Brain
Two groups of invertebrates have notably complex brains: arthropods (insects, crustaceans, arachnids, and others), and cephalopods (octopuses, squids, and similar molluscs). The brains of arthropods and cephalopods arise from twin parallel nerve cords that extend through the body of the animal. Arthropods have a central brain with three divisions and large optical lobes behind each eye for visual processing. Cephalopods such as the octopus and squid have the largest brains of any invertebrates.
Arthropods and cephalopods have brains that come from a pair of what?
parallel nerve cords
The brains of arthropods and cephalopods arise from twin parallel nerve cords that extend through the body of the animal.
Brain