虾塘投饲船载自适应速度投饲系统设计与实现

为了让投饲船能根据实时船速自动调整投饲速率,从而把虾饲料比较均匀地抛撒至沿着虾塘四周的"食道"上,研制了一种根据虾塘四周"食道"而设计的实时船速自动调节投料量的投饲系统。该系统采用超带宽(UWB)定位系统来定位船体的位置,由单片机解算出投饲船的实时行驶速度,根据船速、虾塘"食道"周长和总投饲量计算出投饲船的实时投饲速率。投饲控制系统根据计算出的实时投饲速率控制投饲机构中的舵机转角,舵机的转角与投饲机构投料口的开度一一对应,从而实现均匀投饲。在个人电脑(PC)端上位机上输入投饲船初始参数,同时显示投饲船船速和投饲机构开度大小。船速获取精度试验和投饲机构投料口开度试验显示:投饲机构投料口能在1 s内打开到与船速相对应的开度,实现投饲速率的实时调整;在船速0.5～2 m/s的工作情况下,该投饲系统投饲速率误差在2.5%以内,能够实现饲料在虾塘"食道"上的均匀投放,有较好的实用价值。     

梭子蟹单筐养殖自动投饲系统设计与试验

为解决梭子蟹单筐养殖模式下的自动投饲问题,设计了一套轨道式自动投饲系统。自动投饲系统由行走系统、投饲机、供电系统和控制系统组成。在单片机系统的控制下,行车由直流电机驱动在轨道上行走,当行车上的定位传感器感应到养殖筐边沿上的定位识别板后,投饲机对一排养殖筐同时下料。当行车走到轨道末端时,行程开关可控制行车停止前进,避免行车脱轨。试验结果表明:自动投料系统实现了定量定位自动下料,称料误差在0.3 g以内,投料精度为97%,定位识别率为100%。当水位在0.5 m范围内变化时,定位误差小于3.5 cm,满足梭子蟹单筐养殖自动投喂的要求。     

详解渔业投饲机械(下)

<正>三、工厂化养殖自动投饲机1.工作原理在鱼池上方架设跑道式H型钢轨道,导轨的长度和形状可根据现场鱼池的分布做出相应的调整,在每个鱼池的正上方设置相应的定位识别点。该样机使用反射面为80毫米×150毫米的鱼池定位识别板实现系统定位,投饲装置沿轨道行走到识别点后,安装在投饲装置上的超声     

一种水陆两用自动投饵机设计与试验研究

<正>自动投饵机是提高饲料利用率,降低养殖成本的重要设施。为解决小型池塘的投饲浪费,提高工厂化养殖水平,设计研发出一种新型的水陆两用自动投饵机。根据其工作原理,对投饵机的供料装置、高压流体装置、饵料释放装置和控制系统进行了设计与分析,采用高压流体作为供料能源,管道作为输送机构,混料释放仓作为撒料装置,PLC3系统作为控制器,并按要求制作了样机进行投喂试验。结果表明,该投饵机可以实现底部投喂,投饲深度和投饲距离具有可调性,可以满足不同池塘的需求;投饲的同时还具有增氧的作用。较传统投饵机,该投饵机具有减少饲料浪费,优化鱼类摄食环境,减少局部缺氧的优点,适合现代化渔业养殖的推广和应用。     

轨道式自动投饲系统设计与试验

针对工厂化养殖中人工投饲劳动强度大、投饲误差大、不均匀等问题,研究并设计了一种轨道式自动投饲系统。该系统由上料装置、行走装置、投饲装置和控制装置4个部分组成。控制部分以可编程辑控制器(PLC)为核心、触摸屏为人机界面,采用低压气力输送的方式上料,驱动行走小车运行的方式进行饵料输送,控制螺旋下料装置和旋转抛撒盘的方式进行定量、均匀的饵料抛撒。结果显示:可以实现4个养殖池的饵料投喂,6次投喂等待时间设定,行走速度达18.75 m/min,投饲量精度在0.5%~2.2%,投饲速度1 kg/min左右,定位精度110 mm左右。该投饵系统具有投饲精度高、均匀、高效率等特点,可有效提高饲料利用率和降低劳动强度,从而减少工厂化养殖成本。     

多层水槽式工厂化循环水养殖系统智能投饲车设计

为解决多层水槽式工厂化循环水养殖模式中人工投料操作空间局促、劳动强度大、饲料利用率低等缺点,设计了一套基于K60单片机的小微型智能投饲车。该投饲车由循迹小车、投饲装置和控制系统等组成,在特定投饲跑道上行驶,根据红外对管采集的轨道信息和压力传感器采集的饲料信息判别是否投饲或补料,进而实现智能定点定量投饲。初步试验运行结果显示,该投饲车运行稳定可靠,运行速度0. 5～2. 2 m/s,投饲的定位精度误差在2 cm以内,投饲量误差在10 g以内,基本满足设计要求。     

投饲范围可控的自动投饲机研究

为解决水产养殖用投饲机投饲范围固定、投饲不均匀、饲料利用率低及污染严重等问题,提出并研制了基于气力输送和单片机控制的投饲范围可控的自动投饲机.根据其工作原理,对该自动投饲机的供料系统、抛撒系统和控制系统进行了设计,采用气力作为供料能源,喷嘴和凸台组合作为抛撒机构,选用STC90C516RD+作为控制单元.工作过程表明,与传统投饲机相比,该自动投饲机具有结构简单、饲料不易破碎、饲料利用率高、噪声污染小等特点,并可实现对投饲范围的调节和控制,达到预期投饲范围调节和均匀投饲的效果.     

一种集成自动投饲与排污的鱼类养殖系统

为提高鱼类养殖中投饲和排污的定时、定量精度及节水效果,降低劳动强度,采用新型PLC、螺旋杆送料机构、减速电机、撒料盘、液位传感器、造流器、电动阀、自动双通道排污装置等,参考人工养殖流程设计开发出一套集成自动投饲与排污的鱼类养殖系统,该系统容积1.57 m~3,适宜养殖密度低于23 kg/m~3。对系统进行了设备性能测试及鱼类养殖试验,结果显示:该系统可自动进行喂食前水流调控及自动投饲后的自动排污步骤,其中投饲机部分投饲能力0.3 kg/min,投饲量误差在±0.5 g以内,且撒料均匀度高,使用该系统养殖的2018年长江鲟子三代较传统流水养殖的鱼体平均增重提高了35.56%,饲料系数降低了26.28%,养殖初末体质量变异系数下降了31.46%;运行过程无需人工参与,集排污效果与大换水排污无明显差异,且节水90%。测试中系统运行稳定。     

基于摄食声学的投饵系统设计

针对现在船载式投饵机自动化程度低,人工抛撒成本高、劳动强度大、抛撒不均匀,该文提出了一种基于声学的投饵系统设计。该装置利用Labview声信号采集控件通过罗非鱼鱼群喂食时现场的水下声信号识别,监测和分析鱼群摄食情况,分析该鱼群进食欲望,反馈并制定投饲决策,并驱动舵机和电动推杆实现水平和垂直方向的调整,实现投饲点的控制。该设计可实现对投饲现场的声信号采集和分析,实现对养殖的罗非鱼提供投喂决策。以stm32单片机作为核心,设计的投饵控制系统,驱动执行机构完成抛撒饵料动作。这个设计有望改变目前传统人工以手执投料管的形式定量投饵的行业现状,实现养殖鱼饲料的定向按需投喂。     

高密度养殖池塘自动气力投饲机的设计试验

为解决池塘高密度养殖过程中的投饲机承载量小、投饲不均匀、投饲范围小、饲料利用率低等问题,提出一种基于气体输送原理的自动投饲机。根据其工作原理,对投饲机的供料系统、输送系统、抛料系统和控制系统进行了设计与分析,采用气力作为供料能源,管道作为输送机构,撒料盘作为抛料机构,西门子S7-200PLC作为系统控制单元。结果显示,该自动投饲机能同时满足6个池塘的投喂,并能单独控制,满足池塘的投饲需求;投饲距离达20 m,平均投饲速度400 kg/h,破碎率低于0.9%,基本满足设计要求。与传统池塘投饲机相比,该投饲机具有结构简单、操作方便,饲料不易破碎、饲料利用率高等特点,并可实现对投饲量精确调节与控制。     

Association between the interannual variation in the oceanic environment and catch rates of bigeye tuna (Thunnus obesus) in the Atlantic Ocean

The environmental processes associated with variability in the catch rates of bigeye tuna in the Atlantic Ocean are largely unexplored. This study used generalized additive models (GAMs) fitted to Taiwanese longline fishery data from 1990 to 2009 and investigated the association between environmental variables and catch rates to identify the processes influencing bigeye tuna distribution in the Atlantic Ocean. The present findings reveal that the year (temporal factor), latitude and longitude (spatial factors), and major regular longline target species of albacore catches are significant for the standardization of bigeye tuna catch rates in the Atlantic Ocean. The standardized catch rates and distribution of bigeye tuna were found to be related to environmental and climatic variation. The model selection processes showed that the selected GAMs explained 70% of the cumulative deviance in the entire Atlantic Ocean. Regarding environmental factors, the depth of the 20 degree isotherm (D20) substantially contributed to the explained deviance; other important factors were sea surface temperature (SST) and sea surface height deviation (SSHD). The potential fishing grounds were observed with SSTs of 22–28°C, a D20 shallower than 150 m and negative SSHDs in the Atlantic Ocean. The higher predicted catch rates were increased in the positive northern tropical Atlantic and negative North Atlantic Oscillation events with a higher SST and shallow D20, suggesting that climatic oscillations affect the population abundance and distribution of bigeye tuna.     

Protein and amino acid composition from the mantle of juvenile O ctopus vulgaris exposed to prolonged starvation

Protein and amino acid composition of the mantle of juvenile O ctopus vulgaris (Cuvier, 1797) during fasting for 27 days were determined. Average protein content of octopus mantle was of 711.19 ± 46.80 g kg^?1 DW, and it decreased with increasing fasting days. The non‐essential amino acids content was higher (486.18 ± 11.08 g kg^?1 protein) than essential amino acids (425.82 ± 9.15 g kg^?1 protein) at the start of the experiment (unstarved animals). The results suggest that the amino acid profile of the mantle where the most abundant amino acids are Arg, His, Lys, Gly, Leu and Pro could indicate a prolonged fasting condition (>20 days) or poor nutrition of O . vulgaris. This study supports the idea of using mantle for metabolic needs of starved O . vulgaris suggesting that the degradation pathway of amino acids to pyruvate and tricarboxylic acid cycle intermediates was favoured contrary to the degradation pathway of ketogenic amino acids. Special considerations should be taken concerning Thr, Ile, Ser, Ala, Asx (Asp, Asn), Glx (Glu, Gln) (because of their fast intake) and Lys and His (due to their stable contents) during a prolonged period of fasting.     

Growth performance,digestive enzyme activity and immune response of Japanese sea bass,Lateolabrax japonicus fed with fructooligosaccharide

In this experiment, a feeding trial was performed to determine the effects of fructooligosaccharide (FOS) on growth performance, digestive enzyme activity and immune response of Japanese sea bass, Lateolabrax japonicus juveniles (initial weight 38.3 ± 0.5 g), and the fish were examined following feeding with six levels of FOS (0, 0.5, 1, 2, 4 and 6 g/kg) for 28 days. Significant enhancement of weight gain (WG) and specific growth rate (SGR) was found in fish fed 1 g/kg FOS incorporated diets (p < .05), while the feed conversion ratio (FCR) in the 1, 2 g/kg FOS groups reduced significantly compared with the control (p < .05). Besides, the crude lipid in the 4, 6 g/kg FOS groups increased significantly compared with the control (p < .05). On the other hand, the erepsin and lipase activities significantly elevated in intestine of fish fed 2 g/kg FOS (p < .05) and the lysozyme activity in serum of fish fed 2 g/kg FOS were significantly higher than that in the control (p < .05). Moreover, the alkaline phosphatase activities in serum of fish fed 0.5, 1, 2 g/kg FOS were significantly higher than in control (p < .05). Regression analysis showed that the relationships between dietary FOS levels and either SGR, FCR, erepsin or lysozyme activities were best expressed by regression equations, and the optimal inclusion levels are 1.37, 1.80, 3.06, 3.11, 1.93 and 1.80 g/kg for SGR, FCR, erepsin, lipase, lysozyme and total superoxide dismutase activities, respectively. Overall, this study revealed that FOS incorporated diets could beneficial for L. japonicus culture in terms of increasing the growth, digestion and immune activities. Under the present experimental condition, the optimal supplementary level of FOS in the diet of L. japonicus is 1–3 g/kg.     

美人鱼发光杆菌对凡纳滨对虾非特异性 免疫功能及抗病力的影响

在基础饲料中分别添加0.1%和1%美人鱼发光杆菌灭活菌、0.1%美人鱼发光杆菌活菌配制成3种免疫实验饲料,以基础饲料为空白对照组饲料,每组设3个平行样。对个体质量为(4.83±0.36)g的凡纳滨对虾进行为期20 d的饲养实验,分别在0、5、10、15和20d进行取样,以血清中的酚氧化酶(PO)、酸性磷酸酶(ACP)、碱性磷酸酶(AKP)、超氧化物歧化酶(SOD)和溶菌酶(UL)活性为免疫指标,探讨了美人鱼发光杆菌作为免疫制剂对凡纳滨对虾非特异性免疫效应的影响;在投喂免疫饲料后的第22天,按0.004 2 kg/kg体重的剂量,直接投喂对虾白斑综合征病毒(WSSV)病料,并记录累积死亡率。结果表明,美人鱼发光杆菌免疫实验组对凡纳滨对虾血清中PO、ACP、AKP、UL和SOD活性影响明显高于对照组,并且在饲料中添加美人鱼发光杆菌后,明显提高了对虾抵御WSSV感染的能力。其中0.1%美人鱼发光杆菌活菌实验组的抗病毒感染能力最强,WSSV感染14d内累计死亡率为63.3%±5.8%;而对照组为96.7%±3.3%。研究表明,美人鱼发光杆菌添加在对虾饲料中能提高凡纳滨对虾非特异性免疫水平,增强抵抗疾病的能力,将其作为对虾免疫增强剂具有良好的应用前景。     

Effects of Spirulina platensis as a feed additive on growth and coloration of blue dolphin cichlids (Cyrtocara moorii Boulunger, 1902)

This study was carried out to investigate the effects of replacing fish meal with dietary Spirulina as a feed supplement on the growth performance and coloration of blue dolphin cichlids (Cyrtocara moorii). Five isonitrogenous (47% crude protein) and isocaloric (17.36 kJ/g digestible energy) diets were for formulated to replace FM with 0, 5, 10, 15 and 20% Spirulina (designated as Control, SP5, SP10, SP15 and SP20 respectively) and fed to the fish (initial body weight, 3.15 ± 0.01 g). Fish were randomly distributed into fifteen 120 L aquariums (26.5 ± 1.00°C), 15 fish per aquarium. The diets were tested in triplicate for 12 weeks. Experimental groups were fed twice daily (09:00 and 17:00) by hand to satiation. At the end of the feeding trial, significantly (p < 0.05) higher weight gain (WG), specific growth rate (SGR), protein efficiency ratio (PER) and lower feed conversion ratio (FCR) were observed in fish fed the SP10 diet when compared to the SP20 diet. There was no significant difference in these parameters between the other groups. The skin coloration of blue dolphin cichlid fed a diet containing Spirulina meal was enhanced. The best coloration was observed in the SP15 group. These impressions were objectively validated by chemical determinations of carotenoids extracted from fish skins and passed statistical tests of significance. The study findings show that Spirulina meal does not diminish growth rates except at very high levels.     

Dietary thiamin and pyridoxine requirements of fingerling Indian major carp,Cirrhinus mrigala (Hamilton)

Two experiments were conducted to quantify the dietary thiamin (experiment I) and pyridoxine (experiment II) requirements of fingerling Cirrhinus mrigala for 16 weeks. In experiment I, dietary thiamin requirement was determined by feeding seven casein–gelatin‐based diets (400 g kg^?1 CP; 18.69 kJ g^?1 GE) with graded levels of thiamin (0, 0.5, 1, 2, 4, 8 and 16 mg kg^?1 diet) to triplicate groups of fish (6.15 ± 0.37 cm; 1.89 ± 0.12 g). Fish fed diet with 2 mg kg^?1 thiamin had highest specific growth rate (SGR), protein retention (PR), RNA/DNA ratio, haemoglobin (Hb), haematocrit (Hct), RBCs and best feed conversion ratio (FCR). However, highest liver thiamin concentration was recorded in fish fed 4 mg thiamin kg^?1 diet. Broken‐line analysis of SGR, PR and liver thiamin concentrations exhibited the thiamin requirement in the range of 1.79–3.34 mg kg^?1 diet (0.096–0.179 μg thiamin kJ^?1 gross energy). In experiment II, six casein–gelatin‐based diets (400 g kg^?1 CP; 18.69 kJ g^?1 GE) containing graded levels of pyridoxine (0, 2, 4, 6, 8 and 10 mg kg^?1 diet) were fed to triplicate groups of fish (6.35 ± 0.37 cm; 1.97 ± 0.12 g). Fish fed diet containing 6 mg kg^?1 pyridoxine showed best SGR, FCR, PR, RNA/DNA ratio, Hb, Hct and RBCs, whereas maximum liver pyridoxine concentration was recorded in fish fed 8 mg kg^?1 dietary pyridoxine. Broken‐line analysis of SGR, PR and liver pyridoxine concentrations reflected the pyridoxine requirement from 5.63 to 8.61 mg kg^?1 diet. Data generated during this study would be useful in formulating thiamin‐ and pyridoxine‐balanced feeds for the intensive culture of this fish.     

Sea bream culture in Egypt; status, constraints and potential

Marine fish farming in Egypt began in 1976 with the culture of gilthead sea bream, (Sparus aurata) as this fish was notably adaptable to brackish and marine pond conditions. Today, marine fish and shrimp farms amount to about 19,000 ha, out of which 42% is already in production while the rest, i.e., 58% is still under construction. In 1997, cultured gilthead sea bream production of 2,250 tons made up 3% of the 75,000 tons total aquaculture catch. In polyculture, usually with the grey mullet and sea bass, gilthead sea bream contributed 440 kg ha^–1 to the total yield of 1,700 kg ha^–1 (26%) over a period of 16 months. For the same period, the yield of monoculture ponds averaged 100 kg ha^–1, while in marine cages, yields ranged from 4–10 kg m³. In 1996–1997, fry of 0.25–1 g and fingerlings 1–10 g with a total of 3 million, were collected from the wild and 1 million fry were produced in the three marine hatcheries out of the four existing ones. The development of sea bream culture in Egypt is now severely inhibited by the shortage of seeds and adequate feeds. Exports of both sea bream and sea bass, during 1994–1996 averaged 1,300 tons per year.     

A Minchinia mercenariae‐like parasite infects cockles Cerastoderma edule in Galicia (NW Spain)

The cockle Cerastoderma edule fishery has traditionally been the most important shellfish species in terms of biomass in Galicia (NW Spain). In the course of a survey of the histopathological conditions affecting this species in the Ria of Arousa, a haplosporidan parasite that had not been observed in Galicia was detected in one of the most productive cockle beds of Galicia. Uni‐ and binucleate cells and multinucleate plasmodia were observed in the connective tissue mainly in the digestive area, gills and gonad. The parasite showed low prevalence, and it was not associated with abnormal cockle mortality. Molecular identification showed that this parasite was closely related to the haplosporidan Minchinia mercenariae that had been reported infecting hard clams Mercenaria mercenaria from the Atlantic coast of the United States. The molecular characterization of its SSU rDNA region allowed obtaining a fragment of 1,796 bp showing 98% homology with M. mercenariae parasite. Phylogenetic analysis supported this identification as this parasite was clustered in the same clade as M. mercenariae from the United States and other M. mercenariae‐like sequences from the UK, with bootstrap value of 99%. The occurrence of M. mercenariae‐like parasites infecting molluscs outside the United States is confirmed.     

Involvement of gonadal steroids in final oocyte maturation of white perch (Morone americana) and white bass (M. chrysops): in vivo and in vitro studies

Plasma estradiol-17 (E₂), testosterone (T), 17,20-dihydroxy-4-pregnen-3-one (DHP) and 17,20,21-tri-hydroxy-4-pregnen-3-one (20-S) levels were measured by radioimmunoassay (RIA) in white perch (Morone americana) and white bass (M. chrysops) that were induced to undergo final oocyte maturation (FOM) with human chorionic gonadotropin (hCG). Plasma DHP levels increased in females of both species in association with oocyte germinal vesicle migration (GVM) and germinal vesicle breakdown (GVBD) and decreased thereafter. Plasma 20-S levels also increased with oocyte GVM in white bass, but were several-fold lower than DHP levels. Circulating E₂ and T levels were greatest during GVM and GVBD in both species and decreased to low levels during oocyte hydration and ovulation. Follicles from white perch and white bass which received a priming injection of hCG in vivo, produced both DHP and 20-S in vitro after exposure to hCG and their oocytes underwent GVBD. Ovarian incubates from unprimed fish of either species produced only E₂ and T and their oocytes did not complete GVBD. Oocytes from unprimed bass, but not perch, matured when follicles were exposed to hCG in vitro. Both trilostane and cycloheximide blocked in vitro production of DHP and 20-S and oocyte GVBD by white perch follices. DHP and 20-S were equipotent inducers of FOM in the GVBD bioassay. None of several other structurally-related steroids tested were effective within a physiological range of concentrations. These results indicate a role for DHP and 20-S in the control of FOM in white perch and white bass.