The heart beating frequency, gill ventilating frequency and survival were observed in the Siberian sturgeon （marketable fish with mean body weight of 1.09± 0.58kg, and mean body length of 60.1 ±6.13cm, and juveniles with mean body weight of 24.69± 5.14g, and body length of 19.27± 2.43） exposed to acute changes in temperature from 25 ℃ to 1-2℃ without water during the acute cooling, and the recovery process, and at 2℃. It was found that the Siberian sturgeon had a decline heart beating intensity, and then showed decrease in heart beating frequency. The gill ventilating frequency was found to change from 75 times / min gradually to 0 times / min, without linear relationship with the heart beating rate. In the recovery process, the heart beating pattern was shown to have a similar tendency to the fish in low temperature, with the enhanced strength and increase in the heart beating frequency. The juveniles sturgeon was shown to recovery at water temperature of about 12 ℃-15 ℃, and to irritate, rapid swimming, floating heads out of the water, and even death 3h later, mortality up to 100%, at water temperature of higher than 18 ℃. It is suggested that the juvenile Siberi- an sturgeon transportation at low temperature without water be carried out under gradual temperature enhancement for less than 12h.

Abstract： Two indoor trials were conducted to study effects of various light intensities and colors on aggregation of juvenile sea cucumber（Apostichopus japonicus Selenka） with body weight of 0.10-0.17 g. In the first trial, the sea cucumber was stocked into a white plastic tank（50 cm × 40 cm× 30 cm）, 7 cm apart from one end of which 15W, 25W, 40W, 60W, and 100 W bulbs were displaced and covered with black plastic sheet for 24 h. The aggregation of the sea cucumber was observed and recorded in different regions of the tank at water temperature of 9.0-16.0℃ in a 2 hour interval for 24 h with triplication. In the second trial, 50 healthy individuals of sea cucumber were stocked into a flowing sea water plastic tank consisted of a large compartment connected to six small compartments by a 1.5 cm height crevice. There was red （wave length of 639 nm）, yellow （wave length of 587 nm）, green （wave length of 548 nm）, blue（wave length of 435 nm）, or white bulb on the 5 small compartments and no any bulb on the rest small compartment as control. During the second trial, the recycling water tank was covered by a thick paper plate with a photoperiod of 12 h light： 12 h dark, and the number of the sea cucumber was observed and recorded in a 3 hour interval for 24 h with octoplication. The results showed that more sea cucumber were found in the farthest region IV in the tanks, the maximum in the tanks exposed to the 40 W bulb withlight intensity of 12~ 19 lx. More sea cucumber was showed to aggregate in the small compartment exposed to red light than in the small compartments exposed to other light colors, very significantly between in the red compartment and blue and white compartments （P 〈 0.01）, significantly between in the red compartment and in the control compartments （P〈0.05）, significantly between in the white compartment and in the green compartment （P〈0.05）, indicating that the sea cucumber was very sensitive to red light.

The reproductive biology and artificial breeding technology were studied in Hemibarbus maculates Bleeker.In the experiment,the age and minimal size at maturity,fecundity,gonadal development,spawning time and temperature,and morphological distinguishment of sex were understood in Hemibarbus maculates Bleeker.In artificial breeding,the effects of various hormones on spawn induction of the fish were compared in the fish with spawning success of 100%,fertilization rate of 95.3%,hatching rate of 95%.About 1412 00 individuals of fry were obtained.

The embryonic development of burbot（Lota lota） was observed consecutively and divided into 6 stages fertilized egg,cell division,blastula,gastrula,neurula and organogenesis,including twenty developmental phases,whose characteristics were described.The larvae hatched 998 hours after fertilization at water temperature of 0~3℃,with a cumulative temperature of 887~1023h·℃.The comparison of the fertilization rate between spontaneous and artificial insemination showed that there was about 10% higher fertilization rate in the artificial insemination（30%） than that in the spontaneous fertilization（19.4%）.It was found that various embryonic development stages showed different sensitivity to the ambient environment.Three peaks of mortality were observed on from blastdisc stage to two-celled stage and from morula stage to early gastrula stage,and hatching stage during the embryonic development of the turbot.

This paper systematically invested the fish resources included 3095 individuals of the Xiquanyan Reservoir and identified 30 fish species,which belonging to 6 orders,11 families and 30 genera.And the carp families had 21 species and occupied 70% of the total number.And also analysis the fish diversity of the reservoir by three methods such as Pinkas relative importance index,Shannon-Weaver diversity index and Pielou evenness index.The Pinkas relative importance index about Xiquanyan Reservoir（IRI）draw a conclusion that the middle and small fish had three dominant species,which including Hypomesus olidus、Hemiculter leucisculus and Saurogobio dabryi;the dominant species of the stocked carps were Hypophthalmichthys molitrix and Aristichthys nobilis.The Shannon-Weaver index value（H′）varied from 0.1373 to 0.2129 and the Pielou index value varied from 0.0404 to 0.0626.General,the fish diversity in Xiquanyan Reservoir were in low level and the stability was bad.Finally,the paper proposed the protective suggestions of fish species diversity in Xiquanyan Reservoir.

The plankton composition was studied in six mandarinfish Siniperca chuatsi ponds and bait fish ponds in the breeding base in Qingyuan City,Guangdong Province during hot and rainy seasons.The results showed that lower total biomass of plankton were generally observed in the epidemic ponds than in other ponds.Microcystis sp,Oscillatoria sp and other Cyanobacteria were found the dominant phytoplankton species.In addition,Margalef abundance index and Shannon-weaver index were found at a low level when the hemorrhage symptoms appear in the fish,indicating that these two indices were used as disease warning index in reference pond.Read phonetically The water quality should be regulated,especially at poor weather for the diseased ponds,so that biomass and composition of plankton were stable in practices.

The present paper analyzed the spatial and temporal distribution of bacterial community from Hejia village river stretch in Hailang river.The results was concluded that the bacteria isolated from above belonged to five bacterial genera,among which Micrococcus was the preponderant genus and followed by Pseudomonas and zoogloea.For the time distribution,the number of bacterial communities from water samples got the highest value in May 2009 and the minimum in January 2010,whereas the number of bacterial communities from soil samples got the highest value in May 2009 and the minimum in July 2009.For the spatial distribution,the total number of bacterial communities from both water and soil samples in 8,9 and 10 points was higher than the others,but the bacterial genera in various points was not significantly different.

It is significant of rapid measurement of crab sperm counts to study sperm cryopreservation and population reproduction.A spectrophotomeric method was used to determine the sperm concentration of swimming crab Portuns trituberculatus and Chinese mitten crab Eriocheir sinensis at wavelengths of 380,520,and 760 nm.It was found that the sensitive and reliable rapid measurement of crab sperm counts was carried out at 520 nm.A linear relationship between sperm concentration（C） and photometric absorbance（A） was observed for sperm concentration of swimming crab and Chinese mitten crab.The best regression equation for the standard curve at 520 nm was expressed as A= 0.058×C（R2=0.9928） for the swimming crab and A=0.061×C（R2=0.9892） for Chinese mitten crab.Statistical analysis showed that this spectrophotomeric method was fast and accurate for sperm count.

Perca fluviatilis is a kind of high-quality commercial fish which distributes only in Aletai district of Xinjiang in China.To protect and develop this limited resources rationally,genetic diversity and genetic structure of five wild populations of P.fluviatilis from Irtysh-Wulungu river system were investigated based on mtDNA control region sequences.The results of PCR-SSCP analysis indicated that there were 18 haplotypes distributed in five populations of 100 individuals.After these haplotypes were cloned and sequenced,thirteen haplotypes were identified,fourteen variable sites were detected which accout for 1.60% of total sequence.The P.fluviatilis populations showed a high haplotype diversity（0.942±0.034） and a relatively lower nucleotide diversity（0.00242±0.00450）.Tajima’s and Fu and Li’s D index showed that genetic differentiation among P.fluviatilis populations was not significant（P〉0.1）,population structure of P.fluviatilis was stable.There was a gene flow among YBW,BEJH and LSW populations to some extent（Nm〉1）,while the level of gene flow between WLGH population and other populations was low,there was a risk of differentiation due to genetic drift.Sequence difference of five populations was 0.003 which revealed a low level genetic diversity.

Florfenicol,a new type of veterinary chloramphenicols with broad spectrum,has been widely applied in the prevention and control of bacterial diseases in livestock,poultry and aquatic animals.However,it is inconvenience to use due to low aqueous solubility,low concentration of preparations and unstable for long-term storage.In this study,the effects of supplement of dimethyl sulfoxide（DMSO）,methanol and ethanol as a florfenicol cosolvent at a dose of less than 70% on the maximum concentration and the stability of the florfenicol aqueous solution were studied under water temperature of 4℃,20℃ and 30℃.Meanwhile,the antimicrobial effects of the cosolvents were determined by a bacteriostat experiment.The results showed that DMSO was found to be the optimal cocosolvent for the florfenicol aqueous solution and to have the minimum effect on drug potency.As high as 2% florfenicol solution was observed when the methanol was as the cosolvent while only 0.7% florfenicol solution was obtained when the ethanol was as the cosolvent.However,the preparations of florfenicol aqueous solution containing cosolvents methanol and ethanol showed better stability under the lower temperature and long-term storage（7 days） than DMSO did,even though both the methanol and the methanol showed high effect on the bacteriostasis of florfenicol.

The effects of three traditional Chinese medicine compounds（AB,CD,and AH） on lysozyme activities in serum,hepatopancreas and Spleen were studied in 1＋ age health crucian carp（Carassius auratus） weighing（44.6±0.2） g were studied at water temperature of 18 ℃.The fish were fed the diets containing AB,CD,AH or basic diet without any Chinese medicine compounds at a feeding rate of 2.0% for 28 days.Blood and tissue samples were collected 1 day after fasting to be assayed for the lysozyme activity.The results showed that the three Chinese medicine compounds improved the lysozyme activity in the crucian carp.There was significant increase in serum lysozyme activity in the fish fed the diet containing AB than that in the control group.The fish fed the diets containing AB,and CD had significant enhancement of hepatopancreas lysozyme activity.However,significant higher lysozyme activity was found in the spleen of the fish fed the diet containing the three traditional Chinese medicine compounds.It is concluded that the traditional Chinese medicine compounds can enhance crucian carp immunity,and have a value for further research and application.Still,the medicine mechanism and functions are needed for further research due to organ and tissue specialization for the three compounds.

Ozone disinfection of water is one kind of key technology in water treatment of recirculating aquaculture system.This paper describes the physical and chemical nature of ozone and several ways of manufacturing,dissolving and detection of ozone.Based on aquaculture water treatment technology research and development trends,some of the role and the application feature that ozone used in aquaculture water treatment factory are analyzed.In recirculating aquaculture,ozone can be used in disinfection and sterilization,oxidation of organic compounds,suspended solids cohesion,deodorization and decolourization.Meanwhile,the application prospect of ozone was discussed.

The production and developmental process of fish medicines was introduced,and the status of application and management was interpreted in China.And it was very necessary to develop the environment-friendly fishery medicines,the future of which was also stated.Meanwhile,in this paper we pointed out the various problems in several aspects of fishery medicines including basic research,safety use and establishment of management system.In accordance with these problems,some advices were suggested from strengthening basic research,developing new high-efficiency and environment-friendly fishery medicines,and effective evaluation methods and rules,and perfecting the management systems.

This paper mainly discussed the safety management and defensive measures of local area network（LAN） in several aspects,including network segment,VLAN division,firewall technology,network version of antivirus software and prevention of hacker attack.