Sarcocheilichthys vittatus, a new species of gudgeon (Teleostei: Cyprinidae) from the Poyang lake basin in Jiangxi Province, South China

Sarcocheilichthys vittatus, a new species of gudgeon, is described from the Gan-Jiang and Fu-He flowing into the Poyang Lake Basin in Jiangxi Province, South China. It is similar to S. parvus and S. caobangensis in having a longitudinal black band extending from the snout tip to the caudal-fin base, a character separating them from all other congeneric species, but distinct from S. parvus in having more lateral-line scales, no longitudinal yellowish stripe above the lateral black band on the flank and no barbels, and from S. caobangensis in possessing two shorter lateral lobes of the lower lip restricted only to the side of the lower jaw, no black spots along the dorsal-fin base and a stouter caudal peduncle. Its validity was also warranted by a molecular phylogenetic analysis based on the cyt b gene. Critical notes were provided on some currently recognized Chinese congeners.

Testing the utility of DNA barcodes and a preliminary phylogenetic framework for Chinese freshwater mussels (Bivalvia: Unionidae) from the middle and lower Yangtze River

The middle and lower portions of the Yangtze River basin is the most species-rich region for freshwater mussels in Asia. The management and conservation of the taxa in this region has been greatly hampered by the lack of a well-developed phylogeny and species-level taxonomic framework. In this study, we tested the utility of two mitochondrial genes commonly used as DNA barcodes: the first subunit of the cytochrome oxidase c gene (COI) and the first subunit of the NADH dehydrogenase gene (ND1) for 34 putative species representing 15 genera, and also generated phylogenetic hypotheses for Chinese unionids based on the combined dataset of the two mitochondrial genes. The results showed that both loci performed well as barcodes for species identification, but the ND1 sequences provided better resolution when compared to COI. Based on the two-locus dataset, Bayesian Inference (BI) and Maximum Likelihood (ML) phylogenetic analyses indicated 3 of the 15 genera of Chinese freshwater mussels examined were polyphyletic. Additionally, the analyses placed the 15 genera into 3 subfamilies: Unioninae (Aculamprotula, Cuneopsis, Nodularia and Schistodesmus), Gonideninae (Lamprotula, Solenaia and Ptychorhychus) and Anodontinae (Cristaria, Arconaia, Acuticosta, Lanceolaria, Anemina and Sinoanodonta). Our results contradict previous taxonomic classification that placed the genera Arconaia, Acuticosta and Lanceolaria in the Unioninae. This study represents one of the first attempts to develop a molecular phylogenetic framework for the Chinese members of the Unionidae and will provide a basis for future research on the evolution, ecology, and conservation of Chinese freshwater mussels.

Complete maternal mitochondrial genome of freshwater mussel Aculamprotula tientsinensis (Bivalvia: Unionidae: Unioninae)

Aculamprotula tientsinensis is a rare and endemic species of freshwater mussel in China. This study firstly determined the complete F-type mitochondrial genome of A. tientsinensis. The circle genome (15 695 bp) comprises 13 protein-coding genes, 22 tRNA genes, 2 rRNA genes, 1 FORF gene. Except for cob, nad5 and nad6, the remaining protein-coding genes initiate with the orthodox start codon (ATG, ATA, ATT). There are 26 non-coding regions in the mitogenome of A. tientsinensis, ranging in size from 1 to 229 bp. The base composition of the genome is A (37.83%), G (12.69%), T (25.43%) and C (24.06%). Gene order is identical to other female species of Unionidae but for Gonideinae. The phylogenetic analyses of Unionidae indicate that A. tientsinensis is closely related to A. tortuosa and A. coreana, which belong to Unioninae. The complete mitogenome can deepen comparative and evolutionary genomics of Unionidae and be more comprehensive to parse the genetic relationship between the species and the ownership beyond species.