[TECHNOLOGY] Squid and Jellyfish Activities Read By New Tag

In order to learn more about invertebrates like squid and jellyfish, researchers at Stanford University, University of Michigan (UM) and Woods Hole Oceanographic Institution (WHOI) recently developed a new type of tag for logging data. It takes readings of ocean conditions and records in high-resolution animals' responses to their environment.

That is, the team published the results of their earliest uses of tag attachments-used with squid and jellyfish in the lab--and the behavior measurements that were recorded, in the journal Animal Biotelemetry.

While tags that record digitally and acoustically have been used for more than a decade with large marine mammals, their size usually doesn't work on small invertebrates. Conversely, small smaller tags have been used for larger squid and jellyfish, those have the limitation of only tracking swimming depth and some other measurements, according to a release.

"We wanted a tag that would be able to tell us what the animal is doing at that depth--is it hovering or swimming faster or slower? When squid go down to a couple hundred meters, are they foraging at night at that depth, or are they resting and getting away from top predators? What are their respiration rates? These are the types of behavior questions we wanted to answer," Mooney said in the release.

The team had to figure out how to make the tag a workable size plus include sensors, batteries with duration, and the ability to float, noted Kakani Katija, a bioengineer who worked through WHOI and Stanford, in the release.
The tags were able to record behaviors including remaining still or sinking, swimming directly, turning while swimming (jellyfish); and jetting, finning, and reversing direction (squid).

After this the team will test behaviors of jellyfish and squid in the field, the release noted.