略论无公害鱼类生产技术

无公害鱼类生产是未来渔业的发展方向,其中包括场地的选择、亲鱼品种的选择、繁殖、池塘饲养、网箱饲养、安全越冬以及病虫害防治。通过这些环节逐步使渔业的生产繁殖朝着绿色,无污染和无公害方向发展,既保护生态环境,又使消费者满意。

蒲公英提取物的生物学功能及其在畜、禽、鱼类生产中的应用

蒲公英是一种常见的药食两用植物,富含各种化学物质,如黄酮类、三萜类、倍半萜内酯类、香豆素类等物质。蒲公英整株都具有重要的药用价值,其根、叶、花在动物体内均具有多种功能,如抗氧化、抗菌抗炎、抗肿瘤、降血糖、保肝利胆、增强免疫力等生物学功能。本文综述了蒲公英提取物的主要生物学功能及其在畜、禽、鱼类生产中的应用情况,为蒲公英在养殖业中的应用提供参考。

“离水烂”变成了“金疙瘩”——长岛县低质鱼类生产实现产业化高效化

鳀鱼,胶东渔民称之为“离水烂”,因其只有寸把大小,离开海水在短时间内便腐烂,即便及时加工也只能每市斤卖几分钱,因此渔民往往在起网时就将其弃之。 秋汛时节,当山东省长岛县海洋与水产局副局长王庆才告诉我们,鳀鱼等低质鱼类已成为海岛渔村又一增收门路时,我们产生了极大兴趣:“离水烂”是怎样变成“金疙瘩”的?

海水自动化循环养殖系统在养殖鱼类生产中的应用

海洋资源是人类的重要粮仓和能源之源,其中海水中的养殖鱼类一直是海产业链中不可或缺的重要环节。随着社会经济发展和人口增长,传统的养殖方式逐渐不能满足市场需求。而海水自动化循环养殖系统则在这种背景下应运而生,成为了当前海洋养殖业中不可或缺的核心技术之一。海水自动化循环养殖系统的出现,极大提高了养殖效率和品质,并降低了对生态环境的影响。这种系统可以实现对养殖池中水质、温度、氧气含量等多个指标的精确控制和调节,从而避免了传统养殖方式中由于水质差异导致的生长速度不均和损失率较高等问题。其良好的养殖效果和对环境友好的特点让它成为了当前养殖业的首选方案之一,并且该技术的不断进步和完善,也将为未来的海洋养殖业发展提供更加稳定和可靠的技术支持。

闽东渔场不同生态类群的鱼类资源生产量

以历次海洋科学调查在闽东渔场获得的初级生产力为基础,通过2000～2001年对该渔场的鱼类资源结构、浮游植物有机碳含量、生态效率、主要经济鱼类营养级及其有机碳含量等模型参数的调查和检测,采用营养动态模型和Cushing模型估算鱼类资源的生态容量(潜在生产量),进而应用Steele模型分别估算中上层鱼类、底层鱼类的资源生产量,最后从鱼类资源生产量中分离出近底层鱼类的资源生产量.采用Gadima模式估算鱼类及其各生态类群资源的最大可持续开发量,并讨论它们的开发利用程度.估算结果:闽东渔场鱼类资源生产量为63.08×104t,最大可持续开发量为33.82×104t.其中中上层鱼类资源生产量为38.68×104t,最大可持续开发量为20.34×104 t,底层和近底层鱼类资源生产量分别为13.22×104 t和11.17×104t,最大可持续开发量合计为15.50×104 t.底层和近底层鱼类实际年渔获量自1993年以来已连续11年超过其最大可持续开发量,呈过度捕捞.中上层鱼类实际年渔获量也于1998年以来连续6年超过其最大可持续开发量.因此必须加强保护和管理,采取有力措施削减捕捞力量和渔获量,实行捕捞力量和渔获量'负增长',待到渔获量下降到最大可持续开发量水平时,才恢复实施'零增长'制度.

水域生态

常说：“鱼儿离不开水，瓜儿离不开秧”。要搞好养鱼，首先要懂得水，懂得水中有些什么，它们的性质，以及相互之间的关系。用科学的语言来说，就是要懂得水域生态系统的基本知识。

海水自动化养殖与传统养殖的环境影响和经济效益比较分析

海洋资源是人类的重要粮仓和能源之源,其中海水中的养殖鱼类一直是海产业链中不可或缺的重要环节。随着社会经济发展和人口增长,传统的养殖方式逐渐不能满足市场需求。而海水自动化循环养殖系统则在这种背景下应运而生,成为了当前海洋养殖业中不可或缺的核心技术之一。海水自动化循环养殖系统的出现,极大提高了养殖效率和品质,并降低了对生态环境的影响。这种系统可以实现对养殖池中水质、温度、氧气含量等多个指标的精确控制和调节,从而避免了传统养殖方式中由于水质差异导致的生长速度不均和损失率较高等问题。其良好的养殖效果和对环境友好的特点让它成为了当前养殖业的首选方案之一,并且该技术的不断进步和完善,也将为未来的海洋养殖业发展提供更加稳定和可靠的技术支持。

Comparative study of the nutritional composition and toxic elements of farmed and wild Chanodichthys mongolicus

Information of the difference in quality between farmed and wild fish is central to better ensuring fish products produced in aquaculture meet regulatory and consumer requirements. Proximate composition, amino acid and fatty acid profiles, and toxic elements contents of fanned and wild Chanodichthys mongolicus were established and compared. Significantly higher crude protein content while lower moisture content in farmed fish compared to wild fish were observed （P〈0.05）. The percentages of total amino acids （TAA）, total essential amino acids （TEAA）, total non-essential amino acids （TNEAA） and total delicious amino acids （TDAA） in farmed fish were all significantly higher than those in the wild equivalent （P〈0.05）. Compared to the FAO/WHO recommended reference values, the ratios of TEAA/ TAA （39.84%o-40.33%） were comparable to 40% and TEAA / TNEAA （66.22%-67.60%） were above 60%. Fatty acid profiles in both farmed and wild C. mongolicus were dominated by monounsaturated fatty acid （MUFA）, with farmed fish contained much more MUFA content compared to wild counterpart （P〈0.05）. Notably, wild fish exhibited significantly higher levels of total polyunsaturated fatty acid （PUFA） including eicosapentaenoic acid （EPA） and docosahexaenoic acid （DHA） than fanned fish （P〈0.05）. The EPA （C20：503） and linoleic acid （C18：206） were the predominant PUFA in wild and farmed C. mongolicus, respectively. Moreover, farmed fish displayed an overall lower toxic element levels （As, Cd, Pb and Hg） in comparison with wild fish, and both were far lower than the established limit standard. In conclusion, our results suggest that the nutritional quality of fanned C. mongolicus was inferior to their wild counterpart with respect to fatty acids nutrition, and therefore further studies should focus on the improving C. mongolicus diet in order to enhance the overall nutritional composition.

Induced nest spawning and artificial hatching of the fertilized eggs of mudskipper, Boleophthalmus pectinirostris

In this study, nest spawning was successfully induced by exogenous hormone injections and seawater flow stimulation, and optimum condition for hatching fertilized eggs of burrow fish mudskipper, Boleophthalmus pectinirostris, was searched. Apart from spawning inside the nests, females also spawned outside the nests. The percentages of spawned nests were 8.0% to 24.2%. Most eggs were observed adhered to the inner wall of the top half of the nest. Fertilization rates of the nest-spawned eggs varied from 17.3% to 80.8%. Females could spawn after being artificially confined inside the nests with males at ratios of 1:1 or 1:2, but the spawned eggs were not fertilized. Mean hatching rates of artificially fertilized eggs incubated in round plastic buckets were 32.7%-70.6%, and in the net cages, were 4.2%-20.5%, respectively. Mean hatching rates of nest- fertilized eggs incubated in the round plastic buckets were 33.6%-76.3%, and in the net cages, were 5.9%-25.2%. Results showed that round bucket incubation was the best way for hatching fertilized eggs of mudskipper. Keeping the hatching seawater flowing is an important way for increasing the hatching rates of the mudskipper fertilized eggs.

Identification of wild and farmed broadhead catfish (Clarias macrocephalus Günther,1864) based on morphometry,digestive indexes and flesh quality

Wild and farmed fish generally dif fer in their nutritional composition. In this study, adult wild and farmed broadhead catfish( Clarias macrocephalus Günther, 1864) were collected and were assessed for various characteristics, namely morphometrics, digestive indexes, and flesh quality. The morphometrics(standard length, body depth, eye width, fin height and tentacle length) and the digestive indexes(intestosomatic index, digestosomatic index, perivisceral fat index and activities of pepsin and lipase) diff ered significantly between the groups(P <0.05) and can be used to distinguish wild fish from farmed fish. In terms of protein synthesis capacity and color, the flesh quality was similar between the groups. However, radical scavenging activities and reducing power were significantly higher in the wild fish than in the farmraised group. The thermal transition characteristics of sarcoplasmic proteins, as well as myosin denaturation enthalpy and fatty acid profiles(C18:2 n6, C20:0, C22:1 n9, C24:0, Σpolyunsaturated fatty acids, and Σn–6) also exhibited potential to enable calls about the fish origin. The proximate chemical composition of whole body did not diff er between the two fish populations. Our findings suggest bioindicators, in terms of morphometrics, digestive indexes and flesh quality, that can be used to identify the origin of fish for forensic purposes, of for conservation biology of this near threatened species. The new nutritional information may be of interest to marketing, consumers, and has a connection to nutritional eff ects on human health.

Relationship between trawl selectivity and fish body size in a simulated population

Trawl is a main fishing gear in Chinese fishery,capturing large fish and letting small ones at large.However,long-term use of trawl would result in changes of phenotypic traits of the fish stocks,such as smaller size-at-age and earlier age-at-maturation.In this study,we simulated a fish population with size characteristics of trawl fishing and the population produces one generation of offspring and lives for one year,used trawl to exploit the simulated fish population,and captured individuals by body size.We evaluated the impact of the changes on selectivity parameters,such as selective range and the length at 50% retention.Under fishing pressure,we specified the selectivity parameters,and determined that smaller selection rates and greater length at 50% retention were associated with an increased tendency towards miniaturization.

Phosphorus budget of redeye mullet (Liza haematocheila T. & S.) under graded feeding levels

Experiment on phosphorus budget of redeye mullet (Liza haematocheila T. & S.) was con- ducted at water temperature 21℃ and salinity 33. The results showed that the growth phosphorus (phosphorus that allocated into growth, GP) increased from –30.84% to 15.83% by feeding on graded amount of diets (starvation, 1%, 2%, 3%, 4% body weight and satiation). The GP linearly increased with feeding levels (FL) as GP (mg) =–0.785 + 0.604 FL, and at satiation the relationship between GP and body weight (BW) was GP (mg) = 1.5991 BW 0.768 5. In the budget, IP (intake phosphorus) = GP + FP (faecal phosphorus) + EP (excretion phosphorus). FP showed an irregular tendency with different feeding levels, and EP decreased with increasing feeding levels but rebound at satiation. The P budget at satiation was 100IP = 15.84 GP + 64.62 FP + 19.55 EP.

Optimum Fish for Fish Glue Processing for Fish Skin Value Added and the Glue Character

Fish glue is the collagen from scale skin and bone of fish. It is known for value added product from fish processing and the adhesive agent for wood paper book binding etc. This work was aimed with the method to produce fish glue from fish skin through representing optimum fish type and its glue character by study on standard method for fish glue processing （using Oreochromis niloticus skin as the model）, optimum fish type and characterization of the glue from optimum fish skin. Soaking fish skin in 0.1 N NaOH for 6 h and changed it every 3 h for pretreatment before acid extraction with 0.5 M acetic acid was the optimum condition for the standard processing. Among 20 types （O. niloticus, Oreochromis sp., Nemipterus sp., Psettodes erumei, Epiephelus malabaricus, Sphyraena obstsata, Channa striata, Xenentodon cancila, Barbonymus gonionotus, Liza vaigiensis, Anabas testudineus, Chanos chanos, Micronema bleekeri, Thunnus tonggol, Rastrelliger brachysom, Epinephelus lanceolatus, Lutjanus lineolatus, Pomadasys hasta, Selar crumenophthalmus and Sardaorentalis sp.）, Chanos chanos was an appropriate type for glue production. Fat, protein, carbohydrate, moisture, pH and viscosity of Chanos chanos glue were 0.32%, 4.23%, 83.8%, 11.56%, 3.35, 4,978.33-8,180 cp, respectively. The glue was collagen type I which was composed ofal （148 kDa） and a2 （129 kDa） chain and could bind paper, wood and foam sheet.

Clean and Safe Supply of Fish and Shellfish to Clear the HACCP Regulation by Use of Clean and Cold Deep Ocean Water in Rausu,Hokkaido,Japan

For the supply of fish and shellfish to consumers in fresh condition, clean handling after catch from the sea is essential. According to HACCP （Hazard Analysis and Critical Control Points）, it is important to meet such requirement by keeping fish and shellfish under a certain low temperature and clean conditions after catching. The deep ocean water （DOW） characterized by low temperature and cleanliness has been chosen for fish and shellfish handlings, particularly for salmon, cod, and sea urchin in Town ＇Rausu＇ in Hokkaido, Japan. DOW below 2.9℃ of an amount of nearly 5 000 m^3 is planned to be pumped up every day from a depth of about 350 m, and temporarily stored in a large simulated tank on land. DOW is then supplied to fish boats through hydrants distributed throughout the harbor and used for keeping salmon in clean and cold conditions. Ice made from DOW is also used for lowering temperature if necessary. DOW and ice made from DOW are also used during the transportation of fish and shellfish. The entire system is scheduled to be completed by the summer of 2005.

Integrated Water Resources Management for Pond in Bistrica E Pejes

In this century of crisis in water and energy the problem of water resources development is very crucial, especially in countries like Kosova with relatively scarce water resources. In this context the use of water for the production of hydro-energy is essential. Actually the energetic system of Kosova is based on thermo-energy, so the use of water resources for the production of hydro energy will increase further the energy production of the country. On the other hand, a master plan of multiple use of water resources, based on the principle of integrated and sustainable management, will insure better services for other users of the country. There are four basins in Kosovo： basin of the Drini i Bardhe River, basin of Ibar River, basin of Morava e Bing^s and Lepenci Rivers. The watershed of Bistrica e Pejes belongs to the basin of Drini i Bardhe, which belongs to the Adriatic Sea catchment. It has an admirable capacity therefore should be treated as a complex capacity, in which important economic components of water can be introduced such as： drinking water supply, water for irrigation in both sides of valley, fish economy and recreation, hydro-energy etc..