Behind the Scenes at the National Museum of Nature and Science: Essayist Tamaki Miyata in Conversation with Crab Taxonomist Hironori Komatsu (Part 2/2)
Essayist, inveterate marine invertebrate enthusiast, and lover of the weird and wonderful Tamaki Miyata visited the Tsukuba office of Dr. Hironori Komatsu to learn more about the scientist’s work at the National Museum of Nature and Science’s Division of Marine Invertebrates. In part one, we heard how the leading specialist in the taxonomy of crabs was captivated by crustaceans’ “mechanical” appeal. In part two, Dr. Komatsu divulges more of the fascinating gleanings and insights gained through his research at the National Museum of Nature and Science.
What’s in a name? Ask a taxonomist.
Dr. Hironori Komatsu is a specialist in the taxonomical classification of crabs.
This
being a seemingly obscure topic, you might wonder what his day entails. It turns
out that Dr. Komatsu has personally assigned scientific names to approximately
30 species of crabs.
To a
layman like myself, the discovery of dozens of new species sounds monumentally
impressive. However, Dr. Komatsu nonchalantly explains that there are many more
known species that have yet to be named.
“In particular, it’s the small crustaceans who are still nameless.”
Speaking
of miniature crabs, the National Museum of Nature and Science has an excellent
collection. Of the approximately 7,000 species of crabs that have been
discovered across the globe, Dr. Komatsu reports that the majority measure less
than a centimeter across their diminutive shells.
Shockingly
small.
“In reality, only a very limited number of crabs are suitable for human consumption. There are many other crabs out in the wild, the smallest of which measure a mere two millimeters across the carapace.”
It
turns out all the crabs I’ve eaten over the years were, in fact, giants. When I
think about crabs in that light, they begin to feel a little grotesque, as if
the pièces de résistance gracing our dining tables have been sea monsters all
along.
By the
same token, it’s remarkable that scientists are able to locate those
microscopic, two-millimeter crabs in the first place.
“It’s not as difficult as you might expect. We use dredge nets to trawl an area and then sift our catch through a sieve. After that, it’s simply a matter of carefully picking out the remaining crabs.”
Having
selected his specimens, Dr. Komatsu takes a DNA sample to identify the specific
species, and then reports his findings in academic papers.
“I
recently traveled to North Iwo Jima, an island south of Ogasawara in the Bonin
Island archipelago. It took a full 11 hours to reach the uninhabited island by fishing
boat from Chichijima.”
The arduous 11-hour voyage is a modern-day reminder of the age of exploration on the high seas.
Even
thinking about the prospect makes me queasy. What beckoned Dr. Komatsu to brave
sea sickness and visit the island?
“On
this particular trip, I went looking for specimens from the genus Xenograpsus.
I suspected that Taiwan’s Xenograpsus testudinatus and Ogasawara’s Xenograpsus
novaeinsularis were, in reality, the same species. After examining the mitochondrial
DNA, I confirmed that they were indeed one and the same.”
In
such instances, the earlier name takes precedence. Dr. Komatsu’s discovery
ensured that the crabs will now be referred to exclusively as Xenograpsus
novaeinsularis.
“All in another day’s work for a taxonomist.”
Dr. Komatsu points out the hair which grows on the claws of Xenograpsus.
An example of Xenograpsus novaeinsularis, found after an 11-hour journey from Chichijima (the largest of the Bonin Islands) on a fishing boat.
Two crabs named by Dr. Komatsu: Merocryptoides ohtsukai
This is also Nursia alata.Both were previously undiscovered species whose carapaces measure less than three millimeters.
The crab library
Dr.
Komatsu escorted me to the research facility’s archive, a massive storeroom
housed in a separate building from the researchers’ offices. We climbed into an
elevator easily large enough to fit an automobile. The scene was straight out
of a sci-fi film.
Row after row of shelving filled the clinically sterile space, the towering mobile stacks soaring toward the cavernously high ceiling overhead. Dr. Komatsu pressed a button, and the shelves began to creep slowly apart, revealing a narrow passageway.
Stepping
in between the shelves, we found ourselves surrounded on both sides by
biological specimens, suspended in ethanol solutions in innumerable glass jars.
As my eyes excitedly flitted from shelf to shelf, I noticed all the specimens were
crabs. It was a true paradise for an invertebrate enthusiast, and I couldn’t
wait to admire each sample at length. However, when Dr. Komatsu explained that
the archive contains over 26,000 jars for crustacean specimens alone, I realized
it would take many more visits to even see half of their holdings. Moreover, some
of the jars contained multiple samples, bringing the total collection to over
100,000 specimens. That’s a lot of crustaceans.
When I asked how many crabs are in the collection, Dr. Komatsu confessed that even the researchers aren’t sure about the precise extent of their holdings. Although approximately 1,200 species of crab can be found on Japan’s shores, the museum hasn’t necessarily collected samples of them all. Even so, their archive is unmistakably vast, and serves as an indispensable resource when creating exhibitions for the National Museum of Nature and Science.
Dr. Komatsu, a new father, finds that his love for crabs is now rivaled by that for his three-year-old. Science runs in the family, as his wife is a starfish researcher. Dr. Komatsu shares one of his favorite specimens from the genus Calappa. Commonly referred to as a “box crab,” when its claws are folded underneath its carapace, the crab strikes a bulky, round profile.The full National Museum of Nature and Science collection contains approximately 4.2 million zoological and botanical specimens.
One
particular exhibit lingered in memory after my visit to the National Museum of
Nature and Science in Ueno. Located in the Japan Gallery, the exhibit featured
a display case, filled with a dizzying plethora of mini crabs.
Whereas visitors flock en masse to the museum’s grand, showstopping exhibitions, such smaller displays tend to go underappreciated by all but the most attuned eye. However, each of the tiny crabs tells a larger story about the researchers who devote their lives to study of even the smallest sea life. In this sense, each exhibition is the fruition of the combined efforts of a great many researchers, and the culmination of many years of hard work in the field.
“I
contributed a bit to the Japan Gallery exhibit. If another opportunity arises,
I would like to try and better convey the native habitat of each crab. For
example, Trapezia cymodoce live in coral, and always as a male and
female mating pair. When specimens are simply displayed on a shelf, this
backstory isn’t apparent. I hope to find a way to paint a bigger picture with
the next exhibit.”
Dr. Komatsu continues:
“Some
crabs, such as Xenograpsus, maintain a symbiotic relationship with
bacteria that feed on hydrogen sulfide. I’d like to illustrate these ecological
tidbits. Of course, bacterial specimens are too small to be seen with the naked
eye, so it will take a bit of creative finessing to depict. It would be easy to
just project a video and call it a day. But that’s not enough to satisfy me.
Personally, I feel that the whole point of going to a museum is to see the real
deal, the actual specimen.”
In the meantime, I’ll keep my fingers crossed in eager anticipation, and hope that one of Dr. Komatsu’s future exhibitions will shine a light on crabs’ mesmerizingly mechanical morphology.
An exhibition in the Japan Gallery at the National Museum of Nature and Science. For his next exhibition, Dr. Komatsu hopes to depict the creatures in their natural habitat.
Text: Tamaki Miyata Photos: Fumitaka Miyoshi
Hironori Komatsu Senior Curator with the National Museum of Nature and Science’s Department of Zoology, Division of Marine Invertebrates. His specialty is the taxonomic classification of Decapod Brachyurans (crabs). From 2004 to 2006, Komatsu served as a researcher at the Hokkaido Nuclear Energy Environmental Research Center’s Section of Fisheries Research. In 2006, he joined the National Museum of Nature and Science’s Department of Zoology, where he continued his research from 2007 to 2014 within the department’s Division of Marine Invertebrates. In 2014, Komatsu was appointed to his current post as Senior Curator.
Tamaki Miyata Author, essayist. A prolific traveler, Miyata is known for a wide body of work that runs the gamut from travelogues to book reviews. Major publications include: Watashi no tabi ni nani wo suru, Hareta hi ni wa kyodaibutu wo mi ni, Jettokosuta ni mo hodo ga aru, Fushigi bonsai Hòn Non Bộ, Yojigen onsen nikki, Ii kanji no ishikoro wo hiroi ni, and Musekitsui suizokukan. An indefatigable chronicler of offbeat curiosities, Miyata’s eclectic reportage has probed the myriad mysteries of marine life, giant Buddhas, mazes, Vietnamese bonsai, and polished pebbles. Currently, his imagination has been captured by the guardian dog statues found at Shinto shrines. From 2017 to 2019, Miyata served as a book reviewer for the Asahi Shimbun. Recent publications include Nihon no rosenzu (co-author) slated for release in March 2020, and Nippon datsuryoku kamisama zukan, forthcoming in April 2020.
National Museum of Nature and Science
Address: 7-20 Ueno Park, Taito-ku, Tokyo Hours: 9:00 a.m. – 5:00 p.m. (open until 8:00 p.m. on Fridays and Saturdays) *Hours subject to change Closed: Mondays (if Monday is a national holiday, the Museum is open Monday and closed the following Tuesday) *The museum is closed over the New Year holiday (December 28th to January 1st) *Other irregular closures may apply Museum website: https://www.kahaku.go.jp
Note: Information in this article current as of February 2020.
