Rosy tetra with hole in the belly
I was wondering if you could help me.
I have a 25 liters fish tank in which I've been housing 2 females lf rosy tetra
for the last 3 years.
<These are nice, usually unproblematic tetras.>
Fish keeping is not my priority but I've been regularly changing 25-50% of the
water and tried to keep the tank relatively comfortable for these 2 fish to
<Understood. However, 25 litres is much, much too small for these fish.
It's barely adequate even for a single Betta. It would also explain your
A couple of months ago one of them developed a black round dot on it's belly
around the anal area.
<Yes; possibly a wound, but hard to say at this point.>
That dot has slowly grown larger and yesterday I noticed it looked like she had
cotton on the dot. Well today the "cotton"-like fluff disappeared but she has a
massive dent/hole on her belly.
<I can see this, yes. The white stuff coming out from the wound is dead tissue,
likely muscle and skin tissue. It's what we'd call an infected ulcer in the case
of a human, and while the cause is hard to pin down, it's evidently infected
with bacteria that are causing the wound to explain (and preventing it from
She acts normal and eats normal however the wound doesn't look all right at all.
I was wondering if you would happen to know what this is and if there is a way
for me to help her at all?
<Two steps. Firstly, a bigger world with better water quality. With the best of
intentions, as I'm sure you have just reading this message, 25 litres is, what,
6 or 7 US gallons? For this species you'd really need at
least 2-3 times that amount of water to be considering this a "healthy"
environment. Too little water means too many bacteria, and too little water also
means too little dilution of metabolic wastes. Regular water changes help, for
sure, but realistically you'd need to be changing the water every day or two
simply to create conditions similar to, say, a 60-75 litre/15-20 US gallon tank
that received water changes every week or two. There's just no sense to that
amount of work, especially if fishkeeping is a casual
hobby. Put another way, the less work you want to do, the bigger your tank needs
to be. The smaller the tank, the harder work it'll be, and ultimately more
expensive once you factor in dead/replacement fish and medications.
Now, the second thing to do is treat as per Finrot. Again, let me stress here
that medications are like sticking plasters -- they're fine once the injury is
done, but if the patient keeps sticking knives in themselves, plasters aren't
going to help! Similarly, if the water conditions don't improve, you'll be
repeating the medication again and again because the bacteria will keep coming
back. Aeromonas and Pseudomonas spores are everywhere, and you really can't keep
them out of the tank any more than
you can live your own life germ-free. Can I also add that medications vary in
quality. The tea-tree oil ones are generally cheap but unreliable, so avoid.
Salt is equally worthless, though often recommended to inexperienced hobbyists.
Instead look at a proper antibiotic (if available in your country from a pet
store) such as Maracyn 2 or Kanaplex, or else a trusted antibacterial like eSHa
2000 or Waterlife Myxazin.>
Please see some photos attached
Kind regards, Anda
<Hope that this helps. Cheers, Neale.>
Re: Rosy tetra with hole in the belly 10/2/18
I hope you're well. I'm just writing to thank you I've followed your advice of
what medicine give to my fish and it looks like she is now healed.
She's left with the scar in the area but other than that she's absolutely fine.
We will look to move them in a bigger tank soon too.
Thank you so much.
Best regards, Anda
<Glad this worked out, and thanks for letting us know. Cheers, Neale.>
Rosy Tetras and aggression /Neale
Just wondering if anyone there knows if Rosy Tetras are ok with
angelfish and nipping?
<Regarded as a peaceful species, but Hyphessobrycon species generally
can be nippy, particularly if not kept in sufficient numbers. Should be
okay in a big group though.>
I have two 4 inch angels in a 38 tall and have a chance to trade the
Lemons I have for Rosy Tetras. Lemons do not nip, but I fear Rosy Tetras
may, so I was wondering if it is worth the chance? Thank you
<Lemons are outstanding fish if you have soft, acidic conditions that
will bring out their best colours. So a definite option!>
Also wondering why something like a Serpae tetra would be so aggressive
and a Lemon would not be so much. Just wondering what causes aggression
difference in tetras ??
<Nippiness can have two causes. Frustrated social behaviour is one, and
the likely explanation for Tiger Barbs, which can be pretty safe in big
groups. But other species, Serpae Tetras for example, seem to use
nipping as a genuine part of their feeding strategy -- they bite the
scales and fins of other fish. Not much you can do to prevent this.>
Rosy tetras with lemon tetras 2/12/17
Just wondering if it is possible to keep a couple of Rosy Tetras with a
school of 8 lemon tetras or are the Rosies just too aggressive? I wonder
if they would school with the lemons or attack them. Lemons seem to be
one of the most peaceful tetras there are. Thank You
<In theory Rosy Tetras, Hyphessobrycon rosaceus, should get along well
with Lemon Tetras. Two issues though. First is that other look-alike
species may be sold instead of true Hyphessobrycon rosaceus, for example
callistus, a much more aggressive species. Be sure you know the
difference! Secondly, expecting "a couple" of any schooling species to
behave normally is unrealistic. They'll either be terribly shy or
But get 6-8 specimens and you should be fine. Cheers, Neale.>