MASS-SPECTROMETRIC DETERMINATION OF METHYL FARNESOATE PROFILES AND CORRELATION WITH OVARIAN DEVELOPMENT IN THE EDIBLE CRAB, CANCER-PAGURUS

Evidence indicates that methyl farnesoate (MF), produced by the mandib ular organs (MOs), is the crustacean equivalent of the juvenile hormon es of insects. Gas chromatography-mass spectrometry with selected ion monitoring (GC-MS-SIM) was used to measure the titers of MF in the MOs of the crab, Cancer pagurus. Comparison of the amounts of MF detected in groups of left and right MOs from crabs at different stages of ova rian development showed no statistically significant variation. The am ounts of MF detected in MOs were in the range of 230 ng/MO in crabs wi th immature ovaries to 400 ng/MO in crabs with fully developed ovaries . Application of GC-MS-SIM to the measurement of MF in hemolymph was u nsuccessful, leading to the development of a high-performance Liquid c hromatography-MS-SIM (HPLC-MS-SIM) method for analysis of such titers. MF concentrations in hemolymph varied throughout ovarian development, exhibiting a peak at the beginning of secondary vitellogenesis (140 n g/ml), falling to basal levels thereafter.