ABSTRACT
Growth in crustaceans is problematic. Because crustaceans possess a rigid exoskeleton, increases in body size can occur only at the time that the exoskeleton is shed. Growth, therefore, in crustaceans is episodic. The "growth curve" of a typical crustacean resembles a staircase more than the smooth ~haped growth curve of most organisms. Each riser of the staircase represents a molting event - the moment at which the old exoskeleton is shed and the new and larger (albeit soft) exoskeleton is exposed. This new pliable exoskeleton is unfolded by hydrostatic expansion due to internal hemolymph pressure, then hardened in its new dimensions. The size of the new postmolt exoskeleton can represent as little as a 2.4% increase in the fiddler crab, Uca pugilator (Hopkins 1982), to as much as a 77% increase over the premolt size in the crab, Carcinus maenas (Crother 1%7). The mean increase in size in decapod crustaceans is about 25-26% (Hartnoll 1982). The overall larger size of the new exoskeleton is the result of a number of growth events that occur prior to the actual molt itself.
