Seemingly adorable and innocuous, starfish are actually vicious predators, the mere mention of which would fill you with heart-stopping terror if you were a mollusc or other small marine invertebrate. And actually, considering that several starfish species brandish poisonous spines, people should probably be more afraid of them, too. In fact, starfish is too cute a name (and too inaccurate, as starfish are not "fish" at all); I propose that we start calling them death-stars.
Reason 1: They don't unwrap their food.
Image credit: Vancouver Aquarium
We humans bring our food to our stomach. Starfish bring their stomachs to the food. A starfish can stick its stomach out of its body, wrapping it around a meal item and then secreting enzymes that digest the prey alive. However, the enzymes can only attack soft tissues, so for shelled lunches like bivalves, the starfish simply squeezes its stomach inside the armored fortress, absorbing the poor bivalve right out of its shell, leaving behind no evidence of the slaughter besides an unharmed, empty shell.
Reason 2: Their arms have eyes, plus hydraulic legs that can smell.
Starfish arm with tube feet (white protuberances) and eyespot (red dot). Image credit: André-Philippe D. Picard
Forget the nonsense that all starfish only have five arms (which is be bad enough). The nightmarish sunflower seastar wields up to 24 arms, and it's not afraid to use them to manhandle prey. What's more, each arm possesses thousands of tiny tube feet, which the starfish can inflate and deflate with water on command. Starfish move (and feel) by walking on these tube feet, which is to be expected, but they also smell with them. Additionally, each tube foot has adhesive chemicals that gives starfish Spiderman-like abilities to defy gravity. This allows them to grab prey and hold on. Plus, at the end of every starfish arm is an eyespot that detects light. What can't starfish do with their arms?
Reason 3: Starfish are sexy.
It has been shown that physical beauty is a function of symmetry, and while we humans have a mere two planes of symmetry, starfish have five! How sexy is that? Perhaps da Vinci's famous anatomy drawing was an instinctive attempt to try to make the human body as awesome as a starfish's. This five part symmetry, which is a feature of the echinoderm phylum, allows the starfish to sense prey in virtually any direction and immediately adjust its path of travel. Even their aesthetic appeal is secretly a weapon.
