Biochemical composition of pond-reared and lake-stocked Chinese mitten crab Eriocheir sinensis (H. Milne-Edwards) broodstock

The morphological characteristics, tissue indices, proximate and fatty acid compositions of hepatopancreas, gonad and muscle of pond‐reared (PR) and lake‐stocked (LS) Eriocheir sinensis broodstock were compared. Lake‐stocked crabs are characterized by a blue carapace, white abdomen, golden legs and yellow setae while PR crabs have a brown carapace, grey abdomen, black legs and similar yellow setae. The carapace length and width of PR crabs were significantly less than those of LS crabs of the same wet weight (WW). The results showed that the hepatosomatic index (HSI) of PR males was significantly higher, but the gonadosomatic index (GSI) was significantly lower for PR females when compared with LS individuals of the same sex. Regardless of their origin, the muscular index (MI) of males was higher than that of females. The hepatopancreas of LS crabs had higher protein levels and lower lipid levels compared with PR crabs. The results of proximate analysis of male gonads from two different sources were similar, while the protein level in the ovary of LS females was higher than that of PR females. The tissues of males had higher water content but lower lipid and protein levels compared with females regardless of their source. The LS crabs had higher highly unsaturated fatty acid (HUFA) levels than PR crabs in their gonad and hepatopancreas. In conclusion, our results suggest that the nutritional quality of LS crabs is better than that of PR crabs, the nutritional quality of males is poorer than that of females. The reproductive performance and larval quality of crabs from these two rearing systems should be further verified.     

亲本强化培育对中华绒螯蟹雌体生殖性能和Z1幼体质量的影响

系统比较了亲本强化培育和常规培育对池塘养殖中华绒螯蟹的生殖性能和Z_1幼体质量的影响,同时分析2组Z_1幼体的脂肪酸组成。结果表明,①两种培育方式对亲本的成活率和产卵率均无显著影响,强化组亲本的GSI、HSI、产卵量和生殖力显著高于常规组;②两种培育方式对卵的卵径、水分含量、单卵干重和湿重影响不显著,但强化组的受精率和孵化率略高于常规组;③强化组Z_1幼体的头胸甲长度、变态速度和抗逆境能力均高于常规组,这可能和幼体中高含量的HUFA有关;④生产性实验结果表明强化组的出苗率高于常规组,且幼体培育时间减少4～5 d。因此,亲本强化培育可以显著提高绒螯蟹中华的生殖性能和Z_1幼体质量。     

不同饵料对二次抱卵期间中华绒螯蟹生殖性能和HUFA组成的影响

中华绒螯蟹(Eriocheir sinensis)经一次受精便可多次产卵.与其他的虾类一样,在卵巢发育过程中,中华绒螯蟹的肝胰脏需从外界汲取许多能量和营养物质,通过血淋巴转移到卵巢以供胚胎发育和幼体孵化.亲蟹的营养需求可以通过第一次和第二次卵巢发育过程加以研究.第一次抱卵之后亲蟹消耗了大量的营养和能量物质,需要在二次抱卵前的短时间内得到及时补充.通常来说,二次抱卵蟹的产卵力低下,幼体质量差.因此研究饵料对二次抱卵期间中华绒螯蟹生殖性能和幼体质量的影响是很有意义的.本实验分4组,分别以3种天然饵料缢蛏(TC)、沙蚕(TS)、杂鱼(TT)和一种人工饵料(TA)投喂中华绒螯蟹亲蟹,投喂周期为2个月(从初始一次抱卵至二次抱卵结束).天然饵料和人工饵料的日投喂量分别为亲蟹体重的10%和1%～3%,每日下午4点投喂.用PVC板将8m2的玻璃纤维槽隔成4个单元作为试验槽.每个单元底面积为2m2,水深40 Cm.同一槽中的3个单元用做一个试验组的3个重复,每个重复为10只蟹.海水盐度为20 g·L,pH 8.20～8.30,溶解氧为8.40～8.90 mg·L-1,依据水中氨氮和亚硝酸氮的浓度(分别小于1 mg·L-1和0.2 mg·L-1),每2至3天换一次水,水温为15～17℃.实验结束后,对二次抱卵亲蟹的生殖性能(相对饱卵量、卵径和亲蟹成活率)、孵化出的幼体质量(蚤Ⅰ幼体在饥饿状态下的成活率)以及卵、卵巢和肝胰脏的脂肪酸组成进行了测定.结果表明,卵、卵巢和肝胰脏的高级不饱和脂肪酸(HUFA)组成与试验饵料的组成具有很好的相关性,其中卵的DHA与EPA水平、肝胰脏DHA水平与饵料中相应的HUFA水平成正相关(R2＞0.90),说明外界营养物质的吸收和转移对卵巢的二次发育相当重要.统计学分析表明,投喂杂鱼的亲蟹(TT)孵出的蚤Ⅰ幼体对饥饿的耐受力以及投喂缢蛏的亲蟹(TC)的卵径显著高于其他组,各组之间其他指标(相对抱卵量和成活率等)均无显著差异.二次抱卵的中华绒螯蟹的卵、卵巢和肝胰脏中HUFA的水平与试验饵料中HUFA水平具有很好的相关性,说明无论在第一次卵巢发育过程中积聚了多少营养物质,第一次抱卵后消耗殆尽的亲蟹需要从外界食物中汲取大量的能量和营养物质,通过肝胰脏转运到卵巢供二次发育之用.本研究结论与其他作者对其他甲壳类的研究结果是一致的.此外组织器官的HUFA水平不只局限于饵料HUFA水平,还受器官本身对这些脂肪酸特定需求的影响.肝胰脏作为甲壳类动物的脂肪存储器,在饵料中的脂类物质被吸收和利用之前首先将其存储起来.甲壳类动物具有合成更长链的脂肪酸能力,虽然这种能力很有限,但仍能重新合成一定数量的脂肪酸.由于卵巢和卵中的n-3 HUFA,尤其是EPA和DHA含量高于肝胰脏,因此有理由相信它们在中华绒螯蟹繁殖过程中起着非常重要的作用.用人工饵料投喂对中国对虾的研究表明,n-3 HUFA的水平与亲本的生殖性能有很大关系,其中EPA与产卵量有很大的关系,而DHA在胚胎发育早期和幼体孵化起着很大的作用.本实验结果可以推论,EPA和DHA对中华绒螯蟹的卵巢的发育和生殖性能具有相当重要的作用,其中EPA的作用更加明显.遗憾的是本实验没有得出非常明显的相关性结论.应该指出的是本实验所用的不同饵料,不但HUFA含量不同,而且在蛋白质、总脂和微量营养素(维他命、矿物质、胆固醇、磷脂、钙盐等)的组成上差异很大,因此不宜下确定的结论.     

全程投喂配合饲料条件下池养中华绒螯蟹的生长性能及其性腺发育

于2012年5月至2013年11月,对池养中华绒螯蟹(Eriocheir sinensis)全程投喂配合饲料,观测扣蟹和成蟹阶段的生长规律、成活率、早熟率、性腺发育速度、产量、规格分布和饲料系数等。结果表明:(1)扣蟹阶段雌雄生长差异不显著(P0.05),增重率(WG)和特定增长率(SGR)为先上升后下降,整个扣蟹培育阶段的平均SGR为1.9%/d左右;平均成活率和早熟率分别为10.0%和4.9%,雌体的早熟率显著高于雄体(P0.05);一龄早熟蟹和正常扣蟹的平均体重分别为19.8 g和7.5 g左右,一龄早熟蟹和正常扣蟹的平均产量分别为229 kg/hm~2和2433 kg/hm~2;扣蟹培育阶段饲料投喂主要发生在7—10月,占全部饲料用量的80%以上,饲料投喂量与扣蟹体重及池塘水温具有一定的关系,扣蟹阶段饲料系数(FCR)为2.15。(2)成蟹养殖过程中,自6月份起雄体体重大于雌体,整个养殖阶段雄体的SGR显著高于雌体(P0.05);雌雄成蟹最终平均体重分别为126.1 g和181.1 g,雌、雄及总体成活率分别为61.30%、53.47%和58.4%,产量分别为412.20 kg/hm~2、536.10 kg/hm~2和950 kg/hm~2;成蟹养殖的饲料消耗主要发生在7—10月,其中育肥前期(9—11月)的饲料用量占50%左右,整个成蟹养殖阶段的FCR为2.63。(3)池养成蟹的生殖蜕壳主要发生在8—9月,雌体比雄体早20 d左右;雌体的性腺发育主要发生在生殖蜕壳后的9—10月,雄体的性腺发育时间跨度较长,生殖蜕壳前性腺指数已达0.8%左右;雌雄成蟹性腺发育期间肝胰腺指数均呈下降趋势。综上,全程投喂配合饲料能保证池养中华绒螯蟹的正常生长发育,可大规模推广应用于中华绒螯蟹养殖产业。     

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。     

饲料中的钙磷水平对中华绒螯蟹生长与饲料效率的影响

随着中华绒螯蟹（Ｅｒｉｏｃｈｅｉｒ ｓｉｎｅｎｓｉｓ,河蟹）养殖的迅速发展,对河蟹的营养生理和配合饲料方面的研究也有较大进展［１～６］,但迄今有关河蟹饲料中适宜钙磷含量的研究甚少,仅见到有关饲料矿物质适宜总量和钙磷含量对河蟹生长影响的初步报告［７］。本试验旨在了解钙磷对养殖河蟹生长和蜕壳的影响,为确定河蟹饲料中适宜的钙磷含量提供依据。１材料与方法１．１试验蟹及管理 试验蟹取自浙江上虞海涂养殖场,体重２９－３３ ｇ。随机分成９组,分别置于９只水族箱中,每箱２０只。箱内放置数块拱形瓦片供蟹栖息。发现蜕…     

Effect of dietary supplementation of phospholipids and highly unsaturated fatty acids on reproductive performance and offspring quality of Chinese mitten crab, Eriocheir sinensis (H. Milne-Edwards), female broodstock

This study was conducted to determine the optimum phospholipids: highly unsaturated fatty acids (PL/HUFA) ratio in maturation diets for female Chinese mitten crab, Eriocheir sinensis broodstock. Five isolipidtic and isonitrogenous diets were formulated to contain different amounts of pork lard, fish oil and soy lecithin with resulting PL/HUFA levels (%dry weight) of 1.4/0.3 (Diet 1), 1.6/2.5 (Diet 2), 2.3/2.0 (Diet 3), 3.8/1.5 (Diet 4) and 5.1/0.8 (Diet 5). Diet 1 lacked supplemental fish oil and soy lecithin and served as the control. Each of the five formulated diets was fed to a total of 150 female crabs for a period of 7 months. All diet treatments were triplicated with 50 crabs stocked in a pond as a replicate. After 6 months, male crabs were introduced into the ponds where females were kept, mating, spawning and egg hatching (in seawater) occurred in the following month. The nutritional value of various formulated diets was assessed based on survival, gonadosomatic index (GSI), egg production per female, fecundity (eggs/g female weight) of the females fed those diets and egg and larval (newly hatched zoea I larvae) quality.Females fed Diet 1 had the lowest GSI, egg production per female and fecundity while no significant difference were found for survival, hepatosomatic index (HSI) and the percentage of female spawned among the diet treatments (P > 0.05). Although there were no significant differences in egg diameter, egg wet or dry weights among all treatments (P > 0.05), the highest and the second highest proportions of essential fatty acids (EFA), i.e. 20:5n-3 (EPA), 22:6n-3 (DHA) and HUFA were found in the eggs produced by the females fed Diet 3 and Diet 2, respectively. Statistical analysis showed that EPA, DHA and HUFA in eggs produced by females fed Diet 3 were significantly higher than those from the other treatments (P < 0.05). Meanwhile, zoea I larvae from crabs fed Diet 3 had significantly larger carapace length than those from the other four treatments (P < 0.05). The zoea I larvae from crabs fed Diet 2 and Diet 3 also showed generally better tolerance to starvation and osmotic shock.In conclusion, our results indicated that diet included levels of PL/HUFA around 1.6/2.5 or 2.3/2.0 (% dry weight) fed female E. sinensis broodstock supported increased fecundity and elevated level of HUFA in egg, which in turn resulted in improved overall quality of newly hatched larvae.     

不同品系中华绒螯蟹土池生态育苗效果比较

为评估不同品系中华绒螯蟹（Eriocheir sinensis）的繁殖性能和育苗效果,分别采用中华绒螯蟹二龄早熟品系（雌体≥150 g,雄体≥210 g）、“长荡湖1号”A系（雌体≥200 g,雄体≥310 g）、“长荡湖1号”B系（雌体≥250 g,雄体≥360 g）及超大规格品系（雌体≥300 g,雄体≥400 g）作为亲本进行土池生态育苗试验,比较了各品系的抱卵蟹获得率、亲本孵化率、育苗期间的投饵量、幼体变态速度以及大眼幼体产量等指标。试验结果显示：（1）各品系越冬后的抱卵蟹获得率随着亲本规格的增大而明显降低,抱卵蟹成功孵化率随着亲本规格的增大同样呈降低趋势,但组间差异不明显（P>0.05）。（2）各品系投饵量在幼体培育期间呈现先增后减的变化趋势,其中,溞Ⅴ期最高,日投饵量约为75 g/m²;与之相反,幼体蜕皮周期在幼体培育过程中呈现出先降后增的变化趋势,溞Ⅲ-Ⅳ期蜕皮周期最短,仅为5～6 d。（3）除了个别产量异常的池塘外,各品系单蟹产苗量及饵料系数均随着亲本规格的增大而提高,且各品系大眼幼体淡化率差异较小,均在90%左右。结果表明,虽然大规格品系在...     

Effect of dietary soybean lecithin on reproductive performance of Chinese mitten crab Eriocheir sinensis (H. Milne-Edwards) Broodstock

The effect of increasing levels of dietary phospholipids (PL) on the ovarian development and reproductive performance of Chinese mitten crab Eriocheir sinensis were investigated using four semipurified formulated diets supplemented with 0%, 1.2%, 2.4%, and 3.6% PL. Four groups of 40 females, with an average individual body weight of 95–120 g, were fed the experimental diets for a period of 7 months. Male crabs were introduced into the female rearing system in March, and mating, spawning, and egg hatching occurred in the following month. After 10 weeks of feeding, females fed the diet with 2.4% PL had a significantly higher gonadosomatic index (GSI) than females fed the diet with 0% PL, whereas females fed the diet with 1.2% PL had a significantly higher hepatic moisture content and lower hepatic lipid content than the other groups (P < 0.05). After mating, the spawning rate was higher among females fed diets with 3.6% and 2.4% PL (95% and 92%, respectively) compared with females fed diets with 0% and 1.2% PL (both 81%). The results showed that egg production (total number of eggs/female) and fecundity increased with increasing dietary PL level, with females fed diets with 0% and 1.2% PL supplementation having significantly lower values than females fed the diet with 3.6% PL (P < 0.05). In conclusion, our results suggest that dietary PL supplementation has a positive effect on ovarian development and reproductive performance of E. sinensis broodstock. Further study should aim to investigate the optimal PL level in the broodstock diet of E. sinensis in respect to offspring quality.     

沉水植物对中华绒螯蟹生长和非特异性免疫力的影响

从东太湖采集伊乐藻(Elodea canadensis)、金鱼藻(Ceratophyllum demersum)、轮叶黑藻(Hydrilla verticilla-ta)、苦草(Vallisneria natans)、马来眼子菜(Potamogeton malaianus)5种沉水植物分别制成干粉。在基础饲料中添加15%的干粉形成5种不同的配合饲料,分别饲喂体重为(9.37±0.15)g的中华绒螯蟹(Eriocheir sinensis)60 d,分析沉水植物对中华绒螯蟹生长和非特异性免疫力的影响。结果显示:马来眼子菜组的中华绒螯蟹平均增重率显著低于对照组(P<0.05),饲料系数显著高于对照组(P<0.05),其余4种沉水植物组的平均增重率和饲料系数与对照组无显著差异(P>0.05);各组成活率、肥满度及肝体比差异不显著(P>0.05)。沉水植物各组的蟹血清超氧化物歧化酶活力显著高于对照组(P<0.05);与对照组相比,轮叶黑藻组、伊乐藻组和苦草组的中华绒螯蟹血清溶菌酶活性显著升高(P<0.05),金鱼藻组和马来眼子菜组则差异不显著(P>0.05);除马来眼子菜组降低外,其余4种沉水植物组中华绒螯蟹对嗜水气单胞菌的抵抗力强于对照组。因此,除马来眼子菜以外的4种沉水植物对中华绒螯蟹的生长性能无明显的促进作用,但可在一定程度上提高其非特异性免疫力。     

3种品系中华绒螯蟹扣蟹阶段池塘养殖性能比较

为探究不同品系中华绒螯蟹(Eriocheir sinensis)在扣蟹阶段的池塘养殖效果,于2020年在江苏东台进行了3个品系(2龄早熟品系、“长荡湖1号”A系和“长荡湖1号”B系)大眼幼体的池塘养殖试验,比较了各品系扣蟹的平均体质量变化情况、最终养殖性能、规格分布和经济效益。结果表明:(1)虽然3个品系大眼幼体在扣蟹阶段的平均体质量并无显著差异(P＞0.05),但各品系扣蟹平均体质量与亲本规格呈一定的正相关关系,总体上为“长荡湖1号”B系＞“长荡湖1号”A系＞2龄早熟品系;(2)正常扣蟹单位面积产量和扣蟹总产量与亲本规格呈正相关关系,即随着亲本规格的增大而显著增加(P<0.05);此外,“长荡湖1号”B系饲料系数(FCR)显著高于“长荡湖1号”A系(P<0.05);(3)3个品系扣蟹的体质量主要分布于6.0~7.9 g和8.0~9.9 g的规格区间内,其中2龄早熟品系在小规格区间(＜4.0 g和4.0~5.9 g)所占的比例较高,而“长荡湖1号”B系扣蟹在大规格区间(10.0~11.9 g和＞12.0 g)所占比例较高,但组间并无显著差异(P＞0.05);(4)各品系扣蟹的最终收益及投资回报率均随着亲本规格的增大而明显提高。综合来看,相对于2龄早熟品系,“长荡湖1号”A系和“长荡湖1号”B系在扣蟹养殖阶段具有产量高、投资回报率高等特点,市场应用和产业化前景较好。     

模拟快递运输对雌性中华绒螯蟹活力及其蟹肉品质的影响

探究雌性中华绒螯蟹(Eriocheir sinensis)在运输过程中活力、生化特性和滋味品质的变化,并分析三者之间的相关性。通过模拟电商生鲜运输条件,对模拟快递运输24 h、48 h和72 h的中华绒螯蟹活力进行统计和评价,以乳酸、挥发性盐基氮(TVB-N)和pH等分析中华绒螯蟹蟹肉生化特性的变化,同时以游离氨基酸、呈味核苷酸及感官等评价中华绒螯蟹蟹肉滋味品质的变化。结果显示,中华绒螯蟹在24 h的模拟运输下,无死亡且活力强劲,蟹肉乳酸和TVB-N等与0 h组无显著差异,且24 h组蟹肉的苦味氨基酸含量最低,为105.10 mg/100 g,印证了活蟹当日送达的重要性。超过24 h后,中华绒螯蟹的活力显著下降,死亡率上升,其中,模拟运输48 h后死亡率为3.33%,72h后死亡率达40.00%;其蟹肉乳酸、TVB-N及pH显著升高;随着运输时间的延长,蟹肉鲜、甜、苦味游离氨基酸含量均呈先下降后上升的趋势,而在模拟运输72 h后,5′-肌苷酸(IMP)含量显著增加至97.47 mg/100 g,5′-鸟苷酸(GMP)含量骤降至6.49 mg/100 g。感官结果则表明,经过模拟快递运输...     

Growth and immune response of Chinese mitten crab (Eriocheir sinensis) fed diets containing different lipid sources

A 10‐week feeding trial was conducted to evaluate the effects of dietary lipid sources on the growth and immune responses of Chinese mitten crab Eriocheir sinensis. Six isonitrogenous and isoenergetic diets were formulated with fish oil (FO), linseed oil (LO), soybean oil (SO), rapeseed oil (RO), coconut oil (CO) and beef tallow (BT) as the sources of lipid with five replicates each. Thirty crabs (2.35 ± 0.14 g) were stocked into each tank and fed twice daily. Weight gain and specific growth rate of crab fed the FO diet were significantly lower than those fed other diets (P < 0.05), except for crabs fed LO diet (P < 0.05). Crab fed the SO diet weighed more than those fed FO diets (P < 0.05). Serum superoxide dismutase and malondialdehyde of crab fed the FO diet were significantly higher than in other groups (P < 0.05). Crab fed the FO diet had the highest activities of serum phenoloxidase, acid phosphatase, alkaline phosphatase and lysozyme (P < 0.05). The fatty acid composition in the liver of crab reflected the change in test diets. Our results indicate that the use of dietary vegetable or animal oils can achieve similar growth performance to the use of dietary FO in Chinese mitten crab, but non‐FOs may impair crab immunity. Soybean oil is recommended as a suitable replacer for FO in Chinese mitten crab diet.     

不同脂肪源饲料对中华绒螯蟹幼蟹生长、消化酶活力和脂肪酸组成的影响

选用初始体重为(2.15±0.10)g的中华绒螯蟹(Eriocheir sinensis)雄性幼蟹,随机分为5组(每组12只幼蟹),饲喂100%鱼油组(简称F1组)、100%豆油组(F2组)、100%亚麻油组(F3组)、50%鱼油+50%豆油组(F4组)、50%鱼油+50%亚麻油组(F5组)不同脂肪源配制的5种等氮等能饲料。实验蟹单个体养殖,实验周期为112 d。结果表明,F5组体重、增重率和特定生长率都显著高于其他饲料组(P0.05),各组的蜕壳间隔和肝胰腺指数没有显著差异(P0.05)。肝胰腺组织消化酶活力测定结果表明,F1组幼蟹肝胰腺的类胰蛋白酶活力显著高于其他各组(P0.05);F3组的胃蛋白酶活力显著高于其他各组(P0.05);F1组、F2组和F4组的脂肪酶活力显著高于其他两组(P0.05);各组的淀粉酶活力差异不显著(P0.05)。脂肪酸测定结果表明,肝胰腺和肌肉中的亚油酸(LOA)(C18:2n-6)、亚麻酸(LNA)(C18:3n-3)、EPA(C20:5n-3)和DHA(C22:6n-3)等主要脂肪酸含量与饲料脂肪酸组成呈正相关关系,F1组的高度不饱和脂肪酸(HUFA)含量显著高于其余各组(P0.05),F2组的LOA含量显著高于其余各组(P0.05),F3组的LNA含量显著高于其余各组(P0.05)。本研究结果表明,以50%的豆油或亚麻油替代鱼油能促进中华绒螯蟹幼蟹的生长,但可能使幼蟹的成活率降低。以豆油或亚麻油替代鱼油会影响幼蟹胰蛋白酶、胃蛋白酶和脂肪酶的活力和肝胰腺、肌肉脂肪酸组成。     

中华绒螯蟹促性腺释放激素类似物的初步分离纯化与免疫鉴定

应用反向高效液相色谱法(RP-HPLC)从中华绒螯蟹脑组织提取液初步分离了促性腺释放激素(GnRH)类似物,使用章鱼促性腺释放激素抗体(anti-octGnRH)对分离组分进行免疫斑点印迹实验鉴定,获得了免疫反应呈阳性分离组分,表明脑组织粗提液中含有GnRH类似物分离组分。对该GnRH类似物进行基质辅助激光解吸/电离串联飞行时间质谱(MALDI-TOF/TOFMS)分析,结果显示多肽物质分子量范围在800～1400u,主要由8种小分子多肽组成,其中一种组分的分子量与章鱼促性腺释放激素(octGnRH)分子量接近。     

Effects of dietary phospholipids and highly unsaturated fatty acids on the precocity,survival, growth and hepatic lipid composition of juvenile Chinese mitten crab,Eriocheir sinensis (H. Milne‐Edwards)

Precocious puberty is one of the major constraints to the further development of Chinese mitten crab (Eriocheir sinensis) farming industry. Although dietary phospholipids (PL) and highly unsaturated fatty acids (HUFA) supplementation have been shown to enhance the growth of larval E. sinensis in other studies, it is still unknown whether this also leads to a higher precocity rate for juvenile E. sinensis. This study was conducted to investigate the effects of dietary PL and HUFA on precocity, survival, growth and hepatic lipid composition of juvenile E. sinensis. Two diets were formulated with PL [3.95% dry weight (DW)] and HUFA (0.98% DW) supplementation (diet A) and without PL and HUFA supplementation (diet B) and fed to juvenile E. sinensis. Although dietary PL and HUFA levels did not significantly affect the survival and growth performance of juvenile E. sinensis, compared with crabs fed diet A, a higher precocity rate was found among juvenile E. sinensis fed diet B (P=0.051). A higher total lipid content, but significantly lower levels of HUFA and PL (P<0.05) were found in the hepatopancreas of crabs fed diet B than in those fed diet A. Meanwhile, the precocious females had significantly lower hepatosomatic index, arachidonic acid (20:4n‐6), eicosapentaenoic acid (20:5n‐3) and docosahexaenoic acid (22:6n‐3) contents in their hepatopancreas when compared with that of the normal immature juveniles (P<0.05). The results suggest that the occurrence of precocious puberty among farmed juvenile E. sinensis could be reduced by the inclusion of appropriate level of dietary PL and HUFA.     

中华绒螯蟹亲蟹渗透压调节和抗氧化系统对盐度的响应

探讨了中华绒螯蟹亲蟹血清离子和渗透压对盐度的响应以及肝胰腺抗氧化能力与盐度的关系.设立4个盐度组(盐度6、12、18、24)和1个淡水对照组,检测第4天和第20天时中华绒螯蟹亲蟹血清中Na+、K+、Cl-浓度、渗透压以及肝胰腺超氧化物歧化酶(SOD)、过氧化氧酶(CAT)活性和还原型谷胱甘肽(GSH)、丙二醛(MDA)...     

三种投喂模式对河蟹二龄成蟹养殖性能的影响

比较了池塘养殖条件下,全程投喂配合饲料、杂鱼和传统饵料(以黄豆、小麦和玉米为主,辅以少量饲料和杂鱼)对河蟹(Eriocheir sinensis)二龄成蟹生长、性腺发育、规格分布、成活率、单产、饵料系数和饵料成本的影响。结果显示:(1)无论雌雄,传统饵料组早期(5-8月份)的增重率和特定生长率方面最低,杂鱼组最高;(2)杂鱼组雌体8月份性腺发育速度最快,传统饵料组性腺发育速度最慢,其余月份雌体和雄体的性腺指数和肝胰腺指数均无显著差异;(3)无论雌雄,最终杂鱼组的大规格成蟹(雄体175 g,雌体100 g)比例最高,而传统饵料组的小规格成蟹(雄体100 g,雌体75 g)比例最高,且体重差异较大,配合饲料组的中等规格成蟹较为集中,最终三组投喂模式下雌雄蟹的平均体重并无显著差异,杂鱼组略大于传统饵料组;(4)三种投喂模式下,三者的成活率和平均产量并无显著差异;杂鱼组的饵料系数和饵料成本最高,配合饲料组饵料系数最低,但饵料成本居中;传统饵料组饵料系数居中,饵料成本最低。结果表明,全程投喂配合饲料对河蟹二龄成蟹的养殖性能和性腺发育无显著影响。     

复合蛋白源替代鱼粉对中华绒螯蟹幼蟹生长性能、生理代谢和生化组成的影响

文章研究了复合蛋白源替代饲料中不同水平(0%、16.67%、33.33%、50%和66.67%,分别记为饲料1~#～5~#)的鱼粉对中华绒螯蟹(Eriocheir sinensis)幼蟹成活、生长、生理代谢和生化组成的影响。结果显示:1)随着鱼粉替代水平增加,幼蟹终末体质量、增重率、特定生长率和肝胰腺指数均呈先升后降的趋势,2~#组最高(P<0.05);2)肝胰腺中的谷草转氨酶、谷丙转氨酶活力和丙二醛含量均为4~#组最高,而超氧化物歧化酶活力在1~#组最高(P<0.05);血清中的谷丙转氨酶活力在5~#组最高,甘油三酯含量和超氧化物歧化酶活力则以4~#组最高,而丙二醛含量在2~#组最高(P<0.05);3) 1~#组躯体的粗蛋白和粗脂肪含量均显著高于其他组,而总碳水化合物含量在2~#组最高(P<0.05)。躯体半胱氨酸含量在4~#组最高,而其他氨基酸与总氨基酸含量均在2~#组最高(P<0.05)。结果表明,饲料中过高的鱼粉替代水平(33%～67%)会降低中华绒螯蟹幼蟹生长性能和躯体营养物质的积累,对生理代谢产生不良影响,建议中华绒螯蟹幼蟹饲料中复合蛋白源替代鱼粉的比例为16.67%。     

中华绒螯蟹脂肪酸延长酶(ELOVL)基因全长cDNA 的克隆及其表达分析

根据脂肪酸延长酶保守区序列设计引物,采用RT-PCR和RACE技术首次克隆得到中华绒螯蟹(Eriocheir sinensis)脂肪酸延长酶(ELOVL)基因全长(Gen Bank登录号:KR005628)。分析ELOVL序列表明,该基因c DNA全长2089 bp,开放阅读框(ORF)长1065 bp(包含终止密码子),编码的354个氨基酸具有典型的延长酶特征:1个高度保守的氧化还原中心组氨酸簇HVIHH,多个保守区和多个跨膜区(KFTEFLDT、NTFVHIVMYVYY、TNFQMI)。经氨基酸同源性和系统发育树分析,中华绒螯蟹ELOVL预测氨基酸序列与顶切叶蚁(Acromyrmex echinatior)ELOVL氨基酸序列相似性最高,为59%;同时与家蝇(Musca domestica)聚为一支,进而与日本囊对虾(Marsupenaeus japonicus)等聚为一大支。通过实时荧光定量PCR技术研究ELOVL m RNA在中华绒螯蟹不同组织中的表达量,及投喂不同配合饲料后在可食部位组织中的表达情况。结果显示,ELOVL在各组织中均有表达,在肝胰腺和肠道中表达量最高,心脏中最低,其他组织中少量表达。养殖98 d后分析表明,卵巢和肝胰腺组织中ELOVL m RNA在SO饲料组中表达量最高,并且表达水平随着饲料中鱼油(富含n-3 PUFA)比例减少、豆油(缺少n-3 PUFA)比例增加而显著升高(P0.05);精巢组织中ELOVL m KNA表达量在SO饲料组中最高;肌肉组织中ELOVL m KNA表达水平较低,且各饲料组间表达量差异不显著(P0.05)。以上结果表明,中华绒螯蟹存在ELOVL基因,并且ELOVL的表达受饲料脂肪水平的影响,这为探究中华绒螯蟹自身合成HUFA途径及调节机制奠定了基础。