Sunday, December 9, 2012

Mollusc Week: I've saved the best for last.

Hoo boy, it's been a weird week. Molluscs are strange creatures in general, and picking out exceptionally strange or obscure ones makes them look even weirder. Cephalopods are slowly taking over the world. So, what could possibly top flying squid?

Tell me if this doesn't sound like crack to you: Antarctic oysters that can change sex.

Belongs to the Smithsonian. Yep, that's an oyster, all right.

Lissarca miliaris is far from an impressive oyster.  It's small, unassuming, and lives in a place that most sane people would dare not venture to. If it involves Antarctica and not penguins, people just plain won't go; this says nothing about one's willingness to dive beneath the ice for shellfish. Again, not penguins. Only marine biologists acknowledge this thing's existence.

These weird little oysters follow the same reproductive strategy that tunicates and some fish have: they start out as fertile males, then mature into egg-bearing females. They may also go back to being males when brooding their young. At first, researchers were only looking at breeding females; then they found males with the mollusc equivalent of "junk" as well as eggs. Yep, these little molluscs are genuine, natural, breeding hermaphrodites.

Of course, there is a natural advantage to changing sex. Antarctica is a harsh environment.  The more viable mating partners there are, the better; mating at a young age is also a good idea in such an environ. These oysters have all the reason in the world to be natural transexuals. Why should we think of them as freaks for it?

So yeah. There's your awesome week of molluscs! They solve mazes, stick really hard to rocks, fly, and now change sex! A few of them also taste terrible, but most of them can be seen at your local sushi bar. In case of mollusc world takeover,  prepare the tempura batter and chopsticks.