A new evolutionary family tree, or phylogeny, investigating the relationships between glyptosternoid catfishes has just been published.
Biologists Peng, He and Zhang from the Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China, used a molecular technique to study nucleotide sequences of the complete mitochondrial cytochrome b gene region of the DNA of glyptosternoid catfishes in the Sisoridae family.
They studied 13 species of glyptosternoid, plus six non-glyptosternoids, spanning 10 genera within the sisorid family.
Like previous studies of the group, their results show that glyptosternoids have evolved from a single common ancestor, however, their conclusions on the relationships of the fishes within the group are strikingly different.
They found that Glyptosternum and Exostoma are the most primitive in the group, and that Euchiloglanis and Pareuchiloglanis form a sister-group. These two, in turn, form another sister-group with Pseudexostoma and Oreoglanis.
Based on the DNA evidence, they're also suggesting that Pareuchiloglanis anteanalis is actually the same fish as Parechiloglanis sinensis, throwing it into synonymy.
Euchiloglanis may also be monotypic, with Euchiloglanis davidi as its sole member.
For more details read the full paper: Peng Z, He S, Zhang Y. (2004) - Phylogenetic relationships of glyptosternoid fishes (Siluriformes: Sisoridae) inferred from mitochondrial cytochrome b gene sequences.
Mol Phylogenet Evol. 2004 Jun;31(3):979-87.