Because It Seems To Shock Someone Every Time I Say It And I Love Seeing People Awed, Horrified And Delighted

Because it seems to shock someone every time I say it and I love seeing people awed, horrified and delighted by new information let’s appreciate again that this animal is a predator. These are the various ways starfish kill things:

Many stars just eat anything slower than they are, including many that will feed on plant matter, algae or carrion. When it comes to live food, some species prey only on mussels, some only on corals or sponges, and others are opportunists that will even consume fish that they often catch asleep! The grip of their sucker-tipped tube feet is incredibly strong and in the second it takes a sleepy fish to wake up it can already be too late to wriggle free.

To feed, a star protrudes its stomach outside of its body, enveloping the food in a sticky, gelatinous sac that slowly digests it over the course of many hours or even days.

Some stars have “pedicellariae” on their surface, which are like extremely tiny sets of “jaws.” These form the “fur” on this Labidiaster star. Pedicellariae are usually used for defense, but this and other species will consume tiny creatures that get caught on the velcro-like carpet of microjaws, and will spend many hours just holding their arms up in the water as a trap.

Finally there are the “ambush stars,” like Stegnaster inflatus. It’s likely many sea stars hunt this way from time to time and there may be many we just never observe doing so, but a few species are particularly devoted to it. These just stand up on their arms for long periods of time to form what small animals mistake for a safe shelter, and then you can guess what happens!