The Phylogeny And Biogeographic Analysis Of Catfish Glyptosternoid (Siluriformes: Sisoridae) In China

Glyptosternoid fish belongs to Sisoridae of Siluriformes. This group records 8 genera in China, including Glyptosternum, Glaridoglanis, Euchiloglanis, Pareuchiloglanis, Parachiloglanis, Oreoglanis, Pseudexostoma and Exostoma. There are divarications in the phylogeny study of glyptosternoid fish in China. There is no a consistent opinion what Glyptosternum and Exostoma originate from. And there is a dispute whether glyptosternoid fish is a monophyletic group or not. It is necessary to collect all species of glyptosternoid fish as possible, which will be helpful to discuss their phylogeny and biogeographic pattern by means of comparative anatomy of their external features, muscle and skeleton.The author examined 6 genera and 24 species of glyptosternoid fish, among of what 21 species were chosen as the objective for phylogeny study after considering their distribution and morphological features. Conventional anatomy was adopted for muscle comparison. Skeleton specimens were made by process of pancreatinum digestion, colouration and vitrification. All pictures were drawn with a binocular microscope (Motic D400). Bagarius yarrelli was chosen as the species of outgroup. Characters of specimens were polarized with the method of outgroup comparison. The character matrix was analyzed by the PAUP 4.0 and all trees were redrawn by using Treeview software. Based on the relative relation of glyptosternoid, the cladistic biogeography research was conducted by using software COMPONENT 2.0.After compositively comparing shape, counted and measured external characters , and inner characters of shape, muscle and skeleton, 120 steady characters were selected. Then 120-character matrix was computed in Order mode and just yielded a most-parsimonious tree, which indicated Glyptosternoid fish is a monophyletic group. According to the tree, Glyptosternum was the most primitive genus; Euchiloglanis was the second primitive genus but not a monophyletic group. E. longibarbatus and E. kishinouyei did not converge into one clade with E. davidi + E. Longus. Other species of glyptosternoid fish divide into 2 clades. One clade was formed by species of"smooth-Pareuchiloglanis group"whose maxillary barbel and the lower lip were connected directly; another clade was formed by species"sulcus-Pareuchiloglanis group"whose maxillary barbel and the lower lip were interrupted by an obvious shallow sulcus, Oreoglanis, Pseudexostoma and Exostoma."Sulcus-Pareuchiloglanis group"formed a sister group with Exostoma + Oreoglanis + Pseudexostoma. Eliminating character 31, the matrix of the other 119 characters was computed in Unorder mode, and a most-parsimonious tree yielded which was resembled the tree computed in Order mode.Strict-consensus tree was just the same construction as the most-parsimonious tree computed in the Order and Unorder mode. When 120 character matrix was computed in Order mode an unique Bootstrap 50% majority-rule consensus tree was yielded, which had 2 differences from most-parsimonious tree. In the bootstrap 50% majority-rule consensus...