Glycoconjugates in the otolithic membrane of herring larvae: a possible framework for encoding the life history recorder in fishes

Glycoconjugates in the inner ear of herring Clupea harengus larvae, investigated by laser confocal and electron microcopy, were located mainly in the gelatinous layer of the otolithic membranes, forming a collar around the proximal surfaces of the otoliths. The site of secretion was located on the surface of the sensory macula, from which a colonnade of glycoconjugate streamers projected through the subcupular region to connect with the gelatinous layer of each otolith. An electron dense,component of the outer gelatinous layers. shown by TEM to be closely associated with the sensory kinocilia. suggested that they provided a basis for the streamers and offered a potential role in directing the path of secretion, It is hypothesized that this highly structured glycoconjugate framework could provide a mechanism for localizing and containing ionic and protein gradients previously detected in this vicinity and which are considered to have a key role in driving the differential growth and mineralization of the otoliths, (C) The Fisheries Society of the British Isles. Published by Elsevier Science Ltd. All rights reserved.