Perhaps this thread should be in the freshwater disease forum, but I put it here for two reasons- For one, the little guy I'm posting about isn't sick, per se. (You'll what I mean when you keep reading.) And for two, and frankly, the disease forum isn't much help, not enough activity over there.
So I'm gonna give a lot of detail, because maybe I'm missing something with these guys. So sorry its long, but maybe I'm missing something in the details. I hope someone has some suggestions!
So the story is that I got 4 Corydoras Oiapoquensis on February 4th at a local swap meet. (They look similar to Corydoras panda.) The room was pretty cold, and most everyone that bought fish there (of most any species) found their fish to be slow to rebound even when properly acclimated. I acclimated mine slowly, and they did okay.
They all have been very skittish from day one. They've actually made the other corys in there, 5 Corydoras trilineatus, much more skittish than previsouly, too. The only other fish in the 55g were 7 Bloodfin Tetra. There's also 1 Ghost Shrimp, MTS, Ramshorns, and (recently added) 2 Olive Nerite Snail.
All corys are about half grown, and the Bloodfins were almost grown. So, pretty lightly stocked.
They tank is still growing in, so plants are a bit sparse. But they have two good-size caves made by arches in driftwood that they've made good use of. There's plenty of cave space for everyone, with one cave on each side of the 55g. There's also some light leaf litter that forms a few hiding spots.
The tank has always been healthy, no sign of disease ever. All other fish are not only healthy, but vigorous and thriving.
The pH stays at 7.4, the water is moderately hard. The temp stays at 75-77F. Tank parameters are within ranges for oiapoquensis listed on various sites.
Ammonia and Nitrites are always 0ppm, and Nitrates stay at or below 10ppm.
I do 50% water changes every 1 to 2 weeks with siphoning off the top of the sand. (I know, I know! BAD Mina! Do my water changes EVERY week regardless, I know! My life has been especially turbulent lately, and I rationalize it because the tank is so lightly stocked and my parameters stay great. But, I know, shame on me.
So 3 of the oiapoquensis look pretty good. They're colored well, and are eating well, there's certainly no sign of disease. They're not as active as the 5 trilineatus, but they get out and about sometimes. Like I said, they're skittish, and various sites confirm they're very shy.
The 4th oiapoquensis is also eating well, and certainly shows no signs of disease. But he rarely goes out of his cave, and his body color (the salmon colored part) is paler than the rest of his friends. The black on his eyes, dorsal fin, and tail stripes are normally colored.
Last weekend I sold all the Bloodfin Tetra, and had to totally break down the tank to get them out. This was stressful to all of the fish, but my 1 oiapoquensis lost nearly all of his color, even the black was just a light grey! Poor guy! I did a 75% water change at that time. His color was back to his usual (i.e. body color still pale) by the next day. Appetite was unaffected.
There is no aggression in this tank, all very peaceful.
Their staple is a sinking Omega One pellet. Occasionally they get a sinking Omega One shrimp pellet. They've had live black worms a handful of times, and I just got some more tonight. I'm going to add in some frozen daphnia tomorrow.
So what am I missing? What can I do to get the pale oiapoquensis thriving like the rest of the fish?
Thanks in advance! And even if you can't help, thanks for reading!