What Is A Tetra?

[The-Wolf]

this is something that has bemused me for a while,

I think I'm correct in saying that all Characiformes (characins) have teeth (even if too small to be seen by the naked eye)
and all have an adipose fin, or remnants of an adipose fin (even if that can't be seen by the naked eye)
but what exactly makes a tetra a tetra and not, say, a charicine?
(for instance Apareiodon affinis is called the Darter characine and not the darter tetra, why?)

 

[The-Wolf]

no one with an answer of any kind?

 

[three-fingers]

Not a very good answer, but 'tetra' is just part of the common name of the fish right? I don't think there is a specific set of criteria a fish has to meet to be called a tetra, it's just whatever name catches on. It tends to mainly be used for small South American characins, but other fish like congo tetras share the name too.

 

[JamesC]

three-fingers seems to be spot on. Wikipedia's entry for tetra - http/en.wikipedia.org/wiki/Tetra

James

 

[The-Wolf]

I was kind of hoping for some kind of scientific criteria that makes a tetra a tetra
but I guess it is really down to 'common names'

 

[nmonks]

Indeed. Tetra comes from a genus, Tetragonopterus, and the subfamily Tetragonopterinae. This subfamily includes a bunch of genera rich in aquarium species (Paracheirodon, Hyphessobrycon and Hemigrammus for a start). Beyond that, it doesn't really mean anything, and a lot of things called "tetras", such as Congo tetras and Nurse tetras, aren't members of the Tetragonopterinae so probably don't deserve to be called tetras at all.

Cheers, Neale

I was kind of hoping for some kind of scientific criteria that makes a tetra a tetra
but I guess it is really down to 'common names'

 

[The-Wolf]

thanks Neale
that makes more sense

 

[Lateral Line]

http/www.fishforums.net/index.php?showtopic=25225