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1.
Abstract. Larvae and juveniles of two species of Coregouns sp. were immersed in tetracycline (TC) solutions (200–800)mg/1) and fluorescent marks in the otoliths from fish were identified under a UV-light microscope. Whitefish. Coregonus Iavaretus (L.). juveniles (average weight 191 mg) immersed in TC solution retained their marking until the 127th day, hut 40% of the population lost their TC marking after wintering. Whitefish and peled. C. peled Gmelin, larvae retained TC marking from the TC solution (400 mg/1) if water temperature was higher than 5°C, Whitefish juveniles retained clear marking in the otolith after 120 days of post-immersion rearing. Peled larvae immersed in TC solution were grown in a pond and the fluorescent otolith centre of 55·4-g fish was well visible after processing. Nearly 100% of peled larvae grown for 176 days can he identified based on fluoresceent marks observed under a UV-lighl microscope. 相似文献
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This experiment, designed for the first time in the Middle East region to sustain Coregonus lavaretus production, examined the efficacy of a live organism ( Brachionus plicatilis ), an artificial diet (48% crude protein) and a mixed feed for the first 3 month of rearing fry. Nine rearing cages were floated on the surface of a natural pond supplied with hyporheic-zone river water, each containing 150 numbers of white fish fry, where they were treated with each of the three diets in triplicates. The fry were fed eight times daily starting at the onset of exogenous feeding. Results showed that fry utilized live organisms more efficiently than the artificial and mixed diets. Rotifer-fed group consistently showed higher growth rate during the entire experiment. Length increment (29.6 mm), weight gain (572.3 mg) after 12 weeks of feeding were higher ( P < 0.05) in this group. Also, their mean weekly specific growth rate (4.97% day−1 ) was the highest and feed conversion rate (2.97) was the lowest among all treatments. Survival rates of the fry declined from 75% to 61.4%, from 74.3 to 45.8% and from 72.7 to 54.5% for live feed, mixed diet and artificial diet, respectively. 相似文献
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Steven A. Pothoven 《Ecology of Freshwater Fish》2020,29(1):103-111
A shift towards oligotrophic conditions in Lake Michigan has led to concern that altered trophic pathways are leading to lower early life survival and recruitment for Lake Whitefish (Coregonus clupeaformis). This study evaluated ontogenetic shifts in age-0 Lake Whitefish diets and evaluated how feeding ecology and the amount of food eaten varied with prey abundance and composition at a site in southeastern Lake Michigan during 2014–2017. Although prey densities varied among years, cyclopoid copepods were overall the most abundant prey available. In turn, cyclopoids were the predominant prey item in diets each year, particularly for the smallest larval Lake Whitefish. However, there was a tendency for the importance of cyclopoids to decline somewhat in each diet index as fish grew and other prey such as calanoid copepods, Bosminidae, Daphniidae and/or chironomids increased in importance. High zooplankton abundance, especially high cyclopoid abundance, available to the small size groups of Lake Whitefish (<21 mm) in 2014 was associated with high food mass/fish, high number of zooplankton eaten/fish, and low incidence of empty stomachs compared with 2015–2017. As fish grew, the impact of food abundance on prey consumption diminished somewhat, indicating that the relationship between fish feeding ecology and the prey environment can change quickly with fish size during the early life period. 相似文献
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3种白鲑线粒体细胞色素b和16S rRNA基因片段序列分析 总被引：6，自引：0，他引：6
对黑龙江水域的乌苏里白鲑(Coregonus ussuriensis)和由俄罗斯引种的贝加尔凹目白鲑(C.autumnalis migrato-rius)和高白鲑(C.peled)的线粒体细胞色素b(Cytb)和16S rRNA基因片段进行了扩增和序列测定,分析比较了3种白鲑间的序列差异。在402 bp的Cytb基因片段中,3个乌苏里白鲑个体中出现了2种单倍型,种内个体间有2个碱基的差异,而贝加尔凹目白鲑和高白鲑的个体各出现1种单倍型;在577 bp的16S rRNA基因片段中,3个乌苏里白鲑个体出现了2种单倍型,种内个体间存在1个碱基的差异,而贝加尔凹目白鲑和高白鲑2个种的序列完全相同。研究结果表明,Cytb基因适用于白鲑的分子系统发育研究。基于Cytb基因片段序列,利用Kimura-2模型构建的NJ树表明:乌苏里白鲑与贝加尔凹目白鲑亲缘关系较近;乌苏里白鲑与贝加尔凹目白鲑和高白鲑的分歧时间分别约为62.5万年和152万年,在更新世。[中国水产科学,2007,14(1):8-14] 相似文献
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The effect of water oxygen saturation on growth and haematological profile of juvenile peled Coregonus peled (Gmelin) 
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下载免费PDF全文 Jan Matousek Marketa Prokesova Katsiaryna Novikava Roman Sebesta Eliska Zuskova Vlastimil Stejskal 《Aquaculture Research》2017,48(10):5411-5417
The effect of varying oxygen saturation regimes on growth and haematological profiles of peled Coregonus peled was investigated on fish of initial age 90 days post hatching. Eighty‐five juveniles per group (initial body weight 3.09 ± 0.80 g) were submitted to a 63‐day experiment with one of four water saturation regimes: normoxia (NORm, 80%–90%), hypoxia (HYPo, 50%–60%), hyperoxia (HYPe, 150%–160%) and intermittent hyperoxia (iHYPe, 150%–160% ‐ 80%–90%). Survival rate in NORm, HYPe and iHYPe ranged from 96.3 ± 2.1% to 97.7 ± 2.7, but survival 87.5 ± 3.0 was significantly lower in the HYPo group. No differences were observed in feed conversion ratio. The highest final body weight of 18.2 ± 4.6 g and a specific growth rate of 2.81 ± 0.01%/day were seen in the NORm group. Significant differences were found in haemoglobin concentration with increased saturation. The fish had lower haemoglobin 55.00 ± 5.72 and 51.35 ± 10.89 g/L in treatments HYPe, iHYPe with compared to the normoxia (64.22 ± 5.78 g/L). Haematocrit was similar in the groups HYPo, NORm and iHYPe (0.55 ± 0.04, 0.58 ± 0.05 and 0.54 ± 0.09) with the exception of HYPe, which was significantly lower (0.48 ± 0.06). Significantly lower count of erythrocyte was observed in iHYPe group (0.88 ± 0.20) with compared to the normoxia (1.06 ± 0.13). The supersaturation level was not associated with effects on growth and survival, and adding oxygen is not recommended for intensive rearing of peled. The results showed normoxia oxygen level to be the most suitable conditions for peled. 相似文献
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N. Papandroulakis M. Kentouri E. Maingot P. Divanach 《Aquaculture International》2004,12(4-5):345-355
Species diversification is today considered as a major issue for the sustainable development of the Mediterranean aquaculture. For successful propagation of any species however, larval rearing is considered a bottleneck and therefore the development of appropriate tools is essential. Mesocosm is a semi-intensive technology that facilitates larval rearing of several species integrating principles of both intensive and extensive aquaculture, which solves biological problems and many of their technical, human and economical consequences. The extensive (and now even the semi-extensive) strategy is used in the most critical segments of the rearing process during the early developmental stages, when larvae are still extremely weak, sensitive to intensive environment, easily stressed and difficult to feed. The intensive strategy is used as soon as larvae are considered mature enough to be reared easily using classical methods. The technology was used for the rearing of two species, with potential for aquaculture, the sharpsnout seabream (Diplodus puntazzo) and the white seabream (Diplodus sargus sargus). Three groups of each species were monitored for a period of 50–70 days post hatching. Survival for both species was about 54% at the end of the trials. Sharpsnout seabream larvae reached 19.6 ± 0.9 mm total length and 107.2 ± 31.9 mg body weight 50 days post hatching. White seabream larvae 60 days post hatching reached 32.7 ± 2.7 mm total length and 450 ± 70 mg body weight. In order to verify the economical viability of the technology, the individual production cost for each species was estimated and reached ¢0.027 for white seabream and ¢0.043 for sharpsnout seabream. Results indicate the reliability of the technology for the larval rearing of the two species. 相似文献
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微粒粘合饲料饲养鲤鱼苗的试验 总被引：3，自引：0，他引：3
要用自制的微粒粘合饲料及浮游动物进行了鲤鱼苗的对比饲养试验，经１５天饲养，试验组和对照组鲤鱼苗的平均增重分别为２０．００ｍｇ和１１．４２ｍｇ；生长比速分别为１５．３４和１１．６０；成活率分别为７５．００％和８３．８４％。 相似文献
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The paper presents the results of observations on gonad development in whitefish (Coregonus lavaretus L.) in the fourth year of culture in illuminated like cages. Whitefish ovaries attained stage III of maturity. Stage IV of maturity was attained by only a few individual females. Disturbances in the development of the ovary were observed, consisting of asynchronous growth of the oocytes, their partial resorption, and delayed trophoplasmatic growth. Development of male gonads was also disturbed. Different males matured at different times, and their testes were in different stages of maturity. Fishes did not attain sexual maturity by the end of the fourth year of cage culture, so that no spawning could have taken place. 相似文献
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1. A static life table for Loch Lomond powan, Coregonus lavaretus (L.) has been constructed from data obtained during 1980–1988, as a basis for monitoring any changes in the population which may ensue from exploitation of the Loch. 2. Mortality was 99.95% during the first year of life, and adult mortality highest at 5–6 years. 3. Average fecundity was 20.7 ova mm?1 fork length. 4. Mortality and fecundity have not changed in 25 years. 5. It is not yet possible to assess the effect of the recent introduction of ruffe, Gymnocephalus cernuus (L.) into Loch Lomond, but their effect on recruitment into the vulnerable 0–1 year-class may be critical. 相似文献
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Data from 2 years of experimentation on rearing of coregonid larvae are presented. Control fish were fed live Artemia nauplii and small cladocerans and reached 188 mg and 64 mg in 1983 and 1984, respectively. Growth of fish was considerably improved when they were fed dry diets at a water temperature of 18°C in 1984. Attractants (betaine, inosine and amino acids) added to dry diets had no significant effect on fish growth and survival. In the 1984 experiment, fish fed dry diets reached 90–103 mg within 26 days and survival was 43–52%. The swim bladder was filled at a fish size of 25–35 mg and there was no difference in the morphology of the digestive tract between fish fed zooplankton and those fed dry diets. 相似文献
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Bartosz Mysłowski Remigiusz Panicz Jacek Sadowski Paulina Hofsoe 《Aquaculture International》2013,21(4):739-750
The aim of this study was to characterize whitefish and peled populations in Miedwie Lake by means of the genetic analysis of ND-1 (NADH dehydrogenase 1) gene and the ITS-1 (internal transcribed spacer 1) region in order to distinguish native forms from whitefish/peled hybrids. In the analysis, archival specimens of Coregonus lavaretus maraena from the Berlin Museum für Naturkunde were used. Genetic analysis performed with the aid of MEGA 4.0 software explicitly indicated that samples from Miedwie Lake belonged entirely to a native (rapidly growing) form of whitefish. Furthermore, the conducted research has also provided crucial information for a C. lavaretus management program for Miedwie Lake. 相似文献
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H. Hogendoorn 《Aquaculture (Amsterdam, Netherlands)》1980,21(3):233-241
The suitability of some common, natural and artificial feedstuffs for the rearing of fry of Clarias lazera (C. & V.) was investigated in 2 experiments.It was found that a dry trout starter, an experimental dry feed and dried inactive yeast were not suitable feeds for rearing C. lazera fry. Neither could ground Clarias fingerlings or frozen zooplankton be used. By contrast, frozen Artemia and especially live Artemia and live zooplankton gave good results. After 4 weeks the fish thus fed had attained an average weight of 0.3 to 1 g and survival ranged from 50 to 96%.Feeding in excess of satiation and feeding 24 h/day gave the fastest growth, although the differences in comparison with feeding Artemia or live zooplankton to satiation 4 times per day were not significant. The specific growth rate (% body weight) of these fish decreased from 68% at the start of the experiment to 9% after 28 days. 相似文献
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Pratap Chandra Das Joykrushna Jena Bibhudatta Mishra Bikash Kumar Pati 《Journal of the World Aquaculture Society》2012,43(1):128-134
Impact of aeration on growth of silver barb, Puntius gonionotus during fingerling rearing was studied through a 100‐d rearing experiment conducted in 18 concrete tanks of 50 m2 (10 × 5 × 1.2 m) size. Fry (0.74 ± 0.27 g, 35 ± 6 mm) were stocked in the experimental tanks at three stocking densities (25, 50, and 75 fry/m2) and were evaluated with and without provision of 6 h (2400–0600 h) of night time aeration. Aeration resulted in higher pH and dissolved oxygen regime and increased fingerling length and weight. The results suggest a rearing density of 75/m2 to be ideal for rearing fry to fingerling of this species when aeration is provided, whereas, under non‐aerated condition, rearing the fry to fingerling stage at 50/m2 was found advantageous over those at 25 and 75/m2. 相似文献
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K.J. Rana 《Aquaculture (Amsterdam, Netherlands)》1985,46(2):119-131
The variation in egg size within and between egg clutches of O. mossambicus, and the subsequent influence of mean egg size on growth, feeding incidence and survival of unfed fry were investigated.The individual egg sizes within 90% of the egg clutches examined were normally distributed and the coefficient of variation of egg size within clutches ranged from 7.4% to 15.4%. Fry emerging from the small, medium and large egg size groups reached their maximum length and weight at 9, 9 and 12 days after hatching, respectively. Maximum attainable fry length and weight were significantly correlated with egg size (r = 0.885 and 0.947, respectively, with P < 0.01).Egg size had little influence on the onset of feeding. Fry were capable of exogenous feeding within 6 to 7 days of hatching. Fry originating from small and medium egg size classes reached the point-of-no-return at 15–16 days after hatching compared to 21 days for fry from the large egg size class. The mean survival time (ST50) of fry on their yolk reserves was significantly correlated (r = 0.923; P < 0.01) with their original mean egg weight and ranged from 9.5 days for fry hatching from 0.91-mg eggs to 21 days for fry from 1.93-mg eggs. 相似文献
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2011年4月～6月,从湖北引进平均全长8mm,平均体重0．006g的匙吻鲟（Polyodon spathuk）水花50000尾,进行了大规格鱼种培育技术研究。苗种培育前期主要采用枝角类作为生物饵料,当鱼苗全长达到50mm时开始进行人工微颗粒配合饲料驯化,经一周左右驯化,鱼苗均可摄食微颗粒配合饲料。经过48d培育,鱼苗平均全长为186mm,平均体重为25．635g,存活率达57．8％,取得了较好的培育效果。 相似文献
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The effect of water temperature on growth parameters of intensively reared juvenile peled Coregonus peled 下载免费PDF全文
下载免费PDF全文 Jan Matousek Vlastimil Stejskal Marketa Prokesova Jan Kouril 《Aquaculture Research》2017,48(4):1877-1884
The effect of water temperature on growth and food intake of juvenile peled Coregonus peled was tested with specimens of initial age 75 days and 230 days posthatching (dph). The 75‐day group (initial body weight 0.6 ± 0.04 g) were reared for 63 days and 230‐day group (initial body weight 13.75 ± 2.93 g) for 42 days at temperatures of 13, 16, 19, 22 and 25°C under 12:12 L:D photoperiod. The optimal temperature range for the 75 dph fish was found to be 19–22°C. The fish reached final mean weight of 9.7 ± 2.5 g at 19°C and 9.0 ± 2.7 g at 22°C. Final mean weight of 230 dph fish did not differ significantly among temperature groups. Mortality increased at higher temperatures, with the critical temperature of 25°C for both age groups. Maximum food intake (19.0 ± 4.7, 18.8 ± 5.2, 18.6 ± 4.6 g kg?1biomass) was observed in groups reared at temperatures of 19, 22 and 25°C with no significant differences among groups. 相似文献
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Combined effect of weaning time and co‐feeding duration on growth and survival of peled Coregonus peled (Gmelin) larvae 下载免费PDF全文
下载免费PDF全文 V. Stejskal J. Matousek M. Prokesova P. Podhorec R. Sebesta B. Drozd 《Aquaculture Nutrition》2018,24(1):434-441
The study investigated the combined effect of weaning from live feed to a commercial dry pellet at 10, 15, 20, 25 or 30 days posthatching (dph) and co‐feeding for 1, 3 or 6 days on survival and growth of Coregonus peled larvae. Additional groups fed only live Artemia sp. nauplii (ART), and only Biomar LARVIVA ProWean 100 (DRY) were included. A final survival rate of 66.4%–85.5% was observed in groups weaned after 20 dph. Final body weight (BW) and total length (TL) were significantly lower in groups weaned at 10 and 15 dph, regardless of the duration of co‐feeding. Larvae reached 29–37 mg BW and TL of 17.7–19.0 mm in groups weaned at 20, 25 and 30 dph. The recommended minimum duration of feeding with live food, based on these results, is 20 days. Based on the significantly higher yield of larvae weaned after 20 dph irrespective of co‐feeding duration, it can be concluded that abrupt weaning to dry food after 20 days of feeding with live prey can provide adequate production while reducing the effort and costs associated with live feed. 相似文献