The life history of the mangrove tree crab, Aratus pisoni

Aratus pisoni (Milne Edwards) breeds throughout the year according to a lunar rhythm; the hatching of the eggs occurs at both full and new moon. Females become mature at about six months old or 12 mm carapace width and from then on, ovulate, on the average, once every intermoult; the number of eggs laid is directly proportional to the volume of the crab. By the time a female is eighteen months old at a size of 18 mm carapace width it will have laid 27,500 eggs and passed through seven moults. Mortality is greatest during the larval life and is caused mainly by predation.