lol, everything just turned into a huge debate.... Anyway... back to the keeping fish in odd numbers thing: I have read on multiple fish sites that it is beneficial to keep shoaling/schooling fish in odd numbers so they cannot "pair up" I suppose this would be especially useful for fin nippers or aggressive fish. It kinda makes since. I suppose fish like to stay in equal numbered schools/groups or something and if there is an odd number they cant do so? I don't know how true it is that the fish will pair off, or how detrimental it would be if they happened to do so, however during my ridiculously heavy research on the subject of "fish keeping" I came across numerous webpages telling me just that.
Maintaining fish in even or odd-numbered groups is solely a matter of personal choice. I happen to like odd numbers, for no reason other than one is told to have 5 rather than 4 roses in a vase. Psychologically, I prefer 7 or 9 or 11 rather than 6 or 8 or 10. But it makes not one iota of difference to the fish.
Aggression and nipping occur because it is the fish's nature to do so. Some species do this regardless, others only when stimulated by environmental conditions that are not favourable; too small a swimming space, too few fish of the same species, etc. I recently posted a link to a scientific study on this topic, which is the first actual scientific proof that what many authorities have been saying for decades is true, that shoaling fish will be healthier in larger groups. There was no distinction between even or odd numbers. Kept in small groups, in pairs or singly, fish that are biologically programmed to be in a group will frequently become highly stressed, resulting in heightened behaviours of aggression. Fish that would not normally nip, will. And shoaling fish do not pair off except to spawn.
And note, we are talking shoaling forest fish. Not dwarf cichlids for instance which in some species do best in groups of 1 male to 3-4 females. That is something different again.
I would be very interested in seeing these references, if you could provide the links please. While I know they have no scientific basis, I am nevertheless interested in their reasons for making such erroneous statements.
Human beings are inherently inclined to argue about the most minuscule things. Silly humans...
While true in many respects, I do not consider an informed discussion on a topic that has two diametrically opposite views but which is critical to the life of the fish in the aquarium
to be minuscule. And while I have scientific evidence for my position, Matt has provided none. Anyone is free to challenge the statements of a scientist as eminent as Stanley Weitzman, but without scientific evidence to refute Dr. Weitzman's position, the challenge is meaningless.
Science tells us the earth is spherical, yet there is a group of individuals who believe it is flat. I cannot prove it either way, but I accept the majority of scientific fact and take that position. Though in this example, little harm will be done to my aquarium inhabitants whatever I may believe about the earth's shape. In the case of salt, things are much different because the stress will cause immune system problems and health issues, and likely result in a shorter-than-normal lifespan.