养殖密度对日本囊对虾生长与存活的影响

在模拟工厂化养殖环境下开展日本囊对虾不同密度的生长与存活试验,实验设置5个密度水平,50、100、150、200、250尾/m~2,每个试验组设2个重复。结果表明,不同密度条件下,日本囊对虾生长性状、存活率与饵料系数存在显著差异(P0.05)。20日龄,不同密度间的生长性状无统计学意义差异(P0.05);40日龄,密度组间的生长性状存在统计学意义差异(P0.05),密度50、100、150尾/m~2显著大于密度250尾/m~2(P0.05);60日龄时,密度100尾/m~2的平均体长、腹长与体质量分别为(7.28±0.74)cm,(4.72±0.43)cm,(3.59±0.98)g,显著大于密度150、200、250(P0.05),为生长最快的密度组。密度对存活率有极显著影响,存活率变化范围为(23.98%±2.25%)~(69.95%±2.38%),密度50和250存活率分别最高和最低,密度50、100的存活率极显著大于密度150、200、250尾/m~2(P0.01)。饵料系数的变化范围为(1.63±0.08)~(3.99±0.31),最低为密度50尾/m~2,饵料系数1.63±0.08。最高为密度250尾/m~2,饵料系数为3.99±0.31。当密度低于100尾/m~2时,日本对虾生长表现最好,该密度下对虾生长速率快、存活率高、饵料系数低。本研究为日本囊对虾的工厂化养殖生产提供理论参考。     

悬沙胁迫下日本囊对虾仔虾的生长和DNA损伤

以日本囊对虾(Marsupenaeus japonicus)仔虾为受试生物,研究不同悬沙浓度(0、l0、50、100、500和1 000 mg/L)下仔虾的存活率、增重率、RNA/DNA比率变化和DNA损伤情况,探讨悬沙对仔虾的影响.结果表明,低浓度悬沙(＜500 mg/L)对仔虾的存活率、增重率、RNA/DNA比率和DNA损伤指标无显著影响.高浓度悬沙(≥500 mg/L)为仔虾生长蜕皮提供隐蔽场所,减少自残,但在提高存活率的同时,影响仔虾摄食,表现为仔虾的增重率和RNA/DNA比率与对照组相比显著下降(P＜0.05),且增重率和RNA/DNA比率之间具有显著的正相关性(P＜0.05).在高浓度悬沙组(≥500 mg/L)中,作为DNA损伤指标,彗星细胞拖尾率、尾长和尾矩与对照组相比均显著增加(P＜0.05),但不同的指标灵敏度不同,尾长和尾矩灵敏度较拖尾率更高.结论认为,RNA/DNA比率和DNA损伤指标能够有效评估悬沙对仔虾生长的影响.     

盐度对日本囊对虾生长性能影响

在盐度7~42范围内设置8个盐度梯度,每个梯度3个重复。研究盐度对日本囊对虾成虾的生长、存活与饵料系数的影响,结果表明,日本囊对虾生长、存活率、增长率与饵料系数均有统计学意义差异(P0.05),盐度27的生长最快,显著大于盐度组7(P0.05);存活率变化范围为(18.79%±1.94%)~(91.71%±3.68%),盐度27存活率最高,高盐度或低盐度的存活率均低于中间盐度,但高盐度的存活率要比低盐度高;生长性状的增长率变化范围(2.47%±0.25%)~(84.42%±5.22%),增长率最快为盐度22~32;饵料系数最低为盐度27。日本囊对虾成虾最适生长盐度范围为22~32,该盐度范围内对虾生长速率快、存活率较高、饵料系数低;日本囊对虾成虾的最适盐度范围较窄,并且高盐度下的日本囊对虾存活率更高。     

温度对对虾仔虾至幼虾阶段成活率及生长影响的实验研究

<正> 近几年,随着对虾亲虾越冬技术的推广,虾苗的生产期不断提前。放养期越来越早,不少地区已由5月中旬提前至4月下旬;放苗温度也由《规程》上要求的14℃左右降至12～13℃(中间遇到寒潮甚至降至10℃以下)。为了掌握温度对虾苗成活率和生长速度的影响,以探求合理的放养时机,1990年春我们进行了温度对对虾仔虾至幼虾阶段成活率及生长影响的生产性实验,取得了比较有价值的技术资料。     

强壮藻钩虾对中国明对虾与日本囊对虾生长和抗病力的影响

以强壮藻钩虾(以下简称钩虾)作为中国明对虾和日本囊对虾的天然饵料,以对虾人工配合饲料为对照研究钩虾对中国明对虾和日本囊对虾生长和抗病力的影响。对两种规格的中国明对虾[体质量分别为(0.33±0.0204)g和(2.07±0.184)g,分别记为SF组和MF组]和日本囊对虾[体质量为(0.25±0.018 1)g,记为SM组]分别投喂人工配合饲料和钩虾,养殖35 d。结果显示:(1)与人工配合饲料相比钩虾可以提高MF组和SM组对虾的特定生长率和SM组对虾的成活率;(2)钩虾可以显著提高SF组和SM组对虾血细胞总数(P<0.05);(3)钩虾可以显著提高3组对虾血清总蛋白含量(P<0.05)及SF组和SM组血蓝蛋白含量(P<0.05);(4)钩虾可以显著提高日本囊对虾溶菌酶活力(P<0.05);(5)钩虾可以显著提高FM组和SM组对虾酚氧化酶活力和超氧化物歧化酶活力(P<0.05);(6)钩虾可以显著性提高SF组和SM组对虾血清过氧化物酶相对活力(P<0.05);(7)对虾健康指标总得分与其感染WSSV后的100%致死时间关系密切,两者之间呈现一定的线性关系(R2=0.948 9)。研究结果表明,钩虾与对虾人工配合饲料相比可以促进中国明对虾和日本囊对虾的生长及提高对虾抗病力。     

pH对日本囊对虾的急性毒性初步研究

采用静水试验方法,研究低pH对日本囊对虾(Marsupenaeus japonicus)的急性毒性。试验用日本囊对虾平均体长(48. 87±4. 81) mm,设定pH梯度为3. 8、4. 1、4. 4、4. 7、5. 0,对照组pH为8. 0±0. 1,统计日本囊对虾在低pH胁迫下的死亡率,分析pH对日本囊对虾的半致死摩尔浓度(LC50)和半致死时间(LT50)。结果显示:在相同pH下,日本囊对虾的死亡率随时间延长而增加;在相同的胁迫时间内,日本囊对虾死亡情况与水体pH呈负相关(R <0,P <0. 01); pH对日本囊对虾胁迫48 h、72 h、96 h的半致死摩尔浓度(LC50)分别为:7. 907×10^-5、5. 140×10^-5和3. 673×10^-5mol/L,安全摩尔浓度(SC)为3. 673×10-6mol/L,对应的pH分别为4. 102、4. 289、4. 435、5. 435;水体pH 4. 1、pH 4. 4、pH 4. 7胁迫日本囊对虾的半致死时间(LT50)分别为58. 821、93. 771和139. 549 h。本研究可为研究日本囊对虾的养殖、对低pH的耐受性及耐低pH品系选育提供参考。     

包装密度对放流对虾仔虾存活的影响

对中国对虾和日本对虾仔虾不同包装密度下的存活率进行监测,在获得各时间段仔虾的存活率及其存活时间的同时,得出不同包装密度下中国对虾仔虾存活率差异显著（P〈0．05）,日本对虾仔虾存活率差异极显著（P〈0．01）,2种对虾仔虾存活率与包装密度呈负相关。结合增殖放流实际,给出了放流对虾仔虾最适包装密度。     

Ca2+、Mg2+对长毛对虾(Penaeus Penicillatus Alcock)仔虾生长和成活率的影响

研究了Ca^2和Mg^2 对长毛对虾仔虾生长和成活率的影响。实验结果表明：盐场水库水体中Ca^2和Mg^2 质量浓度及它们之间的比例是影响长毛对虾（Penaeus penicillatus Alcock)仔虾生长和成活率的重要因素；当水体中Mg^2 质量浓度为877.8mg/l,Ca^2 含量为278．7－292．6mg/l，并且Mg^2/Ca^2 =3.00-3.15/l时长毛对虾仔虾生长发育最佳。     

2个凡纳滨对虾群体仔虾的生长比较

以凡纳滨对虾二代群体自交、选育家系(♀)×引进SPF(♂)群体杂交,通过自然交配和人工培育获得2个仔虾群体,待仔虾长至体长0.8～1.0 cm时,随机选取60万尾放养于3口0.133 hm2的对虾养殖高位塘中,密度150万尾/hm2,其中二代仔虾2口塘,杂交仔虾1口塘.投喂"恒兴"牌饲料,相同的养殖环境和管理措施,养殖30 d后,每隔10 d进行一次生长测定.结果表明,杂交仔虾的生长速度和成活率高于二代仔虾,体质量和体长的总生长率高于二代仔虾,抗应激能力强于二代仔虾,较二代仔虾均匀;在40 d的观测期内杂交仔虾体长的绝对增长量为4.49 cm,二代仔虾为3.66 cm,提高22.68%,杂交仔虾体质量的绝对增长量为3.73 g,二代仔虾为2.20 g,提高69.55%,杂交仔虾生长优势明显.     

Effects of salinity and pH on ion-transport enzyme activities, survival and growth of Litopenaeus vannamei postlarvae

Effects of the salinity and pH on ion-transport enzyme activities, survival and growth of Litopenaeus vannamei postlarvae were investigated. Shrimp were transferred from salinity 31‰ and pH 8.1 to different salinity levels of 22, 25, 28, 31 (control), and to different pH levels of 7.1, 7.6, 8.1 (control), 8.6 and 9.1. The results showed ion-transport enzyme activities and weight gains of postlarvae were significantly affected by salinity and pH variation, which had no obvious effect on survival rate. The changing salinity affected the activities of total ATPase and Na⁺-K⁺-ATPase notably (F > F_0.05), meanwhile, non-significantly to the activities of V-ATPase, HCO₃⁻-ATPase. Within 48 h of salinity changing, the activities of ATPase, Na⁺-K⁺-ATPase in each treatment group gradually increased with the sampling time and reached their climax at 48 h, and then stabilized, showing negative correlation with salinity. The changing of pH affected greatly the activities of ATPase, Na⁺-K⁺-ATPase, V-ATPase and HCO₃⁻-ATPase (F > F_0.05), the activities of ATPase, Na⁺-K⁺-ATPase in each treatment group (pH = 7.1, 7.6, 8.6, 9.1) showed peak change within 72 h and stabilized afterwards, and the Na⁺-K⁺-ATPase activities came back to the level of the control group; Meanwhile the changing extent of V-ATPase and HCO₃⁻-ATPase activity corresponded with the grads of pH, and these ATPase activities showed negative correlation with pH changing, the activities of V-ATPase, HCO₃⁻-ATPase in postlarvae of each treatment group came to stable level after 24 h. The experiment also indicated the strength order of these ion-transport enzyme activities were as follows: Na⁺-K⁺-ATPase > V-ATPase > HCO₃⁻-ATPase. Na⁺-K⁺-ATPase was the chief undertaker of osmoregulation under the salinity effects, while V-ATPase and HCO₃⁻-ATPase were the chief osmoregulation undertakers under pH changing. In different salinity environment, the contributions of Na⁺-K⁺-ATPase, V-ATPase and HCO₃⁻-ATPase of L. vannamei postlarvae approximately accounted for 62.0-78.0%, 15.9-29.0% and 2.03-4.12% of ATPase activities in total, respectively. Meanwhile, in different pH medium, the contributions of these ATPases approximately accounted for 50.7-67.4%, 21.3-31.8% and 2.15-7.90% of total ATPase activities, respectively. Weight gain of shrimp transferred to salinity 31 (control) and 28‰ was significantly higher than that of shrimp reared at 25 and 22‰, and weight gain of shrimp transferred to pH 8.1 (control) and 8.6 was significantly higher that that of shrimp transferred to pH 7.1, 7.6 and 9.1. It was suggested that during the process of desalting and culturing of postlarvae, the salinity changing should not exceed 3 and pH variety not more than 0.5.     

2种盐度和3种糖源对凡纳滨对虾生长和糖代谢的影响

为研究肌醇对不同盐度 (4和28) 条件下凡纳滨对虾 (Litopenaeus vannamei) 幼虾生长、血清生化指标和非特异性免疫的影响,选取初始体质量为 (0.75±0.03) g的凡纳滨对虾为研究对象,以添加0、100、200、400、800和1 600 mg∙kg⁻¹肌醇的6种等氮等脂饲料持续投喂10 周。结果表明,高盐度对虾终末体质量、增重率、成活率、特定生长率、蛋白质效率、蛋白质净利用率、总胆固醇含量、酸性磷酸酶、碱性磷酸酶、总超氧化物歧化酶和一氧化氮合酶显著高于低盐度 (P<0.05),饲料系数和水分则相反。饲料系数和总胆固醇含量随饲料中肌醇水平的升高而降低,终末体质量、增重率、成活率、特定生长率、蛋白质效率和蛋白质净利用率则相反,肌醇添加组的肝体比、酸性磷酸酶和碱性磷酸酶活性显著高于对照组 (P<0.05)。综上,饲料中添加肌醇可促进凡纳滨对虾的生长发育,提高其成活率和非特异性免疫力;低盐条件下凡纳滨对虾的生长发育和免疫力受抑制,肌醇水平不低于100 mg∙kg⁻¹能使其生长发育恢复至高盐水平,不低于200 mg∙kg⁻¹可在一定程度上提高其免疫力。     

温度、pH对泥鳅肠道消化酶活性的影响

以泥鳅(Misgurnus anguillicaudatus)为研究材料,测定不同温度及不同pH条件下肠道中蛋白酶、淀粉酶和脂肪酶的活性。结果表明,随温度、pH值的升高,三种酶活性的变化均表现为先增高后降低。蛋白酶、淀粉酶、脂肪酶的最适温度分别为50℃、50℃、40℃,最适pH值分别为7.0、7.0、7.5。     

pH对西施舌受精卵与幼虫生长发育的影响

研究了在室内控制条件下,pH对西施舌（Coelornactra antiquata）受精卵的孵化与面盘幼虫生长发育及附着变态的影响。试验结果表明,西施舌受精卵孵化成担轮幼虫的最适pH为7．0～8．5;从担轮幼虫发育成直线铰合幼虫的最适pH为7．5～8．5。在pH8．0～8．2面盘幼虫生长较快,日平均壳长增长15．0～16．5μm。在水温26．4&#177;0．45℃,盐度25．50,pH8．0—8．2的条件下,平均壳长196μm的西施舌壳顶面盘幼虫经72h培育,幼虫附着变态率为51．66％～53．00％。     

饥饿对凡纳滨对虾仔虾摄食行为和消化酶活力的影响

2004年5月,在中国海洋大学海水养殖教育部重点实验室内营造半精养、精养养殖模式,研究短期饥饿(0(对照组)、1、2、3、4、5、6d)对凡纳滨对虾仔虾摄食行为、摄食率及消化酶的影响。结果表明,两种模式中仔虾的摄食行为和摄食率都随饥饿天数的增加而呈现先上升后下降的趋势;半精养模式中,经饥饿再投喂后仔虾的胃蛋白酶、类胰蛋白酶和淀粉酶活力均随饥饿天数的增加呈现先上升后下降的趋势;精养模式中,胃蛋白酶活力也呈现以上趋势,但类胰蛋白酶和淀粉酶活力则在饥饿初期波动,然后下降。凡纳滨对虾仔虾遭遇饥饿胁迫后,通过提高摄食强度、摄食率及消化酶的分泌量来进行能量补充。但随着饥饿时间的延长,其应对饥饿胁迫的能力下降,各种消化酶活力呈降低趋势。实验表明,在半精养模式中,凡纳滨对虾对饥饿胁迫的承受能力高于精养模式。     

Effects of garlic powder on feeding attraction activity,growth and digestive enzyme activities of Japanese seabass,Lateolabrax japonicus

The study was to investigate the effects of garlic (Allium sativum) powder on feeding attraction activity, growth performance and digestive enzymes of juvenile Japanese seabass, Lateolabrax japonicus (initial weight: 29.82 ± 0.24 g). Six concentration gradients (0, 5, 10, 15, 20 and 25 g/kg diets) were formulated for luring and feeding experiment. The results showed a clear attractive trend of garlic powder for L. japonicus. A 28‐day feeding experiment indicated garlic could reduce the feed conversion ratio (FCR) (p < .05). The content of the body crude lipid was significantly increased at 10–15 g/kg diet (p < .05). Digestive enzyme activities including trypsin, amylase (AMS) and lipase (LPS) in the intestine were the highest at 10 g/kg diet (p < .05). Overall, garlic powder provides a promising and effective method for Japanese seabass healthy culture by improving fish growth and digestive ability. The results of this research suggested the additive suitable dosage of garlic powder was about 10 g/kg diet.     

The effect of dietary protein and total energy content on digestive enzyme activities, growth and survival of Litopenaeus setiferus (Linnaeus 1767) postlarvae

The effect of dietary protein and energy content on the activity of digestive enzymes (total proteinases, trypsin, chymotrypsin α‐amylase and lipase), and growth and survival of Litopenaeus setiferus postlarvae was investigated under controlled conditions. There was a clear relationship between the diet fed to the postlarvae, growth and survival. Highest weight gain (2110 ± 96.7%) was obtained with a 400 g kg^?1 protein and low energy diet (13.9 kJ g^?1) (P < 0.05). The optimal protein to energy ratio (P/E) estimated was 28.8 mg of protein kJ^?1. Good survival was obtained with low energy diets containing between 200 and 400 g kg^?1 protein and with high energy diets containing 300–500 g kg^?1 protein. Higher values for total proteinases, trypsin and α‐amylase were obtained with the low energy, 400 g kg^?1 protein diet. Chymotryptic activity was considerably lower than that of other proteinases and lipase activity was too low to be reliably measured with the turbidimetric method employed. Total proteinase activity was significantly lower than in experimentally grown postlarvae. The α‐amylase activity was at least two orders of magnitude higher in wild postlarvae than in animals fed with the best experimental diet. Protein requirement was related to total energy content of the diet: best growth and digestive enzyme activity coincide with the low energy, 400 g kg^?1 protein diet. These results suggest that dietary carbohydrates cannot spare protein because growth rates obtained with diets containing 200–300 g kg^?1 protein (337 and 226 g kg^?1 dextrin content, respectively) were significantly lowered.     

pH胁迫对中国明对虾抗氧化系统酶活力及基因表达的影响

研究了pH胁迫对中国明对虾(Fenneropenaeus chinensis)抗氧化系统的影响,将中国明对虾暴露于pH7.0、9.0的水体中148 h,于胁迫后0、3、12、24、48、72、96、120、148 h测定鳃、肝胰腺、肌肉和血淋巴总抗氧化活力(T-AOC)、抗超氧阴离子活力、过氧化氢酶(CAT)活力和CA...     

温度与pH对华贵栉孔扇贝淀粉酶和纤维素酶活力的影响

从湛江乌石养殖群体随机选取30个华贵栉孔扇贝性腺成熟个体繁殖子代,比较温度和pH对华贵栉孔扇贝淀粉酶和纤维素酶活力的影响.结果表明温度和pH对淀粉酶和纤维素酶活力均存在显著影(p<0.05).当温度在25～60℃之间时,淀粉酶和纤维素酶的最适温度分别为55℃和45℃;25℃时,淀粉酶和纤维素酶的最适pH值为5.0.