AGE DETERMINATION OF RED DEEP-SEA CRAB (Chaceon quinquedens) BY GROWTH RING ANALYSIS  

The age structure and growth rates of crustaceans are poorly understood due to of their lack of true skeletal structures that do not shed (e.g. shells, scales, otoliths) that have the potential to form annual growth rings. A recent development in crustacean aging is the discovery of growth rings or bands in calcified sections of the gastric mills ossicles. By examining these structures, more accurate and direct age estimates can be determined. We will focus our study on red deep sea crab (Chaceon quinquedens). Which support a minor commercial fishery along the Atlantic continental shelf and slope of North America where they live in deep water from 200 to 1800 meters and temperatures of 5 to 8°C.  Red crabs are a data poor stock, due to insufficient data on their biology, abundance, growth, age, or reproduction. From the gastric mills the mesocardiac and zygocardiac ossicles were separated, embedded in epoxy, then sectioned by a diamond-bladed Isomet saw. Sections will be viewed with a compound microscope. Rings will be counted and compared between ossicles. Estimates of age composition will be used to improve data on growth, recruitment, migration, maturation, longevity and mortality, and will contribute greatly to improved stock assessment for this species.