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为研究腹腔注射Cd2+对黄金鲫血液生化指标的影响,试验将300尾健康黄金鲫随机分为4组,分别为对照K组、A组、B组和C组,其中Cd2+的注射浓度依次为0、1.25、2.50、3.75 mg/kg,测定注射后0、1、3、5、7 d时的血清超氧化物歧化酶(SOD)、酸性磷酸酶(ACP)、碱性磷酸酶(AKP)、过氧化氢酶(CAT)和丙二醛(MDA)的变化。结果表明,鱼体血液中各指标的变化与注射镉元素密切相关。与对照组相比,A组血清中SOD活力在前3天显著升高(P0.05),在第5、7天时差异不显著(P0.05),B组和C组中SOD活力在整个试验期间显著降低(P0.05);A组、B组和C组血清中CAT、ACP活性和MDA含量与对照相比均显著增加(P0.05);A组AKP活性在第1天时与对照组无显著差异,之后显著降低,B组和C组均显著低于对照组(P0.05)。 相似文献
94.
The effect of an 80-day maintenance-feeding period on the acute stress response of common carp, Cyprinus carpio, to net confinement was determined. Fish were raised on an optimal feeding level of 20 g food/kg of metabolic fish weight per day (g/kg0.8 day−1) until 124 days post-hatch (dph). Feeding in group one (L>H) was then reduced to maintenance levels, i.e. 5 g/kg0.8 day−1 until 204 dph, when the feeding was again increased to 20 g/kg0.8 day−1. In group two (H>L), the feeding level was reduced from 20 to 5 g/kg0.8 day−1 on day 146. All fish were sampled at 226 dph. Food ration had significant effects on the growth rate and food conversion values with fish fed the high ration performing better than those on a lower level. Prior to the application of the stressor, only plasma levels of triglycerides were lower in fish fed a low food ration (H>L). Feeding history influenced the onset of the stress response with stressor-induced elevations of plasma cortisol, glucose and free fatty acids being higher in fish fed a high ration compared with those fed a low ration prior to sampling. These results suggest that feeding history through modification of the energy reserves can influence the onset of the acute stress response. 相似文献
95.
A simulation of the effects of predation intensity on zooplankton composition in brackish water nursery ponds was carried out in order to address the problem that commercial fish nurseries encounter in obtaining enough zooplankton of adequate species composition and size when fish larvae start to feed. The experimental system consisted of twelve 130 l containers with treatments of four densities (0, 1, 2, or 4 larvae l−1) of common carp (Cyprinus carpio L.), stocked on the 6th day after filling the containers. Zooplankton-environment relationships were explored using factor analysis. Factor analysis allowed identifying several groups of zooplankters that responded in different ways to fish larvae predation pressure. The first factor represented a general measurement of rotifer abundance, and the second identified the direct effect of size-selective fish predation. Since no rotifers were present in the filling water, all these species were autochthonous populations that hatched from resting forms in the sediment and reproduced. In the absence of fish predation, this led to a steep rotifer increase. Fish predation started when the rotifer concentration was just starting to increase and their direct predation reduced and delayed the rotifer abundance peak. This effect increased with the increase in fish larvae density. Estimations of rotifer consumption by fish larvae in this experiment were higher than similar calculations from data of the literature, which led us to test the hypothesis that factors other than direct predation were affecting rotifer population dynamics. The mechanisms involved in rotifer population regulation are discussed. It was concluded that in commercial nurseries, increased larvae production can be achieved by keeping the larvae density at an intermediate level and stocking fish to match the increasing phase of the rotifer peak. Under reasonable larvae density (up to 2 l−1) it seems that the direct predation effect of fish larvae on rotifer dynamics is minor, compared to fish induced self regulation. 相似文献
96.
Yong Yang Shouqi Xie Yibo Cui Xiaoming Zhu Wu Lei & Yunxia Yang 《Aquaculture Research》2006,37(1):40-48
Triplicate groups of gibel carp Carassius auratus gibelio Bloch (initial body weight: 4.89 g) were fed for 8 weeks at 24.8–30.8°C with nine isonitrogenous and isoenergetic diets. The control diet (F1) used white fishmeal (FM) as the sole protein source. In the other eight diets (F2–F9), 40.5–100% of FM protein was substituted by poultry by‐product meal (PBM) at 8.5% increments. The specific growth rate (SGR), feed efficiency ratio, protein efficiency ratio, protein retention efficiency and energy retention rate for fish fed PBM diets (F2–F9) were all higher, but not always significantly, than those for fish fed F1. All apparent digestibility coefficients for fish fed PBM diets were lower than those for fish fed F1. Fish fed F1 had a significantly higher hepatosomatic index value than fish fed PBM diets (P<0.05). No significant (P>0.05) effect of diet was found in whole‐body moisture and fat content. Whole‐body protein and energy content for fish fed PBM diets were slightly higher than that for fish fed F1. The optimal replacement level of FM by PBM was estimated by second‐order polynomial regression to be 66.5% in protein. 相似文献
97.
彭泽鲫的分子遗传分析及其与方正银鲫A系的比较 总被引:16,自引:2,他引:16
Genetic homogeneity between Pengze crucian carp and strain A of silver crucian carp was studied by using transferrin,isozyme and RAPD markers.The studied individuals of Pengze crucian carp showed transferring patterns were the same of silver crucian carp A strain while distinct from those of other crucian carp populations.As far as isozyme is concerned,the MDH,LDH and EST are all of the same with only slight differences in SOD between them.The RPAD patterns clearly indicated high homogeneity among 16 individuals (6 sampled from individuals of two years old and the others aged one) from crucian carp of Pengze and 5 individuals from strain A of silver crucain carp.Nearly indentical banding patterns were observed among all individuals.Average genetic distance within all the individuals is only 0.011,suggesting crucian carp of Pengze might possess indentical genetic background with strain A of silver crucian carp. 相似文献
98.
Partho Pratim Debnath Nguyen Dinh-Hung Suwimon Taengphu Vuong Viet Nguyen Jerome Delamare-Deboutteville Saengchan Senapin Chadag Vishnumurthy Mohan Ha Thanh Dong Channarong Rodkhum 《Journal of fish diseases》2022,45(1):77-87
Sixteen countries, including Bangladesh, have reported the presence of tilapia lake virus (TiLV), an emerging tilapia pathogen. Fish polyculture is a common farming practice in Bangladesh. Some unusual mortalities reported in species co-cultivated with TiLV-infected tilapia led us to investigate whether any of the co-cultivated species would also test positive for TiLV and whether they were susceptible to TiLV infection under controlled laboratory experiments. Using 183 samples obtained from 15 farms in six districts across Bangladesh, we determined that 20% of the farms tested positive for TiLV in tilapia, while 15 co-cultivated fish species and seven other invertebrates (e.g. insects and crustaceans) considered potential carriers all tested negative. Of the six representative fish species experimentally infected with TiLV, only Nile tilapia showed the typical clinical signs of the disease, with 70% mortality within 12 days. By contrast, four carp species and one catfish species challenged with TiLV showed no signs of TiLV infection. Challenged tilapia were confirmed as TiLV-positive by RT-qPCR, while challenged carp and walking catfish all tested negative. Overall, our field and laboratory findings indicate that species used in polycultures are not susceptible to TiLV. Although current evidence suggests that TiLV is likely host-specific to tilapia, targeted surveillance for TiLV in other fish species in polyculture systems should continue, in order to prepare for a possible future scenario where TiLV mutates and/or adapts to new host(s). 相似文献
99.
From mid-2004 to mid-2005, several grass carp, Ctenophayngodon idella (Valenciennes), showing evidence of spinal deformity were presented to the Aquatic Animal Health Program, Cornell University. The carp were from three separate locations in New York State. The first case involved several fish from a natural body of water in the Catskill Mountain region of south-eastern New York State. The second was a single affected individual from a private pond in the Fingerlakes region of Central New York State. The third was a single individual from the Cold Springs Harbor Fish Hatchery, Cold Springs Harbor, Long Island. All fish were at least 7 years of age. Radiographs and computed tomography (CT) scans revealed the deformities to be of bony origin. The spinal deformities were characterized by variable amounts of kyphosis, scoliosis and rotation. While it is not possible to determine the specific cause(s) of the lesions, we consider a genetic component as a likely contributor to the observed pathology. 相似文献
100.