L-色氨酸和褪黑激素对中华绒螯蟹血清血糖水平及肝胰腺抗氧化能力的影响

为探究L-色氨酸和褪黑激素(MT)对中华绒螯蟹血糖水平及肝胰腺抗氧化能力的影响。实验选取初始体质量为(16.58±2.20)g的雌性中华绒螯蟹,随机分成8组(L-色氨酸和MT处理各4组),实验周期均为30 d。(1)L-色氨酸饲料投喂实验4组:L-色氨酸所占饲料比重分别为0.36%(基础饲料即对照组)、0.47%、0.73%和1.05%(分别记为1、2、3和4组),30 d后分别测定各组蟹的血糖水平及肝胰腺的T-AOC和SOD活性;(2)MT注射实验4组:每组分别在第1天和15天时注射生理盐水(即对照组,C组)和不同剂量的MT 10–6 mol/只(μM组)、10–9 mol/只(n M组)和10–12 mol/只(p M组)。分别于第1天和15天时,收集血淋巴和肝胰腺,分别测定血糖水平、T-AOC和SOD活性。于第30天时,再次收集血淋巴以测定血糖水平。结果显示:不同含量L-色氨酸对中华绒螯蟹血糖水平无明显影响,其血糖含量约为(4.62±0.20)mmol/L。此外,0.73%L-色氨酸的饲料能显著提高肝胰腺SOD活性(82.86±1.07)U/m L;注射MT仅在第1天时对中华绒螯蟹的血糖水平有促进作用,并呈剂量依赖性的方式升高,其中μM组蟹血糖水平高达(7.56±0.36)mmol/L,其值显著高于C、p M和n M组。此外注射MT在第1天时,对肝胰腺T-AOC和SOD活性也有明显的促进作用。其中,μM组蟹肝胰腺T-AOC和SOD活性均显著高于C、p M和n M组。研究表明,饲喂0.73%L-色氨酸的饲料能够提高中华绒螯蟹的抗氧化能力,但对血糖水平的影响不明显;注射10–6 mol/只MT可以在短时间内(1 d)提高中华绒螯蟹的血糖水平和抗氧化能力。     

饲喂不同水平虫草培养残基对中华绒螯蟹营养品质的影响

在基础饲料中分别添加0.25%、0.5%、1.0%、2.0%、4.0%、8.0%、16.0%的蛹虫草培养残基(简称虫草基),以基础饲料为对照,饲喂规格为(4.0±1.0)g的中华绒螯蟹75 d,测定中华绒螯蟹(Eriocheir sinensis)常规营养成分、肌肉与血清氨基酸及肝胰腺脂肪酸含量,研究虫草基对中华绒螯蟹营养品质的影响。结果显示:(1)虫草基对中华绒螯蟹水分和蛋白含量无影响(P>0.05),0.5%和1.0%添加组的全蟹、肌肉、肝胰腺粗脂肪含量显著高于对照组(P<0.05)。(2)适量添加虫草基可增加中华绒螯蟹肌肉游离氨基酸含量,0.5%～2.0%的添加组显著高于对照组(P<0.05),但对氨基酸组成及主要呈味氨基酸含量影响不显著(P>0.05);1.0%和16.0%添加组中华绒螯蟹血清氨基酸和主要呈味氨基酸含量明显提高(P<0.05)。(3)虫草基的添加可提高肝胰腺不饱和脂肪酸及必需脂肪酸含量,且1.0%添加组显著高于对照组(P<0.05)。饲料中添加适量的虫草基可提高中华绒螯蟹肌肉与血清的游离氨基酸、血清必需氨基酸、肝胰腺不饱和脂肪酸和必需脂肪酸含量,从而改善中华绒螯蟹营养品质。     

3种投喂模式对中华绒螯蟹性腺发育和生化组成的影响

2015年4—10月在江苏常州金坛市指前镇芦家村省级高效设施渔业示范点6口面积0.667hm~2试验塘(编号1~6#)中,投放中华绒螯蟹和日本沼虾苗种,密度分别为2.25×10~4只/hm~2和150kg/hm~2,分别投喂配合饲料、冰鲜杂鱼和饲料与冰鲜杂鱼混合,每种投喂模式设两个重复,定期测定肝胰腺指数、性腺指数、出肉率、总可食率和体成分的生化组成。试验结果显示,在体质量接近的条件下,3种投喂模式对成蟹的性腺指数和肝胰腺指数无显著影响(P0.05),9月杂鱼组雌雄个体的性腺指数和肝胰腺指数略低于配合饲料组和混合投喂组,而混合投喂组的性腺指数略高于其他两组。不同投喂模式对各组织中华绒螯蟹的干质量中生化组成影响较小,仅杂鱼组雌蟹肝胰腺中脂肪含量为71.44%,显著低于饲料组(86.94%)和混合组(87.67%)(P0.05)。不同投喂模式对各组中华绒螯蟹组织湿质量中生化组成无显著影响(P0.05)。综上,用投喂配合饲料替代杂鱼投喂成蟹,可以提高雌蟹肝胰腺中的脂肪含量,而对性腺发育和生化组成无不利影响。     

中华绒螯蟹幼蟹碳稳定同位素周转速率与碳、氮分馏系数的测定

为测定生长与新陈代谢对不同规格中华绒螯蟹幼蟹和不同组织碳稳定同位素周转速率的影响及分馏系数，本在水族箱（0.2 × 0.2 × 0.3 m）中分别养殖EA组（4.0 g ± 0.5 g）和EB组（15.5 g ± 0.5 g）2组中华绒螯蟹幼蟹，分别于0、7、14、21和28 d时采集幼蟹的肝胰腺、肌肉和鳃组织，探究其碳稳定同位素周转过程，并测定了幼蟹对食物碳、氮稳定同位素的分馏系数。结果显示，EA组幼蟹碳稳定同位素的周转速率大于EB组，周转速率随着幼蟹规格的增大而减小。幼蟹肝胰腺的周转速率最快，其次是肌肉，最后是鳃，其中EA组幼蟹肝胰腺、肌肉和鳃的半衰期分别为20.88、29.37和34.14 d，EB组分别为21.73、35.18和66.01 d。新陈代谢是驱动幼蟹体内碳稳定同位素周转的主要因子，幼蟹肝胰腺、鳃和肌肉中新陈代谢占碳稳定同位素周转的贡献百分比分别为79.82% ~ 94.04%、（67.00% ~ 81.90%和71.61% ~ 90.36%。幼蟹对饵料碳、氮稳定同位素的分馏系数分别为0.98‰ ± 0.19‰和3.01‰ ± 0.02‰。本研究不仅对中华绒螯蟹幼蟹的营养生态学研究提供参考，还为中华绒螯蟹养殖过程中的饵料选择提供了科学依据。     

伊乐藻对中华绒螯蟹生长和营养品质的影响

本研究分析了有伊乐藻(Elodea nuttallii)组和对照组(无伊乐藻)中华绒螯蟹(Eriocheir sinensis)在生长、肌肉氨基酸和脂肪酸组成等方面的差异,探讨伊乐藻对中华绒螯蟹生长和营养品质的影响。结果显示,有伊乐藻组中华绒螯蟹体重、壳长和壳宽增长率与肥满度均显著高于无伊乐藻组(P0.05),但肝胰腺指数和性腺指数差异不显著(P0.05)。伊乐藻组中华绒螯蟹肌肉的氨基酸总量、必需氨基酸和鲜味氨基酸含量均显著高于无伊乐藻组(P0.05);伊乐藻组的雌蟹肝胰腺中的鲜味氨基酸含量也显著高于无伊乐藻组(P0.05),而伊乐藻组和无伊乐藻组的雄蟹肝胰腺氨基酸含量差异不显著(P0.05)。伊乐藻组和无伊乐藻组的中华绒螯蟹肌肉脂肪酸组成和含量差异不显著(P0.05),但伊乐藻组中华绒螯蟹的肝胰腺饱和脂肪酸(SFA)、单不饱和脂肪酸(MUFA)和多不饱和脂肪酸(PUFA)含量均显著高于无伊乐藻组(P0.05)。综上所述,伊乐藻不仅有利于中华绒螯蟹的生长,而且能改善中华绒螯蟹的营养品质。     

越冬期间投喂不同饵料对中华绒螯蟹扣蟹存活、营养组成、消化及免疫力的影响

为研究越冬期间投喂不同饵料对中华绒螯蟹扣蟹存活、营养组成、消化及免疫力的影响,本实验比较了越冬期间不投喂(NF组)、投喂配合饲料(CF组)以及投喂冰鲜鱼(CTF组)对扣蟹存活率、营养组成、消化酶、抗氧化酶和免疫酶活性的影响。每个处理3个重复,实验周期为70d。结果表明：（1）越冬过后,CF组和CTF组扣蟹的增重率和肝胰腺指数显著高于NF组(P＜0.05),而三组间存活率无显著差异(P＞0.05);（2）越冬过后,CF组和CTF组扣蟹躯体和肝胰腺中脂肪和碳水化合物含量显著高于NF组(P＜0.05),CF组扣蟹躯体和肝胰腺碳水化合含量显著高于CTF组(P＜0.05 ),而NF组扣蟹肝胰腺水分显著高于CF组和CTF组(P＜0.05)。无论投喂与否,越冬过后躯体蛋白质含量显著下降,而肝胰腺中蛋白质显著增加(P＜0.05);（3）脂肪酸组成,CF组扣蟹躯体和肝胰腺中C18:2n6(LA)含量显著高于NF组和CTF组,而CTF组C20:5n3(EPA)和C22:6n3(DHA)含量显著高于NF组和CF组(P＜0.05);（4）越冬过后,扣蟹肝胰腺消化酶CF组胃蛋白酶(pepsin)和α-淀粉酶(α-AMS)活性显著高于NF组和CTF组(P＜0.05);（5）扣蟹抗氧化能力,肝胰腺和血淋巴中NF组超氧化物歧化酶(SOD)活性显著高于CF组和CTF组(P＜0.05),CF组总抗氧化能力(T-AOC)活性显著高于NF组和CTF组(P＜0.05),CTF组扣蟹血淋巴和雌性扣蟹肝胰腺丙二醛(MDA)含量显著高于NF组和CF组(P＜0.05);（6）扣蟹免疫能力,CF组酸性磷酸酶(ACP)和碱性磷酸酶(AKP)活性显著高于NF组(P＜0.05)。综上所述,中华绒螯蟹扣蟹越冬期间应该适量投喂饵料,投喂配合饲料组扣蟹的存活率、肝胰腺指数、增重率以及营养物质积累优于投喂冰鲜鱼组,而且投喂配合饲料有利于扣蟹消化,增强扣蟹抗氧化和免疫能力。本研究为中华绒螯蟹扣蟹越冬饵料的合理投喂提供科学参考和理论基础。     

中华绒螯蟹白壳和绿壳品系成蟹可食率、类胡萝卜素含量和营养组成的比较

为了评估白壳中华绒螯蟹与广泛养殖的绿壳品系成蟹营养品质是否存在差异，本实验通过采集白壳新品系与正常绿壳品系扣蟹在相同池塘中养至性腺发育成熟的商品蟹，测定其可食率、类胡萝卜素含量和营养组成。结果显示，两种色泽中华绒螯蟹组织系数、可食率和肥满度均无显著差异；白壳品系蟹壳湿样和干样亮度值(L^*)显著高于绿壳品系，但红度值(a^*)显著低于绿壳品系，肝胰腺和卵巢色泽参数无显著差异。白壳品系蟹壳总类胡萝卜素和虾青素含量显著低于绿壳品系，但两品系肝胰腺和卵巢中类胡萝卜素含量和组成均无显著差异。两种品系可食组织部分常规生化组成含量无显著差异，但白壳雌蟹肌肉中C20:4n6比例显著高于绿壳，绿壳雌蟹肝胰腺中18:0、18:2n6和DHA/EPA比例均显著高于白壳品系。两品系肌肉中大部分氨基酸组成和必需氨基酸评分均无显著差异，白壳雌体肌肉中异亮氨酸和酪氨酸含量显著低于绿壳雌体。研究表明，白壳和绿壳品系仅蟹壳的色泽和类胡萝卜素含量方面具有显著差异，其可食率、可食组织的常规生化成分、主要类胡萝卜素含量、脂肪酸组成和氨基酸含量接近，说明白壳品系中华绒螯蟹具有较大的推广潜力。研究结果为中华绒螯蟹白壳品系种质资源评价和进一步选育提供理论依据。     

蛋白能量比对中华绒螯蟹蛋白酶活力和饲料消化率的影响

于１９９９年６～７月收集中华绒螯蟹（Ｅｒｉｏｃｈｅｉｒ ｓｉｎｅｎｓｉｓ）粪便，用酸不溶灰分法测定中华绒螯蟹对饲料的消化率，同时测定其胃、肠、肝胰脏蛋白酶活力。结果表明，蛋白质能量比（Ｐ／Ｅ）２８．９３ｍｇ／ｋＪ水平对中华绒螯蟹胃、肝胰脏蛋白酶活性明显高于Ｐ／Ｅ２７．３０ｍｇ／ＫＪ和３０．３１ｍｇ／ＫＪ水平饲料蛋白南、脂肪、能量和总表观消化率分别为８２．５７％、７７．５９％、８３．９４％和９６．９     

2种饵料模式对稻田养殖中华绒螯蟹幼蟹养殖性能和生理代谢的影响

为优化稻田养殖中华绒螯蟹(Eriocheir sinensis)幼蟹的饵料模式，本研究分别采用配合饲料和传统饵料(豆粕、麸皮、玉米和小麦)投喂稻田养殖中华绒螯蟹幼蟹152 d，每种投喂组各3个重复，比较2种饵料模式对幼蟹养殖性能、蛋白质代谢、消化酶、抗氧化和免疫指标的影响。结果显示，配合饲料组的雌蟹和雄蟹体质量均高于传统饵料组，但差异不显著(P>0.05)；就养殖性能而言，2种饵料模式下，配合饲料组正常幼蟹的平均体质量及产量、1龄早熟蟹平均体质量及其产量、总产量和成活率均略高于传统饵料组，饵料系数显著低于传统饵料组(P<0.05)；就蛋白质代谢而言，配合饲料组雌蟹和雄蟹血淋巴中的总蛋白含量显著高于传统饵料组(P<0.05)，而传统饵料组雄蟹血淋巴中的尿素氮含量和肝胰腺中的谷草转氨酶活力显著高于配合饲料组(P<0.05)；配合饲料组雌蟹和雄蟹肝胰腺中的脂肪酶均显著高于传统饵料组(P<0.05)，而雄蟹的α-淀粉酶活力显著低于传统饵料组；配合饲料组的雌蟹血淋巴中总抗氧化能力、碱性磷酸酶、酸性磷酸酶活力和肝胰腺中酸性磷酸酶活力均显著高于传统饵料组(P<0.05)。综上所述，投喂配合饲料可以提高稻田扣蟹的养殖性能、促进蛋白质沉积和脂类吸收、增强幼蟹抗氧化和免疫能力、提高蟹种质量。     

性早熟中华绒螯蟹肝胰腺与性腺的酸性和碱性磷酸酶活性

采用磷酸苯二钠法在520nm波长测定了未成熟、早熟和正常成熟中华绒螯蟹肝胰腺与性腺中的酸性磷酸酶（ACP）和碱性磷酸酶（ALP）。结果表明：（1）各组蟹肝胰腺ACP和ALP活性都显著高于性腺；（2）早熟蟹肝胰腺中ACP活性都显著高于未成熟蟹而低于正常成熟蟹，在各发育阶段没有性别差异，但是，早熟雌蟹和正常成熟雌蟹卵巢中ACP活性都较早熟雄蟹和正常雄蟹精巢低，早熟与正常成熟个体没有差异；（3）早熟雌蟹肝胰腺ALP活性显著高于未成熟和正常成熟雌蟹，而与三组雄蟹处于同一水平，但是，早熟和正常成熟雌雄蟹的性腺中ALP活性没有显著差异。由此得出结论：（1）性腺发育所需营养物质的动员或合成主要与肝胰腺ACP有关；（2）性早熟的发生与肝胰腺中ACP和ALP活性的显著升高有关。     

Use of Microbacterium sp. and Exiguobacterium mexicanum to improve the survival and development of Artemia under xenic conditions

The effect of Microbacterium sp. strain 8L and Exiguobacterium mexicanum strain 8N was evaluated in the diet of Artemia under xenic conditions. Viable cultures of bacteria were provided to xenic cultures of Artemia in combination with Sacharomyces cerevisiae, cornflour or Spirulina, and the effect on the survival and growth was recorded. The use of these bacterial strains improves significantly the survival of Artemia independently of the used food (P < 0.05), and variable results were observed in the growth.     

养殖大菱鲆中牙鲆肠弧菌的分离鉴定及组织病理学

2007年1月，山东省胶南某养殖场人工养殖的大菱鲆（Scophthalmus maximus）发生严重病害并大批死亡。病鱼的主要症状是体表溃疡，腹腔积液，肠道肿胀，肝脏萎缩，胆囊暗绿色等。从病鱼胆囊中分离纯化得到优势菌株，命名为da3。人工感染试验证实，该菌株对大菱鲆有较强的致病性。对体重为25 g的大菱鲆的半数致死量为每尾鱼2×106 cfu。通过细菌16S rDNA序列测定及形态学和生理生化特征研究确定，该病原菌为牙鲆肠弧菌（Vibrio ichthyoenteri）。组织病理学观察表明，病鱼的肝脏、肾脏、脾脏、肠道和脑的微观结构发生了明显的病理变化，由此引起的器官功能衰竭可能是病鱼死亡的主要原因。本文结果对大菱鲆细菌性病害的控制具有参考价值。     

Characteristics of the marine environment and algal blooms in Gamak Bay

This study was conducted to gain insight into the characteristics of algal blooms in relation to the marine environment of Gamak Bay. From the first known occurrence of algal blooms in 1984 until 2006, 23 causal species have been identified, the most common ones being Prorocentrum sp., Cochlodinium polykrikoides, Chaetoceros sp., Skeletonema costatum, and Heterosigma akashiwo. A principal component analysis indicated that blooms of these species develop under different conditions in terms of water temperature, salinity, precipitation, and insolation. Field data showed Cochlodinium polykrikoides to be favored by high temperatures and to be euryhaline, whereas Skeletonema costatum appeared to be eurythermal and euryhaline. Prorocentrum sp. and Chaetoceros sp. appeared to be stenothermal and stenohaline. Finally, Heterosigma akashiwo appeared at the lowest temperature and highest salinity of the five species and was classified here as stenothermal and stenohaline.     

Delivery of HUFA, probionts and biomedicine through bioencapsulated Artemia as a means to enhance the growth and survival and reduce the pathogenesity in shrimp Penaeus monodon postlarvae

One of the major problems in the shrimp culture industry is the difficulty in producing high-quality shrimp larvae. In larviculture, quality feeds containing a high content of highly unsaturated fatty acids (HUFA) and ingredients that stimulate stress and disease resistance are essential to produce healthy shrimp larvae. In the present study, Penaeus monodon postlarvae (PL15) were fed for 25 days on an unenriched Artemia diet (control; A) or on a diet of Artemia enriched with either HUFA-rich liver oil of the trash fish Odonus niger (B), probionts [Lactobacillus acidophilus (C1) or yeast-Saccharomyces cerevisiae (C2)] or biomedicinal herbal products (D) that have anti-stress, growth-promoting and anti-microbial characteristics. P. monodon postlarvae fed unenriched Artemia exhibited the lowest weight gain (227.9 ± 8.30 mg) and specific growth rate (9.95 ± 0.05%), while those fed the HUFA-enriched Artemia (B) exhibited the highest weight gain and specific growth rate (362.34 ± 12.56 mg and 11.77 ± 0.08%, respectively). At the end of the 25-day rearing experiment, the shrimp postlarvae (PL40) were subjected to a salinity stress study. At both low and high (0 and 50‰) salinities, the group fed the control diet (A) experienced the highest cumulative mortality indices (CMI) 935.7 ± 2.1 and 1270.7 ± 3.1, respectively. Those fed diet D showed the lowest stress-induced mortality, and CMI were reduced by 31.1 and 32.3% under conditions of low and high salinity stress, respectively. A 10-day disease challenge test was conducted with the P. monodon postlarvae (PL40–PL50) by inoculating the shrimp with the pathogen Vibrio harveyi at the rate of 10⁵–10⁷ CFU/ml in all rearing tanks. P. monodon postlarvae fed probiont-encapsulated Artemia diets (C1 and C2) exhibited the highest survival (94.3 and 82.3%, respectively) and lowest pathogen load (V. harveyi) in hepatopancreas (5.2 × 10² ± 9.0 × 10 and 4.6 × 10² ± 9.0 × 10 CFU g⁻¹, respectively) and muscle (2.0 × 10² ± 6 × 10 and 1.7 × 10² ± 8.6 × 10 CFU g⁻¹, respectively) tissues. The shrimp that were fed the unenriched Artemia (Control; A) showed the lowest survival (26.33%) and highest bacterial load in the hepatopancreas (1.0 × 10⁵ ± 5 × 10³ CFU g⁻¹) and muscle (3.6 × 10⁴ ± 6 × 10² CFU g⁻¹). The shrimp fed the herbal product (D)-enriched Artemia also exhibited enhanced survival and reduced V. harveyi load in the tissues tested compared to the control diet (A) group. The results are discussed in terms of developing a quality larval feed to produce healthy shrimp larvae.     

Bioaugmentation in the growth and water quality of livebearing ornamental fishes

Bacillus subtilis isolated from the intestine of Cirrhinus mrigala (Hamilton) was incorporated into the rearing water of Poecilia reticulata (Peters), Poecilia sphenops (Valenciennes), Xiphophorus helleri (Heckel) and Xiphophorus maculatus (Gunther) at four different concentrations (5 × 10⁸ cells ml⁻¹, 5 × 10⁷ cells ml⁻¹, 5 × 10⁶ cells ml⁻¹ and 5 × 10⁵ cells ml⁻¹) and its effect on fish growth performance and survival, water quality parameters and bacterial population of water were assessed. The results showed that the addition of bacterial cells in the rearing water resulted in greater survival and a faster growth rate and, hence, greater length and weight increments of the livebearers. The use of a bioaugmentor in the rearing water of the livebearing fishes resulted in significantly lower (P < 0.05) concentrations of dissolved organic matter and total ammonium nitrogen. The counts of motile aeromonads and total coliforms recorded in the water of bioaugmented tanks were also lower than that in the control tank. Bioaugmentation between 10⁶ and 10⁸ cells ml⁻¹ in the rearing water is sufficient in establishing a bioaugmentor and the use of a higher concentration of bacterial cells did not always lead to significantly better results.     

Influence of the antibacterial herbs, Solanum trilobatum, Andrographis paniculata and Psoralea corylifolia on the survival, growth and bacterial load of Penaeus monodon post larvae

The indiscriminate use of antibiotics and chemicals in shrimp hatcheries has led to biomagnification and that in turn could lead to rejection of a whole consignment. The application of the bioencapsulation technique as a tool for curative treatment in shrimp larvae was investigated. Herbs having antibacterial properties such as Solanum trilobatum, Andrographis paniculata and Psoralea corylifolia (methanolic extracts) were bioencapsulated in Artemia and fed to Penaeus monodon post larvae PL 1–25. The post larvae were reared in a medium inoculated with pathogenic bacteria such as Pseudomonas aeruginosa, Staphylococcus aureus, Salmonella typhi and Vibrio sp. Post larvae reared in the non-inoculated water and fed with non-enriched Artemia exhibited 90% survival, highest specific growth rate (12.43%) and reduced bacterial load. P. monodon reared in the bacterial inoculated water and fed with the non-enriched Artemia exhibited the lowest survival (10–30%), specific growth rate (8.42–9.1%) and increased bacterial load (2.86 × 10³ to 3.76 × 10⁵ cfu/g). The methanolic extracts of the herbs helped to increase survival and specific growth rate and reduced bacterial load in the P. monodon culture system. Among the three herbal extracts, P. corylifolia enriched Artemia fed post larvae showed the tendency to higher survival (>50%), growth rate (11.5 averaged) and low bacterial load (1.12 × 10⁵ cfu/g). This revised version was published online in August 2006 with corrections to the Cover Date.     

南海北部陆架水域多齿蛇鲻与花斑蛇鲻的年龄与生长

2014年7月至2015年5月采集南海北部陆架海域的多齿蛇鲻(Sauridatumbil)和花斑蛇鲻(Sauridaundosquamis)样本,测量其叉长、体重、性腺成熟度,并读取其耳石和日龄数据,对这2个种的生物学特征进行比较,发现多齿蛇鲻和花斑蛇鲻叉长、体重雌雄间差异显著(P0.05)。多齿蛇鲻雌性与雄性样本,叉长范围分别为109～310 mm、117～283 mm,体重范围分别为13～358 g、20～297 g,日龄范围分别为76～558 d、73～526 d, von Bertalanffy生长方程的相关参数分别为:L_(∞♀)=278 mm, L_(∞♂)=276 mm; K_♀=1.30, K_♂=1.30; t_(0♀)=-0.07 a, t_(0♂)=-0.08 a。雌性性腺成熟度Ⅲ期样本从350～400 d日龄组开始出现,雌性与雄性样本孵化高峰期在3月、7月、9—10月。花斑蛇鲻雌性与雄性样本,叉长范围分别为105～269 mm、95～264 mm,体重范围分别为11～220 g、8～228 g,日龄范围分别为79～486 d、84～488 d, von Bertalanffy生长方程的相关参数分别为:L_(∞♀)=269 mm, L_(∞♂)=265 mm, K_♀=1.29, K_♂=1.29, t_(0♀)=-0.06 a, t_(0♂)=-0.06 a,雌性性腺成熟度Ⅲ期样本从200～250 d日龄组开始出现,雌性与雄性样本孵化高峰期在6—11月。与历史资料进行对比,发现南海海域多齿蛇鲻与花斑蛇鲻出现个体大小逐渐减小、性成熟提前等适应性特征。结论认为,为了南海多齿蛇鲻与花斑蛇鲻渔业资源的可持续发展,需要降低南海近海的捕捞压力以促进南海渔业资源的发展。     

长江鲟类资源现状及保护

归纳了白鲟、长江鲟、中华鲟近40年自然资源量变化情况，统计了长江鲟和中华鲟人工增殖放流数据，评估了增殖放流成效。因物种特性和分布的差异，放流无效的原因迥异。过度捕捞使人工放流长江鲟在放流后6个月之内难逃被“误捕”，而中华鲟放流数量不足及长江和近海过度捕捞导致中华鲟人工增殖放流的贡献甚微，其结果是长江鲟和中华鲟增殖放流均无法达到自然繁殖群体的补充水平。本文探究了近40年来白鲟、中华鲟和长江鲟在保护、管理和决策上存在的误区和不足，提出在生态大保护的背景下，(1)应编制和实施《长江鲟拯救行动计划》优先项目；(2)应以《中华鲟拯救行动计划》为指引，在就地保护、迁地保护和遗传多样性保护方面提出更具有可操作性的优先计划；(3)应设立中华鲟和长江鲟物种拯救行动计划专项，对现有涉栖息地或保护区生态补偿项目进行优化整合。唯有以恢复长江鲟和中华鲟自然繁殖为核心，才有望延续和恢复其自然种群，实现人与自然的和谐共处，推动长江流域社会经济绿色可持续发展。     

大菱鲆内脏结节病病原的分离与鉴定

2017年8月,天津市滨海新区某养殖场大菱鲆(Scophthalmus maximus)发生病害,累计死亡率约为25%,患病鱼体表无明显症状。通过肉眼和病理组织切片观察发现,患病鱼肾脏、脾脏、肝脏和肠道存在大量圆形结节,肾脏、肝脏和脾脏组织病变明显,肾小管坏死,肝细胞脂肪变性,脾脏中存在大量的坏死细胞。此外,在脾脏和肾脏组织中发现大量的抗酸杆菌。利用传统病原菌分离方法,从具有典型症状的濒死大菱鲆肾脏组织分离到优势菌株myco-10,利用该菌株注射攻毒能导致健康大菱鲆66.7%的死亡率,且表现出与自然发病鱼相同的症状。采用16S rDNA、Hsp65、ropB基因序列分析,构建系统发育树并结合细菌形态特征、生理生化测试对菌株myco-10进行鉴定,结果显示,菌株myco-10的16SrDNA、Hsp65、ropB基因序列与分枝杆菌属细菌(Mycobacteriumspp.)相似度最高,且在系统发育树中与海分枝杆菌(Mycobacteriummarinum)和溃疡分枝杆菌(Mycobacteriumulcerans)聚为一簇,生理生化反应与海分枝杆菌一致。综合生理生化特征和基因序列分析结果,将菌株myco-10鉴定为海分枝杆菌。这是中国首例分枝杆菌引起大菱鲆病害的报道,可为大菱鲆内脏结节病的防治提供参考资料。     

二氧化锗对共培养萱藻丝状体和硅藻生长的影响

为抑制萱藻丝状体保存和扩增过程中出现的小伪菱形藻与碎片菱形藻的生长,本实验应用实验生态学方法,分别建立了丝状体与小伪菱形藻、丝状体与碎片菱形藻、丝状体与小伪菱形藻和碎片菱形藻的共培养体系,研究了1.00～4.00μg/mL二氧化锗(GeO_2)对共培养条件下丝状体生长发育及附生硅藻生长的影响。结果显示:(1)处理萱藻丝状体和硅藻共培养体系的适宜GeO_2浓度为1.00～2.50μg/mL,各实验组14 d的硅藻抑制率均高于67.33%±5.18%,且丝状体生长发育良好,2.00μg/mL为最适浓度,此浓度下丝状体日均增长率最高,在各培养体系中均大于11.00%,且诱导后孢子囊枝比例和孢子囊直径分别为57.47%±5.31%和(24.55±1.01)μm,与对照组差异不显著;(2) 3.50和4.00μg/mL GeO_2虽对硅藻抑制效果更佳,但同时也会抑制丝状体生长和后期孢子囊的形成与发育,其中4.00μg/mL GeO_2可导致丝状体死亡;(3)碎片菱形藻较小伪菱形藻对GeO_2更敏感。实验14 d,各浓度GeO_2对碎片菱形藻的抑制率为(82.10%±2.40%)～(96.35%±0.79%),均高于同浓度GeO_2对小伪菱形藻的抑制率;同时在丝状体与小伪菱形藻和碎片菱形藻的共培养体系中,碎片菱形藻占硅藻比例随GeO_2浓度升高而相应下降。