 The cave-dwelling predators capture crustaceans under long by entangling them with fine threads, digest them by enveloping them with further threads over the course of a few days, and then return to their normal shape; there is no evidence that they use venom.Most known carnivorous sponges have completely lost the water flow system and choanocytes.However, the genus "Chondrocladia" uses a highly modified water flow system to inflate balloon-like structures that are used for capturing prey.