In this paper, genetic potential and the correlation between markers and economic traits (such as body weight, total length, body length) were analyzed in selective population of Huanghe carp (Cyprinus c arpio haematopterus) using 21 microsatellite markers. The number of effective alleles, observed heterozygosity, expected heterozygosity and polymorphic information content were determined, and the Hardy-Weinberg equilibrium was checked by X2 Test. A total of 122 alleles were identified on 21 microsatellite loci with polymorphism from 56 samples. The average number of alleles was 5.8095 and the average number of effective alleles was 3.3706, and the average observed heterozygosity and expected heterozygosity was 0.5893 and 0.6578 respectively. The average polymorphic information content was found to be up to 0.6108. The findings showed that there was a high genetic diversity among the selective population, with Hardy-Weinberg equilibrium. Eight markers were observed that had significant impact (P〈0.05) on 11 economic traits including body weight, total length, body length, and body depth. CAFS2203 was found to be related with body width, head width and caudal peduncle length significantly, CAFS1603 with snout length and CAFS1639 with peduncle depth (P〈0.01). The findings would be valuable for marker-assisted breeding and selective breeding.

Yolk absorption pattern, and organogenesis and differentiation were observed in different organs in early developmental stage of taimen Hucho taimen under light microscope. The results showed that the yolk was absorbed via blood circulation and early digestive tract, and exhausted within about 60-70 days beginning with yolk sphere, and then oil. The development and differentiation of the organs in the early stage were observed, the digestive tract occurring as a form of single columnar cell layer, liver being derived from the inner cell mass, and the pancreas appearing in a diffuse form of a single cell. Furthermore, the digestive tract, liver, pancreas, gall bladder, swim bladder, eyes and gills were developed and differentiated at a higher degree than the kidney and other glandular organs did. In this paper, the level of yolk absorption and organ development of the taimen through early change in yolk and organs were discussed in detail.

Authors improved method of fish lymphocyte culture using whole blood short-term centrifugation to purify lymphocyte. The separation is good, and can keep the serum in the supernatant so that the method can stimulate growth and multiplication of the lymphocytes. Also, the chromosome preparation gives a good result, having lots of mitotic figure and clear background, which is very suitable for research fields ofkaryotype analysis, in situ hybridization, and so on.

The cell line of a caudal fin from koi (Cyprinus c arpio) was established in this study. The detection of the chromosome number, karyotype and DNA content demonstrates that there were no significant differences between the somatic cells and the culture cells; that the chromosome number and the DNA content were in accordance with the proportionate relationship. The established cell line of the koi' s caudal tail fin named as KF-H had the stable heredity.

The pharmacodynamics of florfenicol on bacterium Yersinia ruckeri were studied in vitro including minimal inhibitory concentration(MIC);minimal bactericidal concentration(MBC ); the growth curve of the bacterium; the bacteriocidal curve of the florfenicol and post-antibiotic effect(PAE). The results showed thatthe florfenicol had MIC of 0.5 μg·mL^-1, MBC of 1μg·mL^-1 and MBC/MIC of 2. The logarithmic growth phase was observed in the bacterium cultured in fluid medium for 1 hour and lasted about 7 hours. The florfenicol showed the maximum activity 4-6 hours after administration and was a dose-dependence by the bacteriocidal curve. The value of PAE were found to be 3.71±0.11 in 2 MIC,4.54± 0.27 in 4 MIC, and 5.52± 0.23 in 8 MIC. Florfenicol had the most effective inhibition of Y. ruckeri at pH 6-8. There was no significant impact of Mg2+, serum content, and less than 108 of bacteria quantity on bactericidal activity of the florfenicol. Therefore, the maximal efficacy of florfenicol depends on dose, administration period and the optimal environmental factors.

Crucian carp (Carassius auratus ) with body weight of 37.09_+ 4.09g were reared in tanks at a rate of 15 individuals/tank, and fed diets containing 3 mixtures (groups A, B and C) of Chinese herbal medicines (without addition of Chinese herbal medicine as control group) at feeding rate 2% for 60d to evaluate the influences of the Chinese herbal medicines on some biochemical indices in blood at water temperature of 20~C. Results showed that there were significantly higher activities of the serum aspartate aminotrans- ferase (AST) and alkaline phosphatase (ALP) in groups A, B, and C, but significantly lower contents of uric acid (URIC), total pro- tein (TP), and globulin (GLB). The levels of Fe, and creatinine (CREA), and ALP activity in the liver were shown to be increased in groups A, B, and C, while the levels of Ca, P, cholesterol (CHOL), GLB, and TP, and activities of AST and lactate dehydrogenase (LDH) to be decreased in groups A, B, and C, which may be involved in Chinese herbal medicine formula composition, sampling sites, and tests of biochemical index related.

Neojifu tilapia ( Oreochromis niloticus ) fry with body length varying from 0.7 cm to 1.9cm were fed diets containing different levels ofestradiol benzoate (EB) hormone to induce feminization ofXY neofemales for YY super males twice a daily from July 12th to October 21 st of 2009 and from May 1 st to November 6th of 2010. The fish fed the diet containing EB at a dose of 100 mg·kg^-1 were found to have 80.0% of females in 26 d, 93.4% of females in 36 d, 93.9% of females in 46 d, and 94.0% of females in 59 d and reared for 102 d, 25.2%, 38.6%, 39.1%, and 39.2% higher than that in the control group (54.8%), respectively. There was 83.1% of females in the fish fed the diet containing 200 ·kg^-1 EB for 24 d and reared for 188 d, 36.2% higher compared with the control group (46.9%), and very significant differences by X2 test in the two experiments (P〈0.001). There were no significant differences in the survival rate between the test fish and the control ones, and no abnormal fish were observed. It was found that the final body weight and final total length were very sig- nificantly and significantly smaller in the fish in the two experimental groups than those in the control group(P〈0.01, P〈0.05). There was no significant difference in growth between the experimental sex non-reversal males and the control males (P〉0.50). Thus, it is optimization of feminization protocol that neojifu tilapia fry are fed a diet containing EB at a dose of 200 mg·kg^-1 for about 35 d.

Light intensity as one of the most important environmental parameters has been shown to significantly influence growth and survival of larval or juvenile fish. The juvenile (with body weight of 10.10-+ 0.8g) masu salmon Oncorhynchus masou masou were reared in polyethylene tanks (80 cm diameter, 60 cm tank depth with water level of 40 cm) with a flowing freshwater at light intensity of 1200 lx, 600 lx, and 300 lx)at ambient temperature of 12.1 - 13.9℃ for 50 days to evaluate the effects of light intensity on growth performance. The light intensity was found to influence specific growth rate(SGR ), condition factor(CF) and coefficient variation (CV) significantly (P〈 0.01 ). The juveniles reared in high light intensity ( 1200 lx) had significantly higher SGR and CF than the juveniles reared under light intensity of 600 lx and 300 lx did. However, there was the lower CV under 1200 lx than under the other two light regimes. Correspondingly, the juveniles reared in high light intensity ( 1200 lx) showed significantly higher feeding intake compared to the animals under light intensity of 600 lx and 300 lx, indicating that increasing light intensity led to the positive effects for the growth in the juveniles. These findings contribute valuable information to the continuing development of juvenile culture of the juvenile masu salmon.

A 3 × 3 factorial feeding experiment was conducted to evaluate the optimal dietary protein and lipid levels of juvenile yellow catfish (Pelteobagrus fulvidraco) with average initial body weight of 10.32 g at water temperature of 23± 5℃. The juveniles were randomly stocked into 27 net cages of each 60 cm × 60 cm × 120 cm with flowing water, and fed nine practical diets containing three protein levels (32.0%, 40.0%, and 48.0%), and three fat levels (3.0%, 10.0%, and 17.0%) for 100 d. The for 100 days. The results showed that at 3.0% dietary lipid level, the significantly higher final body weight, and specific growth rate and lower food conversion ratio were found in the fish fed the diet containing 40.0% protein and 3.0% fat levels compared with other protein levels (P〈0.05). At 10.0% dietary lipid level, significantly lower food conversion ratio was observed in the fish fed the diet containing 48.0% and 40%pro- tein level (P〈0.05). The best apparent digestibility of dry matter was found in the fish fed the diet containing 48.0% protein and 3.0% fat levels and 40.0% protein and 10.0% fat levels (P〈0.01). There was the maximal protein digestibility in the fish fed the diet containing 48.0% protein and 3.0% fat levels (P〈0.01). Fat digestibility was the best in the 40% protein and 10% fat group (P〈0.01). It is suggested that the requirement of the juvenile yellow catfish be 40.0% for protein and 10.0% for fat.

Taimen Hucho taimen fry with body weight of 0.129 ± 0.07g were fed by 3 feeding regimes in which the fry were fed zooplankton for 3 days, then Tubifex for 15 days and formulated feed (Group A); Tubifex for 15 days and then formulated feed (Group B); and formulated feed (Group C) for 60 days to evaluate effects of weaning regimes on growth, survival and population coefficient of the larvae and juveniles. The results showed that the fish in Group C had higher specific growth rate in weight (3.577± 0.78%/d) than the animals in Group B (3.024± 0.91%/d) and Group A (3.132± 0.87%/d). There was 84.36% survival rates in Group C, higher than those in Group A (75.67%) and Group B (74.87%). The variation coefficient in body weight was found to be 21.47% in Group A, 22.59% in Group B and 11.32% in Group C, indicating that the weaning pattern of Group C is a feasible method for intensive fay culture in taimen.

Chum salmon (Oncorhynchus keta) breeding population in Amur River immigrated from Okhotsk Sea in Russia runs into two geographic populations Amur population and Ussuri population when the salmon reach China border. In the past decade, China A- mur population developed strong nuptial colors very well, but few Ussuri population showed strong nuptial colors, even did not when they entered China. There were two groups faint color females (red chrominance a*〉13 ) and strong color females (red chrominance a*〈7)in Ussuri females whose breeding parameters were analyzed during 20th~29th of September in 2011 to evaluate the implica- tions of nuptial colors differentiation within a population in Ussuri River. It was found that the age, gonado-somatic index (GSI), egg diameter and weight, body length and body weight of the faint color females were all smaller than the strong color females very signifi- cantly (P〈0.01). The faint color females were found to have less absolute fecundity than the strong color females did significantly (P〈0.05), without significant differences in condition factor between the two groups. Correlations among reproductive parameters between the two groups revealed that the faint color females had lagged gonad development behind the strong color females, indicating that the strong color females shared higher reproductive fitness than the faint color females.

The activities of digestive enzymes in intestine and hepatopancreas and muscular composition of amino acids were moni- tored in redfin culter (Cultrichthys erythropterus Culter erythropteru///) weighing 107.82g collected in January, May, July and September, and the daily changes in muscular composition of amino acids were studied in summer. The results showed that there were significantly higher activities of digestive enzyme in summer and autumn than those in spring and winter, the activity ofprotease higher than amylase in the same season (P〈0.05). The maximum activities ofprotease, amylase and lipase were observed from 19:00 to 21:00, at 19:00 and from 16:00 to 19:00, and the minimum activities were found at 7:00, 7:00 and 21:00. The muscular composition of amino acids was shown to be comprised of 18 kinds of amino acid, glutamic acid being the most abundant and cysine the least. The contents of five essential amino acid (valine, methionine, isoleucine, phenylanine and lysine) were significantly lower in winter than in other seasons (P〈0.05), without seasonal changes in the non-essential amino acids. Both total amino acid and total essential amino acids were found to be the climax in spring and summer and to fall into zenith in autumn and winter, the minimal contents of delicious amino acids in autumn. The findings indicates that wild redfin culter digestive physiology has season and day revolution, and amino content changes in different seasons imply that the metabolism in winter relies on the essential amino acid in the muscle.

The surface of the floating filtering balls were attached by growing biofilms and absorbed the ions in suspended solid particles when the floating type ofbio-filters were applied to effluent treatment in a closed-reeirculating aquaculture. The biofllms and absorbed suspended particles led to plug the gap of float balls, and to increase in the resistance to water flow, even to stop water flowing. So, regular backwashing is important in the normal function of the filtering. In this study, a floating Wpe of bio-fiiter with back back- wash and effluent treatment was designed based on the structural characteristics and fimctional requirements of the float type of bio-filter and tested in practice, with good performance. It was found that the advice showed accurate action, and flowing elimination of the effluent, and that a backwash needed 10 min, and water consumption of 1.5 m3.

The Hox genes as a large family of DNA-binding transcription factors are organized into clusters that are strikingly collinear with their spatial and temporal expression patterns, with each cluster containing no more than 13 different genes, and that appear to play key roles in the body plans of a wide range of metazoan species. The genes order in the cluster is highly conserved through a long evolution terms, suggesting a selective pressure on the entire cluster. A single Hox cluster containing 15 Hox genes is found in chor- date such as amphioxus (Branchiostomafloridae), four Hox clusters distributing on 4 chromosomes are shown in mammals and more than four Hox clusters ray in teleosts, 7 Hox clusters being in zebrafish. Study on Hox genes of fishes will help to understand the evolu- tionary dynamics and patterns of Hox genes family in the short, medium and long evolutionary time, and to explain the formation of new genes, species and genetic differentiation to maintain system stability and other aspects of the role. Therefore, evaluation of DNA sequence homology and phylogenetic relationships between species will show great significance in the conservation of biological di- versity (particularly genetic diversity) and in explanation of the course and mechanismof biological evolution.

Fish secrete different kinds of antimicrobial peptides (AMPs) which are positively charged short amino-acid-chain molecules involved in host defense mechanism. AMPs as the research hotspots in immunology are shown to have many advantages including broad-spectrum antibiotics, good thermal stability and unique antibacterial mechanism. The research progress of fish AMPs major fimctions is reviewed in this paper and its application perspective is also discussed.