With the corys i want 6-8 of 1 species but if possible mixed colours. But only if they would act and live the same way they would if they was all 1 coloured specie. (Hope that makes sense)
Each species of cory will be the same colour/pattern throughout that species, and there are presently more than 160 described or known species of
Corydoras. The only exception is the "albino" form or the "long-fin" form of a few species. So a group of say
Corydoras aeneus (the Green or sometimes Bronze Cory common name) will all have the same basic colour/pattern. Sometimes there may be a slight variation, but it is minimal.
You can mix species as I outlined previously, and the cories seem to chum around just the same. The main thing is number; the more cories in the group the better for them. This is programmed into their DNA and must be provided.
You mentioned you had a single male ram and a pair in your tanks before. in your experience would you say the ram on its own was happy or is it better to have company with this species?
This species,
Mikrogeophagus altispinosus, is found in slow-moving streams and still waters (ponds) of the Rio Guapore and Rio Mamore systems in Bolivia and Brazil. Observations made in the habitat suggest that this species lives in solitude (individual fish alone) apart from reproduction periods (Linke & Staeck, 1994). Single fish are therefore good cichlids for a community aquarium. More than one can be housed if the tank provides sufficient floor space for individual territories but this requires at least a 4-foot tank. The fish remains in the lower third of the water column, spending most of its time browsing the substrate for bits of food. A single male Bolivian Ram makes one of the most ideal "specimen" fish in an average-sized [meaning tanks that are minimum 30 inches in length up to four feet length] community aquarium of smaller peaceful shoaling fish and catfish. It will consider the entire tank its own territory, and it will communicate this to every fish in the tank--and enforce it when necessary [anecdote below].
As for pairs to spawn...like all dwarf cichlids the pair must select each other and bond. Any male will not accept any female and vice versa. It is usually fairly easy to see likely bonded pairs in a tank of this species. Even so there is no absolute guarantee that the fish may not turn against one another after a few spawnings, but it seems less likely if they bond to begin with. So if you want to observe spawning, which is certainly interesting, and do not mind if the fry don't necessarily make it (letting nature take its course), finding a bonded pair is the way to go. Or, a single Bolivian Ram, a male preferably as they have a bit more "personality," will work. The other fish in the aquarium must be peaceful, and not overly active. Rams, like all neotropic cichlids, are sedate fish and should never be combined with active fish (fish like danios and most barbs are out) nor those with a tendency to fin nip.
The anecdote. I had a male Bolivian Ram in my 5-foot Amazon riverscape some years ago, along with the 40+ cories and about a hundred plus upper characins including a group of 8 Bleeding Heart Tetras. One day I noticed the Bleeding Hearts were clustered together mid-tank (length-wise) and just above mid-line (vertically). The Ram had positioned himself half-way between the group and the substrate. If one of the BH's began to swim out of the group, the Ram would turn toward them and swim a few inches, and the tetra would immediately re-enter the group. This lasted for some time. I hadn't seen what initiated it, but the Ram must have been annoyed by the BH's, perhaps beecause they were attempting to eat "his" selected shrimp pellet or whatever. He had had enough, and laid down the law as it were--and the tetras didn't intend arguing. Fish communicate visually, but also by chemical signals, pheromones (read by the species) and allomones (read by other species) and the species usually have enough sense to understand the consequences if they do not obey.
