东北蝲蛄室内人工养殖病害防治

<正>东北蝲蛄是东北地区特有的1种淡水螯虾，20多年前在东北的山溪石头下经常能看到，但由于种种原因，现在很难再寻觅到它们的踪迹。人工养殖东北蝲蛄是解决东北蝲蛄资源枯竭的有效途径，人工养殖过程中容易出现的东北蝲蛄病虫害防治工作极为重要。     

一例东北拟蜊蛄钟虫病的诊治

<正>东北拟蝲蛄肉质鲜美、风味独特,具有较高的经济价值,近年来,由于环境恶化和过度捕捞,自然资源趋于枯竭。为了有效地保护东北拟蝲蛄,一些科技工作者和养殖场开展了东北拟蝲蛄的人工养殖和苗种繁育的研究工作。2019年3月,大连海洋大学大连市海珍品疾病防控重点实验室接诊了一例养殖东北拟蝲蛄鳃部寄生虫病例,现将诊治情况报道如下,以供相关人员参考。     

东北喇蛄人工养殖技术要点

正东北蝲蛄(Cambaroides dauricus)不仅有传承悠久、味道鲜美的蝲蛄豆腐,还是娱乐价值极高的观赏螯虾品种之一,具有很高的经济、观赏价值和很大的开发潜力。我国东三省对于东北蝲蛄的食用历史久远,消费市场有一定规模,近几年广东、天津、台湾等水族集散地对东北蝲蛄的需求逐年递增,亟待解决的人工养殖技术是制约东北蝲蛄发展的关键,因此,笔者进行了其人工养殖技术要点的初步研究,望为后续高效人工养     

东北蝲蛄的生物学特性及现状分析

东北蝲蛄是亚洲原产淡水螯虾中的食用和观赏品种之一,具有较高的开发价值。东北蝲蛄的群体恢复能力较差,加上过度捕捞等因素的影响,其自然群体的数量急剧下降。文章介绍了东北蝲蛄的生物学特性,分析了其资源变化和现状,提出加强我国东北蝲蛄自然资源的保护力度,更深入系统地开展其生物学、增养殖技术、分子遗传学等方面研究的建议。     

东北蝲蛄运输入池方法及恢复期养殖措施

正蝲蛄是螯虾科中唯一分布于亚洲的类群,其中东北蝲蛄(Cambaroides dauricus)是分布于我国东北地区的最广为人知的土著淡水螯虾,具有较高的经济、娱乐和开发价值~([1])。随着东北蝲蛄自然群体数量的急剧下降,政府及相关单位对其重视程度逐年提     

防治河蟹蜕壳障碍症

一、病因引起病理性蜕壳不遂的几个主要原因：①黑亮蟹不蜕壳，病蟹壳呈灰黑色、坚硬钙化、不吃食，爬上岸边无水处十足撑起、腹部悬空，口不吐泡沫，蜕壳困难；②长毛蟹不蜕壳，在河蟹体表大量原生动物及霉菌附着生长，蟹不吃食；③黑鳃、藻类鳃、烂鳃、甲壳溃疡引起的不蜕壳症；④河蟹因水肿病、肠胃炎引起的不蜕壳症；⑤因寄生虫、蟹奴寄生而引起的不蜕壳。 二、症状与病变病蟹头胸甲后缘与腹甲交界处出现裂痕，但无力蜕壳或蜕出部分壳而导致死亡。 三、流行情况本病在池塘养蟹中较为常见。大规格蟹种、后期成蟹等常会发生此病，严重影响…     

河蟹不蜕壳症的起因及其防治方法探讨

河蟹靠蜕壳不断生长,不蜕壳非但不能正常生长,而且因此引起大批死亡。近年来江苏、安徽、辽宁等地养殖的河蟹因长期不蜕壳而大批死亡,经调查95％以上死亡蟹存在各种程度的蜕壳不正常。造成不能蜕壳的原因很多很复杂,笔者在长期调查和试验的基础上初步了解掌握了几种不蜕壳的特征及解决的方法,以供参考。 1.不蜕壳症的几种特征 (1)黑壳蟹不蜕壳 病蟹壳呈灰黑色,坚     

虾类有别--不要误食蝲蛄

龙虾与蝲蛄同属虾类,但不同种,前者是海水虾类,后者是淡水虾类.龙虾是个体最大的一种虾,体长可达30厘米左右,肉从壳少,其味鲜美可口,原产我国南海和东海南部,蝲蛄略似龙虾而小,体长10厘米左右,肉少壳多,其味较为鲜美,原产我国东北各省内陆水域.     

东北蝲蛄稻田养殖技术

东北蝲蛄(Cambarus dauricus)广泛地分布于黑龙江流域的河流、湖泊、水库、沟渠及沼泽地天然泡沼中,资源丰富,三江平原和松嫩平原沼泽区每人每天可捕到35～60公斤。其肉味鲜美、营养丰富,是一种颇具开发价值的水产资源,不仅可与鱼类池塘混养,还可稻田养殖。 1.田块与工程 养蝲蛄稻田,要求水源充足、水量丰富、无污染、灌排方便、保水性能好,面积以1000～1500平方米为宜,最好是呈东西向的窄条田,以延长输水距离,利于升温。由于水稻在生长季节适宜水深为10厘米左右,而蝲蛄     

不同水温对个体养殖系统中华绒螯蟹幼蟹蜕壳生长和摄食率的影响

为探讨不同水温对中华绒螯蟹(Eriocheir sinensis)幼蟹蜕壳、生长和摄食率的影响,本研究应用恒温的河蟹个体养殖系统,分析不同水温(10、15、20、25、30℃)对中华绒螯蟹幼蟹的成活率、蜕壳次数、蜕壳间隔、蜕壳增重率、肥满度和摄食率的影响。结果显示:在133 d的试验中,各饲养水温的中华绒螯蟹成活率均在89%以上;10℃和15℃水温的实验蟹只蜕壳1次,20℃和25℃水温组的实验蟹蜕壳2次,30℃水温组的实验蟹蜕壳3次;五个水温组的平均蜕壳间隔分别为109.39、67.92、46.63、43.69、38.01 d;蜕壳增重率随水温升高呈总体增加的趋势,30℃水温组的蜕壳增重率显著高于其他水温组;平均绝对生长率和相对生长率均随着水温的升高而逐步增大,且各水温组间差异显著;肥满度随水温的升高而逐渐下降;五个水温组的平均日摄食率分别为1.58%、1.97%、3.54%、4.79%和5.25%。腿部肌肉切片观察发现,低水温组(10、15、20℃)的肌纤维直径显著大于高水温组(25、30℃)。结果表明:随着饲养水温的增加,河蟹的蜕壳速度加快,增重率增加,肥满度下降,摄食率增加,以30℃水温时的河蟹生长最佳。     

克氏原螯虾繁殖生物学研究

对克氏原螯虾(Procambarus clarkii)繁殖生物学进行了研究。结果显示:克氏原螯虾的性成熟年龄为1年左右;雌虾最小体长为6.4 cm,最小体重为10 g;雄虾最小体长为7.1 cm,最小体重为20 g。5~9月为交配期,其中以6~8月为交配高峰期。克氏原螯虾交配后大约为30 d左右产卵。繁殖期为7~10月,高峰期为8~9月。10月底以后抱卵的虾由于水温逐步降低,一直延续到第2年春季才孵化。克氏原螯虾的繁殖行为与掘洞行为密切相关,繁殖期的掘洞数量较非繁殖期明显增多。7~10月,亲虾均栖息在洞内繁殖,洞穴深度为50~80 cm。卵巢为一次产卵类型。雌雄比例为1∶1。克氏原螯虾的个体绝对繁殖力的变动范围为172~1158粒,平均为517粒。个体相对繁殖力(F/W)的变动范围为2~41粒/g,平均为21粒。个体相对繁殖力(F/L)的变动范围为47~80粒/cm,平均为63粒。     

Mating and spawning of freshwater crayfish, Austropotamobius pallipes Lereboullet, under laboratory conditions

Abstract. The study includes mating and spawning data of freshwater crayfish, Austropotamobius pallipes Lereboullet, obtained in four consecutive years (1987–1990). A total number of 586 wild-caught female A. pallipes in the 21·65 mm to 45·60mm carapace length (CL) size were held under laboratory conditions at different dates in September–October. Initial densities at mating time were 21 and 24 crayfish/m² with a 1:2 male:female ratio. High percentages of mating were obtained (97·4–100%) except in 1989 (57·5%). In all years, most of the matings (90%) were concentrated in a period of 8–12 days with mean water temperatures between 12°C and 13·5°C. Spawning took place a few days after mating (minimum 2 days, maximum 14 days) at mean water temperatures between 8·2°C and 10·8°C. In the first 3 years, almost 100% of mated females spawned. However, in the fourth year (1990), when the mean size of crayfish was smaller, only 72·4% of mated females spawned. The mean number of pleopodal eggs was 64 (maximum 220, minimum 18). Egg diameter ranged between 2·30 and 3·25 mm (mean value 2·78 mm). Pleopodal egg number was positively correlated with carapace length ( r = 0·72).     

Effect of density on brood size in noble crayfish,Astacus astacus L., subjected to indoor rearing conditions*

Abstract. The effects of density, cover, and individual versus communal holding on brood size and female survival during the breeding period were examined in a large-scale experiment, involving 3591 mature noble crayfish, Astacus astacus L., females. Crayfish density during both mating/spawning and winter incubation had major effects on egg survival. In the high density experiment (67 and 44 individuals per m² during mating/spawning and winter incubation respectively) mean pleopod egg number in April was 18-20. Lowering the density to 50 during mating/spawning (still 44 individuals per m² during winter incubation) gave mean pleopod egg numbers of 31-38. In the low density experiment (50 and 33 individuals per m² during mating/spawning and winter incubation) mean pleopod egg numbers were 44-46. Egg-bearing females held in individual compartments with perforated bottom had a mean pleopod egg number of 25. Female survival during winter incubation was high, ranging from 91.8 to 98.3%. Covering the basins had no distinct effect on egg and female survival. In Astacus astacus culture we recommend that crayfish density should not exceed about 50 individuals per m² during mating/spawning and about 33 individuals per m² during winter incubation.     

Effects of dietary l-tryptophan on the agonistic behavior,growth, and survival of freshwater crayfish Astacus leptodactylus Eschscholtz

In this study, the effects of dietary tryptophan (a precursor of 5-hydroxytryptamine, 5-HT, serotonin) on the agonistic behavior, growth, and survival of freshwater crayfish were investigated. For this aim, a control diet (D1) and three experimental diets (D2, D3, and D4) were prepared. D1 contained no additional tryptophan (TRP), but D2, D3, and D4 diets were supplemented with TRP at 0.50, 0.75, and 1.00 % in dry diet, respectively. The control contained 0.33 % TRP. Results revealed that higher supplemental dietary TRP levels caused a significant decrease in the aggressive behavior (P < 0.05), but an increase in the calmness of crayfish. In addition, the results showed that 5-HT levels in the hemolymph before the fight (after 15 days of feeding; resting) were significantly different (P < 0.05) between D1 and D4. There was a significant difference (P < 0.05) in the 5-HT level of hemolymph between the crayfish fed control and D4 after 15 days of feeding. However, after the fight, 5-HT concentration was significantly higher (P < 0.05) in TRP-supplemented A. leptodactylus as compared with the control. The findings of this study showed that supplemental dietary TRP caused a significant increase (P < 0.05) in the growth and survival rate of A. leptodactylus. The crayfish fed D4 had the best survival rate at the end of the experiment (91.60 % in August). The findings of this study also showed that difference in survival rate between the crayfish fed control and D2 in June, July, and August was not significant (P > 0.05). In addition to these, supplemental dietary TRP gave rise to significantly higher specific growth rate (SGR) values in June and July (P < 0.05). For example, in June, it was 0.38 for the crayfish fed D4, 0.28 for the crayfish fed D3, 0.18 for the crayfish fed D2, and 0.13 for the crayfish fed control. However, in August, the highest SGR (0.56) was obtained from the crayfish fed control. The results also showed that the SGRs of females were lower than the males in June, July, and August (P < 0.05). In conclusion, this research shows that the aggressive behavior of A. leptodactylus can be suppressed, and rearing efficiency (i.e., increased growth and high survival rate) of this species can be improved by increasing TRP levels to 1.00 % in its diet.     

A review of genetic improvement in growth rate in redclaw crayfish Cherax quadricarinatus (von Martens) (Decapoda: Parastacidae)

This paper provides a review and summary of strain comparison and selective breeding work carried out on redclaw crayfish Cherax quadricarinatus (von Martens) at the Queensland Department of Primary Industries, Freshwater Fisheries and Aquaculture Centre, Walkamin. Redclaw crayfish are a highly marketable, environmentally tolerant, freshwater crayfish with a moderately fast, but variable, growth rate. Five strains of the species were assessed morphologically and in terms of age at maturity. A non‐replicated production trial was also carried out before two strains, from the Gilbert and Flinders rivers in North Queensland, were chosen to be part of an experimental selective breeding programme for improved growth. Initially, 14 families of each strain were randomly mated and grown out. At this point, a size‐related selection took place, with the largest animals from each family forming a selected line, and individuals from around the mean forming a control line. Within‐family selection and reciprocal mating between families was performed. Data were collected after each of two generations of growout and analysed by analysis of variance. Significant differences (P < 0.05) were measured between strains, sexes and between selected and control lines. Selected individuals grew 9.5% faster than the controls. Recommendations for selective breeding research involving freshwater crayfish are presented.     

Crayfish in central and southern Ukraine with special focus on populations of indigenous crayfish Astacus pachypus (Rathke, 1837) and their conservation needs

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The decline of endangered stone crayfish (Austropotamobius torrentium) in southern Germany is related to the spread of invasive alien species and land‐use change

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2019年秋冬季南设得兰群岛南极磷虾集群时空分布特征

为了进一步研究南设得兰群岛附近海域南极磷虾集群时空分布特征,基于2019年秋冬季（4—7月）中国南极磷虾生产渔船声学调查及商业捕捞数据,从时空两个维度对南极磷虾集群中心深度、集群所处水深水温和集群形态进行了分析。结果显示,南设得兰群岛附近海域南极磷虾集群中心深度、集群所处水深水温和集群形态存在明显的时空差异。平均集群中心深度在4—7月总体呈递增趋势(变化范围为34.39～86.12 m),昼夜差异较小(P=0.325),峰值时段为日升阶段(sun rising, SRS)(64.06 m)和夜间(night, NIT)(65.32 m);平均集群中心深度低值区间为62.75°～63.75°S和58.25°～59.75°W,高值区间为61.75°～62.25°S和60.25°～61.75°W。平均集群所处水深水温在4—7月总体呈递减趋势(变化范围为-1.71～-1.50℃),昼夜集群水温差异明显,峰值时段为NIT(夜间)(-1.46℃)和暮光(evening twilight, ETW)(-1.4℃);平均集群所处水深水温低值区间为62.75°～63.75°S和61.25°～61.75°...     

Relative impacts of native and non‐native crayfish on shelter use by an indigenous benthic fish

• 1. The North American signal crayfish Pacifastacus leniusculus has been widely introduced throughout Europe where it is expanding its range and in many areas replacing the native white‐clawed crayfish Austropotamobius pallipes. There is concern with regards to the impact of this species replacement on benthic fish. Interspecific behavioural interactions and competition for shelter between the benthic fish, bullhead Cottus gobio and A. pallipes and P. leniusculus were measured to assess the comparative impact of native and non‐native crayfish.
• 2. Both white‐clawed crayfish and signal crayfish were dominant over bullhead. Bullheads moved away from approaches of crayfish, left shelters on entry of crayfish and rarely entered an occupied shelter. Signal crayfish made significantly more aggressive approaches towards bullheads than white‐clawed crayfish.
• 3. Alone, bullheads spent most of their time by day under shelter (median 96%), reflecting a highly entrained behavioural response, which was relaxed by night (median 60%). Both crayfish species reduced shelter use by bullheads although the extent of shelter sharing by bullheads was higher in trials with white‐clawed crayfish than with signal crayfish.
• 4. Sampling in the River Wharfe, northern England, where signal and white‐clawed crayfish and bullhead currently exist, demonstrated a negative relationship between the densities of signal crayfish and bullhead, with high bullhead abundance where crayfish were absent or where white‐clawed crayfish were present at low density.
• 5. Assuming that shelter is sometimes limited under natural conditions, crayfish are likely to displace bullheads from shelters, which may increase predation risk for bullheads. Although the effects of signal crayfish on bullhead shelter use were more intense, the pattern was highly evident for the native white‐clawed crayfish. The higher fecundity and densities attained by signal crayfish may be more significant than differences in the behaviour of the two crayfish species in determining the impact of crayfish on bullheads.

Copyright © 2008 John Wiley & Sons, Ltd.     

Estimates of genetic parameters for growth-related traits of the red swamp crayfish,Procambarus clarkii

In this study, technologies of family construction and grow-out culture in the same pond were studied for red swamp crayfish. A total of 77, 110 and 78 families were constructed in 2011, 2012 and 2013, respectively. Heritability, genetic and phenotypic correlations were estimated for body weight, body length and carapace length through performance testing in progeny of 2012 at 5 and 10 months of age, resulting from a nested mating design. At 5 months of age, none of the estimated heritabilities were significant (0) based on sire components (h _s ² ) for these traits, the genotypic correlations, either; only the phenotypic correlations were significant (0.8561–0.9420). At 10 months of age, the estimated heritabilities (h _s ² ) were low for the three traits (0.1429–0.1632); the phenotypic and genetic correlations were significant, 0.8148–0.9052 and 0.9981–0.9993, respectively. It was concluded that genetic improvement through selective breeding conducted on red swamp crayfish might be feasible and would be an efficient method to obtain a positive response to selection for the 10-month-old red swamp crayfish.