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Biodiversity and Biooptics 2020 Expedition – Log 3

Biodiversity and Biooptics 2020 Expedition – Log 3

Today was an exciting day because we thought we were going to be weathered out at first (GALE WATCH, NO!). Luck was on our side in the ‘hole of hope’ and the wind and waves enabled us to collect five species of ctenophores that we are currently studying. This is an important site for our population genetics work because we have collections of animals from the Monterey Bay, Hawaii, and the Gulf of California, but animals from Southern and Central California will help to fill in where we have sampling gaps. These data will allow us to understand how ctenophores move throughout the world ocean.

First, we launched the ROV and almost right away, we found not one but three Deiopea comb jellies! This was amazing because Deiopea are rare, and we have been studying them from Hawaii and Monterey Bay, so it was good to have samples from Southern California. While the ROV was still underwater, we set off for a blue-water SCUBA dive, which was incredible. We were just off Catalina Island, and the water was clean, clear, and bright blue. We felt like we could see for miles. This was a dramatic change from diving in the very productive Monterey Bay, where the water is often thick with algal blooms. As soon as we began our dive, we saw hundreds of ctenophores! It was like swimming in a beautiful, sparkly soup. We saw many Eurhamphaea vexilligera, Pleurobrachia bachei, Cestum, Leucothea, and several species of Beroe. We were busy well into the night, photographing and dissecting our precious samples. Days like today remind me how lucky we are to work on such interesting, amazing creatures.

From Manabu Bessho:

I am a postdoc working with Steve Haddock. My scientific interests are bioluminescence and evolution. Bioluminescence is one of the most remarkable phenomena that occurs in the ocean. More than three-quarters of animals in the water column and more than a quarter on the deep seafloor can produce light by themselves. The special low-light camera deployed on the ROV is highly sensitive and enables us to observe bioluminescence in an animal’s natural conditions. I am looking forward to discovering new species that have bioluminescent capabilities.

On this expedition, I am mainly focusing on bioluminescent deep-sea corals. Corals (Class Anthozoa) are a diverse group of animals. Luminous groups are scattered across the anthozoan tree of life. This raises the question, “Has bioluminescence evolved multiple times independently or once (or a few), then lost many times?” To discover the answer, I study the biochemistry of corals. For example, if bioluminescence evolved independently, the chemical mechanisms will be different from each other; if it evolved once, the mechanism will be shared among descendants. During the cruise, I have been testing corals brought up from the bottom of the ocean to see if they glow in the darkroom. Then I extract a variety of enzymes and organic compounds and analyze them.

That’s a wrap! Other highlights from the cruise: