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1.
昆虫方面研究提示自噬在病毒侵染增殖中发挥了重要作用,而虾类自噬研究报道极少,了解虾类细胞自噬将为虾病害免疫研究开辟新的思路。自噬相关蛋白LC3是自噬过程的标志性蛋白,存在于自噬体膜上,前期生物信息学分析发现,红螯光壳螯虾自噬相关蛋白LC3(CqLC3)和微管蛋白α-tubulin (Cqα-tubulin)具有互作关系。为深入揭示红螯光壳螯虾细胞自噬体的运输途径,本实验通过体外重组构建了蛋白表达载体pET-HISCqLC3和pET-GST-Cqα-tubulin,并诱导表达,利用亲和层析法分别纯化获得HIS和GST融合表达蛋白HIS-CqLC3和GST-Cqα-tubulin,利用GST pull-down实验验证发现,CqLC3与Cqα-tubulin存在相互作用。微管抑制剂长春新碱解聚微管后,利用MDC染色法检测自噬体发现,红螯光壳螯虾细胞微管解聚破坏后自噬体积累增多,细胞不能正常完成自噬反应,因此可知,红螯光壳螯虾细胞自噬体可通过CqLC3与微管相互作用,微管在红螯光壳螯虾细胞自噬过程中对自噬体的运输具有重要作用。本文首次揭示了虾类细胞自噬反应中自噬体的运输途径,研究结果为虾类细胞自噬的研究奠定了基础。  相似文献   

2.
为探究眼柄摘除对红螯光壳螯虾(Cherax quadriarinatus)生长、性腺发育及体色的影响,对6月龄红螯光壳螯虾[体质量(47. 47±3. 48) g]进行了摘除眼柄处理实验。结果显示,4周后摘除双侧眼柄组红螯光壳螯虾体质量为(84. 40±13. 41) g,显著高于不摘除眼柄组[(49. 63±6. 47) g]和摘除单侧眼柄组[(51. 47±4. 08) g](P 0. 05);摘除双侧眼柄组红螯光壳螯虾存活率为60. 0%±4. 8%,显著低于不摘除眼柄组和摘除单侧眼柄组(分别为94. 4%±2. 3%和97. 2%±2. 1%);摘除双侧眼柄组红螯光壳螯虾性腺指数为1. 23±0. 50,显著高于不摘除眼柄组(0. 20±0. 06)和摘除单侧眼柄组(0. 35±0. 08)。利用Image J软件对红螯光壳螯虾体色RGB值分析表明,摘除双眼柄组红螯光壳螯虾体色G值和B值(分别为99. 26±5. 23和98. 40±3. 58)显著高于摘除单侧眼柄组(59. 02±3. 85和44. 07±4. 57)(P 0. 05)。结果表明,眼柄摘除能促进红螯光壳螯虾生长和性腺发育,影响体色变化。  相似文献   

3.
红螯螯虾的繁殖与苗种培育技术   总被引:2,自引:0,他引:2  
红螯螯虾是原产于澳大利亚的大型经济虾类,经引种养殖试验证明很有推广价值。为推广该虾在我国的养殖,我们经几年的试验研究掌握了其繁殖习性和苗种培育技术。1 红螯螯虾的繁殖技术1.1繁殖习性 红螯螯虾雌雄异体,在正常情况下幼虾经180~240天饲养,达到性成熟,成熟后水温在20℃左右即可交配产卵,卵粒粘着在腹肢上进行孵化,抱卵孵化时间与温度有直接的关系。红螯螯虾卵粒较大,怀卵量与亲虾体重呈正相关,据报道,对体重为13~112g范围的个体,其线性关系方程为C=106 6.5W(R2=0.46)(C为抱卵数,W为体重)。孵化过程中有一部分卵不能正常  相似文献   

4.
红螯螯虾人工繁殖技术研究   总被引:1,自引:0,他引:1  
2006-2010年成功进行了红螯螯虾的人工繁育生产,掌握了红螯螯虾的亲虾培育、抱卵虾孵化和幼虾培育关键技术.红螯螯虾亲虾适宜在土池中进行稀养方式培育,繁殖亲虾规格宜在60 g/尾以上;水温达20℃以上,红螯螯虾可交配产卵;红螯螯虾属一年多次产卵类型.胚胎发育适宜温度20~32℃,孵化时间4~13周,在22~30℃温度...  相似文献   

5.
为了解甲基法呢酯(methyl farnesoate,MF)在中华绒螯蟹(Eriocheir sinensis)卵巢发育中的调控作用,采用离体方法研究了中华绒螯蟹大颚器(mandibular organ,MO)以及X-器官窦腺复合体(X-organ-sinus gland,XO-SG)对卵巢发育的作用。将MO与离体卵母细胞共培养作为实验组1,将MO和XO-SG与离体卵母细胞共培养作为实验组2,仅添加培养液的卵母细胞作为对照组。实验发现,蟹去眼柄(eyestalk ablation,ESA)后的第1、3、6、14天,同对照组相比,MO对其卵母细胞的发育均有极显著促进作用。ESA处理第6天,MO对卵母细胞发育的促进作用最强。XO-SG能逆转ESA处理后MO对卵巢发育的促进作用(P<0.01)。荧光定量PCR技术检测结果显示,ESA处理后,MO中法呢酸甲基转移酶(farnesoic acid O-methyltransferase,FAMeT)mRNA相对表达量上升。同未去眼柄的对照组相比,第1、3天FAMeT mRNA表达丰度无明显变化(P>0.05),第6、14天表达丰度提高至265%左右(P<0.01)。结果表明,中华绒螯蟹MO功能性物质能够促进卵母细胞发育,且ESA处理后第6天MO生物效应最强。MO中FAMeT mRNA的合成受XO-SG的抑制调节。在离体条件下,中华绒螯蟹XO-SG能够抑制卵母细胞的发育。  相似文献   

6.
红螯螯虾的生物学特性及养殖技术   总被引:1,自引:0,他引:1  
红螯螯虾又称淡水龙虾 ,原产于澳大利亚北部的热带地区 ,属甲壳纲、十足目、长尾亚目、拟河虾科 ,是我国新引进的淡水大型虾类之一。其具有个体大 ,食性广、生长快、肉味鲜美 ,可食率高、适应能力强等优点 ,是一种具有推广价值的优良品种。我们于1997年从澳大亚利引进了红螯螯虾原种 ,进行了生物学方面研究及养殖试验 ,并将此列入山东省良种产业化开发项目。通过几年的细致研究 ,掌握了其生物学特性及养殖技术 ,为普及该虾在我国的养殖 ,现将有关方面的内容报道如下 :1生物学特性1.1形态特征红螯螯虾体色为褐绿色 ,头胸部与腹部连接…  相似文献   

7.
澳大利亚红螯螯虾养殖发展趋势初析   总被引:1,自引:0,他引:1  
澳大利亚红螯螯虾养殖发展趋势初析红螯螯虾,它是目前世界上淡水螯虾中最优良的品种。最近几年在它的原产地澳大利亚得到迅速发展。86年澳还成立研究所,对螯虾所属品种进行系统研究,目前已筛选出较为理想的三个养殖品种即:红螯螯虾、马朗虾、亚比。其中以红螯螯虾最...  相似文献   

8.
北京地区的鲜活虾较少,又远离沿海,为了找到一种适合于内陆地区生长和繁殖的虾类,从1994年开始立项研究红螯螯虾。因为该虾的繁殖和生长过程完全是在淡水中。从市场情况看,该虾也受到欢迎,原产地澳大利亚,商品虾规格50克左右的售价为18澳元/公斤。研究出合适的养殖方法和途径,更好的开发这一水产资源,将会产生一定的社会效益和经济效益。 我所对该虾的研究主要是在亲虾培育、繁殖,育种等方面进行了探讨,从理论和实践上取得了一些收获。本文仅就一年多的工作作以下报导。 一、村料和方法 1.实验材料:实验用红螯螯虾(C,quadric arinatus)是1993年12月和1994年初从广东省新会县购进,平均个体50克。运到后,暂养到温室水槽中,水温控  相似文献   

9.
以体质量0.02 g红螯螯虾为研究对象,开展了不同温度(22、25、28、31、34℃)对红螯螯虾虾苗生长影响的试验。试验结果表明随着温度的升高,红螯螯虾虾苗的成活率不断降低,22℃时成活率最高,为48.21%±8.50%,34℃时成活率最低,为21.55%±3.09%,31℃时虾苗特定生长率最高,为7.50%±0.41%。  相似文献   

10.
红螯螯虾原产于澳大利亚地区,最佳生长温度为22~30℃,年可产卵3~5次,6个月即可长至50~80g,达到上市规格。生长快、易驯养是其特点。由于红螯螯虾原产于热带区域,冬季在室外不能存活,因此,成虾和稚虾必须在室内越冬。产卵主要受水温和日照时间的影响...  相似文献   

11.
The Australian red claw crayfish, Cherax quadricarinatus, has recently attracted attention as a potential candidate for aquaculture in the United States. This paper reports the first experimental yield trials of the red claw crayfish in the central United States. Two earthen ponds (0.30 and 0.31 ha) were stocked with juvenile red claw crayfish at either 3.5 or 7.0 crayfish/m2. Crayfish were fed a diet of pelletized shrimp ration supplemented with corn silage. When stocked at 3.5/m2, red claw crayfish grew from an average weight of 3.0 g to 27.0 g in 97 days; average survival was 79.6%; net yield was 653 kg/ha; and feed conversion was 1.4. When stocked at 7.0/m2 red claw crayfish grew from an average weight of 4.1 g to 19.7 g in 99 days; average survival was 70.0%; net yield was 678.9 kg/ha; and feed conversion was 1.8. During the yield trial, temperatures were optimal for growth (25 to 33°C) 60% of the time. These findings are sufficiently encouraging to warrant further trials in locations with a longer growing season, in order to evaluate more fully the potential of the red claw crayfish as a candidate for aquaculture in the United States.  相似文献   

12.
A 117‐day feeding trial was conducted in ponds with juvenile Australian red claw crayfish (Cherax quadricarinatus) to evaluate the effects on growth, survival, body composition, and processing traits when fed diets containing three different protein levels (22%, 32%, and 42%), and the effects of feeding these diets on pond water quality. Juvenile crayfish (mean weight of 4.6±2.2 g) were randomly stocked into nine 0.02‐ha ponds at a rate of 500 per pond (25 000 ha?1), and each diet was fed to three ponds. There were two feedings per day, each consisting of one‐half of the total daily ration. At harvest, there were no significant differences (P>0.05) in the individual weight, percentage weight gain, or specific growth rate among treatments, which averaged 75.3 g, 1535%, and 2.38% day?1 respectively. Red claw fed the 42% crude protein diet had significantly higher (P<0.05) feed conversion ratio (7.34) compared with crayfish fed diets containing 22% (5.18) or 32% (5.13) crude protein, and had significantly lower percentage survival (46.1%) compared with red claw fed diets with 22% (61.1%) or 32% (58.2%) protein. Total yield was significantly lower (P<0.05) in red claw fed the 42% protein diet (640 kg ha?1) compared with red claw fed diets containing 22% (920 kg ha?1) or 32% (904 kg ha?1) protein. Mean total ammonia nitrogen (TAN) levels were significantly higher (P<0.05) in ponds with red claw fed the 42% protein diet (0.55 mg L?1) compared with ponds with red claw fed diets containing 22% (0.32 mg L?1) or 32% (0.38 mg L?1) protein. Mean total nitrite concentrations in ponds with red claw fed the 42% protein diet was significantly higher (0.05 mg L?1) compared with red claw fed diets containing 22% (0.01 mg L?1) or 32% (0.02 mg L?1) protein. These results indicate that a practical diet containing 22% (as fed basis) protein may be adequate for pond production of red claw when stocked at the density used in this study, and that a diet containing 42% protein adversely affected levels of TAN and nitrite, possibly reducing overall survival of red claw. Use of a diet with 22% protein may allow red claw producers to reduce diet costs and thereby increase profits.  相似文献   

13.
Red claw crayfish Cherux quadricarinatus is one of more than a hundred species of Australian freshwater crayfish. However, because of its rapid growth rate, communal and non‐burrowing behavior, ease of spawning, wide temperature and dissolved oxygen tolerance, and no free‐swimming larval stages, red claw may be the best candidate among the Australian crayfishes for semi‐intensive or intensive aquaculture in the United States. The objective of the study was to examine the effects of growth, survival, and fatty acid composition of newly‐hatched red claw when fed four practical diets with or without lecithin and cholesterol. However, little is known of its nutritional requirements or practical diet formulations. An 8‐wk feeding trial was conducted in a recirculating system with newly‐hatched juvenile (mean individual weight, 0.2 g) red claw, each stocked in separate plastic mesh culture units containing their own individual water line. Water was recirculated through biological and mechanical filters. Practical diets were formulated to be isonitrogenous (40% protein) and isocaloric (4 kcal available enerpy/g of diet) and contained menhaden fish meal (25%), soybean meal (35%, except in Diet 4), and shrimp meal (10%, except in Diet 4) as protein sources. Diet 1 had 0.5% lecithin added and 1.0% cholesterol added: Diet 2 contained 0% lecithin and 1.0% cholesterol; Diet 3 contained 0.5% lecithin and 0% cholesterol: and Diet 4 contained 0% lecithin and 0% cholesterol. After 8 wk, juvenile red claw fed diets with 0% supplemental lecithin (Diets 2 and 4) had no significant difference (P >0.05) in final weight and percentage weight gain (5.6 g and 2626%. respectively) compared to red claw fed the control diet (Diet 1) containing 0.5% lecithin. Red claw fed a diet without added cholesterol (Diet 3) had significantly (P 0.05) lower final weight (3.6 g) and percentage weight gain (1,717%) compared to red claw fed the control diet (Diet 1). However, red claw fed Diet 4 (containing 0% added cholesterol and 0% added lecithin) showed no significant (P >0.05) difference in final weight (5.1 g) and percentage weight gain (2254%) compared to red claw fed all other diets. There was no significant difference (P >0.05) among all diets for specific growth rate (SGR) which averaged 5.38%/d. Percentage survival was not significantly different among all treatments and was 76% for red claw fed Diet 1, 64% (Diet 2), 56% (Diet 3), and 80% (Diet 4). These results indicate that red claw fed Diet 4 containing 25% menhaden fish meal, 44.5% soybean meal, 0.5% choline chloride, 2% cod liver oil and 1% corn oil may satisfy the lecithin and cholesterol requirements and that the addition of dietary lecithin and cholesterol may not be necessary for good growth and survival of small (0.2 g) juvenile red claw. This may allow for less expensive diet formulations for use by producers of red claw crayfish.  相似文献   

14.
Abstract

Red claw crayfish, Cherax quadricarinatus, are perhaps the first tropical species of crayfish to be cultured commercially. Culture traits and high market value could allow semi-intensive culture. Feeding strategies used in extensive crayfish ponds in temperate climates may not be the most appropriate for semi-intensive culture systems where year-round growth is possible. The following study was conducted to evaluate differences between using a pellet-based system versus a pellet-plus-forage-based system. The study was conducted in 14 0.3-ha ponds on a commercial farm in Ecuador. Juvenile red claw (1-2 g) were stocked into all ponds at a rate of 4/m2. All ponds received pelleted shrimp rations at a rate of 3% per day. Seven ponds also received dried hay at a rate of 100 kg/ha/mo during the 3-month study. At harvest, red claw weights were similar (30-34 g), but survivals were significantly higher in ponds receiving pellets and hay (65%) than in ponds receiving pellets only (50%). Yields in pellet-fed ponds averaged 594 kg/ha, while red claw receiving pellets plus forage averaged 889 kg/ha. The addition of dried forage was thought to provide a larger variety of natural food organisms throughout a greater area of the pond bottom and provided additional substrate for dispersal and hiding. Addition of grasses from outside the pond is recommended over production of grasses grown within the pond.  相似文献   

15.
Australian red claw crayfish Cherax quadricarinatus is considered a popular crustacean species in several countries around the world because of its large size potential and resemblance to high‐priced American lobsters. However, little is currently known of the nutrient requirements and practical diet formulations for red claw. Lecithin has been shown to be required in the diets of several crustacean species, but there are no reports of dietary lecithin requirements for red claw. A 10‐week feeding trial was conducted in an effort to evaluate lecithin requirements for juvenile red claw. Juvenile red claw (mean individual weight of 1.6 ± 0.91 g) were individually stocked in a recirculating system at random into 80 plastic‐mesh culture units, each containing its own individual water line. There were 20 red claw per treatment (diet). Water was recirculated through biological and mechanical filters. Four semi‐purified diets were formulated to contain increasing percentages of commercial soya bean lecithin (0, 0.5, 1.0 and 2.0%). Diet ingredients included solvent‐extracted menhaden fish meal (FM), casein, dextrin, wheat flour, pellet binder, vitamin and mineral mix, cod liver oil, and corn oil. Semi‐purified diets were formulated to contain 40% protein using casein, menhaden FM, and wheat flour as protein sources. After 10 weeks, no significant differences (P > 0.05) were found in final weight, percentage weight gain and specific growth rate with average values of 13.0 g, 934%, and 3.14% day?1, respectively. Percentage survival was high during the 10‐week period (100, 95, 100 and 95%) as only two individuals died during the study; one of these, because of an escape from the culture unit. There was also no significant differences (P > 0.05) in percentage moisture, protein, fat and ash in whole‐body red claw carcasses (wet‐weight basis) among any treatment (diet) and averaged 77.1, 12.6, 1.3 and 6.2%, respectively. Based upon the present study, these results indicate that a diet containing 5% cod liver oil and 1% corn oil, and having no supplemental lecithin, may be sufficient for growth and survival of juvenile red claw crayfish.  相似文献   

16.
An intracellular bacterium was detected on several occasions in commercial farms in Ecuador culturing red claw crayfish, Cherax quadricarinatus (Von Martens). Cases A, B and C presented mortality rates of 80%, 45% and 80%, respectively. Each incident occurred in grow-out ponds. Moribund crayfish were observed at the edge of the ponds in some cases. Affected crayfish presented no external differences from healthy ones, except their smaller size. Histological examination of affected red claw crayfish revealed that the cytoplasm of cells in the hepatopancreas, cuticular epithelium, and connective tissue of all organs had been replaced by massive granular and basophilic material. In the hepatopancreas, the tubules were intact but the intertubular connective tissue was replaced by Gram-negative microcolonies. Columnar cells in the cuticular epithelium also contained Gram-negative microcolonies and were necrotic. The heart and nerve cords also contained basophilic material. Transmission electron microscopy showed that the microcolonies consisted of a rod-shaped, obligately intracellular bacterium. The bacterium was delimited by a cell membrane that was composed of two electron-dense zones. Cells contained a single, compact, cytoplasmic condensation that was circumscribed by an electron-lucent halo. The bacterium replicated within the cytoplasm of host cells, which is pathognomic of rickettsiales infections. No host cell nuclei were infected.  相似文献   

17.
A study was conducted to determine the effects of different sources of dietary lipid that differ in fatty acid (FA) composition on growth, feed conversion ratio (FCR), survival, and whole‐body proximate and FA composition of juvenile red claw. Juvenile red claw (0.55 ± 0.02 g) were reared over a 12‐week period. Five practical diets were supplemented with 70 g kg?1 oil (by weight) from either linseed oil (LO), canola oil (CAO), corn oil (CO), beef tallow (BT) or menhaden oil (MO) and formulated to contain 400 g kg?1 crude protein. Red claw were fed three times daily (800, 1200 and 1600) to controlled excess. At the conclusion of the experimental period, there were no significant differences (P > 0.05) found in percentage survival and FCR among dietary treatments and values averaged 85.4% and 3.4, respectively. However, final mean weight and specific growth rate of red claw fed Diet 1 (LO) was significantly higher (16.44 g and 3.95% day?1, respectively) compared with that of red claw fed Diet 4 (BT; 12.24 g and 3.43% day?1, respectively), but not different from red claw fed the other three diets. Likewise, red claw fed Diets 1 (LO) and 2 (CAO) had significantly higher percentage weight gain (2990 and 2880%, respectively) compared with the BT diet (2124%), but not different from red claw fed Diets 3 (CO) and 5 (MO). Whole‐body fat and ash composition was significantly affected (P < 0.05) by source of added lipid, but no differences were found in whole‐body moisture and protein. Moreover, whole‐body FA composition showed differences among the varying oil sources and primarily reflected the FA in the diets. Results of the present study indicate that plant oils LO, CAO and CO rich in linolenic acid (18:3n‐3), linoleic acid (18:2n‐6) and oleic acid (18:1n‐9) perform as well as MO containing high levels of n‐3 highly unsaturated fatty acids eicosapentanoic acid (20:5n‐3) and docosahexaenoic acid (22:6n‐3) for juvenile red claw crayfish grown indoors lacking natural food items. Further, red claw fed a diet containing BT, which has a high percentage of saturated FA, performed poorly compared with LO and CO in regards to weight gain. It appears that juvenile red claw can be fed diets containing less expensive plant‐based oils with high levels of 18‐carbon unsaturated fatty acids. This could reduce diet costs for producers and allow for profitability.  相似文献   

18.
To be profitable, producers must reduce diet costs, which can be as high as 80% of the variable costs of an aquaculture expense. As vitamin and mineral premixes represent a significant cost, eliminating addition of these premixes could reduce diet costs if no adverse effects were observed for growth and production parameters. A 105‐day feeding trial was conducted with juvenile Australian red claw crayfish (Cherax quadricarinatus) to evaluate the effects of growth, survival, body composition, processing traits and water quality when red claw were fed a supplemental diet containing 28% crude protein (CP) without vitamin and mineral premixes (and supplemented alfalfa hay) compared with red claw fed a diet (control diet) containing 42% CP, vitamin and mineral premixes, and with supplemented alfalfa hay, and compared with red claw only fed alfalfa hay when grown in ponds. Juvenile red claw (mean weight of 15.7 ± 1.0 g) were randomly stocked into nine 0.02‐ha ponds at a rate of 640 per pond (3.2 per m2), and each treatment was used in three ponds. There were two feedings per day, each consisting of one‐half of the total daily ration. At harvest, individual weight, percentage weight gain, specific growth rate, survival and total yield of red claw fed a control diet was significantly higher (P < 0.05) (83.0 g, 398%, 1.53% day?1, 65.1%,and 1708 kg ha?1 respectively) compared with red claw only fed alfalfa hay (44.9 g, 202%, 1.04% day?1, 30.3% and 431 kg ha?1, respectively), but not different (P > 0.05) from red claw fed the supplemental diet without vitamin and mineral premixes (76.2 g, 367%, 1.47% day?1, 57.2% and 1378 kg ha?1). There were no significant differences (P > 0.05) in feed conversion ratio (FCR) among treatments, which averaged 5.0 (based on prepared diet input). These results indicate that vitamin and mineral supplementation in a diet is not necessary when diet containing 28% CP and alfalfa hay are used in combination for pond grown red claw. These results may help reduce diet costs and possibly increase producers’ profits which might allow for industry expansion.  相似文献   

19.
应用实时荧光定量PCR技术,结合生物酶和代谢产物测定,研究了氨氮急性胁迫对红螯光壳螯虾幼虾代谢及免疫系统的毒性影响及其毒后恢复情况。实验首先进行3 d的氨氮胁迫,取样后剩余虾移入曝气自来水进行7 d的毒后恢复实验。结果表明,3 d氨氮胁迫后,肌肉ACP、AKP、SOD活性表达均受到显著影响,随着氨氮浓度的升高酶活性分别降低,最高浓度组(16 mg/L)降低为对照组的76%、68%和62%。线粒体MnSOD、胞外Cu/ZnSOD的mRNA表达量也随着氨氮浓度增加而下降,最高浓度组降低至对照组的69%和68%。CAT、GPX活性以及GPX和GST的mRNA表达量变化不显著。肝胰腺中可溶性蛋白和甘油三酯含量随着氨氮浓度升高而降低,最高浓度组分别降低至对照组的72%和59%,AST活性在12 mg/L浓度组显著升高至对照组的134%。7 d恢复期过后,ACP和AKP活性以及各代谢指标恢复到正常水平;而SOD和GPX活性高于对照组。各抗氧化基因的表达量都不同程度高于对照组。实验表明,高浓度氨氮胁迫能抑制部分免疫相关酶的活性及基因表达,对免疫系统造成损害。氨氮胁迫下,红螯光壳螯虾动员蛋白质和脂肪来供能应对胁迫。7 d的恢复时间不足以让红螯光壳螯虾从胁迫中完全恢复,其肌肉仍处于轻度氧化应激状态。  相似文献   

20.
Juvenile red claw, Cherax quadricarinatus, were obtained from a commercial supplier and stocked into twelve 0.04‐ha ponds with an average water depth of approximately 1.1 m at a rate of 1100 red claw per pond (27,170 red claw/ha). Mean stocking weight (±SD) was 6.25 ± 3.0 g. Three replicate ponds were randomly assigned to each of the four treatments. In Treatment 1 (TRT1), red claw were stocked into ponds to which dried alfalfa hay (forage) was added at a rate of 500 kg/ha/mo; Treatment 2 (TRT2) consisted of red claw being fed a prepared diet containing 13% protein; in Treatment 3 (TRT3), red claw were fed a diet containing 13% protein at which had dried alfalfa hay been added at a rate of 500 kg/ha/mo; and in Treatment 4 (TRT4; control), red claw were fed a complete diet containing 28% protein. Water quality measurements were made three times weekly for dissolved oxygen and temperature (am , pm ), pH, total ammonia nitrogen, nitrite, and alkalinity averaging 7.17 mg/L, 8.96 mg/L, 25.5 C, 27.3 C, 8.68, 0.39 mg/L, 0.012 mg/L, and 106.5 mg/L, respectively. After 113 d, the final mean weight of red claw fed TRT3 was significantly (P < 0.05) higher (68.10 g) compared to that of red claw fed hay only (49.40 g) but not different from red claw fed TRT2 (56.03 g) and TRT4 (62.10 g). Likewise, red claw fed TRT3 had significantly higher percent weight gain (990%) compared to that of red claw fed hay only (690%) but not different from TRT2 (796%) and TRT4 (893%). Feed conversion ratio of TRT2, TRT3, and TRT4 and percent survival among all treatments did not differ significantly (P > 0.05), averaging 2.85 and 66.8%, respectively. Total yield of red claw fed TRT3 and TRT4 (968 and 952 kg/ha) was significantly (P < 0.05) higher compared to that of red claw fed hay only (617 kg/ha) but did not differ from red claw fed TRT2 (882 kg/ha). Tail meat yield of male red claw in TRT3 was significantly (P < 0.05) higher (17.3 g) compared to that of male red claw in TRT1 (12.7 g) and TRT2 (14.9 g) but not significantly different (P > 0.05) from male red claw in TRT4 (16.9 g). Tail meat yield of female red claw in TRT3 and TRT4 was significantly (P < 0.05) higher (14.2 and 13.9 g, respectively) compared to that of female red claw in TRT1 (10.5 g) and TRT2 (10.4 g). Tail muscle proximate compositions showed no significant differences (P > 0.05) in protein (wet weight basis) between males and females among treatments (diet) which averaged 16.2 and 14.6%; however, there were little to no significant differences in fat and ash between males and females among treatments. Results from this study indicate that pond‐cultured red claw stocked at 27,170 red claw/ha can be fed a practical diet containing 13% protein, with or without forage (alfalfa hay), compared to red claw fed a complete diet containing 28% protein; however, if alfalfa hay is added to the pond at 500 kg/ha/mo as the sole source of added nutrients, growth is reduced. Therefore, the use of alfalfa hay, in combination with a low‐protein pelleted diet may be a production method for pond‐grown red claw that may reduce costs for producers and thereby increase profits.  相似文献   

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