Fluctuations in Ca, Mg and P levels in the hemolymph, muscle, midgut gland and exoskeleton during the moult cycle of the Indian white prawn, Penaeus indicus (Decapoda: Penaeidae)

Abstract

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, midgut gland and muscle showed a high content of Ca during late premoult stages and low content in late postmoult and intermoult stages. In exoskeletal tissue the Ca level was high in intermoult and early premoult stages and the lowest level was recorded in the early postmoult stage. Magnesium showed an almost similar trend to that of Ca. Phosphorus content did not show noticeable changes in haemolymph and muscle during moult cycle; in exoskeleton, higher levels were recorded in last premoult and early postmoult stages. 3. The quantitative distribution of Ca, Mg and P in different parts of the exoskeleton was mapped.