Alaska crustacean age determination study: band count and endocuticle measurements across three shell conditions of terminally molted snow crab, 2016-2018

These data are part of a crustacean age determination project. Specifically, these data describe production of band count estimates and endocuticle measurements from zygocardiac ossicles across new, old, and very old shell class terminally molted snow crab. The data set consists of two comma separated files exported from a Microsoft excel workbook. "Shell_Condition_and_Endocuticle_Measurements" data consists of 1. three independent band count estimates for each standardized zygocardiac ossicle thin section examined including the shell condition and animal size, and 2. structure and endocuticle measurements. "Endocuticle_Measurements" data consists of two sets of endocuticle measurements taken independently from the same thin sections. Sixty large (>80 mm carapace width, the minimum harvestable size in the commercial fishery) terminally molted male snow crab (20 each of three shell condition classes: new shell, old shell, and very old shell) were haphazardly collected during the NMFS Eastern Bering Sea crab and groundfish bottom trawl survey in July 2016. Crab were frozen whole at sea. Carapace width and shell condition data were collected, gastric mill ossicles were removed, cleaned and preserved for at least one week in preservative prior to being processed for the experiment.