Methods for the validation of squid Age from statoliths

Abstract

INTRODUCTIONGrowth laminations were first noted in squid statoliths by Clarke (1966), who suggested they might be useful for age determination. Spratt (1978) presented a detailed age analysis ofLoligo opalescensBerry, 1911, arguing that some rings in the cephalopod statolith were deposited daily, as are fish otoliths (Panella, 1971). Growth rings inIllex illecebrosus(Lesueur, 1921) statoliths were illustrated by Lipinski (1978) with similar interpretation to that of Spratt (op. cit.). Several further attempts have been made to validate and/or to discuss age determination from statoliths (Hurley, Drew & Radtke, 1979; Hurleyet al.1983; Wiborg, 1979; Hurley & Beck, 1980; Kristensen, 1980; Lipinski, 1980, 1981; Rosenberg, Wiborg & Bech, 1981; Martins, 1982; Radtke, 1983; Daweet al.1984), and several other attempts are in preparation (R. J. Hanlon, G. V. Hurley, M. R. Clarke & R. L. Radtke, personal communications).