So it looks like Humboldt squid don't kill divers after all. At least, they haven't done so yet.
Meanwhile, two different species of very large squid are going on display at opposite ends of the commonwealth. That plastinated giant squid (Architeuthis) hit the museum in New Zealand, and a colossal squid (Mesonychoteuthis) is on display at the Natural History Museum in the UK. Their press release has a nice description of the cephalopod circulatory system:
The colossal squid has an impressive 3 hearts, (2 branchial hearts and 1 systemic heart). The branchial hearts pump blood to the gills, where oxygen is taken up. Blood then flows to the systemic heart, where it is pumped to the rest of the body. Squid blood is blue, not red as in humans. This is because squid blood contains a copper-containing compound called haemocyanin.
It should be clarified, though, that the three-heart system is a general cephalopod trait, common to all squids, octopuses, etc., and not unique to the colossal squid.
"Where's the heart?" and "Is that blood?" are two of the most common questions I get at squid dissections, and I always delight in providing the surprise answers: "Actually, there are three hearts!" and "That red stuff is just stomach juice; their blood is blue."
My hope is always that this anatomical awesomeness will overcome most dissection-goers' aversion to the dead squid smell, sending them away with the impression, "Squid are very cool," rather than just, "Squid are very stinky."
The smell is particularly on my mind tonight, since I just came home from doing a couple of Humboldt squid dissections (with the Squids-4-Kids program) at an Expanding Your Horizons conference in Los Angeles. Forty awesome young ladies crowded around the squid, asking fabulous questions, boldly poking, prodding, and exploring. An excellent time was had by all, except for my sneakers, who really, really wished I had remembered to pack squid-juice-proof boots.
At times I can be callous about such things, but even I wasn't about to inflict the squid-sneaker odor on an airplane full of commuters. So I packed the shoes in a plastic bag and took the trip home barefoot. Which prompted this awesome conversation with a fellow traveler:
Normal Person: Where are your shoes?
Me: It's kind of a long story.
Normal Person: ??
Me: They smell like squid. So I put them in my bag.
Normal Person: That sounds like the beginning of a novel.
