Does spine removal affect molting process in the king red crab (Paralithodes camtschaticus) in the Barents Sea?

The red king crab (Paralithodes camtschaticus) is an important commercial species native to the Pacific Ocean. In the 1960s it was introduced into the Barents Sea. Russia started commercial fishing of this species in 2004. Despite the long history of red king crab investigations both in the native areas of its habitat and throughout its new distribution, little is known about the impact of carapace and limb damage on the molting process in P. camtschaticus. We conducted a laboratory study to test the hypothesis that spine removal affects molting frequency in red king crabs. We found that the duration of the intermolt period was significantly lower in crabs after removing their limb spines (54 ± 8 days) compared to crabs with their carapace spines removed (82 ± 7 days) and intact controls (95 ± 3 days). Spine removal did not affect mortality rates nor growth-per-molt increments. Although this method of inducing ecdysis has a weaker effect than other techniques such as multiple autotomy, eyestalk ablation or hormone injections, it has no negative impacts on the animals (abnormal molting, growth reduction or high mortality) and can be used in aquaculture of juvenile crabs released into the sea to increase the stock size and amounts of catch.