Mature female red king crabs must stay in warmer water (near 4 °C) to ensure the eggs will be ready for hatching, while the male red king crabs stay in relatively cold water (near 1.5 °C) to conserve energy. In spring (May), female red king crabs move to shallow coastal areas to molt and spawn, and males join the females in the shallow water before molting. In the summer (mid-June through mid-November), these crabs spend their time in fairly deep water, below the established summer thermocline. When the thermocline breaks down, the red king crabs migrate back to intermediate depths, where they stay until the female red king crabs release the eggs fertilized in the previous spawning.