Embryology of Decapod Crustaceans I. Embryonic Development of the Mangrove Crabs Goniopsis Pulchra and Aratus Pisonii (Decapoda: Brachyura)

The complete embryonic development of the mangrove crabs Goniopsis pulchra and Aratus pisonii is described based on morphological features observable in live eggs. Periods of development are defined in steps of 48 hours each and in relation to the time of embryonic development. Eight periods were described and illustrated for Aratus pisonii and nine for Goniopsis pulchra. Embryo development from recently spawned eggs to hatching lasted 14 days for Aratus pisonii and 15 for Goniopsis pulchra at 26–28°C. The embryonic development of the two species was very similar; growth was synchronous, appendages were formed during the same periods, complexity of abdominal and ocular processes were chronologically comparable. Goniopsis pulchra eggs were slightly larger, while in Aratus pisonii the digestive gland was easier to observe in later periods and the telson grew larger. Cromatophores were more evident in Aratus pisonii embryos, especially those of the telson.