1. Southwest Fisheries Center Honolulu Laboratory, National Marine Fisheries Service, Honolulu, Hawaii 96812, and Department of Zoology, University of Hawaii, Honolulu 96822
2. Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena 91125
3. Southwest Fisheries Center La Jolla Laboratory, National Marine Fisheries Service, La Jolla, California 92038