polymorphism
From ZooTerms (Dictionary of Invertebrate Zoology)
polymorphism (noun; Greek polys, many; morphe, form): 1. The simultaneous occurrence of two or more distinctive and discontinuous genetic types existing in a population.
2. (Arthropoda: Insecta) In social insects, the coexistence of two or more phases or castes, belonging to the same sex, within an individual colony. a. In Formicidae, the occurrence of nonisometric growth of size variation in a normal mature colony, thus producing individuals of distinctly varying proportions.
3. (Bryozoa) Repeated, discontinuous variation in zooid morphology in a colony.
