元江鲤与荷包红鲤的生态类型及其杂交后代(荷元鲤)经济性状的分析

以属于华南鲤Cyprinus carpio rubrofuscus lacepede的高原河流性野生种元江鲤为父本与经人工选育的地方养殖种荷包红鲤为母本进行杂交获得的F1（荷元鲤），具有明显的杂种优势。     

Effects of body size and water temperature on food consumption and growth in the sea cucumber Apostichopus japonicus (Selenka) with special reference to aestivation

To investigate the effects of body size and water temperature on feeding and growth in the sea cucumber Apostichopus japonicus (Selenka), the maximum rate of food consumption in terms of energy (C_maxe; J day^?1) and the specific growth rate in terms of energy (SGRe; % day^?1) in animals of three body sizes (mean±SE) – large (134.0±3.5 g), medium (73.6±2.2 g) and small (36.5±1.2 g) – were determined at water temperatures of 10, 15, 20, 25 and 30°C. Maximum rate of food consumption in terms of energy increased and SGRe decreased with increasing body weight at 10, 15 and 20°C. This trend, however, was not apparent at 25 and 30°C, which could be influenced by aestivation. High water temperatures (above 20°C) were disadvantageous to feeding and growth of this animal; SGRe of A. japonicus during aestivation was negative. The optimum temperatures for food consumption and for growth were similar and were between 14 and 15°C, and body size seemed to have a slight effect on the optimal temperature for food consumption or growth. Because aestivation of A. japonicus was temperature dependent, the present paper also documented the threshold temperatures to aestivation as indicated by feeding cessation. Deduced from daily food consumption of individuals, the threshold temperature to aestivation for large and medium animals (73.3–139.3 g) was 24.5?25.5°C, while that for small animals (28.9–40.7 g) was between 25.5 and 30.5°C. These values are higher than previous reports; differences in sign of aestivation, experimental condition and dwelling district of test animals could be the reasons.     

Effect of dietary protein reduction with lysine and methionnine supplementation on growth performance,body composition and total ammonia nitrogen excretion of juvenile grass carp,Ctenopharyngodon idella

A 63‐day growth trial was undertaken to estimate the effects of supplemented lysine and methionine with different dietary protein levels on growth performance and feed utilization in Grass Carp (Ctenopharyngodon idella). Six plant‐based practical diets were prepared, and 32CP, 30CP and 28CP diets were formulated to contain 320 g kg^?1, 300 g kg^?1 and 280 g kg^?1 crude protein without lysine and methionine supplementation. In the supplementary group, lysine and methionine were added to formulate 32AA, 30AA and 28AA diets with 320 g kg^?1, 300 g kg^?1 and 280 g kg^?1 dietary crude protein, respectively, according to the whole body amino acid composition of Grass Carp. In the groups without lysine and methionine supplementation, weight gain (WG, %) and specific growth rate (SGR, % day^?1) of the fish fed 32CP diet were significantly higher than that of fish fed 30CP and 28CP diets, but no significant differences were found between 30CP‐ and 28CP‐diet treatments. WG and SGR of the fish fed 32AA and 30AA diets were significantly higher than that of fish fed 28AA diets, and the performance of grass carp was also significantly improved when fed diets with lysine and methionine supplementation (P < 0.05), and the interaction between dietary protein level and amino acid supplementation was noted between WG and SGR (P < 0.05). Feed intake (FI) was significantly increased with the increase in dietary protein level and the supplementation of lysine and methionine (P < 0.05), but feed conversion ratio (FCR) showed a significant decreasing trend (P < 0.05). Two days after total ammonia nitrogen (TAN) concentration test, the values of TAN discharged by the fish 8 h after feeding were 207.1, 187.5, 170.6, 157.3, 141.3 and 128.9 mg kg^?1 body weight for fish fed 32CP, 32AA, 30CP, 30AA, 28CP and 28AA diets, respectively. TAN excretion by grass carp was reduced in plant‐based practical diets with the increase in dietary protein level and the supplementation of lysine and methionine (P < 0.05). The results indicated that lysine and methionine supplementation to the plant protein sources‐based practical diets can improve growth performance and feed utilization of grass carp, and the dietary crude protein can be reduced from 320 g kg^?1 to 300 g kg^?1 through balancing amino acids profile. The positive effect was not observed at 280 g kg^?1 crude protein level.     

Effects of genetically modified and non‐genetically modified soybeans with different heat treatments on growth and health of Cyprinidae species with different feeding habits

An 8‐week growth trial was conducted to investigate the effects of non‐genetically modified (nGM) soybean (Youchun 06‐1) and genetically modified (GM) soybean (Roundup Ready^®) with and without a heat treatment on the growth and health of three Cyprinidae species with different feeding habits (grass carp Ctenopharyngodon idellus, gibel carp Carassius auratus gibelio, and black carp Mylopharyngodon piceus; body weight: 283.0 ± 2.0 g, 60.5 ± 0.7 g, and 261.4 ± 3.1 g). Five diets (FM, nGMS, hnGMS, GMS, and hGMS) were made with fishmeal and full‐fat soybean (Youchun 06‐1, heat‐treated Youchun 06‐1, Roundup Ready^®, and heat‐treated Roundup Ready^®). The FM diet contained fishmeal as the sole protein source. The experimental diets contained full‐fat soybean meal as 60% of dietary protein. Both temperature (60, 80, 100, and 120°C) and duration (1 and 2 hr) of heating influenced trypsin inhibitor activity (TIA) and protein solubility of nGM soybean and GM soybean. The TIA in GM soybean was higher than that in nGM soybean. After heating at 120°C for 2 hr, each amino acid of soybean treatment showed a slight decline. Neither source of soybean nor heat treatment affected the growth performance, feed utilization, chemical composition of the whole fish body and muscle, and lipase or amylase activity of the three Cyprinidae species (p > 0.05). Heat treatment of soybean meal slightly increased the plasma antioxidant capacity of the three fish and plasma cholecystokinin of black carp and grass carp. The unheated soybean treatment adversely affected the height and density of black carp intestinal villi, and all the soybean treatments caused disruption of the grass carp intestinal epithelium.     

Generation and characterization of aptamers against grass carp reovirus infection for the development of rapid detection assay

Grass carp reovirus (GCRV) causes devastating viral haemorrhagic disease in farmed grass carp (Ctenopharyngon idellus). As novel molecular probes, aptamers have been widely applied in rapid diagnosis and efficient therapies against virus or diseases. In this study, three single‐stranded DNA (ssDNA) aptamers were selected against GCRV‐infected CIK cells via SELEX (systematic evolution of ligands by exponential enrichment technology). Secondary structures predicted by MFOLD indicated that aptamers formed stem‐loop structures, and GVI‐11 had the lowest ΔG value of ?30.84 KJ/mol. Three aptamers could specifically recognize GCRV‐infected CIK cells, with calculated dissociation constants (Kd) of 220.86, 176.63 and 278.66 nM for aptamers GVI‐1, GVI‐7 and GVI‐11, respectively, which indicated that they could serve as specific delivery system for antiviral therapies. The targets of aptamers GVI‐1, GVI‐7 and GVI‐11 on the surface of GCRV‐infected cells could be membrane proteins, which were trypsin‐sensitive. Furthermore, FAM‐labelled aptamer GVI‐7 could be applied to detect GCRV infection in vivo. It is the first time to generate and characterize aptamers against GCRV‐infected cells. These aptamers have great potentials in development of rapid diagnosis technology and antiviral agents against GCRV infection in aquaculture.     

Effects of dietary lipid level on growth performance,body composition and digestive enzymes activity of juvenile sea cucumber,Apostichopus japonicus

A feeding trial aimed to determine the effects of dietary lipid level on growth performance, body composition and digestive enzymes activity of juvenile sea cucumber, Apostichopus japonicus. Diets with six crude lipid levels (1.9, 13.8, 29.1, 43.6, 59.6 and 71.6 g kg^?1) were fed to sea cucumbers (initial weights 0.65 ± 0.01 g) at a density of 30 juveniles, once a day. After 60 days, body weight gain (BWG), specific growth rate (SGR), feed intake (FI) and protein efficiency ratio (PER) decreased with increasing dietary lipid levels. The sea cucumbers fed 1.9 g kg^?1 crude lipid showed significantly higher (P < 0.05) BWG than those of the sea cucumbers fed 59.6 and 71.6 g kg^?1 crude lipid. Intestinal protease and lipase activities generally increased with increasing dietary lipid levels. Eicosapentaenoic acid (EPA) content of body walls generally increased with increasing dietary lipid levels. Docosahexaenoic acid (DHA) content of body walls reached the maximum value at a dietary lipid level of 13.8 g kg^?1. N‐3 highly unsaturated fatty acid content followed the same pattern of DHA. According to the growth performance and body composition of sea cucumbers, it can be indicated that the optimum dietary lipid level for juvenile sea cucumbers is between 1.9 and 13.8 g kg^?1.     

白鲢出血病病原菌的鉴定

从患出血病的白鲢体内分离出两株细菌(编号为水_1、水_2),分别感染健康白鲢,人工复制白鲢出血病获得成功。对这两株细菌进行形态、营养需求、生长特性、以及生化反应等观察,作者认为,水_1菌为产碱假单胞菌(Pseudomonas alcaligenes);水_2菌为嗜水气单胞菌(Aeromonas hydrophila)。前者隶属于假单胞菌科(Pseudomonaceae),后者隶属于孤菌科(Vibrionaceae)。     

Validation of Xanthophyll Levels in Catfish Fillets Using Digital Photography

Catfish fillets with yellow coloration have become a prevalent problem for the catfish industry. This problem is due to the unacceptability in the market because the shift in fillet color is considered of lower quality by the consumers. To help the catfish industry better understand the yellow coloration of catfish fillet, a digital photography measurement method was developed to evaluate the yellowness. Sixty catfish fillets with a range of degrees of visible yellowness were taken directly from the processing line. The fillets were photographed in a light box with a digital camera. The photos were calibrated with the X-Rite ColorChecker standardized color target. CIELAB readings of the fillet photos were recorded, and the b* value was used to indicate the yellowness of catfish fillets. The xanthophyll levels of fillets were analyzed with high performance liquid chromatography. The actual xanthophyll level in catfish fillet was calculated as the sum of lutein, zeaxanthin, and alloxanthin. A linear correlation was found between the LAB b* values and xanthophyll levels of the 60 catfish fillets.     

饥饿和再投喂期间尼罗罗非鱼生长、血清生化指标和肝胰脏生长激素、类胰岛素生长因子-Ⅰ和胰岛素mRNA表达丰度的变化

在室内可控条件下,对尼罗罗非鱼[初始体质量(62.50±3.44)g]进行饥饿28d和随后再投喂21d的处理,于饥饿第0、7、14、21、28天和再投喂第14、21天进行采样分析,研究饥饿和再投喂期间尼罗罗非鱼生长、血清生化指标和肝胰脏生长激素(GH)、类胰岛素生长因子-Ⅰ(IGF-Ⅰ)和胰岛素(IN)mRNA表达丰度的变化。结果显示,与饥饿第0天相比,饥饿超过7d鱼体体质量显著降低(P<0.05),再投喂21d显著增加(P<0.05);肝体比随饥饿时间延长显著降低(P<0.05),恢复投喂后较饥饿时升高,但显著低于饥饿前水平(P<0.05)。在血清指标上,甘油三酯、血糖、碱性磷酸酶、谷草转氨酶和谷丙转氨酶均随饥饿时间延长而逐渐降低,恢复投喂后均有不同程度提高,但转氨酶活性显著低于饥饿前水平(P<0.05);饥饿和再投喂对血清总胆固醇、高密度脂蛋白胆固醇和低密度脂蛋白胆固醇无显著影响(P>0.05)。在激素方面,与饥饿第0天相比,饥饿使血清GH含量及其肝胰脏mRNA表达丰度显著升高,血清IGF-Ⅰ及其肝胰脏mRNA表达丰度降低,恢复投喂后两者均显著升高(P<0.05);INmRNA表达丰度在饥饿7~21d显著升高(P<0.05),饥饿第28天时无显著差异(P>0.05),再投喂后显著降低(P<0.05)。     

An artificial oyster‐shell reef for the culture and stock enhancement of sea cucumber,Apostichopus japonicus,in shallow seawater

Because of its high nutritional value and health benefits, aquaculture production of Apostichopus japonicus in China is the largest of any single species. Therefore, the development of new farming methods is of considerable significance. In this study, discarded oyster shells have been used to create an artificial reef for the culture of this species. The results have shown that from 6th March 2009 to 26th November 2009, the wet weight of sea cucumber increased from 49.57 ± 1.16 to 79.87 ± 1.46 g ind^?1. Between 16th July and 18th October, the specific growth rate and daily weight gain of A. japonicus differed significantly from other periods. Population density was higher within the reef compared with outside the reef area, and the difference was significant (P < 0.01). The maximum distance between A. japonicus individuals within the reef area on 3rd March and 16th July was 65.0 ± 3.3 and 62.9 ± 4.4 cm, respectively, but the difference was not significant (P > 0.05). The diatom species attached to the oyster shells were similar to those found in the stomach content of A. japonicus. In conclusion, the oyster‐shell reef provides a suitable habitat and shelter for the culture of the sea cucumber, A. japonicus.