Sterbai Cory Missing Pectoral Fin

[nehpets81]

Right, so after a bit of a break from the forum I am back with a bit of a problem.
I have just completed a stupidly arduous fishless cycle - it has taken me about 140 days! I got completely sick of looking at the empty tank. Anyhow, today I purchased my first fish - 6 x Guppies and 6 x Sterbai Cories.
When I got them home, the Guppies seemeed to settle very quickly but the Cories were a bit shy. I noticed that two of the Corys are missing a pectoral fin each (the orange ones on the side, I think they are pectorals) I tested the water and found my Nitrate was rather high - it looked to be somewhere between 40-80ppm but I find it really hard to tell. After doing a water chande this has come down to about 40ppm (my tap water is about 40ppm) and the Corys are now much more active, swimmng around a lot and sifting through the sand, even the ones with missing fins - although their movement is hampered a little.
Basically I'm wondering about the missing fins - could these be phyical damage receieved at the lfs; chemical stress from the high Nitrate or something more sinister like a fungal or bacterial infection. Do I need to treat the water with an anti fungal? Some more details of my setup are below:



Tank size: 125L
pH: 7.4-7.6
ammonia:0ppm
nitrite:0ppm
nitrate:Now about 40ppm, was higher.
kH: 9-10
gH: Sky high london tap water - well over 200
tank temp:26
My tank has a play sand substrate with rocks and bog wood. It is planted with Amazon Swords, Valis, Horn Wort, Money wort and has a Fluval U3 filer.

Let me know if you need any more info.

 

[primagen]

are the edges of the fins clear or whitish? whitish would indicate fin rot, which is bacterial. clear could mean that the fin is growing back. i'd use melafix to help encourage fin regrowth and see if it helps.

 

[nehpets81]

are the edges of the fins clear or whitish? whitish would indicate fin rot, which is bacterial. clear could mean that the fin is growing back. i'd use melafix to help encourage fin regrowth and see if it helps.

The fins seem to be completely removed, with no stump. I don't think I noticed any white areas but they are quite skittish tend not to allow me much time to observe them when I approach the tank. I will get hold of some Melafix to see if that helps, thanks for the help.

 

[fluttermoth]

It could be a congenital abnormality; missing fins (and gill covers) is one of the more common results of inbreeding IME.

 

[nehpets81]

Ah, Ok. I will see if I can keep notice whether any more seem to be missing fins. I wish I had looked a bit more closely when they were in the tank at the lfs now. Would there be any issue if I added Melafix in case, or should I hold off?

 

[Athena]

They could also have lost their fins at the LFS, if they were kept in tanks with gravel substrate.

But if that's the case, then those fins do grow back eventually - just ensure that you keep their water in pristine condition and all should be well. Glad to hear you have a sand substrate as that'll be gentler on their fins and bellies.

Regards, Athena

 

[nehpets81]

They could also have lost their fins at the LFS, if they were kept in tanks with gravel substrate.

But if that's the case, then those fins do grow back eventually - just ensure that you keep their water in pristine condition and all should be well. Glad to hear you have a sand substrate as that'll be gentler on their fins and bellies.

Regards, Athena

Yeah, I wondered about this too - I remember that the lfs had sand substrate, but the 6 that we purchased were among the last of their batch - I think they only had a couple left after we bought ours so perhaps they had been there a while. Their barbels were all intact so I don't think the lfs substrate was the problem but they were in with other fish, however, so perhaps they got into a few scraps in there?

They all seemed very active this morning and the water tests showed zero Ammonia and Nitrite. Nitrate was bright red on the API tests which seems to my eyes to correspond to several different levels but as my tap Nitrates are so high I have a very hard time keeping these down in the tank.

I will definitely pick up some Melafix this eve and hope that no others have lost fins... Thanks again for the help guys!

 

[nehpets81]

Well, I have a bit of an update here. I have used a round of Melafix which, apart from seemingly sending the little guys loopy for a couple of hours doesn't seem to have done much. In fact, poor Jim, which is what we have named the Cory that arrived without a pectoral has lost pretty much all his pectoral fins, and the other small fins on his underside (the ones the Cories seem to "stand" on). Another Cory now has a pectoral fin that seems to be disintegrating. Looking at the rest, some of the fins that were once bright orange are turning black and I fear it is only a matter of time before they start disappearing too. It is not affecteing their tails or dorsal fins, or any of the larger fins (yet), just the small orange ones so they can still swim ok.

I have not seen Jim eating yet either - he does not seem to have lost any weight and is still very active so I assume he's getting food from somewhere.

I have recently been syphoning my sand with an airpipe once every two or three days (great advice that from someone on this forum) to get rid of all the Guppy poo as I was concerned this might be harming them. Although the Ammonia and Nitrite has been constantly zero I am having more of a problem controlling NitrAte. My tapwater is about 30-40 ppm which is making it very hard to get the levels in the tank under 30ppm - I have a big mass of Hornwort which is getting bigger by the hour and several other plants but this doesn't seem to help much.

Sorry this is a bit of an essay but I really want the little Sterbai's to get better, I'd be gutted if I lost any so soon. Could the high nitrate be harming their fins? Could this be fin rot? Or some other infection?

 

[Louiseness]

The way their fins are slowly deteriorating does sound like fin rot. Melafix is basically a tea tree oil treatment which is a good preventative but won't do much for established finrot, as far as I'm aware. Personally I'd do a finrot treatment and just keep up the water changes. Good luck!

 

[fluttermoth]

I think that's good advice from Louiseness.

Nitrate is only dangerous at much higher levels than yours; I've seen 300ppm quoted in some places, although obviously lower is better.