Question: are cuttlefish related to squid?
Answer: Cuttlefish or cuttles are marine molluscs of the order Sepiida. They belong to the class Cephalopoda, which also includes squid, octopuses, and nautiluses. Cuttlefish have a unique internal shell, the cuttlebone. ... Cuttlefish also have one of the largest brain-to-body size ratios of all invertebrates.