The Use of Cyanobacteria Arthrospira platensis and Cladoceran Daphnia magna as Complementary Protein and Lipid Sources in Transitional Diet for Common Carp (Cyprinus carpio L.) Nursery

This study was conducted to evaluate the use of cyanobacteria Arthrospira platensis and cladoceran Daphnia magna biomass as complementary protein and lipid sources in diet supplementation for common carp (Cyprinus carpio L.) nursery. Three experimental diets containing A. platensis and D. magna meal at different concentrations were compared to the commercial (control) diet. Each experimental diet (ED) was set to contain D. magna and A. platensis meal at a specific combination: 2% and 5%, 2% and 7%, and 4% and 5% for ED1, ED2 and ED3, respectively. The protein and lipid content of the experimental diets ranged from 43.20% to 44.60% dry weight (DW) and 10.64% to 13.42% DW, respectively;while the protein and lipid content of the control diet were 43.00% DW and 6.72% DW, respectively. After 20 days of feeding period, ED3 group obtained the highest final body weight (BW) (58.18 ± 35.24 mg), total biomass (1936 ± 1625 mg), food conversion rate (1.34 ± 0.04), and specific growth rate (12.86 ± 0.03% BW day–1) among all treatment groups (P > 0.05);while ED1 group obtained the highest survival (75.5% ± 7.47%) among all treatment groups (P > 0.05). The total bacterial count and total pathogenic Aeromonas sp. in the culture water of the treatment groups (ranged from 2.00 to 2.65 × 105 CFU mL–1 and 3.50 to 4.12 × 103 CFU mL–1, respectively) were lower compared to the water of the control group fed (3.73 × 105 and 4.70 × 103 CFU mL–1, respectively). No significant differences in physicochemical water quality parameters were observed among treatments (P > 0.05). The current study suggests that the combination of A. platensis and D. magna biomass can be used as complementary protein and lipid sources in diet supplementation for common carp larvae and can result in a comparable fish growth, survival and feed utilization in common carp culture at the nursery phase.

Quantitative genetic estimates of growth-related traits in the common carp(Cyprinus carpio L.):A review

The common carp(Cyrpinus carpio L.)is the oldest cultured and the most domesticated fish species,as well as one of the most important freshwater fishes in the world.However,scientific studies on evaluating the growth-related quantitative traits in this fish are limited.Heritability,the most important parameter in selective breeding programs,was extensively studied for the growth-related traits.The values varied widely among the experiments and methods used because of the existence of common environmental,dominance and maternal effects.However,correlations in phenotypic and genetic levels first evaluated several years ago were limited.On the other hand,heterosis was widely reported and easily obtained for growth-related traits in the common carp.Meanwhile,genotype environment interaction and prediction of breeding values have been studied recently,and are very important in conducting selective breeding programs.The developmental quantitative genetics of growth-related traits was first analyzed in the common carp for reasonable selection during ontogeny.It is expected that genetic improvement will be achieved by carrying out direct selective breeding in the common carp.

养殖池塘黄河鲤肠道硫酸盐还原菌群落特征解析

为探究鱼类肠道硫酸盐还原菌(sulfate-reduction bacteria,简称SRB)的群落特征,本研究选用黄河鲤(Cyprinus carpio L.)为研究对象,通过SRB功能基因(dsrB)高通量测序技术,对黄河鲤前、中和后肠SRB功能群进行检测。研究结果显示:黄河鲤肠道SRB主要分布在中肠和后肠,中肠SRB主要包括变形菌门(Proteobacteria)的脱硫球茎菌属(Desulfobulbus)、脱硫弧菌属(Desulfovibrio)、互营杆菌属(Syntrophobacter),厚壁菌门(Firmicutes)的脱亚硫酸菌属(Desulfitobacterium)和绿弯菌门(Chloroflexi)的暖绳菌属(Caldilinea);后肠SRB主要分布在变形菌门的脱硫球茎菌属、脱硫弧菌属、脱硫菌属(Desulfotalea)、互营杆菌属、脱硫念珠菌属(Desulfomonile)和鞘氨醇单胞菌属(Sphingomonas)。依据高通量测序结果的FAPROTAX(Functional Annotation of Prokaryotic Taxa)数据库代谢功能预测显示,黄河鲤肠道SRB主要参与硫化合物呼吸、硫酸盐呼吸和化能异养功能。