Dive 14: “Keli” Ridge – Southeast Guyot Ridge and Midwater Transects
July 28, 2017
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Dive 14: Totally New and Unexpected

This snailfish, in the family Liparidae, is likely a new species, meaning folks tuning in for the live video were the first people to see this fish alive. Seen at a depth of 2,555 meters (~8,380 feet) while exploring a guyot ridge. Video courtesy of the NOAA Office of Ocean Exploration and Research, 2017 Laulima O Ka Moana.. Download larger version (mp4, 31.0 MB).

When Deep Discoverer reached 2,555 meters (~8,380 feet), the bottom was rocky and composed of a solid, cemented surface. As the remotely operated vehicle climbed the slope, it became increasingly steep with large blocks, boulders, and craters. Sponges were the dominant fauna. The glass sponges observed included Bolosoma, Caulophacus, smaller vase sponges, and an unusual glass sponge no one had seen before. Octocorals were observed frequently and included chrysogorgiids, primnoids, isidids, and several precious corals. Black corals, a cup coral, zoanthids, hydroids, a dandelion siphonophore, and sea anemones were also present. Multiple colonies of a frond-like bryozoan were tentatively identified. Several species of sea stars were observed, including a brown morph of Hymenaster, a large Lophaster, and a new species of goniasterid. Other echinoderms were a small white urchin tentatively identified as being an “irregular urchin,” a purple crinoid, a brisingid, several feather stars, and brittle stars observed as commensals on corals and sponges. Numerous dead barnacles were present in unusual wave-shaped forms on the rock edges. Shrimps and squat lobsters were seen. One unusual fish was a likely new species of snailfish. Other fishes included several grenadiers and cusk eels. On the latter half of the dive a huge abundance of narrow, needle-like carnivorous sponges covered numerous rocky surfaces in dense but evenly spaced aggregations; abundance varied, with dense aggregations near areas of high current flow and less abundant populations away from these areas. Near the end of the benthic portion of the dive, we observed these sponges as part of a widespread community with bryozoans and zoanthids.

The midwater transects began at 800 meters (2,625 feet). The dominant fauna observed was siphonophores. Larvaceans were also common. Other animals included comb jellies, jellyfish, polychaete worms, shrimps, radiolarian colonies, and other protists. Arrow worms were frequently observed. Several fish, including juvenile eels and bristle mouths, were surveyed.