Intro to Invertebrates . Chapter 25 Sections 1 & 2. Invertebrates (inverts) include all animals that lack a backbone, or vertebral column. This includes 33 Phyla. Phylum Porifera. The term Porifera means “pore-bearers” in Latin. This phylum includes Sponges.
Intro to Invertebrates
Sections 1 & 2