Cephalopod sense organs, nerves and the brain: Adaptations for high performance and life style

The morphological and physiological adaptations that the cephalopod sensory organs and nervous system underwent during the course of evolution are briefly summarized. Special emphasis is paid (i) to the vertebrate-like lens eyes with their complex extraocular eye muscle system, (ii) to the vestibular analogue statocysts with hair cell receptor systems for linear and angular accelerations and an elaborate afferent and efferent nerve supply, (iii) to the epidermal head and arm lines which are analogous to, and as sensitive as, the lateral lines of fishes and aquatic amphibians, (iv) to the giant fibre system for escape jetting, and (v) to the highly centralized brain which is capable of different forms of learning and memory.