Crucian carp Carassius auratus is rich in genetic diversity, and becomes a good candidate for research of molecular markers or genes associated with those growth traits. In the current study, 79 SSR and 22 EST-SSR markers were chosen to analysis the genom- ic of 181 progenies from a crucian carp F2 family. A GLM （General Linear Model） procedure was used to analyze the correlation be- tween markers and four growth traits including body weight, body length, body depth and body width. The significance testing by Per- mutation test（ 10 000 replicates）, 22 makers were shown to fit the correlation from four growth traits （P〈0.05）, very significant corre- lation （P〈0.01） for HLJYJ15 and HLYJ244. Markers and gene types related to the four growth traits were obtained from this research, which gives effective basis to the study of crucian carp marker-assisted breeding and genetic mechanism of growth traits.

The chromosome numbers and karyotypes were observed, and compared in offsprings of backcross of purse red carp （hybrids of common carp Cyprinus carpio and crucian carp ♂ Carassius auratus × purse red carp 8 Cyprinus carpio var. wuyuanensis） by intraperitoneal injection of phytohemagglutinin （PHA） and colchicines to evaluate the chromosome genetics of the offsprings. The results showed that the chromosome numbers of the two backcross offsprings of common carp and crucian carp were both 150, and divided into four chromosome groups of each being consisted of 3 homologous chromosomes, depending upon the position of centromere. In the backcross offsprings of the purse red carp, chromosome numbers and karyotypic formula were expressed to be 3n = 150, NF=252 and 3n=66m＋36sm＋18st＋30t. The backcross offsprings of common carp, chromosome numbers and karyotypic formula were found to be 3n=150, NF=234 and 3n =60m＋ 24sm＋ 36st＋30t.

In vivo pharmaeodynamics of high （50 mg·kg^-1 ） / middle （20 mg·kg^-1 ） / low （5 mg·kg^-1 ） concentration of florfenicol and chloramphenicol （ 10 mg·kg^-1, control group） were studied through negative control group （no bacterial infection or drug given） and positive control group （infected by bacterial but no drug given and by establishment of a pathological model in Siberia sturgeon （Acipenser baeri）infected by pathogenic bacterium Yersinia ruckeri. The cumulative mortality rates were found of 0% in negative control group and of 50% in positive control group three days after continuous oral administration of florfenicol, indicating that the pathological model was successful, the cumulative rate of 30% in low florfenicol group, 0% in middle florfenieol group, 0% in high florfenicol group, and 10% in treatment control group. After healing, no bacterial infection was found in the fish blood. The pathogenic bacterium Y. ruckeri was isolated from the liver and kidney of the experimental fish except negative control group, causing no death. The results showed that florfenicol had better effects in treatment of Siberia sturgeon infected by Y. ruckeri than chloramphenicol, and replaced chloramphenicol to treat bacterial diseases in fish.

Residues of florfenicol and its major metabolite florfenicol amine were detected in vivo in common carp （Cyprinus carpio） with body weight of （ 100＋ 10） g orally gavage administrated 3 times in a 24 h interval at a dose of 15 mg·kg^-1 body weight by high performance liquid chromatography tandem mass spectrometry to evaluate the withdrawal period of the drug at water temPerature of （ 18±1 ）℃. The contents of florfenicol and florfenicol amine were monitored in the muscles and skins 0.5h, lh, 2h, 4h, 8h, 12h, 24h, 2d, 3d, 5d, 7d, 10d, 15d, and 20d after the drug delivery. The results showed that the florfenicol in the common carp was metabolized in vivo rapidly, peak in 2-4 hours. There was more florfenicol and its metabolite florfenicol amine residues in the muscles than those in the skin, and the florfenicol contents in the muscles and skins higher than the florfenicol amine residues in the same tissues, showing rapid metabolism in the skin. The withdrawal period of the drug was found to be over 2 d according to EU standard and over 10d ac- cording to Japanese standard.

A feeding trail was conducted to investigate compensatory growth in NEW GIFT tilapia （Oreochromis nilotic us ） fed by vari- ous patterns. The NEW GIFT with initial body weight of about 31.65 g were reared in 12 stainless steel tanks with a diameter of 1.0 m at a rate of 20 individuals per tank and fed daily （ group A, control group ）, once every other day （group B ）, fed for three days every 1 day starvation （ group C ） and fed for five days every 1 day starvation （ group D ） for 47days with triplication at water temperature of 23.7 ℃ -31.2 ℃. The growth rate were shown to be significantly higher in group D than other group （including the control group ） （P〈0.05）, reached164.76%;The food intake and specific growth rate were shown to be significantly higher in group B, group C and group D than those in the control group （P〈0.05）;There was significantly higher feed efficiency in group B and group D than that in control group （P〈0.05）,all reached above 70%. It indicated that over-compensatory growth ability was observed in group D, whereas only partial compensation growth was found in group B and group C. The compensatory growth in the NEW GIFT after starvation was primarily attributed in enhancing appetite and food intake, but the improvement of feed efficiency has certain contribution to the com- pensatory growth. The results have certain guiding significance for scientific breeding and the production oftilapia.

The half-smooth tongue-sole （Cynoglossus semilaevis Gu ntuer） with body weight of （ 120.65± 1.57g）were reared in circu- lar 0.75 m： bottom surface area tanks at a rate of 30 fish/tank under photoperiod of 0L：24D, 6L： 18D, 18L：6D and 24L：0D for 28d at water temperature of 25.2 -8.2℃ to evaluate effects of photoperiod on growth and antioxidant index.. The results showed that the minimal food conversion ratio, and the maximal weight gain rate and net weight gain were observed in the fish in photoperiod of 6L/18D. Under the photoperiod of 24L/0D, the maximum specific activity of superoxide dismutase （SOD） was found in the liver of the fish while there were no significant differences in SOD activity in the spleen and kidney （P〉0.05）. The maximal specific activity of catalase （CAT） was found in the serum in photoperiod of 6L/18D, significant higher in spleen in 6 L/18D than that in other groups （P〈0.05）. There were no significant differences in CAT activity in liver and kidney under four photoperiods （P〉0.05）. There was sig- nificant higher glutathione （GSH） content in the liver than that in the serum, spleen and kidney （P〈0.05）. The GSH content in the liv- er was found significantly higher in 6L/18D than that in OL/24D and 24L/0D （P〈0.05）while the malonaldehyde （MDA）content in serum significantly lower than that in other groups （P〈0.05）. The MDA in the liver was found to be the minimum in 0L/24D, signifi- cant higher in 18L/6D than that in 0L/24D （P〈0.05）. The minimum MDA activity in spleen and kidney was observed in 6L/18D, indicating that 6L/18D is the optimum photoperiod for growth of the fish.

The sperm motility of Siberian char （Salvelinus leucomaenis） was observed in the semen activated by activators water or BSS. The results showed that the rapid movement time of A and B degrees was 34.83±2.15 s and 36.70±3.26 s, respeetively. The life span of the spermatozoa was shown to be 120.26±5.75s when the semen activated by water and 117.45±4.33s when activated by BSS, with activating ratio of more than 98%. BSS was found to have a better performance on activating than water. There was a nega- tive correlation between sperm motility, activating ratio, life span and storage time at the water temperature of 4℃ and 15℃. The sperm preserved in 1 -2 h had better motility and quality without significant effect on artificial insemination.

Fertilizing rates were determined at various developmental stages of rainbow trout embryos by fluid J1, and fluid J2 and fixed by Bouin＇s fluid and then stripped membrane. The fertilizing rates of the embryos treated by differential fluid J1 were found to be 53.21% at two cell stage, 77.89% at four cell stage, 82% at eight cell stage, 88.2% at morula stage, 87.71% at early blastula stage, and 81.43% at mid-gastrula stage. The embryos treated by differential fluid J2 had fertilizing rates of 51.64% at two cell, 77.86% at four cell stage, 81.43% at eight cell stage, 89.07% at morula stage, 87.50%, at early blastula stage, and 81,86% at mid-gastrula stage. The results suggested that the two kinds of differential fluid be all used detection of fertilizing rate in production practice without sig- nificant differences from the Bouin＇s fluid treatment （P 〉0.05 ）. There was different distinguishing accuracy at various developmental stages, far lower at cell division stage than from morula stage to blastula stage, which is attributed to the asynchrony of embryonic de- velopment and small amount of embryonic cells in prophase. The optimal developmental stage for detection of fertilizing rate of rain- bow trout was observed from morula to blastula （ 12-24℃·d）.

An investigation was conducted on the community structure ofmacrobenthos in the Xunbiela River from September to Oc- tober in 2011, and the water quality was assessed with biotic indices. A total of 55 species of macrobenthos were collected, belonging to 15 orders and 28 families, with 37 species of aquatic insects （67.27% of the total） belonging to 16 families and 7 orders. Pentaneura sp., Radix lagotis and Polypylis hemisphaerula） were of the first three species in incidence order. The macrobenthos were found at an average density of 64.80 ind·m^-2 and at a biomass of 4.43 g·m^-2. The predators including 23 species were predominately found in all fimctional feeding groups, the others including 15 shredders, 11 collectors and 6 scrapers. The BI assessment revealed that the water quality in Xunbiela River was clearer.

The benthic fauna and biodiversity surveys were carried out in Zhalong Nature Reserve located in the Songnen Plain, the first nature reserve for red-crowned cranes and other large waterfowls and wetland ecosystems, in the spring, summer and antumn of 2008. The results showed that the benthic fauna were composed ofArthropoda, Mollusca and Armelida, and a total of 93 species （gen- era） were observed in Zhalong Wetland. The maximal number of macrobenthos species was found in spring and autumn months, and the minimal number of species in summer. The Margalef species richness index （d）, Shannon-wiener index （H＇） and Pielou evenness index （J） for the benthic fauna were found to be the maximum in spring and the minimum in summer; Sirmpson dominance index （D） , however, was found to be the maximum in summer, followed by in autumn, and the minimum in spring.

The analysis of successive three year data from 2009 to 2011 revealed that the power station construction had some impact on partial Haba River reach, the ecological community gradually changing from natural river type to reservoir type, and diversity of aquatic higher plants being changed consequently. During the development of power station, the aquatic higher plants was changed from the river type emerged plants and hygrophytes to reservoir type submerged plants and marsh plants, and the furthest distribution distance Lmax was reduced from 33 m to 12 m. In the diversity index, there were no higher plants in the reservoir area of power station A which was under construction, with richness index of 0.57 in its lower reach. The value of its reservoir area was found 0.42, and the value of lower reach 0.57 in the power station C where was built many years ago, indicating that power station development affected richness index temporarily, without significant variation in number of aquatic plant species composition. The 13 diversity index was found to be changed by 100% during the construction process, and as high as 87% before and after running of the power station, show- ing significant differences in the β diversity index for aquatic higher plants.

In order to ensure fish survival instead of winterkilling due to suffocation during wintering, wireless monitoring of dissolved oxygen level and control system of an aerator is designed in this paper. The system works safely and reliably, ensuring the security of the over winter fish production, and has improvement of the fish survival rate during wintering.

Biological study of Silurus glaris Linnaeus that was transplanted in Yili River before was conducted, including of morpholo- gy measurement, age and growth relationship, reproduction and feeding habit. Growth equation of this fish species was calculated based on Von .Bertalanffy＇s method. The fish catches composed of individuals with body length of 16-121 cm, mainly in 40-70cm （60.36%）, individuals with body weight of 50-13400g, mainly in 500-20000g （56.7%） and individuals at 0^＋-8^＋ years old, mainly at 1^＋-3^＋ ages （55.85%）. The number of recruit populations was more than that of residual populations. The growth parameters were L∞=191.1cm, W∞=59 875g, -k=0.087, t0=0.038, tmax=34.5 and trt=12.7, respectively. Silurus glaris were able to achieve sex maturity and reproduce in June every year as it growed 4^＋ years old, 70cm and 3500g. The male fish had habits of construction net and protection egg, which were behaviors of typical carnivore. This fish species have advantages of fast growth, big body, strong adaptation and ex- tensive abilities, and easy to form populations when transplanted, therefore, Silurus glaris had become one of ecological fish species in Yili River.

An industrial aquaculture system, a kind of aquaculture practiced industrial technology, is characterized by high density, saving water resources and less pollution. The efficient and reasonable increase in dissolved oxygen level can effectively improve the efficiency of facilities, equipment, and reduce the costs of production, and thus is one of the key technologies in the industrial aquacul- ture system. The present paper describes some characteristics of ventilative equipment and technology and the efficiency of aeration. Meanwhile, some problems of the oxygenation technology are analyzed and the trend of aeration application and innovative technolo- gy is discussed to provide information on increase in dissolved oxygen level in an industrial aquaculture system for further study.

Reduction of alkalinity via aquaculture＇ is an effective approach to exploit 46 million hm^2 saline-alkali waters in China. The osmotic pressure, energy budgets, growth and development, organization function, plasma electrolyte concentration and many oth- ers aspects in fish are influence by high salinity in the water, and the high alkalinity leads to ＂alkali disease＂ and various abnormal re- actions of physiological, biochemical and behavioral, even quick death. Some synergistic effects of salinity, alkalinity and pH are found, and the higher concentration of saline-alkali than the normal values will result in synergistic toxicity in the fish, with the more synergistic effects with increase in pH values. The information on effects of salinity, alkalinity and pH on growth and development in fish is summarized, and the growth mechanism of fish in the saline-alkali waters is discussed in order to provide theoretical basis for the development and utilization of the low-lying saline-alkali waters.