Behind the Scenes at the National Museum of Nature and Science: Essayist Tamaki Miyata in Conversation with Crab Taxonomist Hironori Ko-matsu(Part 1/2)
Established in 1877, the National Museum of Nature and Science has long served Ueno as home to an exhaustive collection of all things pertaining to the natural sciences. In addition to hosting public exhibitions, the museum is also an active research institute and a premier repository for research materials, including an ever-growing collection of scientific specimens. Our correspondent recently travelled to the museum’s research facilities in Tsukuba, Ibaraki Prefecture, to speak with scientists and learn more about the cutting-edge research that occupies their days. In this installment, we meet Dr. Hironori Komatsu, a researcher studying marine invertebrates, with a specialization in the taxonomy of crabs. Our intrepid interlocutor for the day is Tamaki Miyata, author of Musekitsui Suizokukan (“The Invertebrate Aquarium”), and an acclaimed essayist known for his uncommon love of the many strange and peculiarly fascinating wonders of the world. Read on to discover everything you never knew you wanted to know about the secret life of crabs, in part one of a two-part special feature on the National Museum of Nature and Science.
The Coral Reef Inn
The halls
of the National Museum of Nature and Science are lined with endless displays of
biological specimens and fossils. However, these exhibits are not simply
assembled without rhyme or reason, a compulsive collection assembled ad hoc. Rather,
each display case tells a story, and is a tangible testament to the
crystallized fruits of an individual researcher’s labors, preserved for
posterity.
One such
particularly unique exhibit can be found in the Japan Gallery, showcasing the
diverse array of marine life that inhabits hermatypic (reef-forming) coral,
including the numerous species of small crabs that depend on coral for
sustenance and shelter.
The exhibit is a surprising demonstration of just how many of the remarkably miniature crabs manage to cram into a single piece of coral reef. Clearly, this captivating exhibit was the product of meticulous scholarship. Curious to hear more, I sought out one of its creators, a researcher studying crabs at the National Museum of Nature and Science’s Research Department in Tsukuba.
An exhibit housed in the Japan Gallery at the National Museum of Nature and Science in Ueno. Filling an entire display case, the numerous specimens illustrate the diversity of life found in a coral reef, and underscore the surprising variety of small crabs that reside in coral.
Why crabs?
Arriving in
Tsukuba, I was ushered into an office overflowing with books and papers.
Peeking through the pages, I noticed a vast collection of glass bottles,
occupying every last nook and cranny left on the bookshelves. Upon closer
inspection, I realized all the bottles contained crab specimens, suspended in
stasis.
The room was a fitting reflection of its occupant, Hironori Komatsu. A 46-year-old researcher with the Division of Marine Invertebrates at the National Museum of Nature and Science’s Department of Zoology, Dr. Komatsu is a leading specialist in the taxonomical classification of crabs.
Mild-mannered and unfailingly gracious, Dr. Komatsu welcomed this layman into his office with a smile.
Although I can’t claim to have any specialized scientific training to speak of, I have long entertained a dilettante’s interest in crabs. This enthusiasm extends to marine life in general. To be more precise, I have a particular weakness for invertebrates, those spineless creatures whose malleable bodies assume all sorts of strange and marvelous forms. I’m fascinated by the striking contrast of invertebrate lifeforms to the familiar existence of humans and our mammalian brethren. I can hardly fathom how it must feel to go through life shuffling sideways on eight spindly legs. It’s a thrilling thought.
After the
requisite opening small talk, I cut to the chase and asked Dr. Komatsu what
compelled him to choose crabs, of all subjects. Like me, was his curiosity
piqued by their oddly idiosyncratic appearance?
As Dr.
Komatsu bashfully reminisced, “As a child, I used to catch my fair share of
crayfish. Come to think of it, I suppose that may be as good an impetus as
any.”
In other words, his love of nature was engrained from a young age.
But it
takes much more than boyish interest to become a scholar. Although Dr. Komatsu
had an early hunch that we wanted to pursue a future in biology, he initially
doubted the field’s career prospects, and instead studied chemistry at
university.
However, first loves die hard. Upon entering graduate school, he changed course, and majored in molecular biology. Before he knew it, his dream had come true, and he had become a crab researcher.
“Would you say your interests are specifically in marine and aquatic life?” “I love crayfish and insects, all arthropodsin general. They’re pretty cool.” “Arthropods? Cool?”
Dr.
Komatsu chuckled, anticipating my surprise.
“Yes, their bodies are, how can I say, rather mechanical.”
An interesting choice of adjective. “Mechanical” would seem an antonym at odds with the biological world. However, I understand what he means. Come to think of it, crabs and beetles are ensconced in hard shells. In that sense, they do bear a resemblance to machines.
Crab taxonomy specialist Dr. Hironori Komatsu, proof that boyhood dreams can come true.
“Crabs and insects are both arthropods. The centipede is a good example. Its body is structured around a series of segments, each of which connects to a pair of leg. The crab is an extension of this principle, a few transformations out. It’s hard to discern at first glance, but if you look closely at the sides of its body, you’ll see how the legs branch out from each segment. What’s truly fascinating is how each of these metameres is slightly different, and specifically articulated to fulfill a particular function.”
By articulation,
I presume Dr. Komatsu is referring to how the crab’s two anterior legs work
together as powerful pincers, while their remaining four sets of posterior legs
are generally used for locomotion. In some crab species, the fourth sets of
legs have adapted specifically for swimming. Other species have legs protruding
up out of their backs, useful when carrying items on their carapace.
“That’s not all. Crabs have antennae, which, it turns out, actually evolved from legs. Their mouthparts feature six appendages that are angled inward, and used to ferry prey, facilitating feeding. Crab abdomens also bear the vestiges of evolution. Females have four modified appendages that serve to protect a brood of eggs, while a pair of modified legs form the phallic organ in males.”
In other
words, crab penises evolved from legs.
“Evolution
takes place gradually, over the ages. Incidentally, the shrimp’s long antennae
similarly evolved from legs.”
At this point, it seems safe to assume that most crustacean features were once legs.
As shrimp
and crabs are related, fellow members of the phylum Arthropoda, it came
as a surprise to learn that Dr. Komatsu’s attitude toward shrimp is merely
lukewarm. Evidently, their thin shells leave something to be desired. As for
hermit crabs, Dr. Komatsu is decidedly not a fan, citing the soft abdomens
tucked up inside their shells. In a crustacean, he’s looking for solidity, that
element of adamantine strength.
Naturally, it was only a matter of time before he would fall in love with crabs, certainly among the most rigid, mechanical-looking, armor-clad creatures in the sea.
“Crab
legs are spectacularly diversified, but so also are the teeth lining their
claws. Some are sharp, while others resemble blunt molars. These teeth allow
crabs to crack open the shells of prey. They also have fine, comb-like teeth
which are used to snatch ragworms and other long, thin sources of nourishment.”
Listening to Dr. Komatsu, I begin to envision crabs as living Swiss Army knives, equipped with an array of attachments that are ready to spring out at just the right moment. The word “mechanical” suddenly seemed all the more apt, and offered a clue as to why these mysterious creatures continue to captivate Dr. Komatsu even after all these years of study.
A menagerie of preserved crab specimens (and even a few origami models) were interspersed among the books and papers in Dr. Komatsu’s office.Although not a PhD, the author still holds his own when it comes to a love of crabs. However, Dr. Komatsu did take note of the biologically infelicitous lapel pin: “Your crab’s missing a few legs.”
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.
