A biologist friend of mine recently heard from a journalist who was fact-checking a squid article. (Go, conscientious journalism!) The article included the line "the Humboldt squid is five feet long from beak to tentacle tip" and the journalist wanted to know: Is that right, or it would be more correct to say six feet long?

The biologist in question was left wondering if the writer had ever, you know, looked at a squid and considered how one might want to measure it:

Although, all snark aside, most people do not have to consider such challenges on a regular basis. I suggested to the biologist that she draw an analogy to human dimensions--if I went around claiming to be three feet tall from mouth to fingertip, everyone would consider me completely bonkers.

But invertebrates are oddly shaped, and it's often hard to recognize the equivalent of "height." I propose that a good rule of thumb is to disregard the appendages and measure the largest remaining dimension.