BIOL10004 Study Guide - Final Guide: Calcareous Sponge, Sponge, Filter Feeder
Document Summary
All animals, even simple ones, are multicellular, heterotrophic organisms. They must therefore ingest food, they cannot make it themselves. This tutorial covers the following phylum: phylum porifera, phylum cnidaria, phylum platyhelminthes, phylum nematoda, phylum annelida. An example of a parazoan is the sea sponge. Figure 38. 3 a cluster of small calcareous sponges of the genus calliapongia, at heron island. Most sponges are marine organisms that filter feed. They do not have a nervous system, circulatory system, a mouth, a gut or an anus. They exhibit a relatively simple organization and have no symmetry. Adult sponges are sessile, being anchored to substrates such as rocks, but sponge larvae are free-swimming. Sponges do not have tissue layers, but have cells grouped in loose layers that have no basement membranes. In the simplest of sponges, their body is tubular with an internal cavity called the spongocoel. Surrounding the spongocoel are flagellated cells called choanocytes.