The complete mitochondrial genome of Pseudobagrus ondon Shaw

Identification and phylogenetic analysis of the mitochondrial genome of Hemibarbus labeo BML (Cypriniformes: Cyprinidae)

The complete mitochondrial genome of Hemibarbus labeo BML (Cypriniformes: Cyprinidae) is 16,612 bases in length. It consists of 22 tRNA genes, 13 protein-coding genes, 2 rRNA genes, and 1 non-coding region. Its overall nucleotide composition is A: 29.85%, G: 17.07%, T: 25.86%, and C: 27.23%, respectively, with an A + T rich feature (55.71%). The gene arrangement and organization of the mitogenome from H. labeo BML were very similar to other Cyprinidae fishes. The phylogenetic analysis showed that H. labeo BML clustered in genus Hemibarbus. These results will contribute to the taxonomy and conservation biology studies of H. labeo.

A Time-Calibrated Mitogenome Phylogeny of Catfish (Teleostei: Siluriformes)

A very significant part of the world's freshwater ichthyofauna is represented by ancient, exceptionally diverse and cosmopolitan ray-finned teleosts of the order Siluriformes. Over the years, catfish have been established as an exemplary model for probing historical biogeography at various scales. Yet, several tantalizing gaps still exist in their phylogenetic history, timeline and mode of diversification. Here, we re-examine the phylogeny of catfish by assembling and analyzing almost all publicly available mitogenome data. We constructed an ingroup matrix of 62 full-length mitogenome sequences from 20 catfish families together with four cypriniform outgroups, spanning 15,557 positions in total. Partitioned maximum likelihood analyses and Bayesian relaxed clock dating using fossil age constraints provide some useful and novel insights into the evolutionary history of this group. Loricarioidei are recovered as the first siluriform group to diversify, rendering Neotropics the cradle of the order. The next deepest clade is the South American Diplomystoidei placed as a sister group to all the remaining Siluroidei. The two multifamilial clades of "Big Asia" and "Big Africa" are also recovered, albeit nodal support for the latter is poor. Within "Big Asia", Bagridae are clearly polyphyletic. Other interfamilial relationships, including Clariidae + Heteropneustidae, Doradidae + Auchenipteridae and Ictaluridae + Cranoglanididae are robustly resolved. Our chronogram shows that siluriforms have a Pangaean origin, at least as far back as the Early Cretaceous. The inferred timeline of the basal splits corroborates the "Out-of-South America" hypothesis and accords well with the fossil record. The divergence of Siluroidei most likely postdated the final separation of Africa and South America. An appealing case of phylogenetic affinity elaborated by biogeographic dispersal is exemplified by the Early Paleogene split between the Southeast Asian Cranoglanididae and Ictaluridae, with the latter radiating into North America's freshwater realm by Eocene. The end of Cretaceous probably concludes the major bout of diversification at the family level while with the dawn of the Cenozoic a prolific radiation is evident at the generic level.

Sequence identification and description of the mitochondrial genome of Abbottina rivularis (Cypriniformes: Cyprinidae)

In this study, the complete mitochondrial genome of Abbottina rivularis was determined; the phylogenetic analysis with other individuals and closely related species of the gudgeons was carried out. The complete mitogenome of A. rivularis was 16,597 bp in length, which consists of 22 tRNA genes, 13 protein-coding genes, 2 rRNA genes, and 2 non-coding regions: (D-loop and OL). The overall nucleotide composition of the A. rivularis mitogenome was A: 29.92%, T: 25.75%, G: 17.15% and C: 27.18%, respectively, with an A + T rich feature (57.1%). This study provides useful data to genetics, conservation and evolution study of the gudgeons.

Description and phylogenetic analysis of the mitochondrial genome of Pseudobagrus ondon Shaw (Siluriformes; Bagridae)

Pseudobagrus ondon is a small benthopelagic freshwater species of family Bagridae. In the present study, the complete mitochondrial genome of P. Ondon has been determined, and phylogenetic analysis with another individual and closely related species are preformed. The complete mitochondrial genome of P. ondon was 16,534 bp in length, containing 13 protein-coding genes, 2 rRNA genes, 22 tRNA genes and 2 non-coding regions: a control region (D-loop) and an L-strand replication origin (OL). It indicated that D-loop, ND1, ND2, ND4, ND5 and CYTB may be appropriate markers for studying population as well as conservation genetics.