Petricola Loss

[660Dave]

Hi, just after some advice, at the weekend i noticed one of my wild Petricola had a light grey patch (circle) on its side/back and it was staying towards the top of the tank. After a few hours i moved him into a hospital tank but he didn't last the night. At first i thought it was down to aggression from the other Syno's but now i'm worried it could be something more sinister and the rest of my fish could be affected. All other Petricola look fine at the moment, eating well and showing no symptoms.
I'm worried it could be columnaris after looking at the symptoms for someone else, do you think it could be? i don't want to try and treat if it's not necessary.
What precautionary measures could i take without using meds? Daily water changes help? any advice appreciated.

[Richard B]

If all the other fish seem to be behaving normally, i would do small daily water changes (for maybe a week - on top of your regular regime), maybe increase the oxygenation & monitor the tank closely. Has there been any new addition? has anything unusual happened thats not a regular occurrance?

Do you have a pic of the mark on the dead fish? It sounds like a typical wound, from Syno fighting

[660Dave]

Thanks Richard, it's a mark i've seen before some time back on one of my original two fish, and he seemed fine and it healed nicely. This guy was a little smaller than the others and certainly seemed to be at the bottom of the pecking order. No new fish have been added recently.
There was an incident however, the day before i noticed this the power to the tank had been accidentally turned off by a family member for maybe 4-5 hours. The temp had dropped to 21c and obviously both the filters were off. Not ideal but i don't think this could lead to an outbreak of disease due to high stress levels? But i could be wrong, i think i'm being a little paranoid maybe...
Cheers for the help.

[660Dave]

All other fish doing fine, must have been due to aggression. Cheers for the help Richard.

[Richard B]

4-5 hours shouldn't be too much of a problem. With specie groups that show a hierarcy & some aggression, like Petricola, i personally believe 5 is the minimum number. Sometimes this number cant be achieved due to costs or specie availability - like my Robertsi for example - i have 2 as thats all i could find (not purchased together) but they show no aggression at all towards each other. A few people have small groups of decorus with virtually no aggression.

Species like schoutedeni, brichardi, petricola, are not reknowned as agressive synos (like angelicus, schall, granulosus) but are capable of dishing it out to others of their kind.

[660Dave]

Yeah i have 10 (was 11!) the one that was lost certainly seemed to be at the bottom of the pecking order. Still trying everything i can think of to get them spawning, had some success with Lucipinnis but no dice with the Petricola yet. Not sure what to try next.

[Richard B]

but no dice with the Petricola yet. Not sure what to try next.

exactly how big are they (SL)?

It may be, as these are long lived, they take a long while to reach maturity? The ones that NHA have for breeding range from large to massive for petricola. estimate 110-150mm SL (which is actually larger than cat-e-log states [although i cannot provide evidence]). There are also a couple of really big ones hiding in the display tank at Wildwoods but you have to look hard to find them in all the rockwork (providing that tank is still running?) MatsP was with me a few years back & might remember seeing them.

NHA use the 3 tank method for breeding them - one tank of males, one tank of females, both conditioned over a period of time, then the likliest pair introduced to each other for the spawning - they didnt reveal what triggers they use, if any, but they use the same method for Granulosus so were a bit scarce on fine details when i talked to Gavin, their head breeder.

In the home, the 3 tank method isn't always possible, so it may be trial & error i'm afraid

[660Dave]

They are a fair size, all between 4 and 5 inches with the biggest of the group being a female who is maybe just over 5 inches. There have been positive signs, in the future i guess i could make space to try the three tank method, or maybe just try removing the best pair from the group into their own tank?
I've raised the PH, tried waterchanges of varying % and temps, increasing and decreasing water movement, not sure what else to try.