(plural ceratotrichia))a long, horny or keratinous, non-cellular, cylindrical, flexible and non-segmented ray which supports the fins of Elasmobranchii and arthrodires. They may replace fin radials or be a third element in fin support in a series basals, radials, ceratotrichia. Used to make shark fin soup. Bony, unsegmented, unbranched rays superficially resembling ceratotrichia of Elasmobranchii are found in the fin membranes of Acanthodii
Dictionary of ichthyology. 2009.