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1.
Total lipids, lipid classes and their associated fatty acids were quantified in developing eggs, yolk-sac larvae and starving larvae (from day 1 to day 5 after hatching) of the Senegal sole,Solea senegalensis Kaup. Larvae during early development and starvation consumed about 0.6% of its dry weight per day, mainly due to lipid catabolism. There was a net consumption of approximately 1.7% total lipid per day, and a net energy utilization of 1.3 kcal g–1 dry weight biomass day–1, mostly derived from lipid depletion. The overall decrease of total neutral lipids (mainly triacylglycerols and sterol esters) was 3.4 faster than that of total polar lipids (primarily phosphatidylcholine), with rates of 29.2 and 8.7 g mg–1 dry weight biomass day–1, respectively. There was a concomitant increase in PE, PS and phosphatidic acid during the period under study. Total saturated and total monounsaturated fatty acids were catabolized (primarily 160 and 161 (n-7)) as energy substrates at rates of 7.4 and 10.9 g mg–1 total lipid day–1, whereas total PUFAs were conserved. DHA was specifically retained in PE, whereas EPA and DHA were catabolized in PC and triacylglycerol. Total DMA and AA contents in total lipid increased during early development and starvation. The data denote a pattern of lipid metabolism during early development of Senegal sole similar to that of other marine larval fish, with eggs containing high amounts of total lipids (presence of oil globule/s), from temperate waters and with short developmental periods; the pattern contrasts with fish larvae from eggs of cold water fish species that contain low levels of total lipids (lack of oil globule/s) and have long developmental periods.Abbreviations AA all-cis-5,8,11,14-eicosatetraenoic acid (arachidonic acid, 204(n-6)) - C free cholesterol - DHA all-cis-4,7,10,13,16,19-docosahexaenoic acid (226(n-3)) - DMA dimethyl acetal - EPA all-cis-5,8,11,14,17-eicosapentaenoic acid (205(n-3)) - HUFA highly unsaturated fatty acids (C20 with 3 double bonds) - PC phosphatidylcholine - PE phosphatidylethanolamine - PI phosphatidylinositol - PS phosphatidylserine - PUFA polyunsaturated fatty acid(s) - SE sterol ester - TAG triacylglycerol  相似文献   

2.
In two separate experiments, haddock (Melanogrammus aeglefinus) larvae were raised under different photoperiods (24L : 0D or 15L : 9D), or different combinations of tank colour (black or white) and light intensity (1.1 mol s–1 m–2 or 18 mol s–1 m–2). Growth (0.8% day–1 in standard length; 2.9% day–1 in body area) and survival (2%) were not significantly different between photoperiod treatments after 35 days. Larval survival was greater in white versus black tanks after 41 days (2% versus l%, respectively). Growth of larvae was impaired in black tanks at low (1.1 mol s–1 m–2) light intensity (0.8% day–1 in standard length and 2.2% day–1 in body area versus 1.1% day 21 in standard length and 3.1% day–1 in body area, for all other treatments). Transmission and reflection of light was low in black tanks at low incident light, and there was very little upwelling light. The resultant poor prey to background contrast probably resulted in larvae being unable to consume sufficient food to sustain a level of growth comparable to that in other treatments.  相似文献   

3.
The changes in proximate composition, amino acid (total and free) and fatty acid content of artificially propagated trout cod, Maccullochella macquariensis larvae from five mothers hatched, weaned and reared separately, each in two groups, one fed with Artemia naupli and the other starved, for 15 days (after yolk resorption), are presented. There was no significant change in the proximate composition of fed larvae with devlopment, but in starved larvae the protein (linearly) and lipid (curvi-linearly) content decreased significantly as starvation progressed. The essential amino acids (EAA) and non- essential amino acids (NEAA) found in highest amounts in trout cod larvae were lysine, leucine, threonine and arginine, and alanine, serine and glutamic acid, respectively. In fed larvae the total amino acid (TAA), TEAA and TNEAA content did not vary significantly as development progressed. In starved larvae the TAA, EAA and NEAA content, as well as all the individual amino acids decreased significantly (P<0.05) from the levels in day of hatch and/or yolk-sac resorbed larvae. The greatest decrease occurred in the TEAA content (7.38±0.76 at day of hatch to 1.96±0.09 15 day starved in moles larva–1; approximately a 74% decrease), whereas the decrease in TNEAA was about 38%. Unlike in the case of TAA distinct changes in the free amino acid (FAA) pool were discernible, from day of hatch and onwards, in both fed and starved trout cod larvae. In both groups of larvae the most noticeable being the decrease of % FEAA in TFAA, but not the % FAA in TAA. Four fatty acids together, accounted for more than 50% of the total in each of the major fatty acid categories in all larvae sampled; 16: 0, 18:1n-9, 22: 6n-3 and 20: 4n-6, amongst saturates, monoenes, n-3 PUFA and n-6 PUFA, respectively. Twelve fatty acids either decreased (14: 0, 16: 1n-7, 20: 1n-9, 20: 4n-6, 20: 5n-3, 22: 5n-3 and 22: 6n-3) or increased (18: 2n-6, 18: 3n-3, 18: 3n-6, 18: 4n-3 and 20: 3n-3) in quantity, after 15 days of feeding, from the base level in day of hatch and/ or yolk- sac resorbed larvae. The greatest increase occurred in 18: 3n-3 from 6.4±0.1 to 106.2±13.1 g mg lipid–1 larva–1, and the greatest decrease occurred in 22: 6n-3 (181.2±12.4 to 81.4±6.2 g mg lipid–1 larva–1). In starved larvae, at the end of 15 days, all the fatty acids, except 18: 0, 20: 3n-3 and 20: 4n-6, decreased significantly (P<0.05) from the levels in day of hatch and/or yolk- sac resorbed larvae.  相似文献   

4.
Samples of fertilized dentex, Dentex dentex, eggs and larvae fed enriched rotifers and Artemia according to standard hatchery procedures were analysed for free, total amino acid and fatty acid contents. Egg free amino acids (53 nmol ind-1) and total lipids (13.5 (g ind-1) levels were considerably reduced in the newly hatched larvae (6.0 nmol and 5.7 (g ind-1 respectively) while the amount of -3 PUFA (Polyunsaturated fatty acid) and 20:4-6 remained unchanged suggesting their possible role as essential fatty acids (EFA) in this species. In general, the changes in pattern of the major biochemical components during early development of dentex was similar to that outlined for other Sparidae species investigated to date. The essential amino acid profile of enriched live food did not show major imbalances when compared to that of dentex larvae. In contrast, the level of docosahexaenoic acid (22:63, DHA) and the DHA:EPA (eicosapentaenoic acid, 20:5-3) ratio in larvae given rotifers and Artemia were significantly lower relative to the corresponding values in the unfed larvae.  相似文献   

5.
Embryonic development and larval hatching of the monogenean Diplectanum aequans, gill parasite of sea bass Dicentrarchus labrax, was studied in relation to different prophylactic treatments. Groups of eggs of D. aequans were submitted to different in vitro treatments: formalin (300 and 100 L L–1 per 1 hour), Neguvon® (trichlorphon 0.2 mg L–1 per 48 hours) and dehydration for 4 and 8 hours. Percentages of hatched larvae, aborted larvae and undeveloped embryos were estimated in comparison with the control group. Results showed that 300 L L–1 formalin and dehydration treatments were able to reduce larval hatching significantly, while Neguvon® and 100 L L–1 formalin treatments had no effect.  相似文献   

6.
Two Swedish landlocked (nonanadromous) salmon (Salmo salar) stocks were investigated with the aim of characterising their egg fatty acid (FA) and carotenoid profiles. Fish from one of the stocks were also cultured over the past few decades as part of the Swedish program for genetic preservation, allowing a comparison between the eggs from females on a diet based on lipids of limnic (natural food chain) origin and eggs from females fed an artificial diet of marine origin. No significant differences in the FA profile of the phospholipid (PL) or triacylglycerol (TAG) fraction were found between the two wild stocks. The content of EPA (20:5n-3, eicosapentaenoic acid) in PL fraction was significantly higher in eggs from cultured females (13.0%) compared with eggs from both wild stocks (5.7 and 6.4%). Further, in PL fraction, AA (20:4n-6, arachidonic acid) levels in these eggs were significantly lower (2.4% versus 6.7 and 6.2%). The AA content of the TAG fraction differed greatly between wild (4.4 and 4.9%) and cultured (1.2%) eggs, whereas this fraction showed almost no corresponding difference in EPA content. The level of DHA (22:6n-3, docosahexaenoic acid) did not differ between the two wild stocks or between wild and cultured fish. This was in spite of widely different levels of DHA in the diet. The composition of carotenoids was altered in the cultured eggs which had a higher proportion and higher content (1.16 g egg–1) of astaxanthin than the wild eggs (0.56 and 0.62 g egg–1, respectively). Hatching success varied markedly between wild (>95%) and cultured fish (40–75%). We conclude that changes in the lipid source in the diet of female salmon during gonadal maturation will alter the egg fatty acid composition with an increased risk of disturbances in embryonic development as a consequence. Further, the lack of any difference between wild and cultured females in terms of their egg DHA content indicates that there is a strong genetic influence on levels of this fatty acid in salmon eggs.  相似文献   

7.
The standard rate of oxygen consumption of ammocoetes (larvae) ofGeotria australis with a mean weight of c. 0.5 g was 9.6, 31.4 and 59.4l g–1 h–1 at 4.5, 15.5 and 25.0°C respectively, which gives an overall Q10 of 2.4. The regression coefficient for the logarithmic relationship between oxygen consumption and body weight at 15.5°C was 0.704. The ammocoetes ofG. australis have a much lower rate of oxygen consumption at 15.5 and 25.0°C than those of holarctic lampreys. This presumably reflects the lower oxygen delivery pressure to their tissues and helps account for their slow growth rate. At 15.5°C, ammocoetes ofG. australis emerged from the substrate at 21–25 mm Hg and, unlike those of the Northern HemisphereIchthyomyzon greeleyi, died at 14–17 mm Hg. Thus, despite having a thinner water/blood barrier in the gills and blood with a higher oxygen affinity and capacity than holarctic ammocoetes, the larvae ofG. australis cannot survive very low dissolved oxygen tensions. This is apparently related to an inability of larvalG. australis to meet the high oxygen requirements of the respiratory pump at these oxygen tensions. During metamorphosis, oxygen consumption at 15.5°C rose from approximately 27l g–1 h–1 at the beginning of transformation to 33.2l g–1 h–1 by Stage 3 and then rapidly to 66l g–1 h–1 at Stage 6. It remained near this level in Stage 7 and the downstream migrant.  相似文献   

8.
Variations in growth and survival of hatchery-reared post-metamorphicjuveniles of great scallop Pecten maximus prompted anexamination of settlement and postlarval development. The effects ofseawater flow and temperature on great scallop metamorphosis andpostlarvae were studied over a 4–5 week period. In allexperiments, and regardless of environmental conditions, great scallopmetamorphosed after a 2–3 week period with values of 35 to70%. Subsequently, spat numbers increased slightly. Spatmortality generally occurred from the third week onward and reachedlevels as high as 30% by the fifth week under standardconditions. At 20 °C, however, 60% mortality levels wererecorded. Differences in spat growth rate, ranging from 37 to 45 mday–1, were noticed at different seawater flow ratesbut no clear tendency could be discerned. Temperature affected spatgrowth with an increase in size from 24 m day–1 at15 °C to 35 m day–1 at 18 °C. Conversely,growth was suppressed at 20 °C (14 m day–1).For optimal metamorphosis and postlarval development in great scallop, aseawater flow of 4.3 L h–1 per sieve and a temperatureof 15 °C are recommended.  相似文献   

9.
The pattern of changes of activity of the urea cycle enzymes and the rate of urea-N excretion were studied in the perfused liver of an Indian air-breathing ureogenic walking catfish, Clarias batrachus. The liver was perfused with different concentrations of NH4Cl for a period of 60 min to determine the role of ammonia for stimulation of hepatic ureogenesis and the threshold level of ammonia loading needed to cause such stimulation. Both the urea-N excretion and the ammonia uptake by the perfused liver were found to be a saturable process. Ammonia accumulated significantly in the liver infused with 1.25 moles g liver –1 min–1 of NH4Cl, followed by a maximum accumulation of about 28.5 moles g wet wt–1 with the infusion of 5.08 moles g liver–1 min–1. The Vmax of the urea-N excretion (0.47 mol g liver–1 min–1) was obtained with the addition of 5.08 moles g liver–1 min–1 of NH4Cl. Both the tissue and the specific activity of the urea cycle enzymes, except ornithine transcarbamylase and arginase, were stimulated significantly with the infusion of either 1.25 or 5.08 moles g liver–1 min–1 of NH4Cl. Maximum stimulation of tissue activity of carbamoyl phosphate synthetase (about 120%) was seen with the infusion of 5.08 mol g liver–1 min–1, and for argininosuccinate synthetase (about 135%), and argininosuccinate lyase (about 50%) with the infusion of 10.81 mol g liver–1 min–1 of NH4Cl. Higher accumulation of ammonia of about 10–15 mol g wet wt–1 from the physiological level in the perfused liver while infusing with NH4Cl was suggested to be one of the major causes of stimulation of ureogenesis. The presence of such physiological adaptive strategy is probably necessary in this unique group of air-breathing walking catfish to survive under hyper-ammonia stress in their normal habitat or while living outside water or while burrowing inside mud.  相似文献   

10.
The capacity of cortisol, ovine growth hormone (oGH), recombinant bovine insulin-like growth factor I (rbIGF-I) and 3,3,5-triiodo-l-thyronine (T3) to increase hypoosmoregulatory capacity in the euryhaline teleost Fundulus heteroclitus was examined. Fish acclimated to brackish water (BW, 10 ppt salinity) were injected with a single dose of hormone suspended in oil and transferred to seawater (SW, 35 ppt salinity) 10 days post-injection. Fish were sampled 24 h after transfer and plasma osmolality and gill Na+, K+-ATPase activity were examined. Transfer from BW to SW induced significantly increased plasma osmolality but not gill Na+, K+-ATPase activity. Cortisol (50 g g–1 body weight) improved the ability to maintain plasma osmolality and to increase gill Na+, K+-ATPase activity. oGH (5 g g–1 body weight) also increased hypoosmoregulatory ability and gill Na+, K+-ATPase activity. A cooperation between oGH and cortisol was observed in increasing hypoosmoregulatory ability but not in increasing gill Na+, K+-ATPase activity. rbIGF-I (0.5 g g–1 body weight) alone was without effect in increasing salinity tolerance or gill Na+, K+-ATPase activity. rbIGF-I and oGH showed a positive interaction in increasing salinity tolerance, but not gill Na+, K+-ATPase activity. Treatment with T3 (5 g g–1 body weight) alone did not increase salinity tolerance or gill Na+, K+-ATPase activity, and there was no consistent significant interaction between cortisol and T3 or between GH and T3. The results confirm the classical role of cortisol as a seawater-adapting hormone and indicate an interaction between cortisol and the GH/IGF-I axis during seawater acclimation of Fundulus heteroclitus.  相似文献   

11.
The ingestion of an inert feed as a sole food source was investigated in larval silver sea bream (Sparus sarba) fed an alginate-based microparticulate diet. Using the auto-fluorescent properties of pigments associated with the alginate base, ingestion and gut content were investigated over a 6 h experimental period in fed and unfed larvae. By extracting and measuring chlorophyll a (Chl a) and phaeopigment content of feeding larval fish and relating this to standardized Chl a and phaeopigment content of the diet, relative to diet weight, it was determined that individual fed 7-day old larvae had a maximum gut content of 1.05±0.09 g diet while 14-day old fed fish had a maximum gut content of 3.17±0.90 g diet. On average, the gut content of 14-day old fish was 2.89 times greater than the gut content of 7-day old fish. The dry weight of larval sea bream increased from 43±4.2 g at day 7 to 134.3±20.4 g at day 14 indicating that growth of fish fed this inert feed was substantial. Gut pigment dynamics suggested that Chl a was degraded to phaeopigments by 7-day but not 14-day old larvae and the individual gut dietary content varied considerably in 14-day old fish. The maximum Chl a and phaeopigment content in larval sea bream was 0.4 ng ind–1 and 0.55 ng ind–1 for 7-day old fish and 1.54 ng ind–1 and 2.81 ng ind–1 for 14-day old fish respectively. The present method may potentially allow simple and direct assessment of larval fish feed ingestion in both an experimental and commercial setting.  相似文献   

12.
Doppler flow probes were fitted around the ventral aorta of rainbow trout, which were exposed to combinations of pH and aluminum (pH 5.1–6.2, Al 0–80 g l–1) for 60 h. Fish accumulated Al at the gill and exhibited decreased blood Na+, Cl–, and Ca2+ concentrations, and increased K+, hematocrit, hemoglobin, glucose, and lactate, indicating increasing ionoregulatory disturbance with increasing Al concentration. Fish exposed to ambient water (6.2) or low-pH (5.3) water without Al exhibited slight reductions in heart rates, as well as increased stroke volume, resulting in little variation in cardiac output. In the presence of Al (20 to 40 g l–1) at low pH (5.1–5.3), fish increased their heart rate slightly and generally maintained their stroke volume, resulting in increased cardiac output in the first two days of exposure. At the highest Al concentration (80 g l–1, pH 5.1), tachycardia was observed, concomitant with a decrease in stroke volume. The ionoregulatory imbalance and resulting increased blood viscosity explain these increases in heart rate rather than stroke volume in fish exposed to high concentrations of Al.  相似文献   

13.
Arctic charr,Salvelinus alpinus L. were fed five test diets containing 0% or 1% of different polyunsaturated fatty acids (PUFA) for 93 days. The fish were injected intraperitoneally with (1–14C)–18:2(n–6) or (1–14C)–18:3(n–3), and the bioconversion to longer chain PUFA studied. The conversion rate in neutral lipids was slow, with most label found as the fatty acid injected, while extensive modification took place prior to or during incorporation into polar lipids. Linolenic acid was preferred over linoleic acid as substrate for elongation and desaturation regardless of diet. In polar lipids, the predominant products of (1–14C)–18:2(n–6) metabolism were generally 20:3(n–6) and 20:4(n–6), while 18:4(n–3), 20:5(n–3) and 22:6(n–3) were the major products of (1–14C)–18:3(n–3) metabolism. The lack of radioactivity in 22:5(n–6) suggests that 4 desaturation is specific for (n–3) PUFA. Feeding the PUFA deficient diet reduced the 5 desaturation compared to fish maintained on PUFA supplemented diets. The 6 desaturation was only reduced in fish fed C18 PUFA and injected with (1–14C)–18:3(n–3). Longer chain C20 and C22 PUFA, particularly those of the (n–3) family, exerted some inhibition on the elongation and desaturation of injected fatty acids compared to those fed C18 PUFA. The incorporation of radiolabelled fatty acids into polar lipids of fish fed a commercial diet was very low, and the desaturation neglectible in both polar and neutral lipids, showing that Arctic charr under culture conditions do not convert short chain PUFA to longer chain metabolites.  相似文献   

14.
The effects of various dietary blends of menhaden oil (MO) with canola oil (CO) on the growth performance, whole body proximate composition, flesh quality (muscle proximate and lipid composition) and thyroidal status of immature Atlantic salmon in sea water were studied.Atlantic salmon (initial weight, 145.2–181.3 g), held on a natural photoperiod and in 1100 L fibreglass tanks that were supplied with running, aerated (D.O., 9–10.5 p.p.m.), ambient temperature (8–10.5 °C) sea water (salinity, 28–30), were fed twice daily to satiation one of four isonitrogenous (36% digestible protein) and isoenergetic (18.8 MJ of digestible energy kg-1) extruded high-energy diets for 112 days. All diets contained omega –3 (n-3) fatty acids in excess of requirements and differed only with respect to the source of the supplemental lipid which was either, 25% MO; 20.75% MO and 4.25% CO; 16.5% MO and 8.5% CO; or 12.25% MO and 12.75% CO. Thus, CO comprised, respectively, 0, 15.5, 31.2, or 47.0% of the total dietary lipid content (28% on an air-dry basis).Dissimilar percentages of saturated fatty acids in the dietary lipids were not found to be consistently related to the apparent gross energy digestibility coefficients of the diets. Atlantic salmon growth, dry feed intake, feed and protein utilization, percent survival, thyroidal status, and whole body and muscle proximate compositions were generally not influenced by the different sources of supplemental lipid. Therefore, our results suggest that canola oil may comprise as much as 47% of the lipid in high-energy grower diets for Atlantic salmon without compromising performance.The muscle lipid compositions generally mirrored those of the dietary lipids which, in turn, were influenced strongly by the concentrations and compositions of the CO and MO in the diet. Hence, as the dietary CO level was increased there were attendant increases in percentages of oleic acid (18:1(n-9)), linoleic acid (18:2(n-6)), total omega-6 (n-6) fatty acid content, and ratios of (n-6) to (n-3) and decreases of eicosapentaenoic acid (EPA; 20:5(n-3)), docosahexaenoic acid (DHA; 22:6(n-3)) and n-3 HUFAs (EPA & DHA) in the flesh lipids. The ranges for percentages of saturated and unsaturated fatty acids in the flesh lipids were, however, much less than those noted respectively in the dietary lipids probably because of selective metabolism of many of the former acids and some of the 18 carbon unsaturates for energy purposes.  相似文献   

15.
The nutritional effect of vitamin E in dietsfor Litopenaeus vannamei postlarve (PL19)was investigated. Four formulated diets withdifferent combinations of -tocopherylacetate (-TA), ascorbic acid (AA) andhighly unsaturated fatty acids (HUFA) weretested, using four replicates.No significant differences in survival wereobserved among treatments after 34 days offeeding. However, shrimp fed with a dietcontaining 2% fish oil (low n-3 HUFA content),200 mg.kg–1 -TA and100 mg.kg–1 AA (diet H/E/C) showedsignificantly better growth than those fed adiet supplemented with 5% fish oil (high n-3HUFA content), 200 mg.kg–1 -TA and100 mg.kg–1 AA (diet H+/E/C). Shrimp fedwith a diet containing 5% fish oil,900 mg.kg–1 -TA and100 mg.kg–1 AA (diet H+/E+/C) showed a significantly higher tissue level of n-6 PUFAthan postlarvae fed diet H+/E/C. No definiteconclusion could be drawn about a possibleinteraction between -TA and AA, since acomparison of the diet containing 5% fish oil,200 mg.kg–1 -TA and700 mg.kg–1 AA (H+/E+/C+) and the dietH+/E/C did not show any significant differencesin any of the measured parameters. Theantioxidative status of the shrimp tissue(measured by means of the thiobarbituric acid(TBA) assay and expressed as nM malonaldehyde(MA) per gramme dry weight) was equal for alltreatments. Nevertheless, there was a slightlylower MA value with the diet H+/E/C+,indicating that AA may be an effectiveantioxidant in the aqueous phase and at thewater/lipid interface of the tissue. The tissuelevels of -T and AA were highlydependent on the amounts in diets and nocorrelation between -T and AAincorporation could be observed.  相似文献   

16.
Sub-lethal cardiac responses of brown trout alevins (Salmo trutta L.) were determined in response to aqueous extracts of the cyanobacterium Microcystis strains PCC 7813 (microcystins detectable by HPLC) and CYA 43 (no microcystins detectable by HPLC) and to the purified cyanobacterial hepatotoxin, microcystin-LR (MC-LR) at concentrations of 5, 50 and 500 g microcystin-LR equivalents l–1. Responses were determined using a flow chamber and video camera attached to a low power microscope. Heart rate in brown trout alevins was acutely sensitive to cyanobacterial extracts and significant increases were observed within 15–60 sec of exposure to aqueous extracts, although no change was observed on exposure to purified MC-LR. Stroke volume increased in all treatments at 50 and 500 g MC-LR equivalents l–1, which may, at least in part, have been due to vasodilation of the yolk-sac blood vessels. Cardiac output increased significantly at all three concentrations of cyanobacterial cell extracts but not at the lowest concentration of MC-LR, although the rate increased at levels at/or above 50 g l–1. Increased heart rate, stroke volume and cardiac output occurred at environmentally relevant microcystin concentrations of Microcystis PCC 7813 and CYA 43 aqueous extracts.  相似文献   

17.
The present study investigated the relationships between egg viability and ovarian fluid composition, egg physiology and egg metabolism in lake trout, Salmo trutta lacustris, to obtain biomarkers for egg quality determination. The ovarian fluid pH, protein levels and activities of aspartate aminotransferase and -d-glucuronidase were significantly correlated with egg viability expressed as the number of eyed stage embryos. Regression models demonstrated that an ovarian fluid pH between 8.44 and 8.57, protein levels below 235.56 mg 100 ml–1ovarian fluid, aspartate aminotransferase activity below 31.65 m min–1 l–1ovarian fluid and -d-glucuronidase activity below 8.62 m min–1 l–1 ovarian fluid characterized egg batches with high viability (80%).The increase in the egg wet weight during water hardening was also significantly correlated with the number of eyed stage embryos, and egg batches with high egg viability (80%) increased in wet weight by 13% during water hardening.From the investigated metabolic parameters the number of eyed stage embryos was significantly correlated with activities of NADP-dependent isocitrate dehydrogenase (egg viability 80% at 2.07 nM min–1 mg–1 protein) and NAD-dependent malate dehydrogenase (egg viability 80% at 47.25 nM min–1 mg–1 protein), with the respiration rate (egg viability 80% at 8.71 nM min–1 mg–1 protein), with the ratio of NADH to NAD levels (egg viability 80% 0.872), with the levels of free, non-esterified fatty acids (egg viability 80% 72.34 g mg–1 protein), and the ratio of non esterified to esterified fatty acids (egg viability 80% at 0.749). Also, subjective and visual control methods were described to distinguish between batches with viable and non viable eggs.  相似文献   

18.
A recombinant carp growth hormone (rcGH) was used to develop for a GH radioreceptor binding assay in the goldfish (Carassius auratus). Specific binding of125I-rcGH to goldfish liver membranes was a pH, time, temperature, and membrane protein dependent process. Scatchard and LIGAND analysis indicated a single class of high affinity and low capacity binding site, with an association constant (Ka) of 1.9×1010 M–1 and a maximum binding capacity (Bmax) of 9 fmol mg–1 protein. Liver tissue displayed the highest125I-rcGH binding of all the tissues examined. Displacement of125I-rcGH with various unlabeled teleost and mammalian GHs and prolactins revealed that the goldfish hepatic binding site was highly specific for teleost GH. Intraperitoneal administration of 0.1, 1.0, and 10 g rcGH g–1 body weight to hypophysectomized goldfish resulted in a 27, 52, and 68% decrease in total binding sites, respectively. Injection of a high dose of rat prolactin (rPRL) (5 g rPRL g–1 body weight) also resulted in a 32% decrease in total binding sites. These results suggest that endogenous GH may have a role in the regulation of its own receptors in the goldfish.  相似文献   

19.
Effects of the native GnRHs and various agonists have been evaluated on the spawning of an Indian catfish, Heteropneustes fossilis. This study tested salmon (s) GnRH agonists and mammalian (m) GnRH agonists where a D-amino acid residue was substituted alone at position 6 or the C-terminal was modified with ethylamide. GnRH agonists with a combination of these structural modifications were also evaluated separately for their effect on the spawning of the catfish. Native sGnRH, [Pro9 NEt]-sGnRH agonist and chicken (c) GnRH-II exhibited similar activity and induced spawning within 14–18 h at a dose of 100 g kg–1 body weight (BW). [D-Lys6]-sGnRH agonist and [D-Lys6 Pro9 NEt]-sGnRH agonist, induced spawning at a dose of 100 g kg–1 BW and 1 g kg–1 BW, respectively. The most notable observation in this study was the ineffectiveness of [D-Ala6]-mGnRH agonist and [Des Gly10 D-Ala6 Pro9 NEt]-mGnRH agonist. The results obtained suggest that substitution at position 6 alone, and in conjunction with an ethylamide-based modification at the C-terminal in the native sGnRH structure, increases the potency of the tested agonists to induce spawning in the catfish. This study also discusses the potential use and incorporation of cGnRH-II for the development of more generic spawning induction therapies.  相似文献   

20.
In this investigation, the efficacy of a single intraperitonealinjection of either flumequine or oxytetracycline hydrochloride to preventoutbreak of atypical Aeromonas salmonicida infection ingoldsinny wrasse, Ctenolabrus rupestris, following stresswas studied. Six groups of goldsinny wrasse, each of 50 individuals, weretreated with an intraperitoneal injection of either propylene glycol : saline(50 : 50), 200 mg kg–1 of oxytetracycline or 50mg kg–1 of flumequine dissolved in propyleneglycol : saline (50 : 50). Three days following medication the fish in allgroups were stressed by an intraperitoneal injection of prednisolone acetate(0.05 ml) and a rise in seawater temperature from 9 to 11°C. Mortality was observed daily for 21 days. Flumequine wasthe more effective with a mean cumulative mortality of 5% compared tooxytetracycline with 54%. The mean cumulative mortality in the unmedicatedcontrol groups was 84%. Bacterial examination of kidneys from dead fishconfirmed the presence of atypical A. salmonicida as theprobable cause of death. Minimum inhibitory concentration (MIC) values forflumequine and oxytetracycline against the isolated A.salmonicida were determined to 0.13 gml–1, and 2.0 g ml–1,respectively.  相似文献   

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