Effect of feeding level on growth and nutrient deposition in rainbow trout (Oncorhynchus mykiss Walbaum) growing from 150 to 600 g

The effects of feeding level on growth and energy partitioning were studied in rainbow trout growing from 150 to 600 g. Triplicate groups of fish (initial weight 158 g fish^?1) were fed a practical diet at various feeding levels (25%, 50%, 75% and 100% of near satiation) for 24 weeks at 8.5°C. The final body weights of fish were 235, 381, 526 and 621 g. Restricted feeding levels significantly reduced live weight gain. Feeding levels had less pronounced effects on feed efficiency ratio, which were 0.98, 1.08, 1.02 and 0.83, respectively, for the 25%, 50%, 75% and 100% feeding levels. The growth of fish fed to near satiation was accurately described by the thermal‐unit growth coefficient. The growth data also showed that the widely used specific growth rate was not an appropriate model. Fish fed at the lowest feeding level (25%), which represented a maintenance ration (energy gain was less than 2 kJ fish^?1 day^?1), showed positive protein deposition but negative lipid deposition. This indicates that fish fed a maintenance ration mobilize body lipid reserve to support protein deposition. The efficiency of energy for growth (k_g) was estimated to be 0.63. The factorial multiple regression approach estimated that the partial efficiencies of metabolizable energy utilization for protein deposition (k_p) and lipid deposition (k_f) were 0.63 and 0.72, and that maintenance energy requirement was about 19 kJ (kg BW^0.824)^?1, for rainbow trout held at 8.5°C.     

Growth and feed utilization of large size rainbow trout (Oncorhynchus mykiss) and Atlantic salmon (Salmo salar) reared in freshwater: diet and species effects, and responses over time

Four diets differing in crude protein/crude lipid concentrations (CP/CL), 570/200, 510/220, 460/240, 430/260 (g kg^?1 dry diet) were fed to near‐satiety to rainbow trout (initial body weight, IBW = 268 g, domestic strain) and Atlantic salmon (IBW = 456 g, wild strain) for 308 days to determine the effect of diets, species and fish size on efficiency of feed, nitrogen (N) and energy utilization. Within species, weight gain, feed efficiency (FE), and energy retention efficiency (ERE, E gain/E intake) were not affected by diet (P < 0.05). N retention efficiency (NRE, N gain/N intake) increased linearly (P < 0.05) with decreasing CP/CL for both species. NRE and FE were higher for salmon compared with trout. Whole body CP of salmon was significantly (P < 0.05) higher, and lipid significantly (P < 0.05) lower, than those of trout. There was a significant (P < 0.05) linear decrease in FE as fish grew, regardless of diet and species. NRE linearly decreased (P < 0.0001) and lipid to protein deposition ratio (LD/PD) increased (P < 0.05) as trout grew. NRE linearly increased (P < 0.05) while ERE and LD/PD linearly decreased (P < 0.05) as salmon grew. Salmon appeared to rely to a greater extent on non‐protein energy‐yielding nutrients to support cost of growth than did trout.     

河北省"十二五"渔业发展规划(摘要)

<正>"十二五"是河北渔业由传统渔业向现代渔业跨越的关键时期。为引领全省渔业经济全面协调可持续发展,根据国家和本省编制"十二五"规划的有关要求,立足河北渔业发展实际,在认真总结"十一五"渔业工作的基础上,制定本规划。1"十一五"渔业发展回顾     

紫红笛鲷人工繁殖及育苗技术研究报告

利用海水土池或网箱养殖三龄以上的紫红笛鲷成鱼,于催产前三个月进行强化培育。在水温达到 20.0℃以上的春、夏季,用绒毛膜促性腺激素(HCG)和释放激素(LRH-A_(2-3))进行催产,混合或单一使用,剂量视亲鱼性腺成熟度而定。受精卵在盐度27.9-33.5,水温26.5-30.5℃,pH8.2的水环境中经15-17h孵化。开口仔鱼在土池水温27.2-35.5℃.盐度:23.5-35.6.pH8.0-9.5的条件下,经28-30d培育.鱼体全长为2.5-3.2cm,仔鱼变态完全,成为幼鱼。     

Harnessing the potential for otolith microchemistry to foster the conservation of Amazonian fishes

1. Freshwater environments host roughly half of the world’s fish diversity, much of which is concentrated in large, tropical river systems such as the Amazon. Fishes are critical to ecosystem functioning in the Amazon River basin but face increasing human threats. The basic biology of these species, and particularly migratory behaviour, remains poorly studied, in part owing to the difficulty associated with conducting tagging studies in remote tropical regions.
2. Otolith microchemistry can circumvent logistical issues and is an increasingly important tool for studying fish life histories. However, this approach is still new in the Amazon, and its potential and limitations to inform fish conservation strategies remain unclear.
3. Here, otolith microchemistry studies in the Amazon are reviewed, highlighting current possibilities, and several key factors that limit its use as a conservation tool in the Amazon are discussed. These include the dearth of spatiotemporal elemental data, poor understanding of environment–fish–otolith pathways, and insufficient funding, facilities, and equipment.
4. A research initiative is proposed to harness the potential of this technique to support conservation in the Amazon. Key aspects of the proposal include recommendations for internal and external funding, which are critical to acquiring and maintaining technical staff, cutting-edge equipment, and facilities, as well as fostering regular scientific meetings and working groups. Meetings can facilitate a systematic approach to investigating environment–otolith pathways, broadening the chemical baseline for most Amazonian tributaries, and exploring potential valuable elements.
5. These outcomes are urgently needed to conserve biodiversity and ecosystem functioning in the Amazon, especially given threats such as widespread hydroelectric damming. The initiative proposed here could make otolith microchemistry an important, cost-effective tool to inform and foster conservation in the Amazon, and act as a template for other imperilled tropical river basins, such as the Mekong and the Congo.

     

振兴对虾产业的实施意见

<正>对虾养殖是河北省渔业的传统主导产业,在"十二五"加快推进现代渔业建设的新时期,我省必须紧紧抓住这一传统优势品种,采取更有力措施,进一步完善其产业技术体系,实现更好更快发展。1河北省对虾养殖业发展回顾及现状     

Biodiversity conservation in human-modified landscapes of Mesoamerica: Past, present and future

Mesoamerica provides a unique context for biodiversity conservation in managed landscapes because of its geography, history of human intervention, and present conservation and development initiatives. The long and narrow form of the Mesoamerican landmass, and its division by a central mountain range, has served as both a bridge and a barrier. Conservation efforts in Mesoamerica are unique for the emphasis they place on regional connectivity through the Mesoamerican Biological Corridor and on biodiversity conservation in managed landscapes. The emphasis on conservation in agricultural systems has fostered innovations in payment for ecosystem services, and provides novel insights on the functional role that biodiversity plays in the provisioning of ecosystem services. The increasing rate of economic development in the region and the advent of new payment for ecosystem service schemes have provided new opportunities for forest regeneration and restoration. However, the small scale of private landholdings and the diversity of land uses featured in the region, while contributing to biodiversity conservation due to their structural and floristic complexity, present challenges for biodiversity monitoring and management.     

建立健全科技人员服务企业行动长效机制的探讨

随着世界经济形势继续好转,我国经济也逐渐企稳回升。科技人员在使企业减轻危机,甚至摆脱经济危机中具有重要的作用。该文通过分析影响科技人员服务企业的各个主要因素,探讨建立健全科技人员服务企业的长效机制的一些做法。     

离体早熟梨芽休眠进程的影响因素研究

以早熟梨离体结果枝为试验材料,通过控制温度、光照条件以及喷施不同种类和浓度的生长调节剂生长调节物质来研究影响早熟梨芽休眠进程的因素。试验结果发现在25℃条件下在0.04%、0.08%的乙烯利和0.1mg/L和0.3ABAmg/L都能在一定时间内抑制萌芽,0.3mg/LIAA处理能促进萌芽,而0.6mg/LIAA和GA3处理效果不明显;而在15℃条件,所有处理的萌芽率都为0;试验结果还表明在1500Lx光照强度下光照时间对早熟梨芽休眠的影响效果不显著。     

FEEDING HABITS OF HAINAN ELDI''''S DEER

Hainan eldi's deer is a precious species of deer in the tropic zone,it is regardedas the first—class animal under protection in China.Based on all-year-round observation on thedeer's feeding habit in the reserve from 1985 to 1988,we discovered that Hainan eldi’s deer is aeuryphangous herbivore.They take various herbs as their main food and have fairly strongselectivity for woody plants,especially tending to eat the tender parts of plants and some fruits andflowers.Like other species of deer,they also like to lick the alkaline soil.This paper reports the re-search and evaluation on the feeding and choosing food characteristics of Hainan eldi’s deer,and onthe palatability of the main plants in the reserve.