Teuthology (from Greek τεῦθος, "cuttlefish, squid", and -λογία, -logia)[1] is the study of cephalopods, which are members of the class Cephalopoda in the phylum Mollusca. Some common examples of cephalopods are octopus, squid, and cuttlefish. Teuthology is a large area of study that covers cephalopod life cycles, reproduction, evolution, anatomy, and taxonomy.
Teuthology is a specific branch of malacology, the study of molluscs. A teuthologist is a scientist who studies teuthology.