by Poncie Rutsch

Dory and Marlin are trapped inside of a whale in the midst of their search for Marlin’s son Nemo. Marlin wants desperately to escape and slams himself into the whale’s baleen. And the whale does spew them out — after a brief Marlin vs Dory struggle…and some excellent footage of the whale’s oral anatomy, complete with a uvula.

If you don’t know what a uvula is, that last sentence probably looked a bit questionable. A uvula is the chandelier of your mouth. It’s a little bit of flesh that hangs down from the roof of your mouth at the opening where your mouth becomes your throat. Say AH and you’ll see it.

[for quality whale uvula footage, fast forward to about 2:00]

But here’s the thing: whales don’t have uvulas. Only a few animals do. And scientists are still trying to figure out whether humans need uvulas in the first place.

In 1992, researchers searched the mouth cavities in a number of animals to see if there was even a trace of something that could have evolved into a uvula – almost like our tailbone shows we may have once had tails. They looked in dogs and horses and cows and apes and sheep. And this is what they found:

“Of all animals in the study, a small underdeveloped uvula was found only in two baboons. We found that the human uvula consists of an intermix of serous and seromucous glandular masses, muscular tissue, and large excretory canals…. Thus, the uvula is a highly sophisticated structure, capable of producing a large quantity of fluid saliva that can be excreted in a short time.”

The researchers also suggested that the uvula lubricates our vocal cords, and could be necessary to make some sounds that are critical for human language. Another camp of researchers disagrees though. They think that it’s just some vestigial trace of our ancestors (again, like your tailbone), without any essential purpose.

Their camp gets a little support from a type of surgery called uvulopalatopharyngoplasty (try saying that five times fast). The surgery doesn’t necessarily remove the entire uvula, but it removes parts of the soft flesh inside the mouth to reduce snoring and sleep apnea. Even those uvula-less patients appear to be communicating just fine.

Look around. Each of the Muppets has a felted uvula so that when they lean back to belt out songs you see a human-like mouth.  I bet you’ll see uvulas everywhere now…or at least in every animated movie.

So why bother stuffing uvulas into animals? It’s not like the uvula is an essential part of the human body, let alone one that seems quintessentially human. It would be easy to overlook, except it’s always there. It would seem like the animators just don’t know any better, but when was the first time you even noticed you HAD a uvula?

And on that note, it’s time for some obligatory Muppet uvulas.

By Poncie Rutsch
BU News Service

For years, scientists have noticed that fish swimming the deep seas contain more mercury than their shallow swimming friends. Now, a recent study from the University of Michigan and the University of Hawaii shows why that discrepancy exists.

The researchers collected nine different fish species and measured the mercury accumulated in the fish tissue. The fish they collected ranged from a lanternfish, which swims as deep as five thousand feet below the surface, to flying fish, which leap out of the water and glide through the air.

The researchers used isotope analysis to determine what kinds of chemical reactions the mercury had undergone. They found that sunlight may help mercury to degrade and published their findings in Nature Geoscience at the end of August.

Fish eat mercury every day when they consume sea plants containing mercury-consuming bacteria. In a pristine environment, their mercury levels remain constant. But because of human activity, fish mercury levels have increased in the past hundred years.

Scientists worried about mercury in fish for decades and have been studying its origins. Mercury in the atmosphere exists in a vaporous, inorganic state that does not cause significant damage to humans. It settles on the sea’s surface, and collects on sea plants. Here tiny microbes digest the mercury and convert it to methylmercury, or organic mercury, which impairs human brain development. The microbes can convert mercury as deep as two thousand feet below the surface. Fish eat the sea plants with methylmercury accruing microbes, and the mercury accumulates in their tissue.

Because the mercury from each source undergoes different chemical reactions, each has a different chemical fingerprint. This makes it fairly easy for scientists to trace mercury in the atmosphere back to its source. The researchers started with the mercury in fish tissue and determined each reaction that had happened to it on its way to the fish.

Although mercury can cause significant damage to developing human brains, lead author Joel Blum said that the increasing mercury doesn’t seem to harm the fish themselves. “Yet,” he said, “if mercury levels double, will there even be fish?”

Previous research linked the mercury in Pacific fish to coal-fired power plants in Asia. According to co-author Brian Popp, mercury levels in Pacific fish are on the rise as Asian manufacturing continues to increase.

“But in the Atlantic,” Popp said, “we see the opposite, probably because of new regulations in North America and Europe.”

The research connects the mercury cycle to the fish we eat. Popp and Blum agree that because even tiny amounts of mercury can cause so much damage, understanding the cycle is vital for choosing which fish to eat and which to avoid.

By Matthew Hardcastle
BU News Service

Meet Cymotha exigua, an adorable crustacean of the Cymothoidae family. C. exigua sometimes goes by the common name “tongue-eating louse,” which is a completely unfair mischaracterization: it’s not a louse at all. The tongue-eating part is accurate though.

Cymothoidae contains a number of fish parasites, but none are as charismatic as our C. exigua. This plucky crustacean lives off the western coast of Mexico and Central America. Though its lifecycle is a bit of a mystery, males can be found attached to the gills of at least eight species of fish. When necessary, one of the males will become female, growing larger and making its way to the fish’s tongue, where the real fun begins.

Rather than selfishly sapping the resources of her host and offering nothing in return, C. exigua decides to do her fishy friend a favor by giving it a brand new tongue. Using specially adapted claws, C. exigua draws blood from the boring, regular tongue of her host, until the organ withers away. Then the crustacean makes itself at home by attaching to the muscles on the stub of the amputated tongue.

C. exigua happily begins her new life as a fish tongue, doing all the regular duties of her host’s old organ. All she asks for in return is the occasional sip of blood or nibble of mucus. The fish doesn’t seem to miss its old tongue at all.

You may find yourself wishing for a happy crustacean like C. exigua to come and live in your mouth, but alas they have no effect on humans, apart from a possible love bite if you handle a live one. Snapper with crustaceans for tongues occasionally wind up in fish markets, but C. exigua is not toxic to humans even if you accidentally cook her up.

Truly, C. exigua is one of evolution’s most whimsical and enchanting creations.

New England fishermen are facing huge cuts in their catch allotments this year, cuts that might put them out of business. Deedee Sun takes us to the port city of Gloucester to see how fishermen and conservation groups are preparing.