Diamond Tetra with stunted nose

[Bgn wood]

I have a 37 gallon aquarium with a school of 7 Diamond Tetras, looking to add maybe 5 more. Other fish include 5 Cardinal Tetras and 2 Clown Plecos. I have 2 Diamond Tetras with their mouth stuck open and their nose is stunted (see image). All are peaceful and get along really well. I can't seem to find much online about this. Should I be worried?

Essential water parameters:
Ammonia: 0 ppm
Nitrite: 0 ppm
Nitrate: <20 ppm

Thank you in advance for any help.

 

[Colin_T]

If the fish is eating and it had the funny nose when you got it, then it is a genetic defect and nothing to worry about.

However, it does appear to have a slightly opaque colour in the muscle tissue that could be something. Can you post some pictures of the other fish for comparison?

 

[Bgn wood]

Thank you so much for the reply.

I found one of them dead yesterday evening. The other is not eating and secluds himself from the school. Today, it looks more red and worse than before.

 

[Colin_T]

The fish has an infection in the lower jaw. I would euthanise it or you can try treating it. You can try salt or a broad spectrum medication but I haven't seen many if any fish recover from that sort of thing.

 

[Bgn wood]

Dang. Thanks for the information.

 

[Slaphppy7]

Injuries are common with diamond tetras, they are boisterous and aggressive, especially at feeding time

 

[Bgn wood]

Injuries are common with diamond tetras, they are boisterous and aggressive, especially at feeding time

I've watched them dart at food like little sharks. I never considered any injuries from it. I cant remember ever seeing them run into anything while eating. Any way to minimize injuries from eating moving forward?

 

[Slaphppy7]

They really belong in a bigger tank, because of how boisterous they are, and their eventual adult size....and they need to be in bigger groups, as you are considering, but that may be hard to do, in a 37G....any chance of rehoming them?

If not, your best bet is a bigger tank, and more of them, to spread the aggression amongst themselves...you need more cardinals, too...and ideally in a 37G, only one pleco, they have a large bioload.

 

[noobfish]

Recently started a tank for our son. 29gal. A couple dwarf gourami's, a bristle nose, a pictus cat, and 3 diamond tetras. After about 2 weeks, 2 of the tetras went on the same day. Tested water and everything was good, but one seemed to have and injured face. After a week we introduced 3 more diamonds. One just died yesterday after about 3 days of looking like the one pictured (mouth agape, red, and just staring at the corner). I wondered if they were perhaps running into something and seems that may be the case. As stated above, it is like a feeding frenzy on shark week every day!
Are there an other larger tetra that perhaps won't injure themselves? Maybe peppermints of skirted?

 

[noobfish]

Did some more investigating since yet another tetra has developed the same thing. Turns out it is mouth rot and now the red flame gourami has it too. None of my local stores carry a lot of Seachem products, but I've ordered ParaGuard and KanaPlex and they should be arriving today. Really hoping to save the gourami (and all the rest that are currently symptom free). Just going to treat the whole tank since they've all been exposed to it for a few weeks now.

 

[Avel1896]

Hello
Do your DT always suffered blocked open mouth or is it new ?
If new this might be lockjaw syndrome.

 

[noobfish]

Hello
Do your DT always suffered blocked open mouth or is it new ?
If new this might be lockjaw syndrome.

It's new. Total of 4 now. Starts as white, fuzzy lips. Then the mouth stays open. And finally the lips/mouth start to disintegrate. Right now the gourami is in the beginning of the disintegration phase.

 

[Avel1896]

Oh, sorry for this.
I'm afraid this is lockjaw syndrome, which can be caused by a punch during a fight or a chase, or in the worst case it is tetanus and there is nothing you can do about it.
Believe me I wish I'm mistaken.
You should do a BIG waterchange.

 

[noobfish]

Oh, sorry for this.
I'm afraid this is lockjaw syndrome, which can be caused by a punch during a fight or a chase, or in the worst case it is tetanus and there is nothing you can do about it.
Believe me I wish I'm mistaken.
You should do a BIG waterchange.

I've been researching for over a week and it is definitely mouth rot, a bacterial infection caused by a type of bacteria called Flexibacter Columnaris or Flavobacterium Columnare, similar to fin rot. The gourami's mouth isn't stuck open, but his lips are falling apart. You can actually see flesh hanging off of the affected fish's mouths. The DT's had no upper lip or lower jaw left at all before I dispatched them. KanaPlex and SulphaPlex by Seachem seem to be the main treatments (I spoke with a rep with Seachem about it).
And for sure, just did a water change on Saturday. Usually do 50% every other weekend. Will do another after first treatment as recommended.

 

[noobfish]

Here's a pic of one of the DT's last week. When I took him out a couple days later the lower jaw was gone.