By guest blogger Beth Alexander
As divers, we encounter many strange and fascinating creatures like cuttlefish — it’s one of the sport’s primary appeals. But how much do we actually we know about these creatures? Always a diver favorite, here are our top seven tidbits about this weird but wonderful creature.
- Despite their name, the cuttlefish is not in fact a fish, but is actually a mollusk. They belong to the same class as squid, octopuses and nautiluses.
- Unusually, the cuttlefish has its shell, called the cuttlebone, on the inside. The animal uses the cuttlebone for buoyancy control, much like we use our BCDs.
- Despite the fact that they are referred to as “chameleons of the sea” due to their ability to rapidly change color and texture to suit their environment or when threatened, cuttlefish are, ironically, colorblind.
- Cuttlefish blood is an unusual shade of green-blue because it uses the copper-containing protein in hemoglobin to carry oxygen around the body.
- Cuttlefish have three hearts in total — two pump blood to the cuttlefish’s pair of gills and the third pumps blood to the rest of the body.
- They eat by extending two hidden feeding tentacles, which snag prey and pull it back to the cuttlefish’s poison beak.
- They mate when the male grabs the female by the face and inserts a specialized tentacle into an opening near the females’ mouth and then inserts sperm sacks. The male then guards the female until the eggs are laid a few hours later. The eggs are widely known as “sea grapes.”