This siphonophore, physonect siphonophore Stephanomia sp., can reach 10 meters in length.
From the guardian.co.uk
This close up view shows several of the red, glowing lures and tentilla on the newly discovered siphonophore.
From the sciencedaily.com
The groove, termed a siphonophore, is ciliated, and helps to circulate water through the gastrovascular cavity.
From the en.wikipedia.org
After discovering lures on this new species of siphonophore, Haddock and his coauthors looked at several related species and noticed similar glowing structures.