Theoretical considerations in determining allometric growth within instars of crustaceans, with special reference to Americamysis bahia.

Allometry in crustaceans is typically considered growth over several instars primarily because crustaceans are presumed to grow only during ecdysis (discontinuous growth). Using theoretical distributions of the sizes of two morphometric variables over several instars, four theoretical instar allometry models are postulated: continuous allometry (indiscrete and discrete); discontinuous allometry (indiscrete and discrete); mixed allometry (simple or complex); and two-rate continuous allometry. The estimates of proportions of allometry within the instars are determined using Y = f(X) and X = f(Y) for variables X and Y.