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The restocking of the endangered Kanglang white minnow ( Anabarilius grahami) in Lake Fuxian, China, has been conducted for 13 years. However, few studies have reported on the effectiveness of the captive breeding and release of this species. Here, we investigated variations in morphology, including body shape and skeletal deformities, and genetic features among hatchery-born and recaptured A. grahami from Lake Fuxian. Results showed that current hatchery-reared fish displayed a stubbier body shape than their wild conspecifics from the 1980s. Furthermore, high skeletal deformity ratios were found in two aquafarms (Luchong, 50%; Haikou, 45.2%), and the release of malformed fish elevated the skeletal deformity rate of wild stocks found near the Lake Fuxian release sites (west coast, 19.0%; east coast, 12.5%). Based on variations in the cytochrome b (cyt b) gene, existing A. grahami populations showed relatively high haplotype diversity and low nucleotide diversity. Hatchery populations exhibited reduced genetic variations based on microsatellite markers and reintroduction led to markedly lower genetic diversity around the west coast release sites of Lake Fuxian. Analysis of molecular variance (AMOVA) of cyt b and microsatellite analysis showed that the greatest genetic variations were found within populations, and genetic distance and Bayesian clustering analysis showed that the 14 populations clustered into one group. Based on morphological and genetic tests, we discuss corresponding recommendations, including release size, feed formulations, breeding strategies, and release tags, to minimize potential risks and improve hatchery practices for better restocking of this species.

Intermuscular bones (IBs) are widely present in morphologically generalized teleost fishes and are commonly found in the Cyprinidae. Intermuscular bones are small, hard spicules of bone that are formed by ossification in the myosepta between neighboring myomeres. Why fish have IBs, and whether there is any evolutionary pattern to their occurrence, has been poorly understood. However, the presence of IBs does substantially affect the meat quality and commercial values of many cyprinid fishes in aquaculture. In this study, we sampled 592 individuals of cyprinid fishes to systematically investigate the evolution of IBs from a phylogenetic point of view. We found that the total number of IBs in the Cyprinidae ranged from 73 to 169, and we clarified that only two categories of IBs (epineural and epipleural) were present in all examined cyprinids. Most of the IBs were distributed in the posterior region of the fish, which might be an optimal target for selecting fewer IB strains in aquaculture. There was a positive correlation between IBs and the number of vertebrae, thus making it possible to predict the approximate number of IBs by counting the number of vertebrae. Although the IBs displayed some correlation with phylogenetic relationships in some lineages and to ecological factors such as diet (especially carnivore), in an overall view the variations of IBs in cyprinids were extremely diverse. The number and patterns of IBs in these fishes may reflect their phylogenetic history, but have been shaped by multiple environment factors. In this study, we also confirmed that X‐ray photography remains an optimal and reliable method for the study of IBs.

In this study, pure‐breeding and crossbreeding of Sinocyclocheilus grahami were established to test heterosis and expression of growth‐related genes which were examined in the first‐generation (F1). Genetic distances results showed that Muyang river (M) and Sanbaimu reservoir (S) populations had smaller interspecific distances (genetic distance: 0.000) while larger distances were shown to other two populations (0.024 of Jiuzhai vauclusian spring [J] and 0.044 of Chenglong vauclusian spring [C]). Full‐sib families were created by using the Muyang river population as females: MM, MS, MJ and MC. Growth performance had significant differences between each group of F1 hybrids; the fastest growth group was shown in MJ while the slowest was in MS. For growth‐related genes, the fast growth group of MJ hybrids showed significantly higher levels of ghrelin expression in strong expression tissues of the intestine and liver. Among the four combinations, mRNA levels of insulin‐like growth factor I (IGF‐I) were the highest expression in MJ hybrids than others in all tested tissues. Myostatin b and somatostatin1 (SST1) were strongly expressed in the brain and MJ hybrids showed relatively lower expression level. In the muscle, slow growth group of MS hybrids showed extremely higher expression levels of these two genes, especially SST1 gene. In conclusion, associating growth with growth‐related genes expression indicated faster growth of crossbreeding in S. grahami and can make a contribution to commercial fish production in the future.

A Yunnan-Guizhou Plateau fish, the Kanglang white minnow (Anabarilius grahami), is a typical “3E” (Endangered, Endemic, and Economic) species in China. Its distribution is limited to Fuxian Lake, the nation’s second deepest lake, with a significant local economic value but a drastically declining wild population. This species has been evaluated as VU (Vulnerable) in the China Species Red List. As one of the “Four Famous Fish” in Yunnan province, the artificial breeding has been achieved since 2003. It has not only re-established its wild natural populations by reintroduction of the artificial breeding stocks, but also brought a wide and popular utilization of this species to the local fish farms. Anabarilius grahami has become one of the main native aquaculture species in Yunnan province, and the artificial production has been emerging in steady growth each year. To promote the conservation and sustainable utilization of this fish, we initiated its whole genome sequencing project using an Illumina Hiseq2500 platform. The assembled genome size of A. grahami is 1.006 Gb, accounting for 98.63% of the estimated genome size (1.020 Gb), with contig N50 and scaffold N50 values of 26.4 kb and 4.41 Mb, respectively. Approximately about 50.38% of the genome was repetitive. A total of 25,520 protein-coding genes were subsequently predicted. A phylogenetic tree based on 4,580 single-copy genes from A. grahami and 18 other cyprinids revealed three well-supported subclades within the Cyprinidae. This is the first inter-subfamily relationship of cyprinids at genome level, providing a simple yet useful framework for understanding the traditional but popular subfamily classification systems. Interestingly, a further population demography of A. grahami uncovered a historical relationship between this fish and Fuxian Lake, suggesting that range expansion or shrinkage of the habitat has had a remarkable impact on the population size of endemic plateau fishes. Additionally, a total of 33,836 simple sequence repeats (SSR) markers were identified, and 11 loci were evaluated for a preliminary genetic diversity analysis in this study, thus providing another useful genetic resource for studying this “3E” species.

In order to simulate the precipitation process of microbial limestone at the offshore of the ancient ocean, different calcites induced by Synechocystis sp. PCC6803 in culture media with low Mg/Ca r...

Summary The present study provides the length–weight relationships (LWRs) for 64 fish species belonging to eight families from the lower sections of Wujiang River, a tributary of the upper Yangtze River in China. LWRs for eight of these species are unknown to FishBase and new maximum body weights are recorded for 25 species. In addition, some basic biological information on 64 fish species is also summarized. These results will be useful for fishery research, management and conservation in the Wujiang River.