Effects of growth hormone on plasma ionic regulation,respiration and extracellular acid-base status in trout (Oncorhynchus mykiss) transferred to seawater     

H. Seddiki  V. Maxime  G. Boeuf  C. Peyraud 《Fish physiology and biochemistry》1995,14(4):279-288

The effects of trout recombinant growth hormone (rtGH) treatment (0.25 g g^–1 by intraperitoneal implant) on plasma ionic regulation, extracellular acid-base status and respiration were investigated in freshwater rainbow trout and during a 4-day period after direct transfer into seawater (35 g 1^–1).In freshwater, rtGH treatment resulted in a significant increase in gill (Na⁺, K⁺) ATPase activity and in standard metabolism (MO₂). The latter would mainly result from a higher rate of protein synthesis. Direct transfer from freshwater to seawater induced a decrease in arterial blood pH, far more pronounced in controls than in treated fish. This effect could be regarded in both groups mainly as a metabolic acidosis resulting from extracellular ion composition changes (i.e., an increase higher in chloride than in sodium, more marked in controls than in treated fish). As the rise in PaCO₂, in spite of an increase in ventilatory activity, is more significant in controls than in treated fish, it can be assumed that rtGH treatment lightened the decrease in the gas diffusing capacity of gills induced by transfer to seawater. The initial increase in MO₂ in both controls and treated fish could be the consequence of an increase in energetic cost of ventilation and osmoregulation. Then, in treated fish, the persistent high level of M may indicate a stimulation of intermediary metabolism by rtGH. In addition, the absence in treated fish of an increase in plasma lactate concentration, as observed in controls, would indicate that rtGH attenuated the decrease in O₂ affinity of haemoglobin foreseeable from the metabolic acidosis.This article is dedicated to Professor Claude Peyraud, whose recent death has deeply saddened us. We respectfully pay a tribute to his memory.  相似文献   

Dietary yeast culture supplementation improves initial rearing of McConaughy strain rainbow trout   总被引：1，自引：0，他引：1  

M.E. BARNES  D.J. DURBEN  S.G. REEVES  & R. SANDERS 《Aquaculture Nutrition》2006,12(5):388-394

The addition of a yeast culture food supplement (DVAqua from Diamond V. Mills, Cedar Rapids, IA, USA) was evaluated during feeding of McConaughy strain rainbow trout Oncorhynchus mykiss. Two trials were run consecutively, starting with initial feeding, and were replicated over 2 years. The yeast culture was added to commercial trout starter at levels of 0.125 and 0.25 g kg^?1. The number of rainbow trout that died during the first 4 weeks of rearing was significantly reduced in the tanks receiving either of the yeast culture‐supplemented diets compared with the tanks receiving a control starter diet. Ending tank weights and gain were significantly and consistently greater in the tanks fed the 0.25 g kg^?1 yeast culture diet. Individual fish weights were also significantly heavier in the fish‐fed yeast culture containing diets in each year of the study at the end of 27 days. In the trials from 4 to 8 weeks postinitial feeding, mortality rates were significantly less only in the tanks receiving 0.25 g kg^?1 yeast culture supplementation. Individual fish lengths and weights at the end of the second trial were significantly greater in the tanks receiving either level of yeast culture compared with the control diet only in 1 year. Total tank weights and feed conversion were not significantly different between any of the treatments. The inclusion of DVAqua yeast culture provided significant increases in trout survival and growth through the first 4 weeks of feeding, with continued benefits for the next 4 weeks.  相似文献   

Effects of sulfide on K+ flux pathways in red blood cells of crucian carp and rainbow trout     

S. Völkel  M. Berenbrink  N. Heisler  M. Nikinmaa 《Fish physiology and biochemistry》2001,24(3):213-223

The effect of sulfide on K⁺ influx pathways was measured in red blood cells (RBCs) of sulfide-sensitive rainbow trout (Oncorhynchus mykiss) and sulfide-tolerant crucian carp (Carassius carassius). In trout RBCs, maximal inhibition of Na⁺, K⁺-ATPase was attained at 10 mol l^–1 sulfide and amounted to 32% without being influenced by pH between 6.7 and 8.3. Ouabain-resistant K⁺ influx in the absence and presence of sulfide was insignificant at pH values between 6.7 and 7.7. At higher pH values ouabain-resistant K⁺ influx increased, but was inhibited to about 15% by 30 mol l^–1 sulfide. In RBCs of crucian carp neither Na⁺, K⁺-ATPase nor ouabain-resistant K⁺ influx were affected by sulfide concentrations up to 850 mol l^–1. Differences in sulfide-sensitivity of K⁺ influx between both species can be based upon different properties of the membrane transporter themselves. The reduced Na⁺, K⁺-ATPase activity in trout RBCs may also result from a slightly reduced (by 9%) ATP level after sulfide exposure. In addition, intracellular sulfide concentrations were higher in trout RBCs as compared to crucian carp. In trout, intracellular sulfide concentrations reached extracellular levels within 5 min of incubation whereas sulfide concentrations in crucian carp RBCs remained about 2-fold lower than extracellular concentrations. Although the physiological basis of sulfide-insensitive K⁺ influx in crucian carp RBCs is currently unknown it may contribute to the extremely high sulfide-tolerance of this species.  相似文献   

绥芬河马苏大麻哈鱼陆封型种群生态学特征及资源保护   总被引：1，自引：0，他引：1  

董崇智  王维坤等 《水产学杂志》1997,10(1):38-43

本文报道黑龙江水系名贵经济鱼类马苏大麻哈鱼陆封型种群生态学。通过57尾标本，对其捕捞群体体长体重组成、年龄与生长、第二性征、性比、肥满度、成熟系娄及摄食等主要生态学特征进行研究，并提出繁殖保护措施。  相似文献   

Changes in plasma prolactin and growth hormone concentrations during freshwater adaptation of juvenile chum salmon (Oncorhynchus keta) reared in seawater for a prolonged period     

Tsuyoshi Ogasawara  Tetsuya Hirano  Toshio Akiyama  Shigeru Arai  Masatomo Tagawa 《Fish physiology and biochemistry》1989,7(1-6):309-313

Freshwater adaptability of chum salmon was examined in juvenile fish reared in seawater for 4 months. The fish, weighing about 40g, were transferred directly to fresh water in October, when their cohorts are migrating in the North Pacific Ocean. Plasma sodium concentration decreased from 167 mM in seawater to about 130 mM during the first 24h, and increased gradually during 2–7 days after the transfer. No immunoreactive prolactin (PRL) was detected in the plasma of the seawater-adapted fish nor during the first 24h in fresh water. Significant levels of PRL were detected after 2–3 days. The maximal level (2.6 ng/ml) was observed after 5 days and became undetectable again after 7 days; no significant correlation was seen between the changes in plasma sodium and PRL levels during the transfer. Plasma growth hormone levels were relatively constant, except for a significant decrease 12h after the transfer. Although plasma thyroxine levels were highly variable during the experiment, a significant decrease and an increase were observed 12h and 5 days after the transfer, respectively. The present study indicates that juvenile chum salmon retain hyperosmoregulatory ability even after prolonged rearing in seawater. Examination of turnover rates, rather than changes in plasma levels, seems to be essential to clarify the osmoregulatory roles of the hormones.  相似文献   

The dynamics of in vitro 17 β-estradiol secretion by isolated ovarian follicles of the rainbow trout (Oncorhynchus mykiss)     

J.A. Haddy  N.W. Pankhurst 《Fish physiology and biochemistry》1998,18(3):267-275

This study investigated the effects of human chorionic gonadotropin (hCG), 17-hydroxyprogesterone (17P) and testosterone (T) on the in vitro production of 17-estradiol (E₂) by isolated ovarian follicles of the rainbow trout (Oncorhynchus mykiss). 17P at 100 ng ml^-1, and hCG at 100 IU ml^-1 stimulated E₂ production relative to controls, whereas lower doses were ineffective. T was the most effective in stimulating E₂ production, followed by 17P and hCG respectively. The timecourse of E₂ production was investigated for both static culture, and incubations with media replacement, with follicles being exposed to hormone treatment for 30 min, 1 or 3 h, or constantly. E₂ production was observed after 30 min, 3 and 3-6 h in response to T, 17P and hCG respectively. Under static culture, E₂ levels reached maximal levels in 6 h. Longer incubations resulted in further metabolism of E₂ to E₂-glucuronide, which resulted in the blurring of treatment effects after 18 h. Incubations with media replacement resulted in higher E₂ production than in static culture. The results indicate that a 6 h incubation period is sufficient to produce significant increases in E₂ production in response to hCG, 17P and T, and that incubations longer than 12 h result in losses E₂ from the incubation media. These findings have implications for the validity of using static cultures to examine the effects of hormone treatment on the activity of steroid converting enzymes in vitro.  相似文献   

The effect of dietary coconut oil on reproductive traits and egg fatty acid composition in rainbow trout (Oncorhynchus mykiss)     

Rodolfo Ballestrazzi  Simona Rainis  Francesca Tulli  Arianna Bracelli 《Aquaculture International》2003,11(3):289-299

Two hundred and twenty rainbow trouts (IBW: 700 g) were randomly allotted to four tanks, with a male/female ratio of 0.56. Fish were fed for 168 d with four experimental diets containing herring oil, cod liver oil and coconut oil with the following inclusion rates: diet A: 12-1-0% respectively; diet B: 6-1-6%; diet C: 0-1-12%; diet D: 0-0-13%. Irrespective of the dietary treatment, weight gains of broodstocks were high (> 3 g/d) and FCR below 2. No significant difference was observed concerning the total amount of eggs spawn, egg average weight (82.5 mg/egg) and lipid content (5.4 mg/egg). However, the fatty acid profile of eggs was significantly affected by the dietary treatments. The content of unsaturated fatty acids, particularly the n-3 fatty acid series (EPA and DHA) significantly decreased with increasing levels of coconut oil in the diet.  相似文献   

Influence of gossypol from dietary cottonseed meal on haematology, reproductive steroids and tissue gossypol enantiomer concentrations in male rainbow trout (Oncorhynchus mykiss)   总被引：1，自引：0，他引：1  

J. Rinchard  K.-J. Lee  K. Dabrowski  A. Ciereszko  J.H. Blom  & J.S. Ottobre 《Aquaculture Nutrition》2003,9(4):275-282

Rainbow trout (Oncorhynchus mykiss) males were fed, during a 9‐month period, five experimental diets where fishmeal proteins were gradually replaced with cottonseed meal (CS) proteins (0, 25, 50, 75 and 100%; diets 1–5, respectively). This study was carried out to evaluate the action and tissue concentrations of gossypol. Growth performance of fish was not affected with the increasing levels of CS in the diets. Haemoglobin concentration and haematocrit significantly decreased in fish fed 100% CS compared with other dietary treatments. Gonadosomatic index, plasma sex steroids (testosterone, 11‐ketotestosterone and 17,20β‐dihydroxy‐4‐pregnen‐3‐one) and sperm characteristics (concentration, motility, protein concentration and lactate dehydrogenase activity) were not negatively affected by increasing levels of CS. For the first time, a comprehensive study of gossypol concentrations, total and (+) and (?)‐enantiomers, in several tissues (liver, blood plasma, spermatozoa and seminal plasma) was performed. The concentrations of both (+) and (?)‐enantiomers significantly increased with increasing levels of CS in the diet. The highest concentrations were found in the liver of fish fed diet 5 (185 ± 18 μg g^?1). In blood plasma, the concentrations of total gossypol were 10 times lower than the one found in the liver, but 10 and 100 times higher than the concentrations in the spermatozoa and seminal plasma, respectively. In all tissues studied, the concentration of (+)‐enantiomer was higher than the (?)‐enantiomer. The ratio (?)‐enantiomer/total gossypol did not change significantly with the increasing levels of CS in the diet. The results of the present study indicate that CS can be used over a period of 9 months to replace fishmeal proteins completely without compromising growth and reproduction of rainbow trout males.  相似文献   

Growth of rainbow trout fed a diet supplemented with earthworms,after chemical treatment     

J. óscar Pereira  Emídio F. Gomes 《Aquaculture International》1995,3(1):36-42

Whole frozen earthworms (Eisenia foetida) were evaluated as a partial replacement for commercial pellets for rainbow trout, Oncorhynchus mykiss. Earthworms were blanched and treated with concentrated sodium chloride (10%). Fish were submitted to four treatments: control fish were fed with a commercial diet and three groups of fish were fed with diets partially supplemented with earthworms. All fish showed the same appetite for the earthworm-supplemented diets as for the control diet during the course of the experiment (8 weeks). No significant differences (p > 0.05) were detected in the mean final body weights of all groups of fish. A significant decrease was found in the whole-carcass lipid content of fish fed diets containing 25%, 50% and 75% frozen earthworms. The results on growth rate and feed utilization efficiency of fish fed diets containing high levels of whole frozen worms suggested an adverse effect of worm incorporation, probably due to dietary energy/protein imbalance.  相似文献   

Effects of light spectrum on growth and physiological status of gilthead seabream Sparus aurata and rainbow trout Oncorhynchus mykiss reared under recirculating system conditions     

Nafsika Karakatsouli  Sofronios E. Papoutsoglou  Gianluca Pizzonia  Georgios Tsatsos  Aristeidis Tsopelakos  Stella Chadio  Dimitris Kalogiannis  Christina Dalla  Alexia Polissidis  Zeta Papadopoulou-Daifoti 《Aquacultural Engineering》2007,36(3):302-309

Previously reported data clearly indicate that depending on species, ambient light spectrum can affect fish growth, physiology, behaviour, reproduction, etc. Since light spectrum can be easily controlled in intensive indoor fish farming facilities, the present study aimed to investigate the effects of coloured light on growth performance (body weight, growth rate, food utilization, carcass composition, etc.) and physiological status (blood and plasma parameters, brain neurotransmitters, tissue fatty acid composition, etc.) of two widely reared fish species, gilthead seabream Sparus aurata and rainbow trout Oncorhynchus mykiss. For this purpose, 240 specimens of S. aurata (29.8 ± 0.13 g) and 60 specimens of O. mykiss (71.4 ± 0.30 g) were exposed to white (full-spectrum, fluorescent lamps), red (605 nm) and blue (480 nm) light (lamps covered with appropriate filters) for 11 weeks under recirculating water systems. Blue light had a significantly negative impact on O. mykiss growth performance accompanied with reduced liver total lipids and plasma glucose and increased brain serotonergic and dopaminergic activity. In the case of S. aurata, red light significantly increased brain dopaminergic activity, while a tendency towards reduced growth was also observed. Since these results indicated the establishment of stressful conditions, O. mykiss and S. aurata should not be reared under blue and red light, respectively. For each species, the effect of the remaining light colours tested, was not clearly differentiated so that an appropriate light spectrum for the most efficient farming of O. mykiss and S. aurata could not be suggested, at least for the time period examined. Nevertheless, present results suggest that light colour should be regarded as a rearing factor worth to be further investigated, especially when recirculating systems are concerned.  相似文献