The mating season of "C. lavauxi" is during the summer months from the middle of October to late December. This mating season is highly synchronous within the population. These crabs are not monogamous and both females and males will mate multiple times during the breeding season. During this reproduction season, there is a lot of male-male competition where bigger males will often attack other males who are in the process of mating with a female, frequently giving the female an opportunity to escape. Likely due to this competition, mating pairs can be found under rocks to hide from other males who might interfere.