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Cephalopod Intelligence
Context:
Many countries and organisations are beginning to adopt animal welfare guidelines for cephalopods, acknowledging their complex sensory systems and behavioural needs.
More on News:
- In 2010, the European Union made it a requirement to consider ethical issues when using cephalopods in research, and in 2015, international guidelines for their care in laboratories were promoted.
- California and Washington state passed laws banning octopus farming in 2024.
Diversity of Cephalopods:
- Cephalopods are a diverse group of molluscs that include cuttlefish, octopus, squid, and the chambered nautilus.
- They range greatly in size—from tiny squid to massive giant and colossal squid—and occupy different habitats, from the deep ocean to coral reefs.
- Their cognitive abilities, including problem-solving and hunting strategies, vary depending on their species, habitat, and evolutionary history.
Brain Structure and Behavior:
- Cephalopod brains vary in size and complexity across species. For instance, octopuses living in reef habitats have more complex, wrinkled brains than those in deep-sea environments, suggesting they may possess higher intelligence.
- Visual camouflage is a notable skill among cephalopods. They use chromatophores to change colours and patterns for communication, camouflage, and hunting.
Measuring Intelligence in Cephalopods:
- Intelligence is difficult to define and measure, especially in animals with vastly different sensory and problem-solving skills.
- One measure of intelligence is the brain-to-body size ratio, with the common octopus (Octopus vulgaris) having around 500 million neurons, similar to a starling or turkey.
- A significant portion of the octopus’s neurons (about 300 million) are located in its arms rather than the brain, a unique feature among cephalopods.
Learning and Memory in Cephalopods:
- Cephalopods like the common octopus and common cuttlefish demonstrate learning abilities comparable to vertebrates.
- They can form simple associations and engage in more complex forms of learning, such as reversal learning (adapting behaviour based on changing stimuli) and impulse control (e.g., waiting for a preferred snack).
Ethical Considerations:
- While animal welfare standards exist for vertebrates like mice, chickens, and fish, similar standards for invertebrates are lacking.
- As cephalopods exhibit complex behaviour and learning, there is increasing advocacy for regulations that ensure the humane treatment of these intelligent creatures, particularly in captivity or research.
