Pacific Science Center

Bringing science to life.


PacSci-Doku: “Ocean Wonder”

By Dennis Schatz – Senior Advisor

Do you Sudoku? It’s one of the hottest number games around! Well, here’s a twist we think you’ll love. We call it PacSci-Doku. Can you guess why? Here’s how it works. Instead of filling in the blanks with numbers, we use letters. Hidden in one of the columns or rows is the answer to a science question. You’ll find information about the answer on the answer tab below.

The question in this edition is:

What has three hearts, nine brains and blue blood?

To find the answer, complete this PacSci-Doku using the following nine letters:

U  o  O  E  S  s  T  P  C

PacSci-Doku: Ocean Wonder

Puzzle Difficulty: Hard

The Answer

PacSci-Doku: Ocean Wonder AnswerThe question in this edition is:

What has three hearts, nine brains and blue blood?

The answer: Octopuses

When you mention octopuses to most people, they think about giant bulbous animals with eight legs covered with suckers ready to capture any nearby animal – including humans. They may also mention that octopuses produce ink to spay at predators to hide their movement. Or people mention that octopuses can change color instantly to take on the color of their background. But what people often don’t know is that octopuses have three hearts, nine brains and blue blood. One large heart circulates blood to its body, and two small ones send blood to its gills. Octopuses have one main brain that controls the overall nervous system, but each arm has a small brain that lets the arms work independently. And then there is the blue blood. Humans have iron-based blood that makes it red. Octopuses have copper-based blood that makes it blue. Read more about this amazing ocean wonder.