PREDICTING THE WINNING OR LOSING OF SYMMETRICAL CONTESTS IN THE AMERICAN LOBSTER HOMARUS-AMERICANUS (MILNE-EDWARDS)

The ability to predict the outcome of symmetrical contests between mal e lobsters (Homarus americanus) on the basis of 21 variables was inves tigated using a stepwise discriminant analysis. Measured variables inc luded wet weight, carapace length, claw length, width and thickness, c law volume, claw contraction force, handedness, antenna length, color, plasma protein level, plasma calcium level, exoskeleton calcium conce ntration and motor activity. Plasma protein level, exoskeleton calcium concentration and claw dimensions were found to be important in the a bove ascending order for discrimination with an average squared canoni cal correlation of 0.55-0.65. The discussion focuses on the variables differentiating winners from losers and whether these variables could also aid competing lobsters when assessing the relative fighting abili ty of their rivals. (C) 1997 Elsevier Science B.V.