Cool Critter: Cuttlefish
Cuttlefish have three hearts and eight arms, yet despite their potential as fabulous lovers, they have one of the most unromantic mating styles in nature.
The cephalopods—cuttlefish aren’t actually fish, they’re relatives of the squid and octopus—get it on by going “head to head.” They join all 16 arms and then the male (who has a special arm just for this purpose) reaches back and grabs a packet of sperm. He passes the packet to the female who tucks it away in a pouch near her mouth where she’s already stored sperm packets from other males. Within a few weeks, the female will select the most appealing sperm packages and use them to fertilize the hundreds of eggs she lays under rocks and in crevices. She’ll die shortly after laying her eggs. (The male dies after the big sperm handoff.)
This mating behavior obviously isn’t what makes the cuttlefish cool, but just about everything else the cuttlefish does makes it a very cool critter. Like their more popular cousins, cuttlefish can squirt a cloud of ink to create an instant smoke screen to hide from predators. But they can also use their ink to form body doubles. As a predator nears, the cuttlefish releases ink in cuttlefish-size globs surrounded by mucous. The predator (a shark, seal, dolphin or other cuttlefish) hesitates and the real cuttlefish sneaks away, leaving its inkblot army behind.
The body double trick is pretty cool, but cuttlefish camo is really where it’s at. All cuttlefish can change shape and color whenever they want, but some, like the broadclub cuttlefish, have trademark moves. When broadclubs hunt, they seem to hypnotize their prey by quickly changing colors and patterns like a strobe light on steroids. As the prey (often a crab) stands stupefied, the cuttlefish’s two tentacles shoot out and grab it.
When two male giant cuttlefish meet, they’ll try to outdo each other with dominant displays of color and macho patterns like zebra stripes. When a male encounters a female, however, he’ll turn himself into Rico Suave, showing her his calm soothing side. But that’s not all. If a male finds himself with an attractive female on one side and a chest-thumping male on the other, he’ll do double duty, flashing dominant displays of masculinity to the male while he’s showing the female his softer side.
Cuttlefish color isn’t all about attraction. Sometimes, cuttlefish adjust their bodies to blend in with their surroundings. They can change the texture of their skin to hide among rocks. But with mating on the line, who would want to look like a rock when you can look like a female? While the big males try to out do each other, smaller males sneak towards the female they’re fighting over. These sneaker males wouldn’t have a chance in Hell if the big guys saw them so they cross-dress by pulling in their webs and changing to a dull mottled pattern. Then they swim under the competing males, sneak under the female, pass her a packet of sperm and get outta there.
And then there’s the flamboyant cuttlefish, the smallest of the cuttlefish crew. Like all cuttlefish, this little guy has a cuttlebone (a porous structure that allows the cuttlefish to be buoyant). But the cuttlebone is so small—flamboyants max out at about three inches—that it’s too dense to provide buoyancy. The flamboyant makes do—by walking instead of swimming. Of course, this makes it even more vulnerable to predators so it protects itself with poisonous skin. When a predator approaches, the flamboyant cuttlefish struts across the ocean floor with the confidence that only a toxic critter has. It throws up its arms and changes from one bright color to another, presenting the cuttlefish version of a flashing neon sign that says, “I wouldn’t eat me if I were you.”
All in all, the cross-dressing, strobe lighting, shape shifting cuttlefish ain’t too shabby for something related to a snail.