Interview with Associate Professor Kaori Wakabayashi
 
It all started with an inquiry from a diver. The photograph showed a strange image they had never seen before—a lobster larva riding on a jellyfish. Since then, she and her team have attempted to clarify the life history of lobsters and to establish aquaculture techniques for them.
 
Attempt to establish aquaculture techniques for spiny and slipper lobsters, one of the most valuable fishery resources in the world
 
  Dr. Wakabayashi currently focuses on research for the realization of aquaculture of spiny and slipper lobsters. She says: “In particular, aquaculture techniques for those lobsters, which are known as one of the most expensive seafoods, have in fact not been fully established, and the current production of them 100 percent relies on natural resources. I aim to advance the techniques as much as possible so that we can produce what we consume.” For this purpose, she conducts basic research.

Commercial aquaculture for black tiger shrimp and white leg shrimp, which we commonly see at supermarkets, was established in the 1990s. Since then, Japan imports these shrimps farmed in Southeast Asian countries, such as Thailand, Vietnam, and Indonesia. In contrast, the aquaculture of spiny and slipper lobsters is our challenge for the future.
 
According to Dr. Wakabayashi, the attempted aquaculture of these lobsters is a challenge with a long history, more than a century in fact, for which our forerunners invested enormous effort. Despite that, no practical development has been achieved. For this reason, research on this subject is now regarded as a reckless and difficult endeavor, and few researchers are currently involved in it.

“Baby lobster is called “juvenile,” and the preceding stage is called “larva.” And rearing at the larval stage is very difficult. Therefore, we are now trying to clarify many factors required to rear larvae, such as appropriate feed and water environment, so that we can improve techniques and produce as many juveniles as efficiently as possible,” Dr. Wakabayashi says.

The goal of this research is to raise their techniques up to the level of practical implementation. The subject of her research is mainly fan lobsters, a relative of spiny lobsters.

“Fan lobster larvae are comparatively easy to rear. Therefore, if we can establish an aquaculture technique for fan lobsters as a role model in the first place, we may be able to apply it to spiny lobsters and other slipper lobsters, which larvae are said to be very difficult to rear. That is why we adopted fan lobsters as the research subject,” Dr. Wakabayashi says.
 
 
Attracted by “jellyfish riders,” fan lobster larvae showing surprising behavior
 
  This research started with an inquiry from an underwater photographer. “The photographs sent by the photographer showed the figures of a slipper lobster larva, called “phyllosoma,” riding on a jellyfish. It is often called “jellyfish rider” by divers. My boss at that time was interested in this behavior and started a research project to explore its ecological meaning. I was involved in this project as a post-doc researcher, and that was the beginning of my involvement in this subject,” Dr. Wakabayashi says.

Even after the project finished, Dr. Wakabayashi continued the research and made various findings.
 
“Fan lobster larvae riding on a jellyfish under the sea were first observed in 1963. At that time, the reason for this strange behavior was unknown. Assuming that fan lobster larvae may be eating jellyfish, we put them both in an aquarium to confirm it. Then, the larvae ravenously ate the jellyfish,” She says.
Succeeding in observing this eating behavior for the first time, Dr. Wakabayashi’s team began researches for the realization of aquaculture with the thought of making use of this finding. To confirm what kind of jellyfish are preferred by fan lobster larvae, the team tried experiments with various kinds of jellyfish. As a result, it was found that they eat “any kind of jellyfish.” The team also experimentally confirmed that fan lobster larvae can be reared by feeding them only jellyfish throughout the larval period, from hatching from eggs until settlement as juveniles that have finished metamorphosis.
 
 
  Although it has not been verified whether fan lobster larvae can develop healthily by obtaining sufficient nourishment from any kind of jellyfish, her research team conducts research toward the utilization of jellyfish, which often impede fishermen by forming huge clusters, as feed for lobsters.

“The state of “jellyfish riders” represents a symbiotic relationship between lobsters and jellyfish, and we are also interested in this point. As a major characteristic of this research, basic research on marine biology could develop into aquaculture scientific research and technical development,” Dr. Wakabayashi says.
“I think that theoretical interpretation of natural phenomena leads to technical development. In other words, if we can clarify the true reason and mechanism of fan lobsters’ exploitation of jellyfish, we should be naturally able to develop aquaculture techniques,” Dr. Wakabayashi says with a strong conviction.
 
Actively involved in collaborative research and the creation of a pictorial field guide. “Do not hesitate to try interesting things!”
 

  Since Dr. Wakabayashi’s unique research has attracted much interest, several collaborative research projects are ongoing both within and outside Japan. One of them is conducted as a part of the project of Tokyo University of Marine Science and Technology that became the first step of her research in collaboration with the Vietnamese Government. In a collaborative research project in Taiwan, the successful production of lobster juveniles for the first time in Taiwan received a lot of media coverage.

In addition, Dr. Wakabayashi created a pictorial field guide together with the said underwater photographer and published “Utsukusii Umino Fuyuu Seibutsu Zukan” (Field Guide to Marine Plankton) as the world’s first field guide book featuring only photographs of living planktonic organisms.

Dr. Wakabayashi says about the fun part of her research as follows: “We can often learn things associated with our own lives from the lives of organisms, and sometimes apply them to our own lives. This kind of research is unique to agriculture and fishery sciences and one of fun parts of our research. Pure academic research on organisms is of course fun, however, we can also conduct research from other perspectives, such as technical establishment and practical implementation.”

With the hope that young people experience the fun of her research, she gives the following advice: “If you are interested in something even a little, do not hesitate to try it.”

“Students of the School of Applied Biological Science are assigned to each laboratory before the second semester of the third grade. However, if you are interested in our laboratory even a little, you do not need to wait until then. Please feel free to visit our laboratory and see what we are doing. We do not care if you are first grade or second grade students, or even high-school students or elementary school students. If you see our laboratory in person, you may become more interested, or conversely, it may be different from what you imagined. In fact, there are some students who came to be interested in jellyfish by seeing them at our laboratory. One of the best parts of being an academic is that we have a fair chance to succeed regardless of our age or gender as long as we have passion and make efforts,” Dr. Wakabayashi says.

She finally added: “Visitors with intense curiosity are welcome anytime!”
 
Kaori Wakabayashi
Associate Professor, Laboratory of Aquaculture

October 1, 2009~March 31, 2013 Post-doc, Faculty of Marine Science, Tokyo University of Marine Science and Technology
April 1, 2013~June 30, 2015 JSPS Postdoctoral Fellow, Graduate School of Marine Science and Technology, Tokyo University of Marine Science and Technology
July 1, 2014~December 31, 2015 Visiting Researcher, Department of Environment and Agriculture, Curtin University
July 1, 2015~March 31, 2019 Assistant Professor, Graduate School of Biosphere Science, Hiroshima University
April 1, 2019~ Associate Professor, Graduate School of Integrated Sciences for Life, Hiroshima University

Posted on Mar 11, 2020