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981.
A. ROSAS R. VÁZQUEZ‐DUHALT R. TINOCO A. SHIMADA L.R. DABRAMO M.T. VIANA 《Aquaculture Nutrition》2008,14(6):481-489
The kinetics of amino acid absorption in the proximal section of three fish species were studied using an everted intestine technique and a pancreatic digest of casein (Tryptone), as the model amino acid mixture. Fresh intestine of rainbow trout (Oncorhynchus mykiss) was used to set up the experimental system, and results were compared with those obtained using intestines from totoaba (Totoaba macdonaldi) and bluefin tuna fish (Thunnus orientalis). The kinetics of amino acid absorption was sigmoidal for all amino acids and for each species of fish tested. In general, specific absorptions of essential amino acids were higher than those of non‐essential ones. No correlation between the concentration of amino acids in the Tryptone solution and the corresponding absorptions was found. The maximum specific absorption rates of all amino acids for trout were 10 times higher than those determined for totoaba and bluefin tuna. The relative amounts of the different amino acids preferentially absorbed in all three species were different. Results obtained from the everted technique may be applicable to the design of formulated diets for large fish species with commercial value. 相似文献
982.
Ella Vázquez‐Domínguez Andrea Bolongaro‐Crevenna Adolfo Sánchez Carlos Rosas 《Aquaculture Research》2008,40(1):91-102
As a function of the water quality provided by square, circular and oval experimental ponds, the growth, survival and oxygen requirements in epibenthic postlarvae of Farfantepenaeus aztecus were analysed in relation to their routine metabolism and apparent heat increment. Temperature, oxygen concentration, pH and salinity were measured daily in two experimental ponds of each shape. The postlarvae oxygen consumption during two 24‐h cycles, their growth, physiological condition and survival and the productivity in the ponds were estimated. Low values of pH, oxygen concentration and phytobenthos productivity, and reduced postlarvae relative growth and survival were observed in the square ponds. We suggest that the latter results from a deficient water circulation related to the effect of the pond's shape on dissolved oxygen levels and, consequently, on growth and survival. The postlarvae routine metabolism, including feeding, varied between 1.91 and 2.25 mg O2 h?1 g?1 wet weight, whereas the minimum oxygen concentration needed in the ponds is approximately 4.25 mg O2 L?1. These conditions were achieved in the oval ponds concurrent with higher survival and growth values, in which individuals distributed randomly, for which we suggest that oval‐shaped ponds could be the most adequate for the culture of this and other penaeid species. 相似文献
983.
A long‐term feeding experiment was conducted to investigate the use of cottonseed and soybean meal (CS) with iron and phosphorus supplements in diets for olive flounder (Paralichthys olivaceus). Olive flounder with an initial average size of 28.5 ± 0.35 g (mean ± SD) were divided into 15 groups (three tanks per dietary treatment) and fed 480 g kg?1 crude protein diets in which each of five isonitrogenous diets was formulated to contain different levels of cottonseed/soybean meal (1 : 1) to replace fish meal (FM) with iron and phosphorus supplementations. The five experimental diets were as follows: diet 1 (control), 0%CS; diet 2, 20%CS; diet 3, 30%CS; diet 4, 30%CS + Fe&P; and diet 5, 40%CS + Fe&P. After 26 weeks of feeding trial, no significant differences were observed in weight gain, feed utilization and survival among all the treatments. The total gossypol accumulation in liver of fish fed diets supplemented with iron was significantly lower than that of fish fed diets without supplementation of iron. The results indicate that the addition of iron in diets could prevent the absorption of free gossypol. The findings in this study suggest that dietary supplements of iron and phosphorus could increase the inclusion of cottonseed and soybean meal for FM replacement in diets for marine fish species. 相似文献
984.
温度和水流对扁吻鱼胚胎发育的影响 总被引:4,自引:0,他引:4
探讨了温度及水流对扁吻鱼(Aspiorhynchus laticeps)胚胎发育的影响。结果表明:在水温15~25℃条件下,扁吻鱼胚胎发育均可以完成,并且温度x与发育时间y呈负相关关系,y=667.72 e-0.0996x,R2=0.9829;与积温的关系为y=-91.017x+3662.3,R2=0.7996。胚胎发育的适宜水温为15~23℃,最适水温为15~21℃。孵化期间辅助于一定的充气条件可缩短出苗时间、提高出苗率,降低畸形率。 相似文献
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990.
JIN Bei-fang LU Qin-zhen ZHANG Yan CUI Ya-lan QIANG Zheng LIAO Man-xi TAN Hui-yuan LIU Fang 《园艺学报》2000,36(9):1625-1630
AIM To explore the effects of oxidative stress and inflammatory response on kidney injury induced by hyperthyroidism in mice. METHODS Forty male Kunming mice were randomly divided into control group (n =20) and L-thyroxine (T4) group (n =20). The mice in T4 group were intraperitoneally injected with T4 diluent at a dose of 1 mg/kg to induce hyperthyroidism, and those in control group were injected with normal saline of the same volume. After 7 weeks, the mice were weighed and dissected, the kidneys were removed and weighed, and the length of tibia was also measured. The activity of superoxide dismutase (SOD) and the content of malondialdehyde (MDA) in the kidney tissues were detected. The pathological changes of the kidney tissues were observed by HE staining. The levels of 4-hydroxynonenal (4-HNE)-modified proteins, interleukin-1 receptor-associated kinase 1 (IRAK1) and tumor necrosis factor receptor-related factor 6 (TRAF6) were determined by Western blot and immunohistochemistry. RESULTS Compared with control group, the body weight of the mice was decreased, while the kidney size and weight were increased significantly in T4 group. In addition, the ratios of kidney weight/body weight and kidney weight/tibia length were also increased (P <0.05). In T4 group, the renal tubules were enlarged, and the epithelial cells of renal tubules were swollen and exfoliated, with vacuolar degeneration. Furthermore, reduced SOD activity, and increased MDA content and 4-HNE-modified proteins were found in T4 group, all of which were related to oxidative stress (P <0.05). The levels of inflammation-related proteins IRAK1 and TRAF6 were significantly increased in T4 group (P <0.05). CONCLUSION Excessive T4 may lead to kidney hypertrophy and injury in mice, and the mechanism may be related to oxidative stress and inflammatory response. 相似文献