The species encountered most often during Windows to the Deep 2021 Dive 06 was a flat hexactinellid (glass) sponge with a breakable branching cluster of flat, thin lobes. The sponge was identified as possibly being Tretopleura sp., but scientists collected a sample so that they can take a closer look at the sponge’s spicules and make a more definitive identification. This boulder, seen at a depth of 3,625 meters (2.25 miles), was home to many of these kinds of sponges.