中华鳖Trionyx sinensis(Wiegmann)病害及其防治研究的动态

本文介绍了中华鳖的多种病害、症状表现、引起中华鳖病害传染和暴发流行的重要病原及其病理学研究动态;举例简介了防治中华鳖病害的方法、途径、某些药物的用法及用量。     

中华鳖生态养殖期的死亡率及其在不同池塘环境下的差异

对5种类型养殖池塘90400只中华鳖在生态养殖期前100d的死亡率进行研究。结果说明,中华鳖温室转外塘生态养殖期的日死亡率呈对数方程分布,且可分成3个养殖阶段,分别为日死亡率快速下降期,日死亡率稳步下降期和日死亡率无显著变化期。中华鳖的日死亡率在不同池塘环境下有显著性的差异,表现为土质池塘的死亡率明显低于水泥池塘,在养殖池塘中种植一定面积的水生植物亦能减低中华鳖的死亡率。总体来说,在其他条件相同的情况下,中华鳖最佳的生存环境为土质池塘种植30％～50％的沉水型水生植物,并且保持池塘生态环境处于相对稳定。     

Effects of stocking density on growth and non-specific immune responses in juvenile soft-shelled turtle, Pelodiscus sinensis

To investigate the influence of stocking density on the growth and non‐specific immune responses of juvenile soft‐shelled turtle, Pelodiscus sinensis, three groups of turtles (initial body weight 74.2±12.2 g) were reared in 80 cm (L) × 40 cm (W) × 30 cm (H) tanks for 35 days at three stocking densities (StD), which were 1 individuals (ind.) tank⁻¹ (3.13 ind m⁻²) for D1, 4 ind. tank⁻¹ (12.5 ind m⁻²) for D2 and 6 ind. tank⁻¹ (18.75 ind m⁻²) for D3 respectively. D1 was the control group. Turtles were weighted individually at the beginning and at the end of the trial. At the end of the rearing trial, non‐specific immune parameters were determined. The results showed that the heterophil:lymphocyte ratio (HLR) increased and the total plasma protein decreased with increasing StD, suggesting a stress response. Specific growth rate (SGR) significantly decreased with increasing StD. Non‐specific immune indicators such as blood cell phagocytic activity, serum haemolytic activity and serum bacteriolytic activity increased clearly at a higher StD, indicating a pattern of immunoenhancement. The results indicated that at StDs of 4 and 6 ind. tank⁻¹, non‐specific immune responses were not suppressed compared with the control, but were inversely enhanced at the cost of growth reduction. A possible energy‐based trade‐off between growth and constitutive immunity may exist in soft‐shelled turtles.     

鳖池一些环境因子变化特征及其对鳖生长的影响

本文通过对鳖池水体进行理化处理,分析了主要的环境因子对养殖鳖生长的影响。结果表明鳖池水体溶解氧的提高对鳖池水质和底质改善及养殖鳖的生长具有明显的促进作用,但对皮肤病的治疗没有明显的作用;大换水后鳖池水体pH值昼夜变化较大,午后出现较高的pH值高峰;午后高pH值对正常养殖鳖虽无明显的不适反应,但在随后的养殖过程中出现较多的疖疮病和白底板病。利用外加电源提高鳖池氧化还原电位,试图改善鳖池底质和水质的方法,未能得到满意效果。     

Effects of dietary vitamin E level on growth and tissue lipid peroxidation of soft-shelled turtle, Pelodiscus sinensis (Wiegmann)

A feeding trial was conducted to determine the effect of dietary vitamin E supplementation on growth, liver lipid peroxidation and liver and muscle vitamin E level of soft‐shelled turtle, Pelodiscus sinensis. Eight experimental diets analysed to contain 0–457 IU vitamin E kg^?1 were fed to juvenile soft‐shelled turtle of 4.8 g initial body weight for 12 weeks. Weight gain (WG) of the turtles fed the diet containing no vitamin E was significantly lower than those fed diets containing 83–457 IU vitamin E kg^?1 (P<0.05). Feed conversion ratio and protein efficiency ratio showed similar trends to that of WG. No significant difference (P>0.05) was found in whole‐body composition among turtles fed the different diets. Dietary vitamin E requirement using WG as the response and estimated using the broken‐line regression model is approximately 88 IU kg^?1. Liver and muscle vitamin E content increased when dietary vitamin E level increased. Ascorbate‐induced lipid peroxidation in liver tissue of turtles fed diets containing 0 and 17 IU vitamin E kg^?1 was significantly (P<0.05) greater than those fed diets containing high vitamin E (≥35 IU kg^?1).     

冬眠中华鳖雌、雄生殖道的精子储存

应用光镜和电镜技术,系统观察冬眠中华鳖(Trionyx sinensis)雌、雄生殖道的精子储存情况,显示与精子储存相关的形态结构和细胞特征。结果表明,中华鳖在冬眠期生精活动处于相对静止状态,仅有1～3层精原细胞排列在睾丸曲细精管基膜附近,其余生精细胞排列松散而紊乱,生精上皮中未见有各级细胞规律性排列,不能形成完整的管壁。附睾管腔增大,腔中储存有大量精子。附睾上皮及附睾管腔中见有PAS反应阳性物质。附睾上皮主要由主细胞、亮细胞和基细胞组成。超微结构显示,附睾上皮细胞中含有大量分泌颗粒,内质网膨大。储存在附睾中的精子结构完整,精子中段由35～40个同心圆状线粒体构成线粒体鞘,中段胞质中含有大量糖原颗粒。雌性输卵管分布着数量不等的精子,尤其狭部最多。狭部黏膜皱襞高度融合,形成大量纵行于输卵管的储精细管。在细管中含有大量精子,精子头部嵌入上皮细胞纤毛中。蛋白部和子宫部也有少量精子存在,但在这些部位不能形成明显的储精细管。PAS反应显示,输卵管狭部储精细管上皮分泌有糖蛋白类物质。储精细管上皮下固有层中分布有大量的管状腺,通过腺导管与输卵管管腔相通。雌、雄中华鳖隔离4个月(12月初至来年3月底)后,在雌性输卵管峡部的储精细管中仍可观察到大量结构完整的精子,表明中华鳖精子在输卵管中至少可以储存120 d。以上结果显示,在冬眠期,雄性附睾和雌性输卵管中有大量精子储存,储存的精子能够渡过漫长的冬季用于来年春天交配或受精,这一特殊的生殖策略对其成功繁殖具有重要意义。本研究还对中华鳖的繁殖特性进行了讨论。     

中华鳖白底板病病原的分析

从患白底板病的中华鳖(Trionyx sinensis)肾、肝、脾分离出致病力较强的细菌TS6-1和TS6-2。同时样品经超薄切片,电子显微镜观察,在脾、肝、肾组织细胞质中观察到直径为30 nm病毒样颗粒。经人工感染试验证实,分离菌株及患病鳖内脏组织过滤液均可导致中华鳖发病死亡,TS6-1和TS6-2的LD50分别为3.2×107CFU/mL和1.0×108CFU/mL。以患病鳖肝、脾组织的过滤液注射健康鳖后,3～5天内所有鳖全部死亡。通过对细菌形态、生理生化特性的测定,判定TS6-2属于嗜水气单胞菌(Aeromonas hydrophila)。同时对TS6-1进行了16S rRNA分子鉴定,将测定的序列递交NCBI进行BLAST同源序列比对,与迟缓爱德华氏菌的16S rRNA基因具有较高的同源性(99%),该序列在GenBank上的登录号为DQ884466。结合细菌的生理生化特性,判定TS6-1属于迟缓爱德华氏菌(Edwardsiella tard)。由此认为中华鳖白底板病由病毒和嗜水气单胞菌、迟钝爱德华氏菌混合感染引起。药敏试验结果表明,TS6-1对先锋V、丁胺卡那敏感,TS6-2对卡那霉素、庆大霉素、丁胺卡那敏感。     

甲鱼对配合饲料中蛋白质、脂肪、碳水化合物的消化率

运用消化生理方法,测定甲鱼对配合饲料中蛋白质、脂肪、碳水化合物的消化率。结果表明,甲鱼对配合饲料中蛋白质、脂肪、碳水化合物的消化率分别为:86.99％、80.4％、65.30％。     

Effect of dietary calcium and phosphorus supplementation in fish meal-based diets on the growth of soft-shelled turtle Pelodiscus sinensis (Wiegmann)

A growth experiment was conducted to determine the effect of supplementing dietary calcium in fish meal‐based diets on the growth of cultured soft‐shelled turtle Pelodiscus sinensis. Juvenile soft‐shelled turtles of 4.1 g mean body weight were fed nine diets containing two levels of phosphorus (2.7% or 3.0%) and analysed calcium levels ranging from 4.7% to 6.6% for 10 weeks. The growth of the turtles was enhanced when inorganic calcium was added to the diets. The weight gain of the turtles fed the control diet containing calcium solely from fish meal was the lowest among the test groups, and was significantly lower than those fed the diet containing 5.7% calcium at the 3.0% phosphorus level (P<0.05). Feed conversion and protein efficiency ratios were not affected by different dietary treatments. Whole‐body moisture and crude protein contents of turtles were not affected by different dietary treatments. The body ash of turtles fed 3.0% phosphorus diets tended to be higher than turtles fed 2.7% phosphorus diets. The body calcium to phosphorus ratio of turtles fed 3.0% phosphorus diets was greater than that of turtles fed diets containing 2.7% phosphorus. Supplementation of Ca in a fish meal‐based practical diet is required for the optimum growth of soft‐shelled turtles.     

中华鳖亲鳖培育技术初探

近几年来,我国特有的中华鳖种苗供求矛盾十分突出,导致境外鳖种苗大量涌入国内市场,不仅给国内甲鱼市场带来巨大冲击,同时也给中华鳖种质资源造成极大污染。因此,如何推进原良种生产体系建设,确保中华鳖优良性状的稳定性和资源的安全性这一课题摆在了我们科技工作者...     

茯苓多糖对中华鳖非特异性免疫功能的免疫调节作用

研究了口服茯苓多糖对中华鳖(Trionyxsinensis)非特异性免疫功能的影响。试验共分3个组,在基础饲料中添加20·0mg/kg茯苓多糖作为试验组,添加500·0mg/kg酵母细胞壁作为免疫刺激剂对照组,以投喂基础饲料作为空白对照组。连续投喂28d后,测定中华鳖血液中白细胞的吞噬活性、血清溶菌活力和补体活性。结果表明:在中华鳖饲料中添加茯苓多糖和酵母细胞壁能显著提高中华鳖白细胞的吞噬活性(t检验,P<0·05),而2个试验组之间中华鳖血液中白细胞的吞噬活性没有显著差异(t检验,P>0·05);2个试验组中华鳖血清中补体C3和C4的活性与对照组之间呈显著差异(t检验,P<0·05),而试验组之间无显著性差异(t检验,P>0·05)。本研究结果说明在中华鳖饵料中添加茯苓多糖和酵母细胞壁对中华鳖的非特异性免疫功能有增强作用。     

Effects of animal–plant protein ratio in extruded and expanded diets on nitrogen and energy budgets of juvenile Chinese soft-shelled turtle (Pelodiscus sinensis Wiegmann)

In this study, we investigated the effects of animal–plant protein ratio in extruded and expanded diets on nutrient digestibility, nitrogen and energy budgets of juvenile soft‐shelled turtle (Pelodiscus sinensis). Four extruded and expanded feeds (diets 1–4) were formulated with different animal–plant protein ratios (diet 1, 1.50:1; diet 2, 2.95:1; diet 3, 4.92:1; diet 4, 7.29:1). The apparent digestibility coefficients (ADCs) of dry matter and crude lipid for diet 1 were significantly lower than those for diets 2–4. There was no significant difference in crude protein digestibility among diets 1–4. The ADC of carbohydrate was significantly increased with the increase in animal–plant protein. Although nitrogen intake rate, faecal nitrogen loss rate and excretory nitrogen loss rate of turtles fed diet 1 were significantly higher than those fed diets 2–4, nitrogen retention rate, net protein utilization and biological value of protein in these turtles were significantly lower than those fed diets 2–4. In addition, energy intake rate, excretory energy loss rate and heat production rate of turtles fed diet 1 were also significantly higher than those fed diets 2–4. Faecal energy loss was significantly reduced with the increase in the animal–plant protein ratio. The ADC of energy and assimilation efficiency of energy significantly increased with a higher animal–plant protein ratio. The growth efficiency of energy in the group fed diet 1 was significantly lower than those in the groups fed diets 2–4. Together, our results suggest that the optimum animal–plant protein ratio in extruded and expanded diets is around 3:1.     

嗜水气单胞菌对中华鳖致病力的研究↑（*）

嗜水气单胞菌菌株Ｔ３、４０１４２Ｇ,５１６１３－１,７０６Ｃ,ＲＴＬ５３１,Ｒ４０２Ｌ,ＲＫ１１１９等分别从患有红底板、腐皮、洞穴及其它症状的病鳖中分离。银鲫对Ｔ３与４０１４２Ｇ的易感性最强,而中华鳖（与小白鼠、青蛙等一样）稍差。各嗜水气单胞菌菌株中,Ｔ３的致病力最强,其致病性随水温升高而增强,随其连续传代而减弱。该菌在用橡皮塞密封的试管中４℃存放时,４００ｄ内致病力基本保持稳定。     

中华鳖血象的研究

本文研究了在温室养殖条件下中华鳖的血象。红细胞数为（1．29±0．42）×1012／L。白细胞数为（1．22±0．44）±109／L。血红蛋白为（8．66±1．95）g％。白细胞分类百分比依次为：中性粒细胞（47．1±11．3）％、淋巴细胞（29．4±13．5）％,嗜天青粒细胞（15．0±6．3）％、嗜碱性粒细胞（7．8±2．8）％、单核细胞（0．67±0．67）％、嗜酸性粒细胞（0．15±0．26）％。中性粒细胞核指数为0．7651±0．1013。     

鳖的规模繁殖试验报告

从亲鳖的选育、雌雄的配比、温度、湿度及水化因子进行人工控制,对鳖进行规模人工繁殖试验,获得每只雌鳖产卵45只以上,受精率90%以上,孵化率87%以上,稚鳖成活率99%以上的结果.     

一株鳖源致病性气单胞菌的分离与鉴定

对典型病症为体表腹甲严重斑块状充血、甚至出血,体表某些部位出现溃疡,严重的会口鼻充血、流血,内脏肝、脾、肾肿大的病鳖进行了病原菌鉴定分析。从肝脏中分离菌株ARC090812,经VITEK-32全自动细菌鉴定仪鉴定,结果为嗜水气单胞菌。药敏实验显示分离菌株对庆大霉素、丁胺卡那霉素等药物敏感,对恩诺沙星及强力霉素中度敏感。致病性实验表明,半数致死量LD50为7.87×108CFU/mL。     

饲料种类对中华鳖营养成分的影响

以每立方米 0 .5只的密度放养体重为 2 5 0g左右的鳖种 ,分别投喂冰鲜鱼、30 %冰鲜鱼 +70 %配合饲料的混合饲料和配合饲料。养殖期 5个月 ,各取 6尾 6 0 0g左右的雄性商品鳖进行营养成分测定和比较。结果表明 :3种鳖的脂肪率、粗蛋白含量和脂肪酸组成差异不显著 (P >0 .0 5 )。但肌肉中的粗脂肪、氨基酸总量和鲜味氨基酸含量均极显著地以冰鲜鱼饲料饲喂的鳖为高 (P <0 .0 1)。肌肉与裙边组织中的氨基酸总量、必需氨基酸和鲜味氨基酸的积累与饲料中相应的氨基酸含量呈显著的相关关系 (r1=0 .784 3,r2 =0 .90 6 2 ,P <0 .0 1) ,其积累量随饲料中含量变化而变化。饲料对商品鳖的风味和营养价值有一定的影响。     

3种药物在甲鱼体内的残留研究

将呋喃唑酮、磺胺嘧啶和诺氟沙星各以3种水平分别混入饲料中投喂甲鱼（中华鳖Trionyx sinensis)，投药饵时间分别为7d和14d。停药后24、72、120和240h分别取血液、肝、肾和肌肉测定药物残留量。结果表明，呋喃唑酮的吸收量甚微，4种样品中均未检出残留，说明该药只适用于肠道疾病的防治；磺胺嘧啶在4种样品中均可检出，在停药后24h，血液中含量最高，然后迅速降低，72h降至最低，240h则不能检出；诺氟沙星的药物残留变化状况与磺胺嘧啶相似。残留排除速度以肌肉中最慢，以停药24h残留量为标准，停药120h磺胺嘧啶残留率为76．8％（1．65－2．37μg/kg），诺氟沙星为46％（0．81－0．93μg/kg）；停药240h则分别为25％（0．63－1．11μg/kg）和24．2％（0．35－0．44μg/kg）。血液、肝、肾和肌肉中的药物残留水平随给药量的增加而增加，给药时间的长短对血液中的药物浓度影响不大，但在肝、肾和肌肉中的药物残留则随给药时间的加长而显著增加（P＜0．05）。建议饲喂磺胺嘧啶或诺氟沙星的甲鱼应在停药10d后上市。     

Lidocaine hydrochloride—sodium bicarbonate as an anesthetic for soft-shelled turtle Pelodiscus sinensis

ABSTRACT:   Attempts were made to understand how the different sizes (mean body weight of 4.1 ± 0.8 g for small and 182.6 ± 23.7 g for large) of the soft-shelled turtle Pelodiscus sinensis are affected by different temperature (25°C or 30°C), and different concentrations (700, 1000 and 1300 p.p.m.) of anesthetic lidocaine hydrochloride–sodium bicarbonate. The soft-shelled turtles were fed to satiation once daily. Three-way anova design (size × temperature × concentration of lidocaine hydrochloride) with duplicate was used. Twenty each of large and small soft-shelled turtles were distributed into six 30-L tanks. Exposure time of the soft-shelled turtle was affected by all factors (temperature, concentration and size). Exposure time of the soft-shelled turtle for anesthetizing decreased with increase in temperature and in concentration of lidocaine hydrochloride, and decrease in size. Recovery time for the soft-shelled turtle was also affected by all factors. Recovery time of the soft-shelled turtle increased with increase in temperature, concentration of lidocaine hydrochloride, and size. According to these results, lidocaine hydrochloride (1000 p.p.m.)–sodium bicarbonate seemed an effective anesthetic for sedating and handling the soft-shelled turtle. However, when an anesthetic is recommended for wide use, especially on commercially important edible organisms, the time organism takes to metabolize and excrete anesthetic chemicals from its body to a safe level must be given to allow fitness for human consumption.     

中华绒螯蟹池塘套养与温室养殖的中华鳖雄体生物学指数和营养成分比较

分别取中华绒螯蟹(Eriocheir sinensis)池塘套养和温室养殖中华鳖(Trionyx sinensis)雄体(分别简称为"套养鳖"和"温室鳖")各5只,解剖取四肢肌肉、裙边和肝脏,分析和比较两种鳖的生物学指数,可食组织常规营养成分、氨基酸含量和脂肪酸组成的差异。结果显示:(1)温室鳖裙边指数(SI)和肝体比(HSI)均显著高于套养鳖(P0.05)。(2)套养鳖肌肉灰分和裙边水分含量均显著高于温室鳖,而裙边蛋白含量则以温室鳖较高(P0.01),套养鳖和温室鳖其余常规营养成分均无显著差异(P0.05)。(3)温室鳖肌肉和裙边中的大部分氨基酸、总必需氨基酸(∑EAA)和总氨基酸(TAA)含量显著高于套养鳖,半胱氨酸含量及EAA/TAA以套养鳖较高(P0.05);套养鳖和温室鳖肌肉和裙边中的必需氨基酸评分(EAAS)较为接近,而EAAS平均值以套养鳖较高。(4)温室鳖肌肉C18:1n9、C18:1n7及单不饱和脂肪酸(∑MUFA)总量显著高于套养鳖,而C22:6n3、总多不饱和脂肪酸(∑PUFA)、∑n-3PUFA、总高度不饱和脂肪酸(∑HUFA)含量及n-3/n-6以套养鳖较高(P0.05);就裙边而言,除温室鳖C17:0和C20:2n6含量显著高于套养鳖外(P0.05),其余脂肪酸含量均无显著差异(P0.05)。综上可见,中华鳖在两种养殖模式下均具有较高的营养价值。