Evolution des acides nucleiques au cours du developpement larvaire de la crevette rose Palaemon serratus (Pennant).
The evolution of nucleic acids in larvae of P. serratus reared in the laboratory from hatching to metamorphosis has been studied. From the 1st larval stage to the post-larval stage, DNA and RNA concn decrease: from 185 to 95 uMoles-bases/g PSD for DNA and from 133.5 to 78.75 uMoles-bases for RNA. The concn decrease is not regular; it is emphasized between stages 4 and 5 on the one hand, and between stage 7 and the post-larva on the other hand. The amount of DNA and RNA per larva increases proportionally to the wet weight from stage 1 to the post-larva. As the weight is multiplied by 7.6, total DNA and total RNA are multiplied by 3.80 and 4.25 respectively. The RNA/DNA ratio has a mean value of 0.77; it increases slightly from stage 1 (0.72) to the post-larva. (0.88). Growth is mostly dependent on cellular and from stage 5 to stage 7. During the transitory periods (from st.4 to st.5 and from st.7 to PL) increase of cellularsize (hypertrophy) intervenes as much as 100% in the weight increase observed. The biochemical variations noticed through the complete larval development of P. serratus seem to agree with some distinct morphological phases.