Significance of the variation in haemolymph copper-free- and -bound proteins during ageing and time of day in the crab Scylla serrata (Forskal).

During growth or ageing the total quantity of copper-free proteins in haemolymph of S. serrata increases at a higher rate than copper-bound proteins. The copper-free proteins are specifically degraded to meet the energy demand imposed by outburst of nocturnal activity during night hours, while the copper-bound proteins remain unaffected, signifying the importance of Cu-bound proteins in the normal physiology of the animal.