Those choanocytes, with epidermal pinocytes, bound a gelatinous matrix known as the mesohyl, which separates the two layers of organisms in this phylum.
One group in this phylum probably descended from heteractinids, which went extinct during the Paleozoic Era. This phylum's immune response includes the accumulation of grey cells. In organisms in this phylum, totipotent amoebocytes allow for reproduction and the distribution of nutrients digested by current-producing choanocytes. Those choanocytes, with epidermal pinocytes, bound a gelatinous matrix known as the mesohyl, which separates the two layers of organisms in this phylum. The asconoid and syconoid body forms also feature an osculum along with spicules produced by sclerocytes. For 10 points, name this invertebrate phylum of sessile, suspension-feeding animals commonly known as sponges.
One group in this phylum probably descended from heteractinids, which went extinct during the Paleozoic Era.
Porifera [accept sponges before the end]