不同开口饵料对克氏原螯虾幼虾发育及消化酶活性的影响

实验采用丰年虫无节幼体、草鱼鱼糜、水蚯蚓、1号人工配合饲料和2号人工配合饲料为克氏原螯虾的开口饵料,观察幼虾存活率和生长情况。经过40d的培育,对幼虾的胃蛋白酶、胰蛋白酶、淀粉酶和脂肪酶的活力进行测定。结果表明：投喂丰年虫无节幼体的实验组幼虾存活率最高,为75,增重率和增长率也最大,分别为4746.00和171.00。幼虾的胃蛋白酶活性与投喂的饵料密切相关,投喂丰年虫无节幼体组幼虾的胃蛋白酶和胰蛋白酶活性分别为2.18U/mgprot和0.96U/mgprot,极显著高于投喂草鱼鱼糜实验组。实验的5种开口饵料中,丰年虫无节幼体是克氏原螯虾幼虾的最佳开口饵料。摄食丰年虫无节幼体可能提高了主要消化酶的活性,从而促进了克氏原螯虾幼体的生长。     

Substrate-SDS-PAGE determination of protease activity through larval development in sea bream

Identification of alkaline proteases produced during larval stages of gilthead sea bream, Sparus aurata was achieved using SDS-PAGE and specific inhibitors. Such techniques were also applied to determine proteases existing in rotifers, Brachionus plicatilis, and Artemia nauplii, which are used as live food for these larvae, as well as proteases of adult fish. The results show a great prominence of trypsin-like proteases during the 4 weeks after hatching, but the number of enzyme species was reduced in adult fish. Alkaline proteases present in the rotifers and Artemia showed clear differences when compared with those of the larvae and were not detected in extracts obtained from fed larvae. The results obtained provide information about the role of exogenous enzymes in larval feeding of sea bream.     

State of the Art of Asian Seabass Lates calcarifer Larviculture

Innovative techniques opened new perspectives in the larviculture of the Asian seabass in the 1980s. Induced spawning maximized egg production while sperm preservation reduced the problem of male brood-stock supply. Studies of biometric characteristics of the fish larvae resulted in improved feeding strategies with live food. This in turn permitted a more rational use of expensive Artemia nauplii. Nutritional enhancement of the highly unsaturated fatty acid (HUFA) composition of the live food resulted in significant improvement of survival and physiological condition of the larvae at metamorphosis. A salinity stress test enabled the evaluation of the larvae's physiological status and estimation of their HUFA-requirements during the hatchery and pre-nursery phase.     

Evaluation of a spray-dried artificial diet for larval culture of freshwater prawn, Macrobrachium rosenbergii, and striped bass, Morone saxatilis

Larvae of the freshwater prawn, Macrobrachium rosenbergii (De Man), and the striped bass, Morone saxatilis (Walbaum), were fed artificial diets manufactured by a spray-drying process or live Artemia nauplii , separately or in various combinations. Spray-dried diets were neutrally buoyant, water stable (low protein leaching rate), and were satisfactorily consumed as verified by the observation of full guts after feeding. Survival and growth of larvae fed live Artemia nauplii was significantly greater than those of larvae fed spray-dried diets. Lowest survival and growth rates were observed when larvae were fed artificial diets exclusively from the onset of exogenous feeding. Survival rates were positively related to the duration of feeding live Artemia nauplii before weaning to artificial diets. The poor performance associated with spray-dried artificial diets may be the result of the digestive capabilities of the larvae of caridean shrimp and striped bass being insufficient to process compact, dense particles.     

New perspectives on aquarium fish trade

ABSTRACT:   Since the 1990s, the international market for importing aquarium fish is suspicious of stock coming from South-East Asia. Fish catches are still executed with cyanide-based toxic products. In the present paper, the potential of the French Polynesian Islands to develop a marine aquarium fish business with a new approach is explored. Coral reef fish are captured at the larval stage with crest nets, then larvae are reared in aquaria before being put on the world ornamental fish market. This approach offers several advantages: (i) larvae are captured with a passive system placed on the reef crest (crest net) that does not destroy the environment and limits the stress on collected larvae; (ii) larvae are then put into farmed basins that allow them to be controlled sanitarily; and (iii) larvae are weaned at the farm and fed rapidly with artificial food. This method increases survival rates as it eliminates the food acclimatization problem of fish captured at adult stage (main cause of fish mortality in aquaria). Overall, reared larvae will constitute a new product in terms of species, sizes and quality of ornamental fish on the aquarium market.     

Ovoviviparously produced Artemia nauplii are a suitable live food source for the larvae of the African catfish (Clarias gariepinus: Burchell, 1822)

Brine shrimp Artemia, the most common live food organism used in larviculture, can reproduce either oviparously (production of dormant cysts) or ovoviviparously (direct production of nauplii), depending on environmental conditions. Ovoviviparous Artemia nauplii have seldom been considered as a source of live food in aquaculture, partly due to the convenience and the developed techniques associated with the production and use of the dormant cysts. In many countries in Africa, however, hatchery managers do not have access to a reliable supply of affordable good quality cysts. In this study, we therefore demonstrated the potential of a system designed for the continuous ovoviviparous production of nauplii at low salinity, using Great Salt Lake Artemia franciscana and micronized agricultural material as feed. The suitability of the produced nauplii was tested by feeding them directly to Clarias gariepinus larvae in comparison with oviparous nauplii and decapsulated cysts. Higher survival (100%), better protein efficiency ratio (2.6 ± 0.1) and food conversion ratio (1.0 ± 0.1) was observed in larvae fed with the ovoviviparous nauplii (p < 0.05). Overall, we conclude that the ovoviviparous nauplii could serve as an alternative live food for larval fish. If optimized, the system could be validated for integration in hatcheries.     

Use of decapsulated Artemia cysts in ornamental fish culture

Two series of feeding experiments were conducted to study the feasibility of using decapsulated Artemia cysts for direct feeding to ornamental fish. The first series evaluated the dietary values of the dried and the brine decapsulated Artemia cysts against two conventional live feeds, Artemia nauplii and Moina for adults and fry of the guppy, Poecilia reticulata Peters. In the second series, brine cysts were used for feeding to fry of four other important ornamental fish species, viz. platy, Xiphophorus maculatus (Günther), swordtail, X. helleri (Heckel), molly, P. sphenops Cuvier & Valenciennes and black neon tetra, Hyphessobrycon herbertaxelrodi Géry, and the results were compared with those fed Moina. Evaluation of the performance of the fish fed the various diets was based on stress resistance, growth and survival of the fish. Our findings indicated that decapsulated cysts could be used as a substitute for Artemia nauplii or Moina in freshwater ornamental fish culture. Apart from being a hygienic off‐the‐shelf feed, the direct use of the cysts also signifies a new area of application for low‐hatch cysts in the ornamental fish industry, with concomitant saving in feed costs.     

Effects of Food and Temperature on Survival and Development in the Peppermint Shrimp Lysmata wurdemanni

Abstract— The effects of four kinds of foods ( Artemia nauplii, rotifer, and microalgae Chaetoceros gracilis and Isochrysis galbana ) and four temperature regimes on survival and development of larval Lysmata wurdemanni , a marine ornamental shrimp, were determined. The larvae fed with Chaetoceros or Isochrysis only survived for a maximum of 17 d, before developing to zoea IV. The survivorship of the larvae fed with Artemia nauplii or rotifer from zoea II to post-larvae was 66.7% and 68.9%. respectively, without significant difference ( P > 0.05). But larvae fed with Artemia nauplii grew significantly ( P < 0.05) faster than those fed with rotifer. Larvae fed with Artemia nauplii reached postlarvae in 29–32 d, compared with 32–36 d in the rotifer treatment. Artemia nauplii are also suitable food for the postlarvae and juveniles of L. wurdemanni . The 30 postlarvae fed on Artemia nauplii all survived to reach sexual maturity in 50 to 70 d, growing from about 7 to 28 mm in total length. The effects of four temperature regimes on larval development of L. wurdemanni was also investigated. The duration (mean ± SD d) to the postlarvae at temperatures of 26 C (37.4 ± 5.4) and of 26–30 C daily (40.2 ± 5.8) was significantly ( P < 0.05) longer than that at 28.5 C (29.3 ± 4.8) and at 27–29 C daily (28.7 ± 3.5).     

Effects of Rotifer and Artemia Fatty-Acid Enrichment on Survival, Growth and Pigmentation of Summer Flounder Paralichthys dentatus Larvae

Abstract— Enrichment of live food for marine fish larvae with highly unsaturated fatty acids (HUFA) has been shown to improve survival, growth and stress resistance in many species and to decrease pigmentation abnormalities in flatfish. In order to aid the developing summer flounder industry, we conducted an experiment in which summer flounder larvae were fed diets differing in HUFA composition to determine whether enrichment with a commercially available product would increase survival and growth and reduce the incidence of abnormal pigmentation. We also examined whether growing unenriched rotifers on different species of algae would affect the survival, growth and pigmentation of the flounder larvae to which they were fed. Growth of summer flounder larvae was significantly better when they were fed HUFA-enriched Mtifers and Artemia rather than unenriched and, among the unenriched treatments, was significantly better when the larvae were fed rotifers raised on Isochrysis galbana rather than on Tetraselmis suecica . The percentage of larvae that failed to complete metamorphosis during the experiment was significantly higher in the unenriched treatments than in the enriched treatments. Neither survival nor percentage of individuals with pigmentation abnormalities were significantly different among the treatments.     

新加坡观赏鱼产业发展的机遇与挑战

新加坡是一个小岛国,农业用地及用于养鱼的海域面积均很有限。但新加坡观赏鱼产业相当独特和成功,是世界第一观赏鱼出口国,向80多个国家出售超过1 000种鱼类,2016年的年收入达到4 300万美元。该产业的成功主要源于其在许可证颁发,生物安全控制,养殖,包装,运输和疾病控制等各方面所具有的独特特征。新加坡正在努力驯养和培育许多高价值的海洋物种和新的淡水物种,并开发新型的循环水养殖系统。上游研究侧重于开发和使用基因组工具来培育新品种并维持野外种类的遗传多样性。但由于养殖鱼类的空间有限,邻国竞争激烈,该行业面临诸多挑战,其市场份额正在减少。在这篇综述中,我们将总结新加坡观赏鱼产业的现状和发展,讨论其面临的挑战,并提出保持该产业领先地位的建议。     

Larval rearing of the shrimps Metapenaeus ensis (de Haan) and Penaeus chinensis (Osbeck) on artificial feed

Abstract. This study explored the feasibility of completely replacing live foods with an artificial diet for rearing the larvae of Metapenaeus ensis (de Haan) and Penaeus chinensis (Osbeck). The artificial diets tested were a microparticulate diet developed at the Centre Océanologique du Pacifique, Tahiti, and Artificial Plankton B.P. (Nippai Shrimp Feed Inc., Japan). Survival and development of shrimp were assessed in 1-l cones stocked with 100 nauplius V-VI or protozoea I larvae. Live feeds of the diatom Chaetoceros gracilis and Artemia nauplii served as controls. Whereas the larvae could be reared to post-larvae with artificial diets alone, the highest survival and development rates were always obtained with live foods. Larvae fed with artificial diets had retarded development and their survival to post-larvae was always lower than those fed live foods. Total replacement of live foods with artificial diets resulted in a reduction in the body length of post-larvae I in P.chinensis . Supplementing Artificial Plankton B.P. with Artemia nauplii enhanced survival and development in this species. It was concluded that the two artificial diets are not satisfactory complete substitutes for live foods in raising the two penaeids but can be used as a convenient supplement when algal diet is limited.     

Heat treatment affects protein quality and protease activity in decapsulated cysts of Artemia when used as starter food for larvae of African catfish Clarias gariepinus (Burchell)

Decapsulated cysts of Artemia subjected to different heat treatments (40, 60, 80 and 96 °C) were fed to African catfish Clarias gariepinus larvae. Heated cysts, untreated cysts and live Artemia nauplii as control constituted the experimental diets. Protein denaturation and solubility, total alkaline protease and specific trypsin activities in the cyst diets were evaluated. The growth of catfish larvae and the proteolytic activity of larval samples during development were also determined. Heat treatment of cysts increased protein denaturation and decreased protein solubility. The protease activity in the cyst diets decreased with higher heating temperatures. The growth of catfish larvae differed according to the diet; higher fish growth was achieved with nauplii and cysts heated at 40 °C. The digestive enzyme activity in larval samples remained similar in all dietary treatments during larval development. The quality of food protein and the way this protein is processed might be more important for successful larval growth than exogenous enzyme supply.     

国内外海水观赏鱼产业与研究现状

海水观赏鱼贸易是海洋水族馆贸易行业的重要部分,是一项价值十几亿美元的产业,每年交易量达数百万尾,且需求量逐年上升,但由于严重依赖野生资源捕捞而使该行业饱受争议。目前,90%~95%的海水观赏鱼由野生捕捞获得,在已知的数千种珊瑚礁鱼类中,有一半以上在缺乏或无监测情况下进行贸易,自然资源面临严重威胁。观赏性水产从业者和消费者有责任保护野生捕获物种的可持续发展,海水观赏鱼的养殖被认为是一种保护野生资源的有效手段,但仍有许多技术问题阻碍其发展。文章结合相关数据和文献,概述了国际海水观赏鱼产业现状及最新研究进展,讨论了海水观赏鱼产业中存在的问题,并提出了一些可行的解决方案,旨在为中国海水观赏鱼产业发展提供一定的借鉴和参考。     

Nutrient requirements of ornamental fish

Although fish have been kept for more than three centuries as ornamentals, and the development of manufactured feed since 50 years ago has contributed to the tremendous growth of this hobby, nutrition of ornamental fish is based on extrapolation of results derived from food fishes under intensive farming conditions. Some research on nutrient (protein, minerals) requirements of growing freshwater ornamental species (live-bearers) in a production environment has been conducted, mainly in Singapore, with emphasis on the provision of live feed during the early stages of the life cycle. Protein requirements varied from around 30% dietary protein for growing omnivorous goldfish (Carassius auratus) to 50% for the carnivorous discus (Symphysodon aequifasciata). Whereas mineral (phosphorus, iron, magnesium, zinc) requirements have received some attention in the guppy (Poecilia reticulata), few researches have concentrated on vitamin requirements of ornamental species. Requirements for fatty acids have been conducted mainly on marine ornamentals (damselfish, seahorses), and accentuated the need for dietary supplementation of n-3 highly unsaturated fatty acids. Fish kept in public and home aquaria presents the problem of diversity of species in the same enclosure, each with its own specific requirements and needs. Maintenance energy levels of ornamental fish varied from 0.068 kJ per day for small neon tetras (Paracheirodon innesi) to 0.51 kJ per day for moonlight gouramis (Trichogaster microlepsis) kept at a water temperature of 26 °C. Research on nutrient requirements of ornamental fish urges for suitable measurements other than only growth rate in order to determine optimal dietary inclusion levels.     

Cofeeding of phospholipids to turbot Scophthalmus maximus L. larvae as a tool to reduce live food consumption

The possible benefits of feeding a formulated diet, together with Artemia , to first-feeding turbot larvae were investigated. Five dietary regimes were used: control ( Artemia only), cofeeding with a diet rich in phospholipid (PL) from bovine brain, cofeeding with a diet rich in free fatty acids (FFA) from the same source, cofeeding with a commercial diet (Lansy A2), and a formulated feed only (PL-rich diet). All treatments with artificial diets and the control treatment that received Artemia exclusively gave a similar survival rate of the fish at day 29. Cofeeding with artificial diets resulted in a lower growth rate than the control treatment. Cofeeding the larvae with PL-rich or FFA-rich diets did not affect the pigmentation or resistance to salt stress of the larvae. Complete substitution of Artemia by the phosholipid diets from day 20, however, resulted in severe stress and pigmentation problems. Cofeeding might have interesting features for application since it may reduce the amount and cost of live food and also offer to the fish larvae essential nutrients that are not contained in sufficient amounts in the (enriched) live food.     

First feeding of freshwater fish larvae with live feed versus compound diets: a meta-analysis

A meta-analysis of published results was used to quantify differences in mortality and growth of freshwater fish larvae when live feed was replaced by compound diets at first feeding. A mean relative risk of 2.4560 (95% confidence interval = 2.0879–2.8891), calculated with 75 observations from 47 studies conducted with 27 freshwater fish species according to a random effects model, indicated that larvae fed on compound diets have a 2.5 times higher chance to die than those fed on live feed. Compared to Artemia nauplii as sole live feed, compound diets were more effective (causing a lower mortality) when replacing zooplankton other than Artemia nauplii. A mean effect size (Hedges’ d) of −3.1813 (95% confidence interval = −3.8099 to −2.5527), calculated (random effects model) from 51 values determined in 33 studies with 21 fish species, represents the size of the negative effect that compound diets would have on growth of larvae. Numerical differences obtained in this study could be use to monitor future development of larval diets.     

不同饵料对3种西藏鱼类仔鱼生长及存活的影响

研究了卤虫无节幼体、专用仔鱼料、鳗鱼仔鱼料等3种不同饵料对西藏尖裸鲤(Oxygymnocypris stewartii)、异齿裂腹鱼(Schizothorax o'connori Lloyd)、拉萨裂腹鱼(Schizothorax waltoni Regan)等3种鱼类仔鱼生长和存活的影响。实验尖裸鲤、异齿裂腹鱼、拉萨裂腹鱼仔鱼的初始全长分别为(13.29±0.52)mm、(12.29±0.44)mm、(15.81±0.50)mm,实验周期分别为25 d、25 d、15 d。结果表明:与其他饵料组相比,投喂专用仔鱼料组,异齿裂腹鱼仔鱼和拉萨裂腹鱼仔鱼的平均全长、全长增加倍数以及存活率均高于其他各组,并有显著差异;尖裸鲤仔鱼的平均全长和全长增长倍数也高于其他各组,但存活率较投喂卤虫无节幼体低,并有显著差异。     

Food consumption and selectivity by larval yellowtail kingfish Seriola lalandi cultured at different live feed densities

Live food supply is a key factor contributing to the success of larval fish rearing. However, live food densities vary greatly between fish species and management protocols across fish hatcheries. The growth, survival, food selection and consumption of yellowtail kingfish larvae were examined at different regimes of live food supply in an attempt to identify a suitable live food feeding protocol for larval rearing in marine fish. This study was divided into two feeding phases: rotifer phase from 3 to 14 DPH (phase I) and Artemia nauplii phase from 15 to 22 DPH (phase II). In phase I, four rotifer densities (1, 10, 20 and 40 mL⁻¹) were used. In phase II, Artemia started at 0.8 nauplii mL⁻¹ on 15 DPH, and then the density of Artemia was daily incremented by 50%, 70%, 90% and 110%, respectively, in four treatments from 15 to 22 DPH. In phase I, rotifer density significantly affected larval growth, but not survival. By 7 DPH, the number of rotifers consumed by fish larvae reached 170–260 individuals, but did not significantly differ between rotifer densities. During cofeeding, fish larvae selected against Artemia nauplii by 10 DPH, but by 14 DPH Artemia nauplii became the preferred prey item by fish larvae exposed to the 10, 20 and 40 rotifers mL⁻¹. In phase II, both fish growth and survival were affected by Artemia densities. Fish daily consumption on Artemia by 20 DPH reached 500–600 individuals but did not significantly differ between prey densities. The result suggests that rotifer densities be offered at 20–40 mL⁻¹ before 6 DPH and 10–20 mL⁻¹ afterwards to support larval fish growth and survival. Likewise, Artemia is recommended at a daily increment of 90–110% of 0.8 mL⁻¹ from 15 to 22 DPH. This study proposes a management protocol to use appropriate type and quantity of live food to feed yellowtail kingfish larvae, which could be applicable to larval culture of other similar marine fish species.     

Application of Marine Foodfish Techniques in Marine Ornamental Aquaculture: Reproduction and Larval First Feeding

The long-term sustainability of the marine ornamental industry is being threatened by environmental pressures that are severely degrading the health of coral reef ecosystems. There is now a compelling need to practice resource conservation through the development of 'reef friendly' aquaculture technologies as an alternative to wild collection practices and to restore degraded wild populations. The commercial culture of marine ornamental finfish is very much in its infancy, but advances can be made more rapidly using insights from years of research and development with marine foodfish species. Many of the bottlenecks and constraints to developing marine ornamental fish culture are those now being addressed with the more challenging species of foodfish being attempted. The two key bottlenecks that currently limit expansion of the marine ornamental industry are the control of captive maturation and spawning and the identification of appropriate first-feed items for marine ornamental fish larvae. This paper highlights basic principles and recent achievements in marine foodfish culture that might be applicable to rapid development of controlled reproduction and propagation techniques for marine ornamental finfish.     

营养强化的轮虫、卤虫对牙鲆仔鱼的成活、生长及体脂肪酸组成的影响

用3种营养强化剂强化的轮虫和卤虫无节幼体投喂牙鲆仔鱼,研究牙鲆仔鱼的生长、成活、体脂肪酸的组成。结果表明:用强化的轮虫和卤虫无节幼体投喂牙鲆仔鱼,成活率、增重均显著高于对照组(p<0 01),其中V号强化剂的效果最好,成活率为29 34%,比对照组提高100%;增重倍数为217 90,比对照组提高68 61%;这是由于V号强化剂强化的卤虫无节幼体体内含有较多的AA的缘故,饵料中AA含量的提高,可以提高牙鲆仔鱼的成活率、促进其生长。牙鲆摄食强化过的轮虫、卤虫无节幼体后,其EPA、DHA、n-3HUFA、PUFA的含量随着饵料中含量的升高而升高,这也是牙鲆仔鱼生长速度和成活率提高的重要因素之一。