Effect of temperature on the morphometric development of eggs in the prawn Macrobrachium americanum (Caridea: Palaemonidae) and larval success under experimental conditions

This study evaluated the effect of temperature on morphometric features of the egg during the embryonic development of the prawn Macrobrachium americanum and the relationship with hatching and the survival of the larvae. Berried females were grouped (n=3) and reared at three different temperatures, 26, 29, and 33 degrees C, for which seven developmental stages were recognized. At each stage, the apical and sagittal diameters of the eggs were measured, the volume was calculated, and the weights were recorded. Additionally, the duration of embryonic development, hatching percentage, and larval survival were determined. At 29 and 33 degrees C, the eggs' volume increased by 50%, but at 26 degrees C, the increase was 25%. Larvae from eggs incubated at 33 degrees C died one day after hatching. At 29 degrees C, larvae survived until Zoea VII. Larvae from eggs incubated at 26 degrees C died at the end of Zoea I. The number of days of embryonic development was 20.5 +/- 1.5 (26 degrees C), 15 +/- 1 (29 degrees C), and 12 +/- 1 (33 degrees C). A temperature of 29 degrees C was the most favorable for embryonic development in M. americanum.