We attached sonic transmitters to a total of 40 octopuses over field efforts in 7 years between 1996 and
2009, yielding a total tracking duration of 566 octopus-days. The smallest instrumented octopus was a 300 g male, and no animal in this study exceed the transmitter to body mass ratio for this animal of 0.7%. Most animals were juveniles15 kg, except two males and two females. In 1996, we mounted the transmitters on a harness attached by cable tie bands to the upper third left arm above the web. Arm-mounted harnesses detached 0–51 days post-release. In 1998 and 2003, transmitters were implanted under the skin of the upper third arm above the web and the wound closed with cyanoacrylic glue. Implanted transmitters detached b1 day or >34 days postrelease.