The use of extractable lipofuscin for age determination of crustaceans: Reply to Sheehy (2008)

Age determination is crucial in a number of biological disciplines, especially fisheries science.Over 8 yr ago, Ju et al. (1999) first presented a new approach to the aging problem in crustaceans, using lipofuscins extracted from neural tissues to estimate age of the blue crab Callinectes sapidus.The examination of lipofuscins (LF), or 'age pigments' as they are also called, was not in itself new; indeed these products have been observed and reported in the literature for well over 100 yr (Hannover 1842).Multiple approaches have been used over the years to follow the formation of this complex material in aging post mitotic cells, as well as the metabolic processes that lead to their accumulation and retention.Microscopic approaches were first used to observe these autofluorescent granules in mammalian neural tissues, and since that time histological