VITELLOGENESIS IN THE GIANT TIGER PRAWN, PENAEUS-MONODON FABRICIUS, 1789

Vitellogenesis can be induced in the ovaries of the penaeid shrimp, Penaeus monodon, by eyestalk ablation; 80% of shrimp spawned within 7 days after ablation. Using immunofluorescence, it was observed that-vitellin commences to accumulate in the yolk globular stage oocytes. The vitellin of atretic oocytes is reabsorbed and transferred to the newly matured oocytes. Four vitellin-like peptides are synthesized in vitro by the ovaries with mol. wt 220, 168, 130 and 74 kDa, respectively. Amongst them, the 168 and 74 kDa peptides are secreted into the culture medium. The results of immunostaining showed that the anti-Ep antisera is able to react with the ovary extracts of Penaeus japonicus. Each antiserum may react to the compatible peptide of the P. monodon vitellin peptide.