My cockney mate, a mature and well reasoned post, which was a pleasure to read. I approve ;-) (and im a grumpy yorkshire man )
Like you says, if you've got a fine balance, and your fish are happy and healthy, then the best of luck with it (you might need it one of these days)
Just keep an eye on the colourful bin lid for me ;-) They are soft as sugar sometimes.
On a closing note (as me and japes mentioned) Ill go into a little more detail on Blood parrots now im not at work.
Their basically a very strange fish, mass produced (most likely via artificial incemination) in the far east by crossing a severum (H.Efasciatus) with atleast 2 other fish.
Now i've looked into this, and the basic principle seems to be to produce a gold severum off the bat. (Can be done by crossing a green severum with an orange midas (Both members of the Heroine tribe).
Once you've got your gold sev, its then a case of crossing it back with another fish. What this fish actually is, i dont have a clue. its most likely one of the Amphilophus (midas) species with a more pronounced nucal hump, giving the Blood parrots their deformed face.
Basically the Severum brings the body shape, the orange midas brings the colour and the mystery fish brings the pointed face.
By cross breeding, you get a fish that shows a lovely colour, nice trailing fins, is notablly differant to any of the parent species, and the deformity in the mouth means that it finds it difficult to bite other fish (more bull dozer then bull dog)
The downfall however is that a good % of its genes have come from VERY aggressive species, and this really shows through in their temper (even if the mouth leaves them without the tools to cause any pysical harm) as their well known for harassing anything else of similar shape (conspecific aggresion at work, which is very common among heroines)
Not a nice fish to observe in my opinion, I'd rather see a fish able to act naturally to its fullest potential, but its a case of each to their own eh?
As for your lonely discus, theres a story there too ;-)
When discus shoal, they opperate a sort of pack system, with an Alpha pair, a Beta Pair (who spawn when they get the chance) the subordinates (who dont get a look in or a leg over) and a runt.
The runts job in the shoal is to basically to act as a punch bag, their generally smaller then the rest of the shoal, feed last, and are usually away from the group alot of the time (which in the wild makes them a Weak link, first to be attacked as prey, giving the stronger fish (where the genetic material is best) the chance to survive. They are still a part of the shoal however.
Now in the wild, these fish will usually be the fry from previous spawns, and will be either pushed away (to form new shoals) or will grow up, and their position will be replaced by younger fish. Once the shoal reaches "Critical Mass" (where it can no longer find enough food to sustain itself, then the runts begin being forced away (working their way though the group until it reaches a workable, efficient level again, with the biggest, strongest fish) (if they live this long)
Makes perfect sense doesn't it? Making a weak link to preserve the better stock, if it survives this process, it will be shipped off to start a new shoal with the adaptations it has developed in its hard life. Evolution at its very finest.
Now, put the same fish into a glass box, add a dash of personification from ourselves, and soon enough your netting him out the runt to give him a better life anywhere you can.
A discus shoal will always have a runt (heck, most shoaling cichlid have one. My Geophagus Aereos are happy as larry, but theres one small female who gets more of a kicking then she deserves (basically being kept out of breeding condition, but otherwise healthy)
That, as contrived as it sounds, is the nature of the beast.
Appologies if my first post was taken a little snappy, was in a rush with work, and i got my back up when i was told i was wrong to voice my opinion ;-)
Just keep a level head, keep on top of your water changes, watch out for aggro and your laughing eh
all the best
Craggy