Today I read “Deep Intellect: Inside the Mind of the Octopus” by Sy Montgomery for what I am not ashamed to admit was probably the fifth time. As I sat in the library, silently weeping and wishing for a tentacled hug, I began to think of my own favorite Cephalopod.
Personally, I’m a fan of the Cuttlefish.
I think it was those W-shaped pupils that won me over first. Don’t mistake my meaning, I love octopuses, but their floppy mantles really freak me out. I said it quite eloquently this morning: “They look like aliens with giant brains, except if then the skull sometimes went like…*flop* and just kinda…splooshed.”
Without further ado, reasons why everyone should have an affinity for the members of Phylum Mollusca, particularly those that are also members of Class Cephalopoda. Actually, I’m really talking about Subclass Coleoidea. That’s where it’s at.
- Cuttlefish are distinguishable from other squishy tentacled things because of their cuttlebone, a hard structure made of aragonite (crystalized calcium carbonite) that controls buoyancy. The anatomy that controls gas flow is called a “siphuncle”, which is surely the best word you’ve come across today.
- They have three hearts, the better to love you with. Two hearts (one each) pump blue-green blood to the gills, and one last heart covers the rest of the body. Their blood uses hemocyanin instead of hemoglobin to carry oxygen (copper vs iron, hence the blue color) so the hearts have to pump faster to get enough oxygen around.
- Cephalopod eyes are the most advanced of all invertebrates. They have a camera-type eye (image projected by a lens onto a retina) like we do but it evolved independently. This is one of the coolest examples of convergent evolution. To summarize, the idea was such a good one that multiple branches of the animal kingdom got to it without any help from each other. Bam. Cuttlefish and their brethren don’t see color, but they can detect the polarization of light.
- Oh yeah: Their eyes also lack the blindspot that we’ve all got, and it’s generally accepted that Cuttlefish start using their eyes while still in their eggs.
- “Sepia” ink is named for the Cuttlefish (genus Sepia) because the Ancient Greeks loved them some Cuttle-juice. Luckily, it’s manufactured now.
- Cuttlefish can change their color at will to communicate with each other and hide themselves from predator detection. It’s pretty trippy.
- Last but not least, these guys are crazy intelligent. Cephalopods actively hunt their food, even going after prey as tricky as crabs. Their tentacles have incredible dexterity, enabling them to open jars and otherwise mess with your business at will.
In conclusion, this is a Sub-class of awesome.