OK, I know I am an Ocean Geek, but this video shows some California Blue Mussel behavior that really made my day. Yesterday I collected several blue mussels from the jetty in Carlsbad for my aquarium (with a fishing license the daily limit is 10 lb - NEVER collect in a protected area, and I would not advise eating mussels except in a reputable restaurant or from a certified seafood purveyor!). Mussels anchor themselves using their foot to string several threads (called byssus) to rocks. I had never seen this, so set up a slo mo video on my iphone. It happens very quickly, once they are pulled free and placed on a new surface. Mussels do not use their foot to move around, only to attach threads to surfaces. In the video it does not look like a foot, but a thin brown appendage. (from Wikipedia: The byssus, which is made of keratin, quinone-tanned proteins (polyphenolic proteins), and other proteins, is spewed into this chamber in liquid form, and bubbles into a sticky foam. By curling its foot into a tube and pumping the foam, the mussel produces sticky threads about the size of a human hair.)You can see a few threads already attached. At the end of the video the mussel does a surprising thing - it flips itself using its foot so that its opening is hanging out in the water stream, and then the foot is retracted. I watched other mussels do the exact same thing, so it is not a fluke. It makes perfect sense for a mussel to extend its opening to the current, as it is a critter that filters its food from the water passing by. Looking a photos of mussel beds you can see that they are all oriented in the same direction. The other thing to note in mussel beds is that often they are tucked in tightly with goose necked barnacles (the white, vaguely beaky-looking critters in the title picture). This also makes sense for the barnacles, as their "necks" are soft and fleshy. Cohabiting with mussels is the perfect protection for them. Goosenecks do not last long in my aquarium unless they are collected in a tight bunch with mussels - my striped shore crabs just love to make a meal of them if they can!
Commentaires