The observation doesn't hold that as a fact, for instance Hoover, 1998, says harlequins attack all species of stars found in their habitat including the crown of thorns. and like I said the first one I found was eating a brittle star. As for the preference order, the hawaiian harliquins don't eat chocolate chips, they don't come from there so the order they eat stars has more to do with availability then other factors. I will agree with you on one thing, mine prefer linkia type stars, but they are not at all limited to them, they will eat Pufferpunks serpent stars the first chance they get if they are hungry