Growth, longevity, and demography of deep-water and other long-lived fishes
Gregor M. Cailliet, Ph.D.
Moss Landing Marine Laboratories
Wednesday, February 25, 2004
Pacific Forum – 3:00 p.m.
Photo by Tory O'Connell (ADFG)
Ageing techniques for deep-water fishes involve analysis of growth zones in skeletal structures, such as vertebral centra, bones, fin rays and spines, and otoliths. Age validation techniques include: 1) tag-recapture analysis, often with oxytetracycline analysis in growth zones upon recapture; 2) analysis of growth zones over time; and 3) radioisotope approaches using radioactive decay series or the time-specific bomb radiocarbon signal as an independent chronometer in skeletal structures. Our studies of age, growth, age validation, and demography of chondrichthyans, deep midwater and benthic bony fishes, and deep-sea corals indicate they are generally long-lived with low population growth rates. Longevities of scorpaenid fishes increase exponentially with depth of occurrence. Reasons for this are uncertain, but it is likely related to physiological adaptation to the deep-sea.