The intrafamilial classification of the largest freshwater fish family in the world, the Cyprinidae, continues to be in a state of confusion, according to a recent study based on a phylogenetic analysis of the family using a nuclear gene for the first time.
The study by Shunping He and co-workers is published in a recent issue of the journal Molecular Phylogenetics and Evolution.
Rasbora borapetensis by Lerdsuwa (Creative Commons)
The authors sequenced and phylogenetically analysed a 1072 base-pair sequence of the first intron of the nuclear S7 ribosomal protein gene for 45 cyprinid species (a taxonomically and geographically broad-based representative sample of the family).
The family Cyprinidae is traditionally divided into the subfamilies Rasborinae (this includes the bariliines, Rasbora and Danio), Leuciscinae (this includes many Eurasian cyprinids such as minnows, tench, rudd), Cyprininae (a large group that include labeonines and barbines), Cultrinae (a group consisting of Eurasian keeled cyprinids), Gobioninae (gudgeons), Gobiobotinae, Xenocyprinae and Acheilognathinae (bitterlings).
Tench, Tinca tinca by Viridiflavus (Creative Commons)
Based on the results of the analysis, the authors found that except for the Cyprininae, all the other subfamilies were not recovered as monophyletic (i.e. they do not share a common, recent ancestor).
As monophyletic groups define current taxonomy, this means that many of the cyprinid subfamilies will eventually need to be reorganized and renamed.
For more information, see the paper: He, S-P, RL Mayden, X-Z Wang, W Wang, KL Tang, W-J Chen and Y-Y Chen (2008) Molecular phylogenetics of the family Cyprinidae (Actinopterygii: Cypriniformes) as evidenced by sequence variation in the first intron of S7 ribosomal protein-coding gene: Further evidence from a nuclear gene of the systematic chaos in the family. Molecular Phylogenetics and Evolution 46, pp. 818"829.