Hardening of red king crab Paralithodes camtschaticus (tilesius, 1815) shells after molting

Abstract

Shell hardness was measured with a durometer for female red king crabs, Paralithodes camtschaticus, held in the laboratory over variable periods up to 107 days after molting. The data were fit best by a hyperbolic equation, with parameters β 0 = 0.216 and β 1 = 0.019 (R 2 = 0.976, n = 199), and an asymptotic value of 50.7 durometer units (DU). The time required to reach 90% of complete shell hardness (H 90 = 45.6 DU) was calculated to be 74.2 days. Molting dates for all crabs were hindcast using the last measurement that was less than H 90 and were within 2.5 ± 6.4 days (mean ± SE, n = 34) of the actual molting date.