Traveling to the Ocean Floor: Professor Studies Deep-Sea Mollusks

From the September 2016 Desktop News While the unique environment of the deep ocean would likely prove nightmarish and panic-inducing for many people, it’s just another day of fieldwork for Department of Biological Sciences’ assistant professor Dr. Kevin Kocot.

This July, Kocot submerged to oceanic depths for the ninth time, joining 21 other marine scientists from universities across the nation who were selected to participate in this year’s Chief Scientist Training Cruise put on by the University-National Oceanographic Laboratory System. In the end, he discovered a new marine species.

The purpose of the expedition was to train early-career research scientists in the use of research submersibles. In doing so, they collected biological and geological samples from the Atlantic Ocean’s bottom.

Kocot is an assistant professor of biology at The University of Alabama and curator of invertebrate zoology at UA’s Alabama Museum of Natural History.

Kocot is an assistant professor of biology at The University of Alabama and curator of invertebrate zoology at UA’s Alabama Museum of Natural History.

Cindy Van Dover, principal investigator of the training cruise, said Kocot was selected for the project because of his expertise in biological oceanography and evolutionary biology.

“Like other participants, he was identified as an individual who would contribute to and benefit from a leadership experience in the field and whose research approach depends upon field research,” she said.

The nearly two-week cruise aboard the research vessel Atlantis departed from the Woods Hole Oceanographic Institution in Woods Hole, Massachusetts, after a two-day training session at the institution.

Once the team reached its destination, scientists, grouped by their interests into teams of three, descended into the ocean aboard the famous deep-sea research vessel Alvin, which can drop to a maximum depth of 14,764 feet.

Research Vessel Atlantis and the human-occupied vehicle Alvin are shown. Divers meet the sub when it surfaces to attach it to a hoist rope and bring it back on board (Image Woods Hole Oceanographic Institution).

Research Vessel Atlantis and the human-occupied vehicle Alvin are shown. Divers meet the sub when it surfaces to attach it to a hoist rope and bring it back on board (Image Woods Hole Oceanographic Institution).

Scientists used the autonomous robotic submersible named Sentry to map the bottom of the ocean, a part of the Earth about which less is known than the surface of Mars. During the expedition, Kocot collected invertebrates including corals, octopods, and a poorly known group of deep-sea worm-shaped mollusks called aplacophorans.

“Because they’re mostly found in the deep sea, they’ve been understudied,” he said of Aplacophora. “Everywhere I go, I find new species.

Kocot is particularly interested in biomineralization, which is the process an organism goes through to create a skeleton or a shell. He said that aplacophora don’t have a shell like other mollusks, but they are covered in tiny spines.

“I want to compare these mollusks that have spines to ones that have shells, like snails and pearl oysters,” Kocot said. “We think the evolution of the genes involved in biomineralization evolve rapidly. With respect to biomineralization, Aplacophora seem to be a more primitive group.”

 

Aplacophora are worm-like mollusks characterized by their lack of shells and tiny units called calcareous spicules.

Aplacophora are worm-like mollusks characterized by their lack of shells and tiny units called calcareous spicules.

Once samples were collected using the submersibles’ manipulator arms and nets, the team hauled their catch back to the ship and conducted morphological work, putting the animals under microscopes and performing DNA sequencing.

“My goals were to try to document the diversity of the animals that I work on in this region and improve understanding of their evolutionary history and the evolution of the process of biomineralization in general,” Kocot said. “Aside from being really exciting and producing some specimens for my research (including at least one new species), this experience was very instructive on the capabilities of this technology and for planning and executing a research cruise in general.”