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Xia S.,CAS Qingdao Institute of Oceanology | Xia S.,Tianjin Fisheries Research Institute | Yang H.,CAS Qingdao Institute of Oceanology | Li Y.,CAS Qingdao Institute of Oceanology | And 3 more authors.
Aquaculture | Year: 2013

The type of diet used in aquaculture systems affects the feed digestibility and energy budget of the organisms under culture. In this study, the sea cucumber Apostichopus japonicus (Selenka) was fed diets produced using four different processing methods (extruded pellet diet, cold-bonded pellet diet, flake diet, and mash diet), and growth performance, digestibility, digestive enzyme activity, and energy budget were quantified for 60 d to identify the optimal feed type for use in culturing this species. The specific growth rate ranged from 0.51 to 0.96; the highest rate occurred in specimens fed the extruded pellet diet and the lowest rate was found in those fed the cold-bonded pellet diet. Sea cucumbers fed the extruded pellet diet had the highest energy deposition as growth (11.45%), whereas specimens fed the mash diet had the lowest (5.79%). The apparent digestibility coefficients for dry matter (ADMD) and gross energy (AGED) of sea cucumbers fed the extruded pellet diet was higher than that of A. japonicus fed the other diets. When animals were fed the extruded diet, the amylase activity in the gut was significantly higher than in animals fed the mash diet (42.61 vs. 28.40). However, the protease activity was significantly higher in animals fed the mash diet than the extruded diet (7.75 vs. 5.55). Overall, the results of this study indicate that the extruded pellet diet is the optimum feed type for use in the culture of A. japonicus. © 2013. Source

Wang X.,CAS Qingdao Institute of Oceanology | Wang X.,Tianjin Fisheries Research Institute | Yang H.,CAS Qingdao Institute of Oceanology | Liu G.,Mariculture Institute of Shandong Province | Wang Q.,CAS Qingdao Institute of Oceanology
Chinese Journal of Oceanology and Limnology | Year: 2011

To assess the toxicity of heavy metal pollution to marine intertidal shellfish, enzymatic responses and lipid peroxidation were investigated in the clam Mactra vereformis exposed to cadmium under laboratory conditions. Three antioxidant enzymes (superoxide dismutase, SOD; catalase, CAT; glutathione peroxidase, GPx), two immune defense enzymes (acid phosphatase, ACP; alkaline phosphatase, ALP), and one lipid peroxidation product (malondialdehyde, MDA) were measured in the gills and the hepatopancreas of the clam exposed to 0, 25, 75, and 125 μg/L cadmium for 0, 1, 3, 5, and 7 d. The results show that the concentrations of antioxidant enzymes in the organs soared to a peak value on the first day and then decreased afterwards in most cases. CAT and GPx activities in the hepatopancreas were higher than in the gills, but the SOD activity was lower in the hepatopancreas. ACP activity was unchanged until Day 3 in the hepatopancreas and until Day 5 in gills, when it began to increase. ALP activity showed no significant relationship with Cd treatment. MDA concentrations increased in the two tissues after Cd exposure, peaked on Day 3 in gills, and on Day 5 in hepatopancreas. These observations show that changes in the activities of antioxidant enzymes and ACP reflect the time course of oxidative stress in the clam caused by Cd, and could be used as potential biomarkers for ecotoxicological bioassays of heavy metals. © 2011 Chinese Society for Oceanology and Limnology, Science Press and Springer-Verlag Berlin Heidelberg. Source

Li J.-T.,Chinese Academy of Fishery Sciences | Hou G.-Y.,Chinese Academy of Fishery Sciences | Kong X.-F.,Chinese Academy of Fishery Sciences | Kong X.-F.,Shanghai Ocean University | And 10 more authors.
Scientific Reports | Year: 2015

Whole genome duplication (WGD) results in extensive genetic redundancy. In plants and yeast, WGD is followed by rapid gene deletions and intense expression differentiation with slow functional divergence. However, the early evolution of the gene differentiation processes is poorly understood in vertebrates because almost all studied WGDs are extremely ancient, and the genomes have returned to a diploid status. Common carp had a very recent fourth round of WGD dated to 8 million years ago. It therefore constitutes an ideal model to study early-stage functional divergence and expression differentiation in vertebrates. We identified 1,757 pairs of recently duplicated genes (RDGs) originating from this specific WGD and found that most ancestral genes were retained in duplicate. Most RDGs were conserved and under selective pressure. Gene expression analysis across six tissues revealed that 92.5% of RDG pairs were co-expressed in at least one tissue and that the expression of nearly half pairs ceased to be strongly correlated, indicating slow spatial divergence but rapid expression dissociation. Functional comparison revealed that 25% of pairs had functional divergence, of which neo- and sub-functionalization were the main outcomes. Our analysis revealed slow gene loss but rapid and intense expression and function differentiation after WGD. Source

Bai X.,Huazhong Agricultural University | Bai X.,Tianjin Fisheries Research Institute | Huang S.,Huazhong Agricultural University | Tian X.,Huazhong Agricultural University | And 3 more authors.
Biochemical Systematics and Ecology | Year: 2015

In this study, genetic diversity and structure of three Misgurnus anguillicaudatus populations from three different geographical locations in China (Hunan, Hubei and Henan province) were investigated using microsatellite markers. High level of genetic diversity of all three populations was revealed by expected heterozygosity (He), observed heterozygosity (Ho) and allele number. Significant genetic differentiations were found between all pairs of populations. The efficiency of eight microsatellite markers in parentage assignment of 540 progeny from twenty full-sib families was evaluated. Simulation based on allele frequency data demonstrated that probabilities of exclusion per locus range from 0.313 to 0.825 when no parent information is available and 0.504 to 0.904 when one parent is known. The assignment success rate based on the real data using eight markers was 96.85%. This study indicates that these M. anguillicaudatus resources are valuable genetic and breeding material for aquaculture and the microsatellite markers will be useful for investigation of genetic background and molecular marker-assisted selective breeding in this species. © 2015 Elsevier Ltd. Source

Li C.-Y.,Chinese Academy of Fishery Sciences | Li C.-Y.,Shanghai Ocean University | Li C.-Y.,Tianjin Fisheries Research Institute | Li J.-T.,Chinese Academy of Fishery Sciences | And 8 more authors.
International Journal of Molecular Sciences | Year: 2014

Both sexual reproduction and unisexual reproduction are adaptive strategies for species survival and evolution. Unisexual animals have originated largely by hybridization, which tends to elevate their heterozygosity. However, the extent of genetic diversity resulting from hybridization and the genomic differences that determine the type of reproduction are poorly understood. In Carassius auratus, sexual diploids and unisexual triploids coexist. These two forms are similar morphologically but differ markedly in their modes of reproduction. Investigation of their genomic differences will be useful to study genome diversity and the development of reproductive mode. We generated transcriptomes for the unisexual and sexual populations. Genes were identified using homology searches and an ab initio method. Estimation of the synonymous substitution rate in the orthologous pairs indicated that the hybridization of gibel carp occurred 2.2 million years ago. Microsatellite genotyping in each individual from the gibel carp population indicated that most gibel carp genes were not tri-allelic. Molecular function and pathway comparisons suggested few gene expansions between them, except for the progesterone-mediated oocyte maturation pathway, which is enriched in gibel carp. Differential expression analysis identified highly expressed genes in gibel carp. The transcriptomes provide information on genetic diversity and genomic differences, which should assist future studies in functional genomics. © 2014 by the authors; licensee MDPI, Basel, Switzerland. Source

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