Gerontological Studies of the Damselfish, Dascyllus Albisella

It may be possible to define physiological age through assays of the gerontological, metabolically accumulated cellular pigment, lipofuscin. The damselfish, Dascyllus albisella, was studied to compare chronological age and physiological age, utilizing major and minor growth patterns of otoliths to determine chronological age and measurement of lipofuscin, in brain tissue, to index physiological age. Measurements of otoliths established the exponential correlation between otolith size and fish size. Examination of otolith micro-structure by light and Scanning Electron Microscopy for rhythmic construction provided evidence for both daily and yearly depositional increments. Assays of chloroform-extractable fluorescent lipofuscin pigments from brain tissue demonstrated that lipofuscin concentrations increased in proportion to both fish size and estimated chronological age. These data provide evidence for presence and accumulation of lipofuscin pigments in brain cells of Dascyllus albisella, and suggest a relationship to the physiological aging processes. Studies of lipofuscin accumulation in fishes hold great potential to answer questions about the aging processes, longevities, and general ecology of fish.