Have you ever wondered what makes this fish so incredibly buttery, delicious, and forgiving to overcooking? Here is an excerpt from the article.
The toothfish, however, possesses one specific quality that has made it the nontraditional fish of choice. Most fish we eat are equipped with an airtight organ called a swim bladder. By filling its swim bladder with air, a fish saves energy, letting the rising effect of gasses do the work of swimming up. The ancestors of the toothfish, however, were benthic fishes - dedicated deep-water bottom feeders that never moved more than a few feet above the sea floor. As such, they lost the need for a swim bladder long ago, and it was soon crowded out by other organs in the fish's gut.The article explains the history of how Patagonian toothfish became the poster child for endangered fish. The picture it paints is rather gloomy: whether we eat wild of farm raised fish, we'll eventually eradicate all ocean wild life. The part that I find ironic is that according to USDA, we are no where near the 3 servings of fish per week that they recommend, yet most fish are considered overfished. So, what's the poor consumer to do? If you persevere through all seven pages and get to the last sentence, you do get a glimpse of hope. Yes, chances are that the future of seafood lies in farming, but we'll find ways to do it better and more environmentally friendly.
But eventually the direct predecessors of the Patagonian toothfish found it advantageous to rise off the bottom and hunt for prey in shallower water. Without a swim bladder to work from, the ur-toothfish needed to develop an alternate buoyancy device. Over time, glands developed under the fish's skin that secreted fats directly into its muscle tissue. Fats, being lighter than water, performed the same function as a swim bladder, lightening the animal and allowing it to rise from depths of 6,000 feet to as shallow as 200 feet with little effort.
This trait made the toothfish a very effective predator for millions of years. But when the modern human seafood diner evolved a taste for fish, the fat-as-flotation scheme made the toothfish into very desirable prey. Because when you secrete fat directly into your body, you are in effect giving yourself a deep-tissue marinade for your whole life.
I wonder how different things would be if food was more local and fish didn't travel half way around the world from the sea to the plate. It used to be that the seas and oceans only fed the people who lived on the coast. But now they have to feed whole continents.