shipworm damage; photo CC flickr user alaskaent
Wood makes for a pretty tough meal. To start with, cellulose -- wood’s primary constituent -- is indigestible by most organisms. If that weren’t bad enough, the cellulose itself is packed in a dense matrix of other intransigent biopolymers like hemicellulose, pectin, and lignin, making it structurally difficult even to get enzymes in and working. And to top it all off, wood contains very little nitrogen -- about an order of magnitude less than most organisms need to grow, relative to carbon.
With such a difficult hurdle to overcome, it’s pretty strange that one of the world’s champion wood-eating animals lives in an environment where no wood grows (the ocean) and belongs to a class that has never even evolved teeth (the bivalves). Thus the somewhat unfortunately named shipworms (family Teredinidae) are something of an enigma.
