From walking on land, to solving complex problems, cephalopods continue to amaze us with their intelligence and nervous system development. In a new study published in Current Biology, Dr. Wen-Sung Chung from the University of Queensland Brain Institute and colleagues decided to take a closer look at what makes their brains unique using MRI imaging.
Compared to other invertebrates, cephalopods are rather brainy. In fact, some cephalopods have over 500 million neurons whereas lab mice only have 70 million or so. Imaging the brains of 4 different species, the researchers discovered differences in the brain structure of animals that lived in sunlit reefs (algal octopus and day octopus) compared to those that live in deep dark waters (vampire squid) and nocturnal animals (blue-lined octopus). Perhaps not surprisingly, the optic (visual) lobe of the brains of both the nocturnal and deep-dwelling animals were less complex and smaller than animals that live in reefs. The reef animals also had larger areas of the brain that are responsible for learning and memory. This higher level of complexity in the reef-dwelling animals may help them navigate and perform complicated tasks in their bright and colorful habitat. Interestingly, they also found that vampire squid brains have features in common with both squids and octopuses. I wonder if vampire squids can open jars or use coconut shells as well as these octopuses:
Chung W-S, Kurniawan ND, Marshall NJ. Comparative brain structure and visual processing in octopus from different habitats. Current Biology. 32(1): P97-110, 2022.