated in these maps.

    Per your second coment, they didn't give us any digital copies of the ultrasound, this time, only a printout from a thermal printer. And without pictures it just didn't seem worth it to do a post.

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