Small Water Column Fish -- Revisited, Apogonid sel.  – 06/15/07
Hey thanks once again Mich.
<Welcome!>
I have access to some Apogon cyanosoma (yellow-lined or gold striped cardinals). Some folks seem to be ok keeping them long term in a small group, others experience aggression as they mature. Any thoughts on these?
<I have never kept this species of fish, so I'm not able to draw on personal experience here, but the literature describes these as one of the "bolder" members of the family and recommends keeping a group of 5-7 individuals, all introduced at the same time. You may want to consider dimming your lighting when they are introduced. There is more info here,
http://www.wetwebmedia.com/cardinal.htm
but nothing as far the behavior of this species versus others in the genus. It can be difficult to predict behavior as it can vary greatly between the individual. Other fish in the system can also impact behavior. I would avoid overcrowding and provide plenty of hiding places. Good luck! Mich>
Randall Douglas

Hardiness of Pajama Cardinals vs. Banggai Cardinals   2/13/07
Hi again crew,
I have been having the same problems with Banggai Cardinalfish that I have read about on your site-- they cease to eat, start breathing rapidly, and then die.
<Does happen... and all too often... and this should not be the case... That is, Apogonids such as these can be, should be raised in captivity... regionally... and be well-ready to withstand the rigors of moving, captivity...>
All of this happens very quickly. I'm not sure, but I think I remember them having stringy, white feces as well.
Recently, I lost eight! I bought these eight in groups of three, three, and two, so they did not all come from the same shipment.  I quarantined them in a 30 gallon bare tank, first all together, and then separated the next batch into three 10-gallon compartments. I tried FW dips before quarantining, and when that batch died, I skipped the FW dip. None of this made any difference.  I have kept many more difficult fish successfully, but I just can't keep the Banggais alive (yes, the water parameters are all where they should be).
<Mmm... I want to say a few things (thanks for this prompting)... the vast majority of Pterapogon ARE cultured (somewhat), but still imported (from Indonesia mainly)... and they ARE way too often BUNK! Your experiences are not atypical...>
The only answer I can comes up with is the mysterious parasite  I have read about which supposedly infects Banggai Cardinals. I was told the fish I purchased were tank-raised, but who knows if this is true-- and maybe tank-raised Banggais carry this parasite as well.
So here is my question: are Pajama Cardinals susceptible to the same parasite?
<... not as far as I'm aware, but have not seen definitive proof of such a parasitic involvement in the high incidental mortality of this species>
I have not seen much written on your site about the Pajamas since they have been so overshadowed by the popularity of the Banggais.
<Are old-timey favorites... the two principal species...>
Have you been receiving emails with Pajama Cardinals suffering from the same symptoms and dropping dead?
<Not as far as I recall, no>
Also, I read that while a group of Pajama Cardinals will establish a pecking order, they do not display conspecific aggression ( aggression to other  Pajama Cardinals, if I used the term incorrectly) to nearly the same degree as Banggai Cardinals, making it easier to keep them in a group. Is this true in your experience, or reports from your readers?
<Mmm, yes... though Sphaeramia can indeed be territorial... though not as often to as the degree as Banggais>
As always, thanks for taking the time to read this and for offering your advice.
Art
<Thank you for asking. Bob Fenner>