Identification and Quantification of the Age-pigment, Lipofuscin, in Brains of the Deep-water Rose Shrimp Aristeus antennatus (Risso, 1816)

Abstract

Aristeus antennatus is a demersal penaeid mainly living at depth of 400-800 m in Mediterranean Sea. Since this specie is a high economic important fishery of the Spanish Mediterranean waters, the studies of age structure of the population are essential for an efficient assessment of the resource. Exist a inability to accurately estimate the age through conventional methods in crustacean and a new methodology have been developed on basis of the gradual deposition of lipofuscin in post-mitotic tissues for the ageing of animals. The identification of the age-pigment have been realized on transversal sections of the olfactory lobe cells mass (OLCM) in brain of wild-caught A. antennatus, observed under epifluorescence microscopy and quantified using image analysis techniques. Three different measurements of lipofuscin levels (% area fraction, granule density and granule mean size) were recorded in ten distinet sections of OLCM by individuals, body size class and sex. Relationship between body size and lipofuscin concentration (% area fraction and density granule) increased significantly linear, however, values of t2 were low. The resolution of age structure from the lipofuscin distributions was more successful than for body size distribution. Growth parameters using Von Bertalanffy function were derived for this specie on basis of the lipofuscin. The present results confirm the potential of the lipofuscin method for the resolution of cohorts in deep-water pennies and suggested that the application of this methodology can be useful in studies of the age structure in wild populations.