A Computer Technique for Estimating the Size of Sexual Maturity in Crabs

• Published in: Canadian Journal of Fisheries and Aquatic Sciences
• Main Author: Somerton, D. A.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Canadian Science Publishing 1980
• Subjects: Aquatic Science; Ecology, Evolution, Behavior and Systematics; Bering Sea; Chionoecetes bairdi
• Online Access: http://dx.doi.org/10.1139/f80-192; http://www.nrcresearchpress.com/doi/pdf/10.1139/f80-192

A new computer technique for estimating the size of 50% sexual maturity from crab morphometric data is described. Using nonhierarchical cluster analysis, crabs are assigned to either of two maturity groups based on the size of one body dimension relative to another. The size of 50% maturity is then estimated by using nonlinear regression to fit a logistic function to percent maturity and size estimates. The size of 50% maturity in the eastern Bering Sea was estimated to be 102.8 and 101.9 mm (carapace length) for male and female Paralithodes camtschatica and 114.7 mm (carapace width) for male Chionoecetes bairdi. These estimates are similar to estimates for these species obtained previously by other techniques.Key words: crabs, growth, sexual maturity, Paralithodes, Chionoecetes