Cephalopods are amazing! I love these boneless little invertebrates. To explain further, Cephalopoda is a somewhat broad classification of animals. When naming creatures, scientists follow a specific taxonomy that formulates a name for an organism consisting of each of the following categories: domain, kingdom, phylum, class, order, family, genus, species. Cephalopoda is the class name referring to a small group of animals known to the general public as squid, octopus, cuttlefish, and nautilus. All of these organisms have a head that is connected to their foot, which makes sense, since “Cephalopoda” literally means “head-foot” in Latin. The head contains a beak for mouthparts and is completely surrounded by a grouping of tentacles, which are different in number according to each species. These curious creatures use jet propulsion to move their bodies through the oceanic water column and often have an ink sack used in times of perceived danger.
A few years ago, I became fascinated by these creatures after watching NOVA’s documentary titled “Kings of Camouflage.” (Click the link to watch it.) The color patterns and textures these animals are able to create without truly seeing color is truly remarkable. Their skin is covered by small cells or plastids called chromatophores. These chromatophores contain pigments (in the case of cephalopods brown, red, and yellow). Chromatophores contract or expand in order to display each color. Another reflective layer lies underneath the chromatophores, allowing them to display colors of blue and green. The video blow allows you to see a close up of this in action…
There is, however, so much about these creatures we don’t know. They seem to be extremely intelligent, but defining that intelligence has proven to be quite a task. We can design tests for these creatures, but how can our land-dwelling definition of “smart” be the same as that of a sea creature?
The book, “Kraken: The Curious, Exciting, and Slightly Disturbing Science of Squid,” by Wendy Williams addresses many of these questions. From start to finish it’s an intriguing read (I read the entire book in a period of 24 hours…). Williams clearly describes each topic she chooses to discuss in regards to cephalopods. She covers their basic history, biology, use in neuroscience, and role in folklore. She also works with and interviews various experts in the field.
Many times, organisms are not credited with the role they play in scientific discovery. For example, did you know that squid are responsible for helping us make many discoveries in regards to cancer? Or that a glowing jellyfish is responsible for understanding how neurons signal each other in the human body? It’s quite amazing. We rely so heavily on many oceanic and terrestrial species, yet we destroy their habitats so readily.
The behavior of these animals remains largely a mystery. Folklore regards them as monstrous creatures, ready to attack a ship, wrap sailors in its wriggling arms, and bring them mercilessly to their awaiting beaks. Is it because we know so little about them that we choose to fear them? Recently, footage of a giant squid has been captured in its natural habitat.
Bodies of these massive creatures have washed up on shores, but we know so little about them in their natural state. It’s fascinating. Experts have gone their entire lives specializing on this species and never seen a live specimen. Talk about dedication!
“Kraken: The Curious, Exciting, and Slightly Disturbing Science of Squid” is a great read. It covers a wide range of topics (more than I mentioned here), explaining them in enough detail without going overboard. Williams style of writing is light, detailed, and, at times, comedic. More than once I found myself grinning at the authors words. For those of you interested in sea creatures and the ocean (or simply find yourself enthralled by a cephalopod), pick up this book! It’s worth your time!