Upon encountering food, a seastar expels its stomach, envelops the food to digest it gradually, then spits out the remainders through its "mouth".
If you flip a seastar over, you'll see its underside has just one "mouth," which it uses both to ingest food and to eject leftovers.
For humans, it belongs to the category of creatures that "eat from the same place they spit out."
Of course, not all seastars share the same diet; different species have different feeding habits, and their methods of ingesting food also differ.
The widely known "stomach spitting" type, or external digestion type, mostly preys on bivalves. They evert their cardiac stomachs, secrete digestive enzymes, consume the flesh and then discard the shells.
There are also seastars that digest internally, where the food is entirely swallowed without the process of egesting the stomach.
And there are cilia filter feeders, among others.
Perhaps there are even types that people have yet to discover.
