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The octavolateralis system consists of several submodalities, including the inertial-sensitive inner ear, the pressure-sensitive ear/air cavity complex (when present), and acceleration- and velocity-sensitive components of the lateral line system (canal and superficial neuromasts, respectively). All four of these channels are responsive to many of the same stimulus sources, particularly moving or vibrating objects within a short distance from the receiver. We therefore argue that the octavolateralis system is an excellent model for the study of multisensory interactions. We focus on the possible ways in which these channels may contribute to source localization mechanisms and to the multisensory guidance of behaviors with strong directional components (e.g., predator avoidance, prey capture and mate attraction). Finally, we define four ways in which information from multiple senses might interact. These include fractionation, synergy, accessory stimulation, and complementation. Although evidence for all types of octavolateralis interactions can be found, the primary modes of interaction appear to be complementation and fractionation. For example, the inertial and pressure-sensitive submodalities of the auditory system provide complementary pieces of information about the direction (e.g., left/right) and polarity (advancing or receding) of a moving source. In contrast, the lateral line canal system subserves short-range localization tasks, whereas the auditory system may subserve longer-range detection and localization tasks.

Bruun, C. B. & Northcurt, R. G. 1997. The lateral line system of hagfishes (Craniata: Myxinoidea) -Acru Zoologicu (Stockholm) 78: 247-268. The morphology of the peripheral lateral line system in Eptutretus stoutii is described using a combination of electron microscopical, histological and immunocytochemical techniques. The epidermis and cranial nerves of Myxine glutinosu were also examined for evidence of a lateral line system. Together with results previously published by other researchers, we conclude that most or all eptatretid hagfish possess a lateral line system composed of shallow trenches, or grooves, lined with a single class of flask-shaped receptive cells. No species of myxinid hagfish has been shown to possess any component of this system. Three groups of lateral line grooves are present in eptatretids: preoptic, dorsal postoptic, and ventral postoptic groups. The preoptic grooves are innervated by a single pair of ganglionated cranial nerves and the two postoptic series of grooves are innervated by a pair of cranial nerves which each possess two ganglia, possibly as a result of fusion of two pairs of ganglionated nerves. Morphometric analysis indicates that these grooves continue to grow throughout life and that the variability in the distribution of grooves between animals may result from developmental instability in lateral line ontogeny. The morphology of the receptive organs is compared to neuromasts of the vertebrate lateral line system and ciliated receptor cells of other chordates. The morphology of hagfish lateral line receptors may represent the primitive condition for craniate lateral line organs, or more likely, they are highly derived as a result of regrehive evolution. 0 1997 The Royal Swedish Academy of Sciences. Published by