Crustacean endocrinology: a retrospective, prospective, and introspective analysis.

From the first discovery of a hormone in a crustacean in the 1920s until the present, the field of crustacean endocrinology has undergone, as do many crustaceans during their development, a marked metamorphosis. The field has moved from the classical era of endocrinological techniques, such as extirpation and additive methods, to the modern era of sophisticated biochemistry and molecular biology. As new investigatory techniques have been devised, crustacean endocrinologists have quickly adopted them and, as a consequence, have made major advances. Nevertheless, there is still much room (and need) for the older techniques, particularly because there is still a vast gap in our knowledge of the endocrine mechanisms of the less highly evolved crustaceans. The bulk of the information we have about crustacean endocrinology has been derived from studies of decapods. Crustacean endocrinology not only provides information about the basic biology of this important group of organisms but also has the potential of greatly enhancing our ability to culture species used as food sources for humans.