General African Cichlid Discussion • Cichlid?

[Itsroger]

How are cichlids determined? I see there are lots of cichlids all over the world, what exactly defines them as cichlids?

[ken31cay]

I remember reading that all Cichlids have just one set of nostrils, where I suppose most other fish have two sets.

[DJRansome]

Wikipedia also says:
A single nostril on each side of the forehead, instead of two
No bony shelf below the orbit of the eye
Division of the lateral line organ into two sections, one on the upper half of the flank and a second along the midline of the flank from about halfway along the body to the base of the tail (except for genera Teleogramma and Gobiocichla)
A distinctively shaped otolith
The small intestine's left-side exit from the stomach instead of its right side as in other Labroidei

[sir_keith]

Wikipedia also says:
A single nostril on each side of the forehead, instead of two
No bony shelf below the orbit of the eye
Division of the lateral line organ into two sections, one on the upper half of the flank and a second along the midline of the flank from about halfway along the body to the base of the tail (except for genera Teleogramma and Gobiocichla)
A distinctively shaped otolith
The small intestine's left-side exit from the stomach instead of its right side as in other Labroidei

The family Cichlidae is a taxonomic grouping of fishes originally defined by a set of morphometric characteristics, including those listed in DJRansome's post, above. The assumption here, and in all traditional taxonomy, is that organisms that share distinctive characteristics are likely to be evolutionarily related by descent. Molecular analyses of DNA sequences over the last few decades have shown that this assumption is not always correct, and there is an ongoing reshuffling of species and genera within families, but it is unlikely that any family as originally defined will be revised by the new molecular data. The simple answer to your question is that Cichlids are a group of fishes that have evolved from a common ancestor

[Itsroger]

Thanks for answering, mainly nostril count, ok .

[sir_keith]

Thanks for answering, mainly nostril count, ok .

Well no; it's a lot more complicated than that. Lots of fishes have only two nostrils; it is the combination of many traits that make a Cichlid.