Invertebrate zoology is the study of animals without backbones—a group that accounts for approximately . From deep-sea hydrothermal vents to frozen Antarctic soils, these organisms serve as the bedrock of global ecosystems.
: Most invertebrates exhibit either bilateral symmetry (two matching halves, like insects) or radial symmetry (parts arranged around a center, like jellyfish) . invertebrate zoology lecture notes ppt new