Are sponges heterotrophs

Sponges are animals not plants and they consist of an outer thin layer of cells and a inner mass of cells. Sponges do not have nervous, digestive or circulatory systems, instead they rely on maintaining a constant flow of water going through their bodies to obtain food, oxygen and to remove waste products. There are 9000 known species of sponges known and about 80% of them are saltwater , the lowest depths of some species of sponges are 8,800 m (5.5mi).