花鲈人工育苗技术的研究

利用人工培育的亲鱼所获得的受精卵 ,孵化出仔鱼 30 0万尾 ,在水温 18～ 2 0℃、微充气的培育条件下 ,使用海水小球藻、轮虫、卤虫无节幼体和不同规格的微颗粒配合饲料进行饲喂 ,经 58d培育出平均全长 2 .3cm的苗种 132万尾 ,育苗成活率高达 64.1% ,单位水体最高出苗量达 1.33万尾 / m3;另外 ,还有 1.3～ 1.9cm的苗种 68万尾     

鲈鱼群体生化遗传学研究 Ⅰ.同工酶的生化遗传分析

于1994年9月－1995年12月，在青岛近海采集37尾鲈鱼的生化样品，采用淀粉胶和聚丙烯酰胺凝胶2种电泳分析，分析了LDH、MDH、MEP、IDHP、PGM、G3PDH、AK、CK、ADH、SDH、G6PDH、GDH、PGDH、CAT、MPI、EST、SOD等同工酶在鲈鱼眼睛、肌肉、心脏、肝脏、肾脏、鳃、胸鳍等7种组织或器官中的表达情况，并对同工酶表型进行了生化遗传分析，以期为其种质资源保护和开发，以及遗传育种等方面的研究提供基础资料。结果表明，17种同工酶由31个基因座位编码，其中Mep-1,Pgm-1,Sdh,Gdh,Pgdh,Mpi,Est-1,Est-4等8个基因座位为多态。多态座位比例为25．8％。     

饲料添加发酵浒苔对花鲈(Lateolabrax japonicus) 生长性能、消化酶活性和免疫的影响

采用单因子试验设计方法, 配制发酵浒苔添加比例分别为0%、1%、2%、3%、4%、5%的 6 种饲料, 探讨发酵浒苔对花鲈生长、体成分、胃、肠消化酶活性及血清、肝脏免疫的影响的研究。 将其饲喂初始平均体重为(6.40±0.14)g 的花鲈28d, 每组饲料设3 个重复, 每个重复投喂30 尾花鲈。 结果表明: (1) 随着发酵浒苔添加水平的升高各组花鲈增重率和特定生长率呈现先升高后降低的趋 势, 且差异性显著(P<0.05), 以2%组添加量最优。相比于对照组, 各添加组饲料系数均有下降。添加 发酵浒苔可适当降低鱼体中的水分, 提高灰分含量但并不显著(P>0.05).同时各添加组的粗脂肪和粗 蛋白含量均高于对照组, 各添加组之间并无显著性差异(P>0.05).(2) 在添加组中, 花鲈淀粉酶、脂 肪酶活性以及胰蛋白酶、胃蛋白酶活性均得到了显著提高(P<0.05).添加水平在2%-3%效果最好。 (3) 添加发酵浒苔可以显著提高血清超氧化物歧化酶、溶菌酶的活性(P<0.05), 但对碱性磷酸酶的活 性差异不显著(P>0.05).本试验中肝脏超氧化物歧化酶、溶菌酶和碱性磷酸酶的活性均得到提高, 在 2%-3%组为最佳。     

刺参血淋巴细胞形态和表面结构观察

通过光镜和扫描电镜观察,较为系统地研究刺参（Apostichopus japonicus）血淋巴细胞的形态和表面结构。根据大小和形态结构,将血淋巴细胞定义为4种类型：小淋巴细胞、吞噬细胞、桑葚细胞和结晶细胞。     

Construction of cDNA library from intestine, mesentery and coelomocyte of Apostichopus japonicus Selenka infected with Vibrio sp. and a preliminary analysis of immunity-related genes

The aquaculture of sea cucumber Apostichopus japonicus (Echinodermata, Holothuroidea) has grown rapidly during recent years and has become an important sector of the marine industry in Northern China. However, with the rapid growth of the industry and the use of non-standard culture techniques, epidemic diseases of A. japonicus now pose increasing problems to the industry. To screen the genes with stress response to bacterial infection in sea cucumber at a genome wide level, we constructed a cDNA library from A. japonicus Selenka (Aspidochirotida: Stichopodidae) after infecting them with Vibrio sp. for 48 h. Total RNA was extracted from the intestine, mesentery and coelomocyte of infected sea cucumber using Trizol and mRNA was isolated by Oligotex mRNA Kits. The ligated cDNAs were transformed into DH5α, and a library of 3.24×105 clones (3.24×105 cfu mL-1) was obtained with the sizes of inserted fragments ranging from 0.8 to 2.5 kb. Sequencing the cDNA clones resulted in a total of 1106 ESTs that passed the quality control. BlastX and BlastN searches have identified 168 (31.5%) ESTs sharing significant homology with known sequences in NCBI protein or nucleotide databases. Among a panel of 25 putative immunity-related genes, serum lectin isoform, complement component 3, complement component 3-like genes were further studied by real-time PCR and they all increased more than 5 fold in response to Vibrio sp. challenge. Our library provides a valuable molecular tool for future study of invertebrate immunity against bacterial infection and our gene expression data indicates the importance of the immune system in the evolution and development of sea cucumber.     

The effect of chemical cues on the settlement of sea cucumber (Apostichopus japonicus) larvae

The effects of four ions and eight neuroactive compounds on inducing larval settlement of A. japonicus were assessed in the present study. All bioassays were conducted in 60 × 9 mm Petri dishes, each contained 10 mL of the test solution and 10 doliolaria larvae. There were significant inductive effects of K+(10- mmol L-1), NH+4(0.1 mmol L1), GABA(10-3 mol L-1), acetylcholine(10-5 mol L-1), L-DOPA(10-5 mol L-1), norepinephrine(10-5 mol L-1) and dopamine(10-7 mol L-1 and 10-5 mol L-1) on the settlement of sea cucumber larvae. L-DOPA and dopamine are the most efficient chemical cues to induce A. japonicus larvae to settle. The highest percentage of larval settlement was induced by 10-5 mol L-1 L-DOPA and dopamine(33% and 40%) compared to the control(7%). However, Ca2+, Mg2+, choline, serotonin, and epinephrine were less effective on larval settlement at all tested concentrations. This study evaluated the stability and feasibility of chemical cues for larval settlement in different culture systems, which can be applied to improve the hatchery production of this valuable species.     

Age and Growth of Chub Mackerel （Scomberjaponicus） in the East China and Yellow Seas Using Sectioned Otolith Samples

Although chub mackerel (Scomberjaponicus) is a primary pelagic fish species,we have only limited knowledge on itskey life history processes.The present work studied the age and growth of chub mackerel in the East China and Yellow Seas.Agewas determined by interpreting and counting growth rings on the sagitta otoliths of 252 adult fish caught by the Chinese commercialpurse seine fleet during the period from November 2006 to January 2007 and 150 juveniles from bottom trawl surveys on the spawn-ing ground in May 2006.The difference between the assumed birth date of 1 st April and date of capture was used to adjust the agedetermined from counting the number of complete translucent rings.The parameters of three commonly used growth models,the vonBertalanffy,Logistic and Gompertz models,were estimated using the maximum likelihood method.Based on the Akaike InformationCriterion (AIC),the von Bertalanffy growth model was found to be the most appropriate model.The size-at-age and size-at-maturityvalues were also found to decrease greatly compared with the results achieved in the 1950s,which was caused by heavy exploitationover the last few decades.     

Effects of photoperiod on daily activity rhythm of juvenile sea cucumber, Apostichopus japonicus (Selenka)

In nature, Apostichopus japonicus exhibits a behavioral characteristic of emerging at night and sheltering during the day. Hence, it was commonly believed that longer and darker light conditions are better for a population of A. japonicus. In aquaculture situations therefore, animals have commonly been cultured without lighting, especially during juvenile-hatching culture. However, how the length of darkness each day affects A. japonicus and what the mechanism is of behavioral response of A. japonicus to different photoperiods remain unclear, and are specifically addressed in this study. We applied nine photoperiod treatments (light:dark (LD) cycles at 0:24, 3:21, 6:18, 9:15, 12:12, 15:9, 18:6, 21:3, and 24:0 under 500 lx) to 60 individuals (29.73 ± 0.23 g) per treatment (with 3 replicates). The environmental conditions were set as: water temperature = 16.9 ± 0.3°C, dissolved oxygen>6.0 mg/L, ammonia<0.3 mg/L, pH = 7.8-8.2, and salinity = 30-32. Under experimental conditions of continuous darkness as well as continuous light, cyclic nocturnal activity patterns of A. japonicus (viz. the animals emerged and fed at night and sheltered during the day) were observed. However, they spent more and less time, respectively, moving and feeding under continuous darkness and continuous light, than those under a natural light cycle. Under photoperiods with 6-12 h of light, the animals showed one sheltering behavior transition and two emerging behavior transitions. These behavior transitions appeared to be governed by some internal physiological factors and induced by daily light variation. The behavior of the animals was significantly affected by different photoperiods, and the distribution rate (DR) of the animals emerging at "daytime" increased with lengthening "light time" (except for the LD 3:21 cycle). We also found that there was no significant difference in mean DR per day under LD cycles of 6:18, 9:15, 15:9, and 12:12. Mean DRs per day were significantly lower for these photoperiods, than for those under LD cycles of 0:24 and 3:21, and significantly higher than for those under LD cycles of 18:6, 21:3 and 24:0. These results imply that 6-15 h light per day were the similar photoperiods to natural sunlight. From the viewpoint of activity and feeding behaviors, these might be the optimal photoperiods for rearing A. japonicus.     

Effects of Pseudoalteromonas sp.BC228 on Digestive Enzyme Activity and Immune Response of Juvenile Sea Cucumber （Apostichopus japonicus）

A marine bacterium,Pseudoalteromonas sp.BC228 was supplemented to feed in a feeding experiment aiming to determine its ability of enhancing the digestive enzyme activity and immune response of juvenile Apostichopusjaponicus.Sea cucumber individuals were fed with the diets containing 0 （control）,105,107 and 109 CFU g-1 diet of BC228 for 45 days.Results showed that intestinal trypsin and lipase activities were significantly enhanced by 107 and 109 CFU g-1 diet of BC228 in comparison with control （P〈0.01）.The phagocytic activity in the coelomocytes of sea cucumber fed the diet supplemented with 107 CFUg-1 diet of BC228 was significantly higher than that of those fed control diet （P〈0.05）.In addition,105 and 107 CFUg-1 diet of BC228 significantly enhanced lysozyme and phenoloxidase activities in the coelomic fluid of sea cucumber,respectively,in comparison with other diets （P 〈 0.01）.Sea cucumbers,10 each diet,were challenged with Vibrio splendidus NB 13 after 45 days of feeding.It was found that the cumulative incidence and mortality of sea cucumber fed with BC228 containing diets were lower than those of animals fed control diet.Our findings evidenced that BC228 supplemented in diets improved the digestive enzyme activity of juvenile sea cucumber,stimulated its immune response and enhanced its resistance to the infection of V.splendidus.     

Effect of Bacillus baekryungensis YD13 supplemented in diets on growth performance and immune response of sea cucumber (Apostichopus japonicus)

The effect of a potential probiotic on the growth performance and immune response of sea cucumber(Apostichopus japonicus) was investigated. Bacillus baekryungensis YD13 isolated from sea cucumber culturing ponds was added to sea cucumber basal feed as a probiotic in different doses(0, the control; 1×104(YD134), 1×106(YD136) and 1×108(YD138) CFU g-1 of diet), and administered orally to A. japonicus(initial mean wet weight 5.44 g ± 0.17 g). The sea cucumbers were fed in 20 aquaria, 5 each treatment, for 60 d. At the end of growth trial, 20 sea cucumbers from each treatment were challenged with Vibrio splendidus. A. japonicus in YD134 and YD136 exhibited significantly better growth performance than control(P 0.05). Five non-specific immune parameters including lysozyme, acid phosphatase, alkaline phosphatase, superoxide dismutase and catalase in coelomic fluid were measured to evaluate the immune response of A. japonicus to the probiotics. Results showed that all parameters were significantly improved when YD11 was supplemented in the dose of 1×106 CFU g-1(P 0.05). The cumulative incidence and mortality after the Vibrio splendidus challenge decreased significantly in sea cucumbers of YD136. Accordingly, 1×106 CFU g-1 of YD13 in diet was recommended for the growth promotion and immune enhancement of A. japonicus.