I also made it to Mitsuwa on Sunday to witness the disassembly of the same magnificent fish Mike Sula has written about. My almost indecent enthusiasm for bluefin sashimi is, like his, colored somewhat by my understanding of the species's dire circumstances, so I've done a little research to attempt to reassure myself that I wasn't party to a bioethical atrocity.
First, this was a Mediterranean-caught tuna. It is legal to fish for bluefin in the Mediterranean, provided that strict quotas are observed. Second, the fish was six or seven years old, which means that it was well past sexual maturity--Mediterranean fish develop much faster than Northern or Pacific bluefin, and almost always begin spawning by four years of age (PDF). This may seem like a trivial point, but the quickest way to crash the population of a slow-growing apex predator like the bluefin is to catch and kill the fish before they can reproduce.
That said, I've only eaten bluefin two or three times in five years, and until wild stocks rebound I think that's probably all I'll be comfortable with.
And now, on to the photos! These two show the carvers removing half the fish's belly meat, from which chutoro and otoro come. Half the back meat, or akami, is already gone.
Here's a good view of the fish's bone structure. You can also see some of the strikingly yellow caudal finlets.
I think this one speaks for itself . . .
And finally, the chutoro and akami I bought at the end of the demo. The first cut is the chutoro, and it was so tender and buttery I could've cut it with the edge of my pinky finger.
I realize my sushi is somewhat wonky. I made too much rice but still wanted to use it all . . .
On a side note, does anybody know where I can find Kikusui junmai ginjo? It comes highly recommended by my colleague Irma Nuñez, who knows a thing or two about getting loaded the Japanese way, but Mitsuwa was fresh out of the stuff.