So…another day goes by and I’ve noticed the following – not only has the Lightning Maroon’s right pectoral fin become damaged, but so has his right ventral/pelvic fin.  It looks to be about the same age as the other damage judging by the condition.  Neither appear to be fresh, and nothing seems to have spread.  Seeing damage on multiple fins really had me thinking “fin rot” until I noticed something else…
The female Bristletail Filefish, Acriecthys tomentosus, has a few chunks missing from her tail.  I think I’m starting to piece things together…I *think* that the male Filefish may be getting a bit nippy with his tankmates.  Certainly, it is conceivable that the fins damaged on the Lighting Maroon were “accessible” to an inquisitive Filefish, which can easily get it’s nose inside the cage through the larger openings in the eggcrate.  These fins would easily be exposed if the Lightning Maroon was resting in the back corner as it sometimes does.
Still, taking no chances, a second dose of Maracyn SW went into the tank tonight.  I will be keeping an eye on the filefish to see if I catch them in the act at all.  I’m back on the fence of how I intend to proceed mate wise, and looking forward to a time when the Lightning doesn’t have to be sequestered in a protective cage (which seems to have failed at its job anyway)!