Endler Is Nigh?

I’d appreciate an opinion on this please, as I can’t work out what’s happening myself.

I think one of my Endlers isn’t long for this tank.  For the last five hours he’s been furiously swimming in the same stationary spot at the surface, mouth constantly open, but not gasping.  It’s really quite heart breaking.

Backstory:
I’m new to this and have been trying to learn as I go along, so am probably making mistakes all over the place.  We bought an aquarium as an alternative to a hamster/puppy/cat/guinea pig at the behest of a medium to small person.  With hindsight, I’d have made some different decisions about what we’ve done if I’d had more time to research more thoroughly.

Anyway, we bought a 37L tank (40cm x 25cm x 40cm) at the beginning of March.  Having done some research I attempted a fishless cycle, dosing 2ppm of ammonia and dumping two bottles of Tetra Safestart in the first couple of weeks (I figured more bacteria couldn’t hurt)..What I didn’t realise was that having planted the tank quite heavily initially I’d retarded the process.  Eventually we got to the point where a dosed 2ppm of ammonia disappeared after 24 hours, although nitrite never went higher than 0.5ppm.  So I’m not sure if the ammonia is being mostly consumed by the plants (which are growing well)or whether the Safestart nitrite eating bacteria got a head start on their ammonia eating cousins.

Generally the water parameters are (measured using either API liquid test kit or API strips):
PH 8ish - variance between 7.5 and 8.2, but some of that could be down to my colour interpretation.
GH 180ppm
KH 180ppm
Nitrate out of the tap is around 15-20 ppm. (Is there actually a difference between the API liquid kit’s colours of orange for this test?)

Last Sunday we bought 6 male Endlers.

Tuesday late evening “Spongebob”, the larger leopard print endler was swimming stationary at the top of the tank in the corner near the feeding hatch.  I checked ammonia levels (0ppm) and adjusted the filter output to make sure it was maximising surface agitation.  After a couple of minutes he swam off and seemed to be behaving normally (swimming at various levels in the tank, interacting with the other fish).

Saturday late afternoon, we noticed he was swimming at the surface, in a stationary position, in the corner of the tank.  He’s facing out from the corner, head towards where the flow from the filter output is coming from.  He’s not gasping, but his mouth is open all the time (I think, they’re tiny and I’m at the age where I need about three different pair of glasses but won’t admit it.  At least I think his mouth is open, it might be damaged, it doesn’t look the same as the others whose mouths are closed most of the time.)

When we fed them, he chased after food and seemed to inhale smaller flakes (Tetra micro flakes that have been ground between fingertips), but gave up on a couple of larger flakes.

Water readings were as normal for ph, gh & kh and just below 26C  Ammonia and nitrite were 0, nitrate was around 25-30.

Saturday is tank cleaning day.  When we turned the filter off, he swam off and behaved normally again.

As part of a general clean around 30-40% water is changed.  Water is dechlorinated with Aquacare tap water conditioner and goes in the aquarium at around the right temperature.

As soon as we turned the filter back on, he was back to the same spot, swimming furiously to stay absolutely stationary.

His tank mates seem perfectly happy, exploring all areas of the aquarium.  Although we have noticed some potential bullying.  Three of his tank mates were regularly nipping/nudging his belly/flanks, although this stopped when the aquarium lights went out.

He’s been in the same spot for the last five hours, only shifting when bullied from the spot, returning as soon as he could.

Any ideas as to what’s happening?
Is he a more sensitive soul than the others and the first to succumb to a apocalypse because I’ve done something wrong?
Has he eaten something too big that he shouldn’t and is paying the ultimate price for it?
Is he just a poor specimen or been physically damaged in some way during the transfer?
Is he a victim of bullying and this is stress behaviour?

Any input gratefully received

Right way up?

I agree with Littlefish, his mouth does look odd in both photos. Is it like that all the time or did you just happen to take the photos while his mouth was open like that?

If it is like that permanently, there is something wrong with him, but I'm not very good at diagnosing illness 

You ammonia and nitrite are perfect, so it's not poisoning by either of them. Nitrate should be kept below 20 ppm where possible, but that doesn't poison fish instantly like the other two, it's a long term effect.

Apart from the mouth and swimming on the spot, are there any other physical symptoms? Any spots or discoloured patches?

How powerful is the filter? In the manual there should be some mention of the turnover in litres per hour (or possibly gallons per hour if it's an American brand). The fact that he swims normally when the filter is off makes me wonder.

The bullying - fish will do their best to hide the fact they are ill. But other fish in the group will pick on sick members, often put down to wanting to kill a fish which will attract predators as a sick fish is easier for them to pick off.










Re setting up the tank, there are tree ways to cycle a tank - there are stickies for fish-in and fishless on here, but we are missing a silent cycle method. This is using plants to cycle a tank. Plants take up ammonia as their preferred source of nitrogen, and when there are enough fast growing plants, they can take up all the ammonia made by a sensibly stocked tank. And plants turn ammonia into protein rather than nitrite.
Assuming your plants are fast growing, they should be able to keep nitrate at tap water level.
Overfeeding the fish contributes to nitrate as it's broken down to ammonia - and if there aren't enough plants the bacteria will turn uneaten food into nitrate. The same applies to fish poop in the substrate.

Photos

You noted in more than one comment that his mouth is open all the time, but he isn't gasping. That isn't normal.
Are there fuzzy edges to his mouth, or does his mouth look complete? In the first set of pics the edges of his mouth looked a but fuzzy/fluffy/uneven, as if he could have had a fungal infection. However, that doesn't seem to be the case in the more recent pics posted today. Even so, the top lip doesn't look quite right to me.
The picture of the tank mate shows what I think of as a healthy endler, so you may have been unlucky with Spongebob, as Sue has mentioned.
For now perhaps keep a close eye on him, and at feeding time do what you have done by crushing flake so he can just suck crumbs in. Please keep us informed and we may need to see how this progresses.

Sorry to hear that Spongebob passed.