川北地区稻田养殖中华绒螯蟹试验初探

本试验在四川山间湿地利用农田0.62公顷养殖中华绒螯蟹，放养苗种为1272只(135只／667m^2)，个体均重7g／只左右，经160d饲养，捕获绒螯蟹875只，个体均重136．7g／只，回捕率为68.8％，饵料系数为2．45，同时水稻产量3529．7kg(375．5kg／667m^2)，其总收获利润为416元／667m^2。     

基于机器视觉的水下河蟹识别方法

为了探测河蟹在池塘中的数量及分布情况,为自动投饵船提供可靠的数据反馈,提出了基于机器视觉的水下河蟹识别方法。该方法通过在投饵船下方安装摄像头进行河蟹图像实时采集,针对水下光线衰减大、视野模糊等特点,采用优化的Retinex算法提高图像对比度,增强图像细节,修改基于深度卷积神经网络YOLO V3的输入输出,并采用自建的数据集对其进行训练,实现了对水下河蟹的高精度识别。实验所训练的YOLO V3模型在测试集上的平均精度均值达86. 42%,对水下河蟹识别的准确率为96. 65%,召回率为91. 30%。实验对比了多种目标检测算法,仅有YOLO V3在识别准确率和识别速率上均达到较高水平。在同一硬件平台上YOLO V3的识别速率为10. 67 f/s,优于其他算法,具有较高的实时性和应用价值。     

Effect of casein substitution with fishmeal, soybean meal and crustacean meal in the diet of the abalone Haliotis discus hannai Ino

The effect of dietary substitution of casein with fishmeal, soybean meal and crustacean meal on the growth of the abalone Haliotis discus hannai Ino was determined. A 350 g casein per kilogram diet was included into the CS diet. The whole casein was then substituted by: (1) 300 g fishmeal and 200 g soybean meal per kilogram diet (FS), (2) 200 g fishmeal, 200 g soybean meal and 130 g krill meal per kilogram diet (FSK), (3) 200 g fishmeal, 200 g soybean meal and 280 g red crab meal per kilogram diet (FSC) or (4) 200 g fishmeal, 200 g soybean meal and 130 g shrimp head meal per kilogram diet (FSS). In addition, a 50‐g by‐product of green tea per kilogram diet was included in the FS diet to form the FSG diet. Sea tangle (ST)diet was supplied to abalone as a control feed. Weight gain, final shell length and final shell width of abalone fed with the various substitution feeds (FS, FSK, FSC, FSS and FSG) were not different from those obtained with the CS diet. All the formulated feeds, however, produced higher weight gain and final shell width values than the ST diet. The results of this study show that casein can be replaced with a combination of fishmeal, soybean meal, krill meal, crab meal and/or shrimp head meal in the diet without a retardation of growth of abalone.     

Reproductive season and female maturity size of coconut crab <Emphasis Type="Italic">Birgus latro</Emphasis> on Hatoma Island,southern Japan

Information about reproductive season, size at sexual maturity and size-dependent reproductive potentials is important for efficient resource management. Such information is necessary to determine seasonal closures and minimum legal size limits. To conserve resources of coconut crab Birgus latro, which are in danger of extinction due to excessive exploitation, their reproductive season, female size at functional maturity and relationship between female size and reproductive potentials were investigated. The reproductive season started in early June and ended late August, and females with higher reproductive potentials showed a tendency to spawn early in the reproductive season. The prohibition of exploiting the resources during the reproductive season, especially early in the season, would be appropriate for sustainability of high reproductive outputs. Fifty percent of investigated females matured functionally at 24.5-mm thoracic length (TL). However, the size at which all females reached functional maturity was 32.3 mm TL, and there was a wide variation in the size of functional maturity among individuals. We must determine minimum legal size by taking the variation into account to allow all individuals to mate at least once before they are caught, which may prevent serious depression in reproductive rate and genetic diversity.     

Effects of different natural or prepared diets on growth and survival of juvenile spider crabs, <Emphasis Type="Italic">Maja brachydactyla</Emphasis> (Balss, 1922)

The effects of different diets (natural or pellets) on growth, survival, and moulting interval of juvenile spider crabs, weighing between 0.011–1.56 g and up to 17.6 mm in carapace length, were tested over a period of 90 days. During experiment I, five diets were tested: (1) frozen shrimp—Paleomonetes sp., (2) fresh mussels—Mytilus sp., (3) white fish fillets—Merlucius merlucius, (4) blue fish fillets—Sardina pilchardus, and (5) commercial crustacean pellets. Spider crabs fed fresh mussels grew larger (0.98 ± 0.69 g) and had higher growth rates (4.0 ± 0.7 %BWd⁻¹) compared to the other four diets. The crabs fed shrimp pellet and frozen shrimp grew to intermediate sizes and were smaller than the ones fed fresh mussels, but they were larger than spider crabs fed either blue or white fish fillets (0.46 ± 0.63 and 0.26 ± 0.13 g, respectively) compared to the ones fed white fish fillets (0.12 ± 0.04) and blue fish fillets (0.04 ± 0.02 g). The spider crabs fed blue fish fillets only lasted until day 60 of the experiment, after this day none of the 20 fed this diet were left. During experiment II, two diets were tested: (1) white and blue fish fillets and (2) commercial fish pellet. There were no differences in growth both in weight or carapace length (2.9 ± 1.8 and 2.1 ± 1.5 g in weight, and 18.9 ± 5.0 and 17.7 ± 3.3 mm, respectively) at the end of the experiment. Similarly, there were no differences in growth rates in weight between the two diets (1.2 ± 0.4 and 0.9 ± 0.3 %BWd⁻¹, respectively) or in carapace length (0.4 ± 0.1 and 0.4 ± 0.2 %BWd⁻¹, respectively). Fresh mussel appears to be a very good diet to culture the early stages of this species, while shrimp pellets also deliver acceptable results. On the contrary, frozen shrimp, fish fillets either from blue or white species (much higher lipid content in the blue species), and fish pellets were found to be bad diets for the culture of the early stages of M. brachydactyla.     

基于PLC的蟹笼渔船诱饵填盒与塞笼自动化流水线方案设计

蟹笼渔船诱捕饵料在使用过程需要经过破冰分离、切块、填盒、塞笼等工序,效率低、劳动强度大.为提升蟹笼渔船的生产效率,需要实现饵料使用自动化.提出了一种实现饵料使用自动化的流水线生产方案,并通过Pro/ENGINEER Wildfire 5.0进行流水线的结构设计建模与原理分析,采用GX works3基于三菱FX5U系列P...     

中华绒螯蟹免疫因子-溶菌酶的初步研究

研究了在自然状态下中华绒螯蟹成蟹血淋巴和大眼幼体组织匀浆上清液中溶菌酶的活性。结果表明,在中华绒螯蟹成蟹血淋巴中均检测出溶菌酶的活性,为(0.0286±0.0081)活力单位(n=30),而在中华绒螯蟹大眼幼体组织匀浆上清液中亦检测到溶菌酶的活性,为(0.0318±0.0073)活力单位(n=4)。     

渔光一体养殖模式对中华绒螯蟹肝胰腺和性腺气味品质的影响

渔光一体养殖模式(photovoltaic fishery breeding mode, PM)是一种采用水下养殖、水上发电的新兴环保养殖模式。本研究比较了渔光一体养殖模式与普通池塘养殖模式(common pond breeding mode, CM)养殖中华绒螯蟹(Eriocheir sinensis)在基本营养成分、感官评价和气味品质等方面的差异。对雌蟹肝胰腺和性腺进行人工及电子感官评价,测定挥发性物质的含量,并对气味品质进行综合评价。结果表明,渔光一体养殖模式能提高雌蟹的性腺指数、增加粗蛋白和粗脂肪含量;PM组肝胰腺表现青草味,电子鼻的响应值最高,PM组性腺的青草味和油脂味更明显;在肝胰腺中,鉴定出44种(PM组)和33种(CM组)物质,PM组总挥发性物质的含量[(70.53±2.91) ng/g]显著高于CM组[(16.63±0.73) ng/g](P<0.05),是CM组的4.2倍,其中油脂味和青草味的物质含量更高;而在性腺中,鉴定出了31种(PM组)和47种(CM组)物质,PM组和CM组总挥发性物质含量分别为(68.80±1.86) ng/g和(71.50±4.17)...     

鱼蟹稻田飞虫捕食装置风光互补供能系统的研究

针对鱼蟹稻田飞虫捕食装置的离网型户外供能需求的问题,着重研究该装置的供能系统方案。基于户外供能合理性要求,采用小型风力发电机和太阳能电池板自主互补发电来进行能源供应;对小型风力发电机和太阳能电池板分别进行Matlab/Simulink建模,着重对叶轮的风能利用系数、叶尖速比和桨距角的相关性进行量化分析,利用单因素分析法对太阳能电池板进行分析;在桨距角确定的条件下,适当取值叶尖速比,能够获得最大风能利用系数。同时,在不同温度和辐射的条件下,太阳能电池板能够取得功率曲线的峰值,为风光互补的最大功率获取提供理论上的支持。针对离网型风光互补系统能源的合理化利用,提出混合供能的能量管理策略,符合该装置的供能需求,对户外同类型装置供能设计提供一定的参考。     

中华绒螯蟹颤抖病的人工复制试验

用在江苏采集的发生“颤抖病”的中华绒螯蟹组织匀浆,经除菌处理,人工接种健康绒螯蟹,约１０ｄ发病,发现典型症状,继而死亡。将人工复制发病的绒螯蟹（ＢＹ１）除菌后,接种健康绒螯蟹,同样使其发病并死亡（ＢＹ２）。电镜观察ＢＹＯ,ＢＹＩ,ＢＹ２的超薄切片,其神经组织和肝胰脏等的细胞质中发现圆形病毒颗粒,大小约５５￣６５ｎｍ,具有外膜样结构,因此,可以在中华绒螯蟹颤抖病的病原为病毒。