Electrophysiological measurements and related cytological controls were done on immature and submature oocytes of Homarus gammarus . By chromatography (HPLC) and radio-immunoassays (RIA) it was established that submature oocytes displayed different ecdysteroids. Furthermore, the structure of the stalk (funiculus) for the laid eggs attachment was analyzed. it consisted of the two superimposed vitelline envelopes which were likely modified by the cortical reaction exudate during the fertilization process. In addition, the successive secretory phases, regarding to the embryonic envelopes were evidenced. Finally, the ecdysteroid titers of embryonic stages were measured. |