FLUCTUATIONS IN CA, MG AND P LEVELS IN THE HEMOLYMPH, MUSCLE, MIDGUT GLAND AND EXOSKELETON DURING THE MOLT CYCLE OF THE INDIAN WHITE PRAWN,PENAEUS-INDICUS (DECAPODA, PENAEIDAE)

1. Fluctuations of Ca, Mg and P in the hemolymph, midgut gland, muscle and exoskeleton of the penaeid prawn Penaeus indicus during different stages of the moulting cycle have been investigated. 2. Haemolymph, m idgut gland and muscle showed a high content of Ca during late premoul t stages and low content in late postmoult and intermoult stages. In e xoskeletal tissue the Ca level was high in intermoult and early premou lt stages and the lowest level was recorded in the early postmoult sta ge. Magnesium showed an almost similar trend to that of Ca. Phosphorus content did not show noticeable changes in haemolymph and muscle duri ng moult cycle; in exoskeleton, higher levels were recorded in last pr emoult and early postmoult stages. 3. The quantitative distribution of Ca, Mg and P in different parts of the exoskeleton was mapped.