[1] Univ Calif San Diego, Scripps Inst Oceanog, La Jolla, CA 92093 USA
[2] Charles Darwin Fdn, Charles Darwin Res Stn, Galapagos, Ecuador
[3] Humboldt State Univ, Dept Fisheries Biol, Arcata, CA 95521 USA
[4] Univ Bremen, ZMT, Leibniz Ctr Trop Marine Res, Bremen, Germany