Krill and the unity of biology

This supplement features some of the printed papers from the Second Interna tional Symposium on Krill (Santa Cruz, Calif., August 1999). Krill have lon g been recognized as key prey species for fish, birds, and marine mammals a nd as a target for fisheries in both hemispheres. However. the study of kri ll can contribute in many other areas of biology. Krill are an excellent mo del system for studies of growth and maturity, for connections between theo ry, experiment, and observation, and for tests of evolutionary theory in th e field. Krill are also ideal model organisms for studying the interaction between environmental and organismal variability. Because they are widely d istributed but only moderately speciose, the study of krill can also shed l ight on the relationship between abundance and range. The study of krill is an inherently interdisciplinary field, crossing boundaries and using a com bination of oceanography, biochemistry, physiology, evolution, and ecology to understand krill and their role in the ecosystem.