Isn't that stunning? It looks like the dust can't figure out which galaxy it would prefer to be a part of, so it's winding back and forth.
By the way, I can't refind it now, but it was posted once before, but in a slightly less clear image in which the right-pointing limb of the inverted Y wasn't evident, which is why I wasn't sure if what I was seeing was really there or not.
Further by the way, this is the second time I've found an image in which a dust lane was following a markedly different trajectory from the luminous components of its galaxy.
I made a thread for it here http://www.galaxyzooforum.org/index.php?topic=280412.0
, asking how the dust lane could be straight while the galaxy is warped. So if you moderators are concerned about server load, feel free to merge these threads. Anyway, how does that dust lane deflection happen?