Y ORGAN CELLS ACTIVITY BASED ON THE COCENTRATION OF ECDYSTEROID FROM HAEMOLYMPH OF MANGROVE CRAB (Scylla olivacea Herbs, 1979)

Y organ or ventral gland is an endocrine gland that synthesizes the crab molting hormone (Moulting Stimulating Hormone) or ecdysteroid. Y organ activity produced molting hormone that was associated with molting stages. Molting in the crab consists of four stages, namely intermolting, premolting, ecdysis and postmolting stages. The concentration of circulating ecdysteroid in the haemolymph usually low during intermolting, increased significantly during premolting and decreases dramatically before ecdysis. This study aims to determine the Y organ cell activity based on the concentration of ecdysteroid. Parameters measured were ecdysteroid concentration and histology of Y organ during the five phases of the moon: the dark moon phase, new crescent, the first half, the first convex and a full moon. Analysis of ecdysteroid samples performed using Ultra-Fast Liquid Chromatography (UFLC). The results showed that the pattern of ecdysteroid concentration indicated a low ecdysteroid concentration in the dark phase of the moon, began to rise in the new crescent moon, reaching the peak in the first half, decreased dramatically in the first phases of the moon convex and lower back at the full moon phase. The pattern of ecdysteroid concentration by a reference to the determination of mangrove crab molting stages. Y organs activity synthesize highest ecdysteroid in the first half of the moon phase coincides with the phase premolting middle (Mid premolt), otherwise low ecdysteroid synthesis activity in the dark phase of the moon coincides with intermolting stage and phase of the full moon coincides with postmolting stage.