Abstract:To make a further clarification of the seasonal dynamics of species composition and abundance distribution of fish larvae and juveniles in the surf zone of the Yangtze River estuary, fish larvae and juveniles were collected at 13 stations by a seine net (1 m ×4 m, 1 mm mesh aperture) monthly from November 2006 to October 2007. There were 77 species of fish larvae and juveniles belonging to 63 genera in 27 families of 13 orders, in which Perciformes and Cypriniformes were the dominant families. The number of species collected in summer,spring,autumn and winter was 37, 20, 13 and 7 respectively. In all seasons, the warm temperate species were absolutely dominant. In terms of the ecological types, the number of estuarine species was as much as that of freshwater species, followed by marine fish, and diadromous species was the least in ecological types. By analyzing the dominance curve of fish larvae and juveniles, we found that the dominance of species was the most prominent in summer, while not obvious in autumn. The shared species in different seasons showed more conformity between summer and autumn, but more difference between winter and other seasons. Catches varied significantly among seasons, peaking in summer with a mean of 1 132 ind./station. The abundance of fish larvae and juveniles was the least and the distribution was the most dispersive in winter, and increased dramatically in spring, then became more abundant and more concentrated in summer. The average density reached 2 729 ind./station, mainly composed of Coilia nasus, at the freshwater or low salinity area of St.4, St.5, St.7 and St.10.

Abstract:The beak length and its relationship with mantle length, body weight as well as age were studied based on 103 beaks and 60 statoliths specimen of the purleback flying squid Sthenoeuthis oualaniensis which were collected during jigging surveys in northwest Indian Ocean from October to December in 2004 and in April of 2005. The results indicated that the beak dimensions were best described by linear functions with mantle length but showed positive exponential correlation with body weight. With the squid ontogenetic growth, size of each part of the beak became larger. Hood and crest grew faster but rostrum and wing grew slower. Hood and crest of the upper beak grew faster than that of the lower beak. Dimensions of each part were best described by linear functions with age except for the wing of upper beak which fitted exponential function. The results provided basic data for the resources estimation of S.oualaniensis.

Abstract:Based on the checklist reference, fifteen indigenous fishes in Tarim River basin were summarized. We found that 9 species belonged to 5 genera in Schizothorace subfamily and 6 species belonged to 1 genus in Nemachiline subfamily. By referring to literature and observing fish specimen, we also compiled bracketed keys for the indigenous fishes in this area which would be helpful for field surveys and identification in future.

Abstract:The decadal biodiversity variations of ichthyoplankton collected at the same locations of the Laizhou Bay of the Bohai Sea in 1982, 1993, 2003 and 2008 were studied. The analyses indicated that the total number of ichthyoplankton species declined from 27 in 1982 to 12 in 2003 and 14 in 2008. The ichthyoplankton abundance also declined substantially, with the amount in 2008 accounting for only .58% in 1982, 0.61% in 1993 and 5.77% in 2003 respectively.Ichthyoplankton composition was significantly different in three decades (P<0.05), and showed accelerating change trend. The biodiversity index was at the lowest in 1993 and increased ever since.

Abstract:A pathogenic bacterial strain CB1008 was isolated from the eyes and internal organs of seven-band grouper Epinephelus septemfasciatus. It was proved to be the pathogen of the diseased seven-band grouper by artificial infection test. Morphological observations showed that it was a short-rod and Gram-negative bacterium with single polar flagella. According to API-32E system, through traditional physiological and biochemical experiments and 16S rDNA gene homology comparison of the bacterium, the results showed that the reisolated strain CB1008 was Vibrio harveyi. The test of sensitivity of strain CB1008 to 36 kinds of antibiotics revealed that the pathogen was sensitive to Chloramphenicol, Nalidixan, Tetracycline, Norfloxacin and Fleroxacin. V. harveyi is a kind of pathogenic bacterium commonly found in cultured marine finfish,but this is the first time that V. harveyi is reported as the pathogenic bacterium of seven-band grouper in China.

Abstract:Turbot Scophthalmus maximus, a benthic flatfish species, is a highly nutritious and valued species currently cultured widely in sea water in China. However,with development of its aquaculture, the growth has been slowed down due to serious germplasm degeneration in recent years and was heavily concerned by national related administrative departments. In this study,growth performance was compared in four different stocks of turbot from Britain, France, Denmark and Norway. The results showed that the difference of body length and body weight among these stocks are much significant (P＜0.01) for 3-month,6-month,9-month and 12-month turbot,and body length and body weight ranked in the same order for the four stocks based on the data collected in respective months. Body length of the four populations of turbot grew as linear functions,while their body weight as exponential functions. Through comparison of AGRW and IGRW at different growth stage,better growth performance was exhibited in France stocks than in the other three stocks,and the order was as follows: France > Britain >> Denmark > Norway. At 3, 6, 9 and 12-month,the variation coefficients of body weight of the four turbot stocks were 22.84%～33.48%,21.36%～30.30%,19.64%～26.97% and 21.06%～35.07% respectively,and all the four stocks were suitable for selection on the basis of the variation coefficients of body weight.

Abstract:Testing records of growth traits in 240-day age Japanese flounder selective breeding families between 2006 and 2009 at the Beidaihe Central Experiment Station, Chinese Academy of Fishery Sciences, were used to analyze the genetic parameters of growth traits by 4 different animal models. The four models examined additive genetic effect, maternal genetic effect and full sib effect. The variance components in different models were estimated with the derivative free restricted maximum likelihood (DFREML) method using MTDFREML software. The differences between different models were tested by likelihood ratio test. The results showed that the maternal genetic effect and full sib effect were significant for body weight (BW), body length (BL) and body depth (BD), and the model Ⅳ should be adopted for analysis. The heritability of BW, BL and BD was 0.30, 0.32 and 0.39, respectively. Positive genetic correlations were found between BW and BL, BW and BD, at values of 0.93 and 0.95 respectively. The positive genetic correlations between BL and BD were 0.90.

Abstract:Advanced metephyrae is one of the growth stages in the life cycles of Nemopilema nomurai and Rhopilema esculentum. In order to distinguish the advanced metephyrae (1～2cm) of N.nomurai and R.esculentum in early resources survey of giant jellyfish in every spring，The morphology of advanced metephyrae of N. nomurai and R.esculentum were studied.Their characteristics were compared and their main differentiae were summarized through laboratory cultivation and observation.The studies showed that the subgenital pits of N.nomurai are fuller and bigger than that of R.esculentum.For R.esculentum,the inside and outside radians of every subgenital pit are closer and the distance between two subgenital pits is greater.Two vertical lines of gastric cirrum are in the stomachic cavity of N.nomurai,with the longer one extending from subgenital pit to the central mouth.By comparison,the gastric cirrum of R.esculentum are distributed in four subgenital pits,and almost none of gastric cirrum is found in the stomachic cavity.When it is in the state of being contracted,the shape of central mouth of N.nomurai is crossed with smaller opening,and the cirrum are distributed anfractuously in the turbination-shaped oral canalis carpi. By comparison, the shape of central mouth of R.esculentum is eight-square,when it is in the state of being contracted, and the cirrum are distributed orderly in the column-shaped oral canalis carpi.The purpose of this study is to offer taxology evidence for investigating advanced metephyrae in natural field and forecasting of jellyfish blooming earlier, therefore to prevent jellyfish disasters.

Abstract:In order to protect the humphead wrasse Cheilinus undulatus (Ruppell, 1835）, an endangered species，the metaphase chromosome preparations of the live fish and its karyotype were studied in this paper. The metaphase chromosome was obtained from the fin and its healing-tissue of one-year old fish by hot air drying methods. The results showed that there were 48 chromosomes in diploid and their karyotype formulae was 2n=4M +10SM + 32ST +2T.Heterotypic sex chromosome was not found since the number of the tested fish was limited and all the young fish were physiologically female.

Abstract:RAPD technology was used to analyze the genetic variations and genetic structure in four geographical populations of Scapharea broughtonii in Korea and China. 171 loci were detected in the four populations through 25 random primers, and 167 of these loci were polymorphic. The results indicated that the genetic diversity of the four populations was rich. The Shannon's index ranged from 0.460±0.232 to 0.491±0.214, and the Nei's genetic diversity index ranged from 0.308±0.171 to 0.331±0.199. Gst values showed that there are significant genetic differentiation between Korean population and the three Chinese populations. The UPGMA dendrogram of four S. broughtonii populations based on Nei's (1972) genetic distance showed that Huangdao and Qiansandao populations clustered first, then clustered with the Penglai population, before further clustered with the Korean population. The UPGMA dendrogram gave a clear division between the Korean and Chinese populations. The information of the genetic variation and differentiation among four S. broughtonii geographical populations can be useful for conservation of S. broughtonii stocks and future genetic improvement by selective breeding.

Abstract:Litopenaeus vannamei at (4.83±0.36)g body weight were fed with 0.1% heat-killed, 1% heat killed and 0.1% living Photobacterium damselae for 21 days respectively. The serum was collected at 0, 5, 10, 15 and 20 days post immunization and Phenoloxidase (PO), acid phosphatase (ACP), alkaline phosphatase (AKP), superoxide dismutase (SOD) and lysozyme activity (UL) in the serum of L. vannamei were determined to evaluate the non-specific immune effect of P. damselae After 21 days, the shrimps were challenged by white spot syndrome virus (WSSV) and the mortalities of challenging test were recorded. The results showed that most PO, ACP, AKP, UL and SOD in the serum of L. vannamei of the test groups were significantly different (P<0.05 or P<0.01), and the resistance ability of shrimps to WSSV was also significantly enhanced by the diet supplemented with P. damselae The group fed with 10g heat-killed P. damselae per 1 kg shrimps exhibited the strongest resistance to WSSV in 14 days and its final cumulative mortality was 63.3%±5.8%, while the control was 96.7%±7.3%. The results indicated that P. damselae improved shrimp non-specific immunity and its resistance to WSSV, suggesting that it might be a promising diet supplement in shrimp farming.

Abstract:Morphological and histological observations of the digestive tract in Sipunculus nudus were conducted with light microscopy. The digestive tract consists of mouth, pharynx, esophagus, intestine, rectum and anus. The mouth is surrounded by tentacles to form a mouth tray, and the pharynx is short and has no clear borderline with the mouth. The esophagus can draw back and forth. The intestine is very long and reverses three times to form a spiral. Caecum is attached to rectum. The wall of digestive tract is composed of mucosa, submucosa and adventitia, having no continuous muscle layer, only with numbers of muscle fibers in the submucosa. The epithelium of the mucosa membrane in digestive tract is mainly composed of columnar cells with developed microvilli except for intestine. The form of plica, the submucosa and the quantity of muscle fibers are also different among various parts of the digestive tract.

Abstract:A hemocyanin gene (FCHc) was cloned from hepatopancreas of Chinese shrimp Fenneropenaeus chinensis by Rapid Amplification Complementary DNA Ends (RACE) method. The full length cDNA of FCHc consists of 2 161bp with a 2 034 bp Open Reading Frame (ORF)，which encoded 678 amino acids，and the predicted molecular mass was 77.59kDa. It showed 82% and 85% homology with those of Litopenaeus vannamei and Marsupenaeus japonicas. The real-time PCR results showed that the expression level of FCHc in hepatopancreas was the highest among seven studied tissues．Real-time PCR analysis showed that the expression of FCHc was up-regulated distinctly in the hepatopanereas of shrimp when they were challenged by Vibrio anguillarum and white spot syndrome virus (WSSV). FCHc showed different expression profiles in the hepatopancreas during V. anguillarum or WSSV virus infection．The results implied that FCHc might play an important role in shrimp immune system．

Abstract:Bryozoans are small sessile aquatic colonial animals, and their phylogenetic position has been controversial for long time. In this paper, we have determined the complete mitochondrial genome of Watersipora subtorquata. It is a circular molecule of 14 144 bp, relatively small compared with most other published metazoan mitochondrial genomes. It is unusual that all genes are transcribed from the same strand. The gene order is unique compared with mtDNA of other metazoans, and drastic rearrangement was also found when compared with mtDNA of the other two bryozoans. It indicates that drastic rearrangement has happened in the mitochondrial genome of bryozoans. Comparison of gene order supports the protostome affinity of Bryozoa, and indicates that comparison of gene order may be especially useful for the establishment of the phylogenetic position of Bryozoa. This study provides important bryozoan molecular data which will facilitate the phylogenetic research of Bryozoa.

Abstract:Bio-film was successfully formed by making use of the natural purifying microbe in the sea for the industrial recirculation aquaculture systems. The nitrification impact factors, including water temperatures, influent ammonia-nitrogen concentrations and hydraulic retention time (HRT) were also explored . The results showed that at the same influent ammonia-nitrogen concentration and HRT, the ammonia-nitrogen concentrations changed significantly at different water temperatures (P<0.05). When the water temperature was 28℃, after purified by bio-film for 120 hours, the influent ammonia-nitrogen concentration dropped to the lowest concentration. The ammonia-nitrogen removal rate and the specific ammonia removal rate were gradually increased as the influent ammonia-nitrogen concentration and HRT increased. However, at the same ammonia-nitrogen concentration, the specific ammonia-nitrogen removal rate decreased as HRT was prolonged.

Abstract:The properties of alginate gel made by using of CaCl2 was studied in this paper. The characteristics of the gel depended on the concentration of CaCl2, temperature and M/G of the alginate. The optimal gelation property was obtained in CaCl2 solution with concentration of 2.0% and at temperature of 50℃. The gel strength of the alginate gel with higher G concentration was better, while the water holding capacity was better with higher M concentration. The change of the gel structure before and after gelation was determined by IR. The results indicated that the OH peak shifted to higher range and the C-H stretching vibration became weaker, which may result from the cross-linking of alginate with calcium.

Abstract:Cell-free supernatant with marine microorganism lysozyme was prepared by centrifugation of culture broth，ultrafiltration and concentration. The crude lysozyme was purified 41.98 fold to electrophoretic homogeneity with recovery of 21.7％ and specific activity of 3 987.7 U/mg by extracting with ethanol, Superdex 75 10/300 chromatography and reversed-phase HPLC. The relative molecular weight of this lysozyme was 17.1 kD determined by SDS-PAGE electrophoresis. Preparations of lysozyme from native marine microorganism were formulated with different additives for lyophillization. The studied additives, including trehalose, sucrose and maltose, showed good protecting effect with trehalose showing the best performance for freeze-drying stabilization. Comparing with the native lysozyme in the absence of protective agents, the activity of the freeze-dried lysozyme treated by trehalose (0.5 mol/L) and Tween 80 (20 mg/L) as protective agents retained more than 95% of the original activity.

Abstract:Carrageenan oligosaccharide (KOS) was prepared through enzymatic hydrolysis. After chemical modification of the produced oligosaccharide via use of formamide-chlorosulfonic acid or DMSO-methanol-pyridine, sulfated derivatives (SKO) and desulfated (DSK) derivatives of κ-carrageenan oligosaccharides were obtained respectively. Herpes simply virus (HSV-1) was used to study the relationship between the content of sulfate group and antiherpesviral activities of the oligosaccharide and its derivatives. The antiherpesviral mechanism of κ-carrageenan oligosaccharide was also studied by the ways of directly inactivating virus, inhibiting virus absorption and influencing virus replication and release. The results showed that KOS and SKO had little cytotoxic effect on Vero cells, and could not directly inactivate HSV-1 or influence its replication and release, but absorption of HSV-1 on the surface of cells was inhibited. SKO had stronger effects on HSV-1 absorption than KOS with the same concentration, while DSK had no effect on HSV-1. So it could be concluded that there was a positive relationship between the content of the sulfate group of κ-carrageenan oligosaccharide and its antiherpesviral activity, which was achieved mainly via inhibiting HSV-1 absorption on the host cells.

Abstract:The antimicrobial activity of different molecular-weight fractions of phlorotannins from Sargassum thunbergii kuntze was screened by plate growth inhibition assay. The results indicated that all the fractions of phlorotannins can inhibit the growth of tested microorganisms including Vibrio parahaemolyticus, Vibrio harveyi, Vibrio nereis, Staphylococcus aureus, Escherichia coli, Vibrio anguillarum, Vibrio alginolyticus and Micrococcus tetragenus. Among them, the antibacterial activity of the lowest molecular-weight fraction I (Mr < 5.0×103) of phlorotannins was the best with the minimum inhibition concentration (MIC) values against the tested microorganisms above as 900，900，900，1 800，1 800，1 800，1 800 and 3 600 μg/ml respectively. Additionally, phlorotannins from S.thunbergii kuntze showed excellent thermal stability, and the best antimicrobial activity to the tested bacteria was in pH 3～4.